linux-stable/drivers/cxl/core/pci.c

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2021 Intel Corporation. All rights reserved. */
#include <linux/units.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/pci.h>
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
#include <linux/pci-doe.h>
#include <linux/aer.h>
#include <cxlpci.h>
#include <cxlmem.h>
#include <cxl.h>
#include "core.h"
#include "trace.h"
/**
* DOC: cxl core pci
*
* Compute Express Link protocols are layered on top of PCIe. CXL core provides
* a set of helpers for CXL interactions which occur via PCIe.
*/
static unsigned short media_ready_timeout = 60;
module_param(media_ready_timeout, ushort, 0644);
MODULE_PARM_DESC(media_ready_timeout, "seconds to wait for media ready");
struct cxl_walk_context {
struct pci_bus *bus;
struct cxl_port *port;
int type;
int error;
int count;
};
static int match_add_dports(struct pci_dev *pdev, void *data)
{
struct cxl_walk_context *ctx = data;
struct cxl_port *port = ctx->port;
int type = pci_pcie_type(pdev);
struct cxl_register_map map;
struct cxl_dport *dport;
u32 lnkcap, port_num;
int rc;
if (pdev->bus != ctx->bus)
return 0;
if (!pci_is_pcie(pdev))
return 0;
if (type != ctx->type)
return 0;
if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP,
&lnkcap))
return 0;
rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
if (rc)
dev_dbg(&port->dev, "failed to find component registers\n");
port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
dport = devm_cxl_add_dport(port, &pdev->dev, port_num, map.resource);
if (IS_ERR(dport)) {
ctx->error = PTR_ERR(dport);
return PTR_ERR(dport);
}
ctx->count++;
return 0;
}
/**
* devm_cxl_port_enumerate_dports - enumerate downstream ports of the upstream port
* @port: cxl_port whose ->uport_dev is the upstream of dports to be enumerated
*
* Returns a positive number of dports enumerated or a negative error
* code.
*/
int devm_cxl_port_enumerate_dports(struct cxl_port *port)
{
struct pci_bus *bus = cxl_port_to_pci_bus(port);
struct cxl_walk_context ctx;
int type;
if (!bus)
return -ENXIO;
if (pci_is_root_bus(bus))
type = PCI_EXP_TYPE_ROOT_PORT;
else
type = PCI_EXP_TYPE_DOWNSTREAM;
ctx = (struct cxl_walk_context) {
.port = port,
.bus = bus,
.type = type,
};
pci_walk_bus(bus, match_add_dports, &ctx);
if (ctx.count == 0)
return -ENODEV;
if (ctx.error)
return ctx.error;
return ctx.count;
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL);
static int cxl_dvsec_mem_range_valid(struct cxl_dev_state *cxlds, int id)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int d = cxlds->cxl_dvsec;
bool valid = false;
int rc, i;
u32 temp;
if (id > CXL_DVSEC_RANGE_MAX)
return -EINVAL;
/* Check MEM INFO VALID bit first, give up after 1s */
i = 1;
do {
rc = pci_read_config_dword(pdev,
d + CXL_DVSEC_RANGE_SIZE_LOW(id),
&temp);
if (rc)
return rc;
valid = FIELD_GET(CXL_DVSEC_MEM_INFO_VALID, temp);
if (valid)
break;
msleep(1000);
} while (i--);
if (!valid) {
dev_err(&pdev->dev,
"Timeout awaiting memory range %d valid after 1s.\n",
id);
return -ETIMEDOUT;
}
return 0;
}
static int cxl_dvsec_mem_range_active(struct cxl_dev_state *cxlds, int id)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int d = cxlds->cxl_dvsec;
bool active = false;
int rc, i;
u32 temp;
if (id > CXL_DVSEC_RANGE_MAX)
return -EINVAL;
/* Check MEM ACTIVE bit, up to 60s timeout by default */
for (i = media_ready_timeout; i; i--) {
rc = pci_read_config_dword(
pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(id), &temp);
if (rc)
return rc;
active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp);
if (active)
break;
msleep(1000);
}
if (!active) {
dev_err(&pdev->dev,
"timeout awaiting memory active after %d seconds\n",
media_ready_timeout);
return -ETIMEDOUT;
}
return 0;
}
/*
* Wait up to @media_ready_timeout for the device to report memory
* active.
*/
int cxl_await_media_ready(struct cxl_dev_state *cxlds)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int d = cxlds->cxl_dvsec;
int rc, i, hdm_count;
u64 md_status;
u16 cap;
rc = pci_read_config_word(pdev,
d + CXL_DVSEC_CAP_OFFSET, &cap);
if (rc)
return rc;
hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap);
for (i = 0; i < hdm_count; i++) {
rc = cxl_dvsec_mem_range_valid(cxlds, i);
if (rc)
return rc;
}
for (i = 0; i < hdm_count; i++) {
rc = cxl_dvsec_mem_range_active(cxlds, i);
if (rc)
return rc;
}
md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
if (!CXLMDEV_READY(md_status))
return -EIO;
return 0;
}
EXPORT_SYMBOL_NS_GPL(cxl_await_media_ready, CXL);
static int wait_for_valid(struct pci_dev *pdev, int d)
{
u32 val;
int rc;
/*
* Memory_Info_Valid: When set, indicates that the CXL Range 1 Size high
* and Size Low registers are valid. Must be set within 1 second of
* deassertion of reset to CXL device. Likely it is already set by the
* time this runs, but otherwise give a 1.5 second timeout in case of
* clock skew.
*/
rc = pci_read_config_dword(pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &val);
if (rc)
return rc;
if (val & CXL_DVSEC_MEM_INFO_VALID)
return 0;
msleep(1500);
rc = pci_read_config_dword(pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &val);
if (rc)
return rc;
if (val & CXL_DVSEC_MEM_INFO_VALID)
return 0;
return -ETIMEDOUT;
}
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
static int cxl_set_mem_enable(struct cxl_dev_state *cxlds, u16 val)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int d = cxlds->cxl_dvsec;
u16 ctrl;
int rc;
rc = pci_read_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, &ctrl);
if (rc < 0)
return rc;
if ((ctrl & CXL_DVSEC_MEM_ENABLE) == val)
return 1;
ctrl &= ~CXL_DVSEC_MEM_ENABLE;
ctrl |= val;
rc = pci_write_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, ctrl);
if (rc < 0)
return rc;
return 0;
}
static void clear_mem_enable(void *cxlds)
{
cxl_set_mem_enable(cxlds, 0);
}
static int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds)
{
int rc;
rc = cxl_set_mem_enable(cxlds, CXL_DVSEC_MEM_ENABLE);
if (rc < 0)
return rc;
if (rc > 0)
return 0;
return devm_add_action_or_reset(host, clear_mem_enable, cxlds);
}
/* require dvsec ranges to be covered by a locked platform window */
static int dvsec_range_allowed(struct device *dev, void *arg)
{
struct range *dev_range = arg;
struct cxl_decoder *cxld;
if (!is_root_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
if (!(cxld->flags & CXL_DECODER_F_RAM))
return 0;
return range_contains(&cxld->hpa_range, dev_range);
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
}
static void disable_hdm(void *_cxlhdm)
{
u32 global_ctrl;
struct cxl_hdm *cxlhdm = _cxlhdm;
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
writel(global_ctrl & ~CXL_HDM_DECODER_ENABLE,
hdm + CXL_HDM_DECODER_CTRL_OFFSET);
}
static int devm_cxl_enable_hdm(struct device *host, struct cxl_hdm *cxlhdm)
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
{
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
u32 global_ctrl;
global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
writel(global_ctrl | CXL_HDM_DECODER_ENABLE,
hdm + CXL_HDM_DECODER_CTRL_OFFSET);
return devm_add_action_or_reset(host, disable_hdm, cxlhdm);
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
}
int cxl_dvsec_rr_decode(struct device *dev, int d,
struct cxl_endpoint_dvsec_info *info)
{
struct pci_dev *pdev = to_pci_dev(dev);
int hdm_count, rc, i, ranges = 0;
u16 cap, ctrl;
if (!d) {
dev_dbg(dev, "No DVSEC Capability\n");
return -ENXIO;
}
rc = pci_read_config_word(pdev, d + CXL_DVSEC_CAP_OFFSET, &cap);
if (rc)
return rc;
rc = pci_read_config_word(pdev, d + CXL_DVSEC_CTRL_OFFSET, &ctrl);
if (rc)
return rc;
if (!(cap & CXL_DVSEC_MEM_CAPABLE)) {
dev_dbg(dev, "Not MEM Capable\n");
return -ENXIO;
}
/*
* It is not allowed by spec for MEM.capable to be set and have 0 legacy
* HDM decoders (values > 2 are also undefined as of CXL 2.0). As this
* driver is for a spec defined class code which must be CXL.mem
* capable, there is no point in continuing to enable CXL.mem.
*/
hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap);
if (!hdm_count || hdm_count > 2)
return -EINVAL;
rc = wait_for_valid(pdev, d);
if (rc) {
dev_dbg(dev, "Failure awaiting MEM_INFO_VALID (%d)\n", rc);
return rc;
}
cxl/port: Enable HDM Capability after validating DVSEC Ranges CXL memory expanders that support the CXL 2.0 memory device class code include an "HDM Decoder Capability" mechanism to supplant the "CXL DVSEC Range" mechanism originally defined in CXL 1.1. Both mechanisms depend on a "mem_enable" bit being set in configuration space before either mechanism activates. When the HDM Decoder Capability is enabled the CXL DVSEC Range settings are ignored. Previously, the cxl_mem driver was relying on platform-firmware to set "mem_enable". That is an invalid assumption as there is no requirement that platform-firmware sets the bit before the driver sees a device, especially in hot-plug scenarios. Additionally, ACPI-platforms that support CXL 2.0 devices also support the ACPI CEDT (CXL Early Discovery Table). That table outlines the platform permissible address ranges for CXL operation. So, there is a need for the driver to set "mem_enable", and there is information available to determine the validity of the CXL DVSEC Ranges. Arrange for the driver to optionally enable the HDM Decoder Capability if "mem_enable" was not set by platform firmware, or the CXL DVSEC Range configuration was invalid. Be careful to only disable memory decode if the kernel was the one to enable it. In other words, if CXL is backing all of kernel memory at boot the device needs to maintain "mem_enable" and "HDM Decoder enable" all the way up to handoff back to platform firmware (e.g. ACPI S5 state entry may require CXL memory to stay active). Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Cc: Dan Carpenter <dan.carpenter@oracle.com> [dan: fix early terminiation of range-allowed loop] Cc: Ariel Sibley <ariel.sibley@microchip.com> [ariel: Memory_size must be non-zero] Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165307136375.2499769.861793697156744166.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-20 18:30:15 +00:00
/*
* The current DVSEC values are moot if the memory capability is
* disabled, and they will remain moot after the HDM Decoder
* capability is enabled.
*/
info->mem_enabled = FIELD_GET(CXL_DVSEC_MEM_ENABLE, ctrl);
if (!info->mem_enabled)
return 0;
for (i = 0; i < hdm_count; i++) {
u64 base, size;
u32 temp;
rc = pci_read_config_dword(
pdev, d + CXL_DVSEC_RANGE_SIZE_HIGH(i), &temp);
if (rc)
return rc;
size = (u64)temp << 32;
rc = pci_read_config_dword(
pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(i), &temp);
if (rc)
return rc;
size |= temp & CXL_DVSEC_MEM_SIZE_LOW_MASK;
if (!size) {
info->dvsec_range[i] = (struct range) {
.start = 0,
.end = CXL_RESOURCE_NONE,
};
continue;
}
rc = pci_read_config_dword(
pdev, d + CXL_DVSEC_RANGE_BASE_HIGH(i), &temp);
if (rc)
return rc;
base = (u64)temp << 32;
rc = pci_read_config_dword(
pdev, d + CXL_DVSEC_RANGE_BASE_LOW(i), &temp);
if (rc)
return rc;
base |= temp & CXL_DVSEC_MEM_BASE_LOW_MASK;
info->dvsec_range[i] = (struct range) {
.start = base,
.end = base + size - 1
};
ranges++;
}
info->ranges = ranges;
return 0;
}
EXPORT_SYMBOL_NS_GPL(cxl_dvsec_rr_decode, CXL);
/**
* cxl_hdm_decode_init() - Setup HDM decoding for the endpoint
* @cxlds: Device state
* @cxlhdm: Mapped HDM decoder Capability
* @info: Cached DVSEC range registers info
*
* Try to enable the endpoint's HDM Decoder Capability
*/
int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
struct cxl_endpoint_dvsec_info *info)
{
void __iomem *hdm = cxlhdm->regs.hdm_decoder;
struct cxl_port *port = cxlhdm->port;
struct device *dev = cxlds->dev;
struct cxl_port *root;
int i, rc, allowed;
u32 global_ctrl = 0;
if (hdm)
global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
/*
* If the HDM Decoder Capability is already enabled then assume
* that some other agent like platform firmware set it up.
*/
if (global_ctrl & CXL_HDM_DECODER_ENABLE || (!hdm && info->mem_enabled))
return devm_cxl_enable_mem(&port->dev, cxlds);
else if (!hdm)
return -ENODEV;
root = to_cxl_port(port->dev.parent);
while (!is_cxl_root(root) && is_cxl_port(root->dev.parent))
root = to_cxl_port(root->dev.parent);
if (!is_cxl_root(root)) {
dev_err(dev, "Failed to acquire root port for HDM enable\n");
return -ENODEV;
}
for (i = 0, allowed = 0; info->mem_enabled && i < info->ranges; i++) {
struct device *cxld_dev;
cxld_dev = device_find_child(&root->dev, &info->dvsec_range[i],
dvsec_range_allowed);
if (!cxld_dev) {
dev_dbg(dev, "DVSEC Range%d denied by platform\n", i);
continue;
}
dev_dbg(dev, "DVSEC Range%d allowed by platform\n", i);
put_device(cxld_dev);
allowed++;
}
if (!allowed && info->mem_enabled) {
dev_err(dev, "Range register decodes outside platform defined CXL ranges.\n");
return -ENXIO;
}
/*
* Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base
* [High,Low] when HDM operation is enabled the range register values
* are ignored by the device, but the spec also recommends matching the
* DVSEC Range 1,2 to HDM Decoder Range 0,1. So, non-zero info->ranges
* are expected even though Linux does not require or maintain that
* match. If at least one DVSEC range is enabled and allowed, skip HDM
* Decoder Capability Enable.
*/
if (info->mem_enabled)
return 0;
rc = devm_cxl_enable_hdm(&port->dev, cxlhdm);
if (rc)
return rc;
return devm_cxl_enable_mem(&port->dev, cxlds);
}
EXPORT_SYMBOL_NS_GPL(cxl_hdm_decode_init, CXL);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
#define CXL_DOE_TABLE_ACCESS_REQ_CODE 0x000000ff
#define CXL_DOE_TABLE_ACCESS_REQ_CODE_READ 0
#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE 0x0000ff00
#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA 0
#define CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE 0xffff0000
#define CXL_DOE_TABLE_ACCESS_LAST_ENTRY 0xffff
#define CXL_DOE_PROTOCOL_TABLE_ACCESS 2
cxl/pci: Fix CDAT retrieval on big endian The CDAT exposed in sysfs differs between little endian and big endian arches: On big endian, every 4 bytes are byte-swapped. PCI Configuration Space is little endian (PCI r3.0 sec 6.1). Accessors such as pci_read_config_dword() implicitly swap bytes on big endian. That way, the macros in include/uapi/linux/pci_regs.h work regardless of the arch's endianness. For an example of implicit byte-swapping, see ppc4xx_pciex_read_config(), which calls in_le32(), which uses lwbrx (Load Word Byte-Reverse Indexed). DOE Read/Write Data Mailbox Registers are unlike other registers in Configuration Space in that they contain or receive a 4 byte portion of an opaque byte stream (a "Data Object" per PCIe r6.0 sec 7.9.24.5f). They need to be copied to or from the request/response buffer verbatim. So amend pci_doe_send_req() and pci_doe_recv_resp() to undo the implicit byte-swapping. The CXL_DOE_TABLE_ACCESS_* and PCI_DOE_DATA_OBJECT_DISC_* macros assume implicit byte-swapping. Byte-swap requests after constructing them with those macros and byte-swap responses before parsing them. Change the request and response type to __le32 to avoid sparse warnings. Per a request from Jonathan, replace sizeof(u32) with sizeof(__le32) for consistency. Fixes: c97006046c79 ("cxl/port: Read CDAT table") Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org # v6.0+ Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/3051114102f41d19df3debbee123129118fc5e6d.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:01 +00:00
#define CDAT_DOE_REQ(entry_handle) cpu_to_le32 \
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
(FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \
CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \
FIELD_PREP(CXL_DOE_TABLE_ACCESS_TABLE_TYPE, \
CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) | \
FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle)))
static int cxl_cdat_get_length(struct device *dev,
struct pci_doe_mb *doe_mb,
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
size_t *length)
{
__le32 request = CDAT_DOE_REQ(0);
cxl/pci: Rightsize CDAT response allocation Jonathan notes that cxl_cdat_get_length() and cxl_cdat_read_table() allocate 32 dwords for the DOE response even though it may be smaller. In the case of cxl_cdat_get_length(), only the second dword of the response is of interest (it contains the length). So reduce the allocation to 2 dwords and let DOE discard the remainder. In the case of cxl_cdat_read_table(), a correctly sized allocation for the full CDAT already exists. Let DOE write each table entry directly into that allocation. There's a snag in that the table entry is preceded by a Table Access Response Header (1 dword, CXL 3.0 table 8-14). Save the last dword of the previous table entry, let DOE overwrite it with the header of the next entry and restore it afterwards. The resulting CDAT is preceded by 4 unavoidable useless bytes. Increase the allocation size accordingly. The buffer overflow check in cxl_cdat_read_table() becomes unnecessary because the remaining bytes in the allocation are tracked in "length", which is passed to DOE and limits how many bytes it writes to the allocation. Additionally, cxl_cdat_read_table() bails out if the DOE response is truncated due to insufficient space. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/7a4e1f86958a79a70f29b96a92199522f08f8322.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:17 +00:00
__le32 response[2];
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
int rc;
rc = pci_doe(doe_mb, PCI_DVSEC_VENDOR_ID_CXL,
CXL_DOE_PROTOCOL_TABLE_ACCESS,
&request, sizeof(request),
&response, sizeof(response));
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
if (rc < 0) {
dev_err(dev, "DOE failed: %d", rc);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
return rc;
}
cxl/pci: Rightsize CDAT response allocation Jonathan notes that cxl_cdat_get_length() and cxl_cdat_read_table() allocate 32 dwords for the DOE response even though it may be smaller. In the case of cxl_cdat_get_length(), only the second dword of the response is of interest (it contains the length). So reduce the allocation to 2 dwords and let DOE discard the remainder. In the case of cxl_cdat_read_table(), a correctly sized allocation for the full CDAT already exists. Let DOE write each table entry directly into that allocation. There's a snag in that the table entry is preceded by a Table Access Response Header (1 dword, CXL 3.0 table 8-14). Save the last dword of the previous table entry, let DOE overwrite it with the header of the next entry and restore it afterwards. The resulting CDAT is preceded by 4 unavoidable useless bytes. Increase the allocation size accordingly. The buffer overflow check in cxl_cdat_read_table() becomes unnecessary because the remaining bytes in the allocation are tracked in "length", which is passed to DOE and limits how many bytes it writes to the allocation. Additionally, cxl_cdat_read_table() bails out if the DOE response is truncated due to insufficient space. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/7a4e1f86958a79a70f29b96a92199522f08f8322.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:17 +00:00
if (rc < sizeof(response))
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
return -EIO;
*length = le32_to_cpu(response[1]);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
dev_dbg(dev, "CDAT length %zu\n", *length);
return 0;
}
static int cxl_cdat_read_table(struct device *dev,
struct pci_doe_mb *doe_mb,
struct cdat_doe_rsp *rsp, size_t *length)
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
{
size_t received, remaining = *length;
unsigned int entry_handle = 0;
union cdat_data *data;
cxl/pci: Rightsize CDAT response allocation Jonathan notes that cxl_cdat_get_length() and cxl_cdat_read_table() allocate 32 dwords for the DOE response even though it may be smaller. In the case of cxl_cdat_get_length(), only the second dword of the response is of interest (it contains the length). So reduce the allocation to 2 dwords and let DOE discard the remainder. In the case of cxl_cdat_read_table(), a correctly sized allocation for the full CDAT already exists. Let DOE write each table entry directly into that allocation. There's a snag in that the table entry is preceded by a Table Access Response Header (1 dword, CXL 3.0 table 8-14). Save the last dword of the previous table entry, let DOE overwrite it with the header of the next entry and restore it afterwards. The resulting CDAT is preceded by 4 unavoidable useless bytes. Increase the allocation size accordingly. The buffer overflow check in cxl_cdat_read_table() becomes unnecessary because the remaining bytes in the allocation are tracked in "length", which is passed to DOE and limits how many bytes it writes to the allocation. Additionally, cxl_cdat_read_table() bails out if the DOE response is truncated due to insufficient space. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/7a4e1f86958a79a70f29b96a92199522f08f8322.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:17 +00:00
__le32 saved_dw = 0;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
do {
__le32 request = CDAT_DOE_REQ(entry_handle);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
int rc;
rc = pci_doe(doe_mb, PCI_DVSEC_VENDOR_ID_CXL,
CXL_DOE_PROTOCOL_TABLE_ACCESS,
&request, sizeof(request),
rsp, sizeof(*rsp) + remaining);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
if (rc < 0) {
dev_err(dev, "DOE failed: %d", rc);
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
return rc;
}
cxl/pci: Handle truncated CDAT entries If truncated CDAT entries are received from a device, the concatenation of those entries constitutes a corrupt CDAT, yet is happily exposed to user space. Avoid by verifying response lengths and erroring out if truncation is detected. The last CDAT entry may still be truncated despite the checks introduced herein if the length in the CDAT header is too small. However, that is easily detectable by user space because it reaches EOF prematurely. A subsequent commit which rightsizes the CDAT response allocation closes that remaining loophole. The two lines introduced here which exceed 80 chars are shortened to less than 80 chars by a subsequent commit which migrates to a synchronous DOE API and replaces "t.task.rv" by "rc". The existing acpi_cdat_header and acpi_table_cdat struct definitions provided by ACPICA cannot be used because they do not employ __le16 or __le32 types. I believe that cannot be changed because those types are Linux-specific and ACPI is specified for little endian platforms only, hence doesn't care about endianness. So duplicate the structs. Fixes: c97006046c79 ("cxl/port: Read CDAT table") Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: stable@vger.kernel.org # v6.0+ Link: https://lore.kernel.org/r/bce3aebc0e8e18a1173425a7a865b232c3912963.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:03 +00:00
if (rc < sizeof(*rsp))
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
return -EIO;
data = (union cdat_data *)rsp->data;
received = rc - sizeof(*rsp);
if (entry_handle == 0) {
if (received != sizeof(data->header))
return -EIO;
} else {
if (received < sizeof(data->entry) ||
received != le16_to_cpu(data->entry.length))
return -EIO;
}
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
/* Get the CXL table access header entry handle */
entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE,
le32_to_cpu(rsp->doe_header));
cxl/pci: Rightsize CDAT response allocation Jonathan notes that cxl_cdat_get_length() and cxl_cdat_read_table() allocate 32 dwords for the DOE response even though it may be smaller. In the case of cxl_cdat_get_length(), only the second dword of the response is of interest (it contains the length). So reduce the allocation to 2 dwords and let DOE discard the remainder. In the case of cxl_cdat_read_table(), a correctly sized allocation for the full CDAT already exists. Let DOE write each table entry directly into that allocation. There's a snag in that the table entry is preceded by a Table Access Response Header (1 dword, CXL 3.0 table 8-14). Save the last dword of the previous table entry, let DOE overwrite it with the header of the next entry and restore it afterwards. The resulting CDAT is preceded by 4 unavoidable useless bytes. Increase the allocation size accordingly. The buffer overflow check in cxl_cdat_read_table() becomes unnecessary because the remaining bytes in the allocation are tracked in "length", which is passed to DOE and limits how many bytes it writes to the allocation. Additionally, cxl_cdat_read_table() bails out if the DOE response is truncated due to insufficient space. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/7a4e1f86958a79a70f29b96a92199522f08f8322.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-03-11 14:40:17 +00:00
/*
* Table Access Response Header overwrote the last DW of
* previous entry, so restore that DW
*/
rsp->doe_header = saved_dw;
remaining -= received;
rsp = (void *)rsp + received;
saved_dw = rsp->doe_header;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
} while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY);
/* Length in CDAT header may exceed concatenation of CDAT entries */
*length -= remaining;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
return 0;
}
static unsigned char cdat_checksum(void *buf, size_t size)
{
unsigned char sum, *data = buf;
size_t i;
for (sum = 0, i = 0; i < size; i++)
sum += data[i];
return sum;
}
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
/**
* read_cdat_data - Read the CDAT data on this port
* @port: Port to read data from
*
* This call will sleep waiting for responses from the DOE mailbox.
*/
void read_cdat_data(struct cxl_port *port)
{
struct device *uport = port->uport_dev;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
struct device *dev = &port->dev;
struct pci_doe_mb *doe_mb;
struct pci_dev *pdev = NULL;
struct cxl_memdev *cxlmd;
struct cdat_doe_rsp *buf;
lib/firmware_table: Provide buffer length argument to cdat_table_parse() There exist card implementations with a CDAT table using a fixed size buffer, but with entries filled in that do not fill the whole table length size. Then, the last entry in the CDAT table may not mark the end of the CDAT table buffer specified by the length field in the CDAT header. It can be shorter with trailing unused (zero'ed) data. The actual table length is determined while reading all CDAT entries of the table with DOE. If the table is greater than expected (containing zero'ed trailing data), the CDAT parser fails with: [ 48.691717] Malformed DSMAS table length: (24:0) [ 48.702084] [CDAT:0x00] Invalid zero length [ 48.711460] cxl_port endpoint1: Failed to parse CDAT: -22 In addition, a check of the table buffer length is missing to prevent an out-of-bound access then parsing the CDAT table. Hardening code against device returning borked table. Fix that by providing an optional buffer length argument to acpi_parse_entries_array() that can be used by cdat_table_parse() to propagate the buffer size down to its users to check the buffer length. This also prevents a possible out-of-bound access mentioned. Add a check to warn about a malformed CDAT table length. Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Len Brown <lenb@kernel.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/ZdEnopFO0Tl3t2O1@rric.localdomain Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-17 21:39:46 +00:00
size_t table_length, length;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
int rc;
if (is_cxl_memdev(uport)) {
struct device *host;
cxlmd = to_cxl_memdev(uport);
host = cxlmd->dev.parent;
if (dev_is_pci(host))
pdev = to_pci_dev(host);
} else if (dev_is_pci(uport)) {
pdev = to_pci_dev(uport);
}
if (!pdev)
return;
doe_mb = pci_find_doe_mailbox(pdev, PCI_DVSEC_VENDOR_ID_CXL,
CXL_DOE_PROTOCOL_TABLE_ACCESS);
if (!doe_mb) {
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
dev_dbg(dev, "No CDAT mailbox\n");
return;
}
port->cdat_available = true;
if (cxl_cdat_get_length(dev, doe_mb, &length)) {
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
dev_dbg(dev, "No CDAT length\n");
return;
}
/*
* The begin of the CDAT buffer needs space for additional 4
* bytes for the DOE header. Table data starts afterwards.
*/
buf = devm_kzalloc(dev, sizeof(*buf) + length, GFP_KERNEL);
if (!buf)
goto err;
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
lib/firmware_table: Provide buffer length argument to cdat_table_parse() There exist card implementations with a CDAT table using a fixed size buffer, but with entries filled in that do not fill the whole table length size. Then, the last entry in the CDAT table may not mark the end of the CDAT table buffer specified by the length field in the CDAT header. It can be shorter with trailing unused (zero'ed) data. The actual table length is determined while reading all CDAT entries of the table with DOE. If the table is greater than expected (containing zero'ed trailing data), the CDAT parser fails with: [ 48.691717] Malformed DSMAS table length: (24:0) [ 48.702084] [CDAT:0x00] Invalid zero length [ 48.711460] cxl_port endpoint1: Failed to parse CDAT: -22 In addition, a check of the table buffer length is missing to prevent an out-of-bound access then parsing the CDAT table. Hardening code against device returning borked table. Fix that by providing an optional buffer length argument to acpi_parse_entries_array() that can be used by cdat_table_parse() to propagate the buffer size down to its users to check the buffer length. This also prevents a possible out-of-bound access mentioned. Add a check to warn about a malformed CDAT table length. Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Len Brown <lenb@kernel.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/ZdEnopFO0Tl3t2O1@rric.localdomain Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-17 21:39:46 +00:00
table_length = length;
rc = cxl_cdat_read_table(dev, doe_mb, buf, &length);
if (rc)
goto err;
lib/firmware_table: Provide buffer length argument to cdat_table_parse() There exist card implementations with a CDAT table using a fixed size buffer, but with entries filled in that do not fill the whole table length size. Then, the last entry in the CDAT table may not mark the end of the CDAT table buffer specified by the length field in the CDAT header. It can be shorter with trailing unused (zero'ed) data. The actual table length is determined while reading all CDAT entries of the table with DOE. If the table is greater than expected (containing zero'ed trailing data), the CDAT parser fails with: [ 48.691717] Malformed DSMAS table length: (24:0) [ 48.702084] [CDAT:0x00] Invalid zero length [ 48.711460] cxl_port endpoint1: Failed to parse CDAT: -22 In addition, a check of the table buffer length is missing to prevent an out-of-bound access then parsing the CDAT table. Hardening code against device returning borked table. Fix that by providing an optional buffer length argument to acpi_parse_entries_array() that can be used by cdat_table_parse() to propagate the buffer size down to its users to check the buffer length. This also prevents a possible out-of-bound access mentioned. Add a check to warn about a malformed CDAT table length. Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Len Brown <lenb@kernel.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/ZdEnopFO0Tl3t2O1@rric.localdomain Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-17 21:39:46 +00:00
if (table_length != length)
dev_warn(dev, "Malformed CDAT table length (%zu:%zu), discarding trailing data\n",
table_length, length);
if (cdat_checksum(buf->data, length))
goto err;
port->cdat.table = buf->data;
port->cdat.length = length;
return;
err:
/* Don't leave table data allocated on error */
devm_kfree(dev, buf);
dev_err(dev, "Failed to read/validate CDAT.\n");
cxl/port: Read CDAT table The per-device CDAT data provides performance data that is relevant for mapping which CXL devices can participate in which CXL ranges by QTG (QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The QTG association specified in the ECN is advisory. Until the cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT data is only of interest to userspace that may need it for debug purposes. Search the DOE mailboxes available, query CDAT data, cache the data and make it available via a sysfs binary attribute per endpoint at: /sys/bus/cxl/devices/endpointX/CDAT ...similar to other ACPI-structured table data in /sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port' objects since switches in addition to endpoints can host a CDAT instance. Switch CDAT support is not implemented. This does not support table updates at runtime. It will always provide whatever was there when first cached. It is also the case that table updates are not expected outside of explicit DPA address map affecting commands like Set Partition with the immediate flag set. Given that the driver does not support Set Partition with the immediate flag set there is no current need for update support. Link: https://www.computeexpresslink.org/spec-landing [1] Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: drop in-kernel parsing infra for now, and other minor fixups] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-19 20:52:49 +00:00
}
EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);
static void __cxl_handle_cor_ras(struct cxl_dev_state *cxlds,
void __iomem *ras_base)
{
void __iomem *addr;
u32 status;
if (!ras_base)
return;
addr = ras_base + CXL_RAS_CORRECTABLE_STATUS_OFFSET;
status = readl(addr);
if (status & CXL_RAS_CORRECTABLE_STATUS_MASK) {
writel(status & CXL_RAS_CORRECTABLE_STATUS_MASK, addr);
trace_cxl_aer_correctable_error(cxlds->cxlmd, status);
}
}
static void cxl_handle_endpoint_cor_ras(struct cxl_dev_state *cxlds)
{
return __cxl_handle_cor_ras(cxlds, cxlds->regs.ras);
}
/* CXL spec rev3.0 8.2.4.16.1 */
static void header_log_copy(void __iomem *ras_base, u32 *log)
{
void __iomem *addr;
u32 *log_addr;
int i, log_u32_size = CXL_HEADERLOG_SIZE / sizeof(u32);
addr = ras_base + CXL_RAS_HEADER_LOG_OFFSET;
log_addr = log;
for (i = 0; i < log_u32_size; i++) {
*log_addr = readl(addr);
log_addr++;
addr += sizeof(u32);
}
}
/*
* Log the state of the RAS status registers and prepare them to log the
* next error status. Return 1 if reset needed.
*/
static bool __cxl_handle_ras(struct cxl_dev_state *cxlds,
void __iomem *ras_base)
{
u32 hl[CXL_HEADERLOG_SIZE_U32];
void __iomem *addr;
u32 status;
u32 fe;
if (!ras_base)
return false;
addr = ras_base + CXL_RAS_UNCORRECTABLE_STATUS_OFFSET;
status = readl(addr);
if (!(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK))
return false;
/* If multiple errors, log header points to first error from ctrl reg */
if (hweight32(status) > 1) {
void __iomem *rcc_addr =
ras_base + CXL_RAS_CAP_CONTROL_OFFSET;
fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK,
readl(rcc_addr)));
} else {
fe = status;
}
header_log_copy(ras_base, hl);
trace_cxl_aer_uncorrectable_error(cxlds->cxlmd, status, fe, hl);
writel(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK, addr);
return true;
}
static bool cxl_handle_endpoint_ras(struct cxl_dev_state *cxlds)
{
return __cxl_handle_ras(cxlds, cxlds->regs.ras);
}
cxl/pci: Add RCH downstream port AER register discovery Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 22:08:06 +00:00
#ifdef CONFIG_PCIEAER_CXL
static void cxl_dport_map_rch_aer(struct cxl_dport *dport)
{
struct cxl_rcrb_info *ri = &dport->rcrb;
void __iomem *dport_aer = NULL;
resource_size_t aer_phys;
struct device *host;
if (dport->rch && ri->aer_cap) {
host = dport->reg_map.host;
aer_phys = ri->aer_cap + ri->base;
dport_aer = devm_cxl_iomap_block(host, aer_phys,
sizeof(struct aer_capability_regs));
}
dport->regs.dport_aer = dport_aer;
}
static void cxl_dport_map_regs(struct cxl_dport *dport)
{
struct cxl_register_map *map = &dport->reg_map;
struct device *dev = dport->dport_dev;
if (!map->component_map.ras.valid)
dev_dbg(dev, "RAS registers not found\n");
else if (cxl_map_component_regs(map, &dport->regs.component,
BIT(CXL_CM_CAP_CAP_ID_RAS)))
dev_dbg(dev, "Failed to map RAS capability.\n");
if (dport->rch)
cxl_dport_map_rch_aer(dport);
}
static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
{
void __iomem *aer_base = dport->regs.dport_aer;
struct pci_host_bridge *bridge;
u32 aer_cmd_mask, aer_cmd;
if (!aer_base)
return;
bridge = to_pci_host_bridge(dport->dport_dev);
/*
* Disable RCH root port command interrupts.
* CXL 3.0 12.2.1.1 - RCH Downstream Port-detected Errors
*
* This sequence may not be necessary. CXL spec states disabling
* the root cmd register's interrupts is required. But, PCI spec
* shows these are disabled by default on reset.
*/
if (bridge->native_aer) {
aer_cmd_mask = (PCI_ERR_ROOT_CMD_COR_EN |
PCI_ERR_ROOT_CMD_NONFATAL_EN |
PCI_ERR_ROOT_CMD_FATAL_EN);
aer_cmd = readl(aer_base + PCI_ERR_ROOT_COMMAND);
aer_cmd &= ~aer_cmd_mask;
writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND);
}
}
cxl/pci: Add RCH downstream port AER register discovery Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 22:08:06 +00:00
void cxl_setup_parent_dport(struct device *host, struct cxl_dport *dport)
{
struct device *dport_dev = dport->dport_dev;
struct pci_host_bridge *host_bridge;
host_bridge = to_pci_host_bridge(dport_dev);
if (host_bridge->native_aer)
cxl/pci: Add RCH downstream port AER register discovery Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 22:08:06 +00:00
dport->rcrb.aer_cap = cxl_rcrb_to_aer(dport_dev, dport->rcrb.base);
dport->reg_map.host = host;
cxl_dport_map_regs(dport);
if (dport->rch)
cxl_disable_rch_root_ints(dport);
cxl/pci: Add RCH downstream port AER register discovery Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 22:08:06 +00:00
}
EXPORT_SYMBOL_NS_GPL(cxl_setup_parent_dport, CXL);
static void cxl_handle_rdport_cor_ras(struct cxl_dev_state *cxlds,
struct cxl_dport *dport)
{
return __cxl_handle_cor_ras(cxlds, dport->regs.ras);
}
static bool cxl_handle_rdport_ras(struct cxl_dev_state *cxlds,
struct cxl_dport *dport)
{
return __cxl_handle_ras(cxlds, dport->regs.ras);
}
/*
* Copy the AER capability registers using 32 bit read accesses.
* This is necessary because RCRB AER capability is MMIO mapped. Clear the
* status after copying.
*
* @aer_base: base address of AER capability block in RCRB
* @aer_regs: destination for copying AER capability
*/
static bool cxl_rch_get_aer_info(void __iomem *aer_base,
struct aer_capability_regs *aer_regs)
{
int read_cnt = sizeof(struct aer_capability_regs) / sizeof(u32);
u32 *aer_regs_buf = (u32 *)aer_regs;
int n;
if (!aer_base)
return false;
/* Use readl() to guarantee 32-bit accesses */
for (n = 0; n < read_cnt; n++)
aer_regs_buf[n] = readl(aer_base + n * sizeof(u32));
writel(aer_regs->uncor_status, aer_base + PCI_ERR_UNCOR_STATUS);
writel(aer_regs->cor_status, aer_base + PCI_ERR_COR_STATUS);
return true;
}
/* Get AER severity. Return false if there is no error. */
static bool cxl_rch_get_aer_severity(struct aer_capability_regs *aer_regs,
int *severity)
{
if (aer_regs->uncor_status & ~aer_regs->uncor_mask) {
if (aer_regs->uncor_status & PCI_ERR_ROOT_FATAL_RCV)
*severity = AER_FATAL;
else
*severity = AER_NONFATAL;
return true;
}
if (aer_regs->cor_status & ~aer_regs->cor_mask) {
*severity = AER_CORRECTABLE;
return true;
}
return false;
}
static void cxl_handle_rdport_errors(struct cxl_dev_state *cxlds)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
struct aer_capability_regs aer_regs;
struct cxl_dport *dport;
struct cxl_port *port;
int severity;
port = cxl_pci_find_port(pdev, &dport);
if (!port)
return;
put_device(&port->dev);
if (!cxl_rch_get_aer_info(dport->regs.dport_aer, &aer_regs))
return;
if (!cxl_rch_get_aer_severity(&aer_regs, &severity))
return;
pci_print_aer(pdev, severity, &aer_regs);
if (severity == AER_CORRECTABLE)
cxl_handle_rdport_cor_ras(cxlds, dport);
else
cxl_handle_rdport_ras(cxlds, dport);
}
#else
static void cxl_handle_rdport_errors(struct cxl_dev_state *cxlds) { }
cxl/pci: Add RCH downstream port AER register discovery Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 22:08:06 +00:00
#endif
void cxl_cor_error_detected(struct pci_dev *pdev)
{
struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached The PCI AER model is an awkward fit for CXL error handling. While the expectation is that a PCI device can escalate to link reset to recover from an AER event, the same reset on CXL amounts to a surprise memory hotplug of massive amounts of memory. At present, the CXL error handler attempts some optimistic error handling to unbind the device from the cxl_mem driver after reaping some RAS register values. This results in a "hopeful" attempt to unplug the memory, but there is no guarantee that will succeed. A subsequent AER notification after the memdev unbind event can no longer assume the registers are mapped. Check for memdev bind before reaping status register values to avoid crashes of the form: BUG: unable to handle page fault for address: ffa00000195e9100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] RIP: 0010:__cxl_handle_ras+0x30/0x110 [cxl_core] [...] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? kernelmode_fixup_or_oops+0x84/0x110 ? exc_page_fault+0x113/0x170 ? asm_exc_page_fault+0x26/0x30 ? __pfx_dpc_reset_link+0x10/0x10 ? __cxl_handle_ras+0x30/0x110 [cxl_core] ? find_cxl_port+0x59/0x80 [cxl_core] cxl_handle_rp_ras+0xbc/0xd0 [cxl_core] cxl_error_detected+0x6c/0xf0 [cxl_core] report_error_detected+0xc7/0x1c0 pci_walk_bus+0x73/0x90 pcie_do_recovery+0x23f/0x330 Longer term, the unbind and PCI_ERS_RESULT_DISCONNECT behavior might need to be replaced with a new PCI_ERS_RESULT_PANIC. Fixes: 6ac07883dbb5 ("cxl/pci: Add RCH downstream port error logging") Cc: stable@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Link: https://lore.kernel.org/r/20240129131856.2458980-1-ming4.li@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-29 13:18:56 +00:00
struct device *dev = &cxlds->cxlmd->dev;
scoped_guard(device, dev) {
if (!dev->driver) {
dev_warn(&pdev->dev,
"%s: memdev disabled, abort error handling\n",
dev_name(dev));
return;
}
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached The PCI AER model is an awkward fit for CXL error handling. While the expectation is that a PCI device can escalate to link reset to recover from an AER event, the same reset on CXL amounts to a surprise memory hotplug of massive amounts of memory. At present, the CXL error handler attempts some optimistic error handling to unbind the device from the cxl_mem driver after reaping some RAS register values. This results in a "hopeful" attempt to unplug the memory, but there is no guarantee that will succeed. A subsequent AER notification after the memdev unbind event can no longer assume the registers are mapped. Check for memdev bind before reaping status register values to avoid crashes of the form: BUG: unable to handle page fault for address: ffa00000195e9100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] RIP: 0010:__cxl_handle_ras+0x30/0x110 [cxl_core] [...] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? kernelmode_fixup_or_oops+0x84/0x110 ? exc_page_fault+0x113/0x170 ? asm_exc_page_fault+0x26/0x30 ? __pfx_dpc_reset_link+0x10/0x10 ? __cxl_handle_ras+0x30/0x110 [cxl_core] ? find_cxl_port+0x59/0x80 [cxl_core] cxl_handle_rp_ras+0xbc/0xd0 [cxl_core] cxl_error_detected+0x6c/0xf0 [cxl_core] report_error_detected+0xc7/0x1c0 pci_walk_bus+0x73/0x90 pcie_do_recovery+0x23f/0x330 Longer term, the unbind and PCI_ERS_RESULT_DISCONNECT behavior might need to be replaced with a new PCI_ERS_RESULT_PANIC. Fixes: 6ac07883dbb5 ("cxl/pci: Add RCH downstream port error logging") Cc: stable@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Link: https://lore.kernel.org/r/20240129131856.2458980-1-ming4.li@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-29 13:18:56 +00:00
if (cxlds->rcd)
cxl_handle_rdport_errors(cxlds);
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached The PCI AER model is an awkward fit for CXL error handling. While the expectation is that a PCI device can escalate to link reset to recover from an AER event, the same reset on CXL amounts to a surprise memory hotplug of massive amounts of memory. At present, the CXL error handler attempts some optimistic error handling to unbind the device from the cxl_mem driver after reaping some RAS register values. This results in a "hopeful" attempt to unplug the memory, but there is no guarantee that will succeed. A subsequent AER notification after the memdev unbind event can no longer assume the registers are mapped. Check for memdev bind before reaping status register values to avoid crashes of the form: BUG: unable to handle page fault for address: ffa00000195e9100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] RIP: 0010:__cxl_handle_ras+0x30/0x110 [cxl_core] [...] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? kernelmode_fixup_or_oops+0x84/0x110 ? exc_page_fault+0x113/0x170 ? asm_exc_page_fault+0x26/0x30 ? __pfx_dpc_reset_link+0x10/0x10 ? __cxl_handle_ras+0x30/0x110 [cxl_core] ? find_cxl_port+0x59/0x80 [cxl_core] cxl_handle_rp_ras+0xbc/0xd0 [cxl_core] cxl_error_detected+0x6c/0xf0 [cxl_core] report_error_detected+0xc7/0x1c0 pci_walk_bus+0x73/0x90 pcie_do_recovery+0x23f/0x330 Longer term, the unbind and PCI_ERS_RESULT_DISCONNECT behavior might need to be replaced with a new PCI_ERS_RESULT_PANIC. Fixes: 6ac07883dbb5 ("cxl/pci: Add RCH downstream port error logging") Cc: stable@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Link: https://lore.kernel.org/r/20240129131856.2458980-1-ming4.li@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-29 13:18:56 +00:00
cxl_handle_endpoint_cor_ras(cxlds);
}
}
EXPORT_SYMBOL_NS_GPL(cxl_cor_error_detected, CXL);
pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
pci_channel_state_t state)
{
struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
struct cxl_memdev *cxlmd = cxlds->cxlmd;
struct device *dev = &cxlmd->dev;
bool ue;
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached The PCI AER model is an awkward fit for CXL error handling. While the expectation is that a PCI device can escalate to link reset to recover from an AER event, the same reset on CXL amounts to a surprise memory hotplug of massive amounts of memory. At present, the CXL error handler attempts some optimistic error handling to unbind the device from the cxl_mem driver after reaping some RAS register values. This results in a "hopeful" attempt to unplug the memory, but there is no guarantee that will succeed. A subsequent AER notification after the memdev unbind event can no longer assume the registers are mapped. Check for memdev bind before reaping status register values to avoid crashes of the form: BUG: unable to handle page fault for address: ffa00000195e9100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] RIP: 0010:__cxl_handle_ras+0x30/0x110 [cxl_core] [...] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? kernelmode_fixup_or_oops+0x84/0x110 ? exc_page_fault+0x113/0x170 ? asm_exc_page_fault+0x26/0x30 ? __pfx_dpc_reset_link+0x10/0x10 ? __cxl_handle_ras+0x30/0x110 [cxl_core] ? find_cxl_port+0x59/0x80 [cxl_core] cxl_handle_rp_ras+0xbc/0xd0 [cxl_core] cxl_error_detected+0x6c/0xf0 [cxl_core] report_error_detected+0xc7/0x1c0 pci_walk_bus+0x73/0x90 pcie_do_recovery+0x23f/0x330 Longer term, the unbind and PCI_ERS_RESULT_DISCONNECT behavior might need to be replaced with a new PCI_ERS_RESULT_PANIC. Fixes: 6ac07883dbb5 ("cxl/pci: Add RCH downstream port error logging") Cc: stable@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Ming <ming4.li@intel.com> Link: https://lore.kernel.org/r/20240129131856.2458980-1-ming4.li@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-29 13:18:56 +00:00
scoped_guard(device, dev) {
if (!dev->driver) {
dev_warn(&pdev->dev,
"%s: memdev disabled, abort error handling\n",
dev_name(dev));
return PCI_ERS_RESULT_DISCONNECT;
}
if (cxlds->rcd)
cxl_handle_rdport_errors(cxlds);
/*
* A frozen channel indicates an impending reset which is fatal to
* CXL.mem operation, and will likely crash the system. On the off
* chance the situation is recoverable dump the status of the RAS
* capability registers and bounce the active state of the memdev.
*/
ue = cxl_handle_endpoint_ras(cxlds);
}
switch (state) {
case pci_channel_io_normal:
if (ue) {
device_release_driver(dev);
return PCI_ERS_RESULT_NEED_RESET;
}
return PCI_ERS_RESULT_CAN_RECOVER;
case pci_channel_io_frozen:
dev_warn(&pdev->dev,
"%s: frozen state error detected, disable CXL.mem\n",
dev_name(dev));
device_release_driver(dev);
return PCI_ERS_RESULT_NEED_RESET;
case pci_channel_io_perm_failure:
dev_warn(&pdev->dev,
"failure state error detected, request disconnect\n");
return PCI_ERS_RESULT_DISCONNECT;
}
return PCI_ERS_RESULT_NEED_RESET;
}
EXPORT_SYMBOL_NS_GPL(cxl_error_detected, CXL);
static int cxl_flit_size(struct pci_dev *pdev)
{
if (cxl_pci_flit_256(pdev))
return 256;
return 68;
}
/**
* cxl_pci_get_latency - calculate the link latency for the PCIe link
* @pdev: PCI device
*
* return: calculated latency or 0 for no latency
*
* CXL Memory Device SW Guide v1.0 2.11.4 Link latency calculation
* Link latency = LinkPropagationLatency + FlitLatency + RetimerLatency
* LinkProgationLatency is negligible, so 0 will be used
* RetimerLatency is assumed to be negligible and 0 will be used
* FlitLatency = FlitSize / LinkBandwidth
* FlitSize is defined by spec. CXL rev3.0 4.2.1.
* 68B flit is used up to 32GT/s. >32GT/s, 256B flit size is used.
* The FlitLatency is converted to picoseconds.
*/
long cxl_pci_get_latency(struct pci_dev *pdev)
{
long bw;
bw = pcie_link_speed_mbps(pdev);
if (bw < 0)
return 0;
bw /= BITS_PER_BYTE;
return cxl_flit_size(pdev) * MEGA / bw;
}