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

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2023 Intel Corporation. All rights reserved. */
#include <linux/acpi.h>
#include <linux/xarray.h>
#include <linux/fw_table.h>
#include <linux/node.h>
#include <linux/overflow.h>
#include "cxlpci.h"
#include "cxlmem.h"
#include "core.h"
#include "cxl.h"
struct dsmas_entry {
struct range dpa_range;
u8 handle;
struct access_coordinate coord;
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
int entries;
int qos_class;
};
static int cdat_dsmas_handler(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
struct acpi_cdat_header *hdr = &header->cdat;
struct acpi_cdat_dsmas *dsmas;
int size = sizeof(*hdr) + sizeof(*dsmas);
struct xarray *dsmas_xa = arg;
struct dsmas_entry *dent;
u16 len;
int rc;
len = le16_to_cpu((__force __le16)hdr->length);
if (len != size || (unsigned long)hdr + len > end) {
pr_warn("Malformed DSMAS table length: (%u:%u)\n", size, len);
return -EINVAL;
}
/* Skip common header */
dsmas = (struct acpi_cdat_dsmas *)(hdr + 1);
dent = kzalloc(sizeof(*dent), GFP_KERNEL);
if (!dent)
return -ENOMEM;
dent->handle = dsmas->dsmad_handle;
dent->dpa_range.start = le64_to_cpu((__force __le64)dsmas->dpa_base_address);
dent->dpa_range.end = le64_to_cpu((__force __le64)dsmas->dpa_base_address) +
le64_to_cpu((__force __le64)dsmas->dpa_length) - 1;
rc = xa_insert(dsmas_xa, dent->handle, dent, GFP_KERNEL);
if (rc) {
kfree(dent);
return rc;
}
return 0;
}
static void cxl_access_coordinate_set(struct access_coordinate *coord,
int access, unsigned int val)
{
switch (access) {
case ACPI_HMAT_ACCESS_LATENCY:
coord->read_latency = val;
coord->write_latency = val;
break;
case ACPI_HMAT_READ_LATENCY:
coord->read_latency = val;
break;
case ACPI_HMAT_WRITE_LATENCY:
coord->write_latency = val;
break;
case ACPI_HMAT_ACCESS_BANDWIDTH:
coord->read_bandwidth = val;
coord->write_bandwidth = val;
break;
case ACPI_HMAT_READ_BANDWIDTH:
coord->read_bandwidth = val;
break;
case ACPI_HMAT_WRITE_BANDWIDTH:
coord->write_bandwidth = val;
break;
}
}
static int cdat_dslbis_handler(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
struct acpi_cdat_header *hdr = &header->cdat;
struct acpi_cdat_dslbis *dslbis;
int size = sizeof(*hdr) + sizeof(*dslbis);
struct xarray *dsmas_xa = arg;
struct dsmas_entry *dent;
__le64 le_base;
__le16 le_val;
u64 val;
u16 len;
int rc;
len = le16_to_cpu((__force __le16)hdr->length);
if (len != size || (unsigned long)hdr + len > end) {
pr_warn("Malformed DSLBIS table length: (%u:%u)\n", size, len);
return -EINVAL;
}
/* Skip common header */
dslbis = (struct acpi_cdat_dslbis *)(hdr + 1);
/* Skip unrecognized data type */
if (dslbis->data_type > ACPI_HMAT_WRITE_BANDWIDTH)
return 0;
/* Not a memory type, skip */
if ((dslbis->flags & ACPI_HMAT_MEMORY_HIERARCHY) != ACPI_HMAT_MEMORY)
return 0;
dent = xa_load(dsmas_xa, dslbis->handle);
if (!dent) {
pr_warn("No matching DSMAS entry for DSLBIS entry.\n");
return 0;
}
le_base = (__force __le64)dslbis->entry_base_unit;
le_val = (__force __le16)dslbis->entry[0];
rc = check_mul_overflow(le64_to_cpu(le_base),
le16_to_cpu(le_val), &val);
if (rc)
pr_warn("DSLBIS value overflowed.\n");
cxl_access_coordinate_set(&dent->coord, dslbis->data_type, val);
return 0;
}
static int cdat_table_parse_output(int rc)
{
if (rc < 0)
return rc;
if (rc == 0)
return -ENOENT;
return 0;
}
static int cxl_cdat_endpoint_process(struct cxl_port *port,
struct xarray *dsmas_xa)
{
int rc;
rc = cdat_table_parse(ACPI_CDAT_TYPE_DSMAS, cdat_dsmas_handler,
dsmas_xa, port->cdat.table);
rc = cdat_table_parse_output(rc);
if (rc)
return rc;
rc = cdat_table_parse(ACPI_CDAT_TYPE_DSLBIS, cdat_dslbis_handler,
dsmas_xa, port->cdat.table);
return cdat_table_parse_output(rc);
}
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
static int cxl_port_perf_data_calculate(struct cxl_port *port,
struct xarray *dsmas_xa)
{
struct access_coordinate ep_c;
struct access_coordinate coord[ACCESS_COORDINATE_MAX];
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
struct dsmas_entry *dent;
int valid_entries = 0;
unsigned long index;
int rc;
rc = cxl_endpoint_get_perf_coordinates(port, &ep_c);
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
if (rc) {
dev_dbg(&port->dev, "Failed to retrieve ep perf coordinates.\n");
return rc;
}
rc = cxl_hb_get_perf_coordinates(port, coord);
if (rc) {
dev_dbg(&port->dev, "Failed to retrieve hb perf coordinates.\n");
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
return rc;
}
struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
if (!cxl_root)
return -ENODEV;
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
if (!cxl_root->ops || !cxl_root->ops->qos_class)
return -EOPNOTSUPP;
xa_for_each(dsmas_xa, index, dent) {
int qos_class;
cxl_coordinates_combine(&dent->coord, &dent->coord, &ep_c);
/*
* Keeping the host bridge coordinates separate from the dsmas
* coordinates in order to allow calculation of access class
* 0 and 1 for region later.
*/
cxl_coordinates_combine(&coord[ACCESS_COORDINATE_LOCAL],
&coord[ACCESS_COORDINATE_LOCAL],
&dent->coord);
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
dent->entries = 1;
rc = cxl_root->ops->qos_class(cxl_root,
&coord[ACCESS_COORDINATE_LOCAL],
1, &qos_class);
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
if (rc != 1)
continue;
valid_entries++;
dent->qos_class = qos_class;
}
if (!valid_entries)
return -ENOENT;
return 0;
}
static void update_perf_entry(struct device *dev, struct dsmas_entry *dent,
struct cxl_dpa_perf *dpa_perf)
{
dpa_perf->dpa_range = dent->dpa_range;
dpa_perf->coord = dent->coord;
dpa_perf->qos_class = dent->qos_class;
dev_dbg(dev,
"DSMAS: dpa: %#llx qos: %d read_bw: %d write_bw %d read_lat: %d write_lat: %d\n",
dent->dpa_range.start, dpa_perf->qos_class,
dent->coord.read_bandwidth, dent->coord.write_bandwidth,
dent->coord.read_latency, dent->coord.write_latency);
}
static void cxl_memdev_set_qos_class(struct cxl_dev_state *cxlds,
struct xarray *dsmas_xa)
{
struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
struct device *dev = cxlds->dev;
struct range pmem_range = {
.start = cxlds->pmem_res.start,
.end = cxlds->pmem_res.end,
};
struct range ram_range = {
.start = cxlds->ram_res.start,
.end = cxlds->ram_res.end,
};
struct dsmas_entry *dent;
unsigned long index;
xa_for_each(dsmas_xa, index, dent) {
if (resource_size(&cxlds->ram_res) &&
range_contains(&ram_range, &dent->dpa_range))
update_perf_entry(dev, dent, &mds->ram_perf);
else if (resource_size(&cxlds->pmem_res) &&
range_contains(&pmem_range, &dent->dpa_range))
update_perf_entry(dev, dent, &mds->pmem_perf);
else
dev_dbg(dev, "no partition for dsmas dpa: %#llx\n",
dent->dpa_range.start);
}
}
static int match_cxlrd_qos_class(struct device *dev, void *data)
{
int dev_qos_class = *(int *)data;
struct cxl_root_decoder *cxlrd;
if (!is_root_decoder(dev))
return 0;
cxlrd = to_cxl_root_decoder(dev);
if (cxlrd->qos_class == CXL_QOS_CLASS_INVALID)
return 0;
if (cxlrd->qos_class == dev_qos_class)
return 1;
return 0;
}
static void reset_dpa_perf(struct cxl_dpa_perf *dpa_perf)
{
*dpa_perf = (struct cxl_dpa_perf) {
.qos_class = CXL_QOS_CLASS_INVALID,
};
}
static bool cxl_qos_match(struct cxl_port *root_port,
struct cxl_dpa_perf *dpa_perf)
{
if (dpa_perf->qos_class == CXL_QOS_CLASS_INVALID)
return false;
if (!device_for_each_child(&root_port->dev, &dpa_perf->qos_class,
match_cxlrd_qos_class))
return false;
return true;
}
static int match_cxlrd_hb(struct device *dev, void *data)
{
struct device *host_bridge = data;
struct cxl_switch_decoder *cxlsd;
struct cxl_root_decoder *cxlrd;
if (!is_root_decoder(dev))
return 0;
cxlrd = to_cxl_root_decoder(dev);
cxlsd = &cxlrd->cxlsd;
guard(rwsem_read)(&cxl_region_rwsem);
for (int i = 0; i < cxlsd->nr_targets; i++) {
if (host_bridge == cxlsd->target[i]->dport_dev)
return 1;
}
return 0;
}
static int cxl_qos_class_verify(struct cxl_memdev *cxlmd)
{
struct cxl_dev_state *cxlds = cxlmd->cxlds;
struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
struct cxl_port *root_port;
int rc;
struct cxl_root *cxl_root __free(put_cxl_root) =
find_cxl_root(cxlmd->endpoint);
if (!cxl_root)
return -ENODEV;
root_port = &cxl_root->port;
/* Check that the QTG IDs are all sane between end device and root decoders */
if (!cxl_qos_match(root_port, &mds->ram_perf))
reset_dpa_perf(&mds->ram_perf);
if (!cxl_qos_match(root_port, &mds->pmem_perf))
reset_dpa_perf(&mds->pmem_perf);
/* Check to make sure that the device's host bridge is under a root decoder */
rc = device_for_each_child(&root_port->dev,
cxlmd->endpoint->host_bridge, match_cxlrd_hb);
if (!rc) {
reset_dpa_perf(&mds->ram_perf);
reset_dpa_perf(&mds->pmem_perf);
}
return rc;
}
static void discard_dsmas(struct xarray *xa)
{
unsigned long index;
void *ent;
xa_for_each(xa, index, ent) {
xa_erase(xa, index);
kfree(ent);
}
xa_destroy(xa);
}
DEFINE_FREE(dsmas, struct xarray *, if (_T) discard_dsmas(_T))
void cxl_endpoint_parse_cdat(struct cxl_port *port)
{
struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
struct xarray __dsmas_xa;
struct xarray *dsmas_xa __free(dsmas) = &__dsmas_xa;
int rc;
xa_init(&__dsmas_xa);
if (!port->cdat.table)
return;
rc = cxl_cdat_endpoint_process(port, dsmas_xa);
if (rc < 0) {
dev_dbg(&port->dev, "Failed to parse CDAT: %d\n", rc);
return;
}
cxl: Compute the entire CXL path latency and bandwidth data CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-21 22:04:04 +00:00
rc = cxl_port_perf_data_calculate(port, dsmas_xa);
if (rc) {
dev_dbg(&port->dev, "Failed to do perf coord calculations.\n");
return;
}
cxl_memdev_set_qos_class(cxlds, dsmas_xa);
cxl_qos_class_verify(cxlmd);
cxl_memdev_update_perf(cxlmd);
}
EXPORT_SYMBOL_NS_GPL(cxl_endpoint_parse_cdat, CXL);
static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
struct acpi_cdat_sslbis_table {
struct acpi_cdat_header header;
struct acpi_cdat_sslbis sslbis_header;
struct acpi_cdat_sslbe entries[];
} *tbl = (struct acpi_cdat_sslbis_table *)header;
int size = sizeof(header->cdat) + sizeof(tbl->sslbis_header);
struct acpi_cdat_sslbis *sslbis;
struct cxl_port *port = arg;
struct device *dev = &port->dev;
int remain, entries, i;
u16 len;
len = le16_to_cpu((__force __le16)header->cdat.length);
remain = len - size;
if (!remain || remain % sizeof(tbl->entries[0]) ||
(unsigned long)header + len > end) {
dev_warn(dev, "Malformed SSLBIS table length: (%u)\n", len);
return -EINVAL;
}
sslbis = &tbl->sslbis_header;
/* Unrecognized data type, we can skip */
if (sslbis->data_type > ACPI_HMAT_WRITE_BANDWIDTH)
return 0;
entries = remain / sizeof(tbl->entries[0]);
if (struct_size(tbl, entries, entries) != len)
return -EINVAL;
for (i = 0; i < entries; i++) {
u16 x = le16_to_cpu((__force __le16)tbl->entries[i].portx_id);
u16 y = le16_to_cpu((__force __le16)tbl->entries[i].porty_id);
__le64 le_base;
__le16 le_val;
struct cxl_dport *dport;
unsigned long index;
u16 dsp_id;
u64 val;
switch (x) {
case ACPI_CDAT_SSLBIS_US_PORT:
dsp_id = y;
break;
case ACPI_CDAT_SSLBIS_ANY_PORT:
switch (y) {
case ACPI_CDAT_SSLBIS_US_PORT:
dsp_id = x;
break;
case ACPI_CDAT_SSLBIS_ANY_PORT:
dsp_id = ACPI_CDAT_SSLBIS_ANY_PORT;
break;
default:
dsp_id = y;
break;
}
break;
default:
dsp_id = x;
break;
}
le_base = (__force __le64)tbl->sslbis_header.entry_base_unit;
le_val = (__force __le16)tbl->entries[i].latency_or_bandwidth;
if (check_mul_overflow(le64_to_cpu(le_base),
le16_to_cpu(le_val), &val))
dev_warn(dev, "SSLBIS value overflowed!\n");
xa_for_each(&port->dports, index, dport) {
if (dsp_id == ACPI_CDAT_SSLBIS_ANY_PORT ||
dsp_id == dport->port_id)
cxl_access_coordinate_set(&dport->sw_coord,
sslbis->data_type,
val);
}
}
return 0;
}
void cxl_switch_parse_cdat(struct cxl_port *port)
{
int rc;
if (!port->cdat.table)
return;
rc = cdat_table_parse(ACPI_CDAT_TYPE_SSLBIS, cdat_sslbis_handler,
port, port->cdat.table);
rc = cdat_table_parse_output(rc);
if (rc)
dev_dbg(&port->dev, "Failed to parse SSLBIS: %d\n", rc);
}
EXPORT_SYMBOL_NS_GPL(cxl_switch_parse_cdat, CXL);
/**
* cxl_coordinates_combine - Combine the two input coordinates
*
* @out: Output coordinate of c1 and c2 combined
* @c1: input coordinates
* @c2: input coordinates
*/
void cxl_coordinates_combine(struct access_coordinate *out,
struct access_coordinate *c1,
struct access_coordinate *c2)
{
if (c1->write_bandwidth && c2->write_bandwidth)
out->write_bandwidth = min(c1->write_bandwidth,
c2->write_bandwidth);
out->write_latency = c1->write_latency + c2->write_latency;
if (c1->read_bandwidth && c2->read_bandwidth)
out->read_bandwidth = min(c1->read_bandwidth,
c2->read_bandwidth);
out->read_latency = c1->read_latency + c2->read_latency;
}
MODULE_IMPORT_NS(CXL);