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

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
#include <linux/memregion.h>
#include <linux/genalloc.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/sort.h>
#include <linux/idr.h>
#include <cxlmem.h>
#include <cxl.h>
#include "core.h"
/**
* DOC: cxl core region
*
* CXL Regions represent mapped memory capacity in system physical address
* space. Whereas the CXL Root Decoders identify the bounds of potential CXL
* Memory ranges, Regions represent the active mapped capacity by the HDM
* Decoder Capability structures throughout the Host Bridges, Switches, and
* Endpoints in the topology.
*
* Region configuration has ordering constraints. UUID may be set at any time
* but is only visible for persistent regions.
* 1. Interleave granularity
* 2. Interleave size
* 3. Decoder targets
*/
static struct cxl_region *to_cxl_region(struct device *dev);
static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
if (cxlr->mode != CXL_DECODER_PMEM)
rc = sysfs_emit(buf, "\n");
else
rc = sysfs_emit(buf, "%pUb\n", &p->uuid);
up_read(&cxl_region_rwsem);
return rc;
}
static int is_dup(struct device *match, void *data)
{
struct cxl_region_params *p;
struct cxl_region *cxlr;
uuid_t *uuid = data;
if (!is_cxl_region(match))
return 0;
lockdep_assert_held(&cxl_region_rwsem);
cxlr = to_cxl_region(match);
p = &cxlr->params;
if (uuid_equal(&p->uuid, uuid)) {
dev_dbg(match, "already has uuid: %pUb\n", uuid);
return -EBUSY;
}
return 0;
}
static ssize_t uuid_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
uuid_t temp;
ssize_t rc;
if (len != UUID_STRING_LEN + 1)
return -EINVAL;
rc = uuid_parse(buf, &temp);
if (rc)
return rc;
if (uuid_is_null(&temp))
return -EINVAL;
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
if (uuid_equal(&p->uuid, &temp))
goto out;
rc = -EBUSY;
if (p->state >= CXL_CONFIG_ACTIVE)
goto out;
rc = bus_for_each_dev(&cxl_bus_type, NULL, &temp, is_dup);
if (rc < 0)
goto out;
uuid_copy(&p->uuid, &temp);
out:
up_write(&cxl_region_rwsem);
if (rc)
return rc;
return len;
}
static DEVICE_ATTR_RW(uuid);
static struct cxl_region_ref *cxl_rr_load(struct cxl_port *port,
struct cxl_region *cxlr)
{
return xa_load(&port->regions, (unsigned long)cxlr);
}
static int cxl_region_invalidate_memregion(struct cxl_region *cxlr)
{
if (!cpu_cache_has_invalidate_memregion()) {
if (IS_ENABLED(CONFIG_CXL_REGION_INVALIDATION_TEST)) {
dev_info_once(
&cxlr->dev,
"Bypassing cpu_cache_invalidate_memregion() for testing!\n");
return 0;
} else {
dev_err(&cxlr->dev,
"Failed to synchronize CPU cache state\n");
return -ENXIO;
}
}
cpu_cache_invalidate_memregion(IORES_DESC_CXL);
return 0;
}
static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
{
struct cxl_region_params *p = &cxlr->params;
int i, rc = 0;
/*
* Before region teardown attempt to flush, and if the flush
* fails cancel the region teardown for data consistency
* concerns
*/
rc = cxl_region_invalidate_memregion(cxlr);
if (rc)
return rc;
for (i = count - 1; i >= 0; i--) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_port *iter = cxled_to_port(cxled);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
struct cxl_ep *ep;
if (cxlds->rcd)
goto endpoint_reset;
while (!is_cxl_root(to_cxl_port(iter->dev.parent)))
iter = to_cxl_port(iter->dev.parent);
for (ep = cxl_ep_load(iter, cxlmd); iter;
iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
struct cxl_region_ref *cxl_rr;
struct cxl_decoder *cxld;
cxl_rr = cxl_rr_load(iter, cxlr);
cxld = cxl_rr->decoder;
if (cxld->reset)
rc = cxld->reset(cxld);
if (rc)
return rc;
set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
}
endpoint_reset:
rc = cxled->cxld.reset(&cxled->cxld);
if (rc)
return rc;
set_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
}
/* all decoders associated with this region have been torn down */
clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
return 0;
}
static int commit_decoder(struct cxl_decoder *cxld)
{
struct cxl_switch_decoder *cxlsd = NULL;
if (cxld->commit)
return cxld->commit(cxld);
if (is_switch_decoder(&cxld->dev))
cxlsd = to_cxl_switch_decoder(&cxld->dev);
if (dev_WARN_ONCE(&cxld->dev, !cxlsd || cxlsd->nr_targets > 1,
"->commit() is required\n"))
return -ENXIO;
return 0;
}
static int cxl_region_decode_commit(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
int i, rc = 0;
for (i = 0; i < p->nr_targets; i++) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_region_ref *cxl_rr;
struct cxl_decoder *cxld;
struct cxl_port *iter;
struct cxl_ep *ep;
/* commit bottom up */
for (iter = cxled_to_port(cxled); !is_cxl_root(iter);
iter = to_cxl_port(iter->dev.parent)) {
cxl_rr = cxl_rr_load(iter, cxlr);
cxld = cxl_rr->decoder;
rc = commit_decoder(cxld);
if (rc)
break;
}
if (rc) {
/* programming @iter failed, teardown */
for (ep = cxl_ep_load(iter, cxlmd); ep && iter;
iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
cxl_rr = cxl_rr_load(iter, cxlr);
cxld = cxl_rr->decoder;
if (cxld->reset)
cxld->reset(cxld);
}
cxled->cxld.reset(&cxled->cxld);
goto err;
}
}
return 0;
err:
/* undo the targets that were successfully committed */
cxl_region_decode_reset(cxlr, i);
return rc;
}
static ssize_t commit_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
bool commit;
ssize_t rc;
rc = kstrtobool(buf, &commit);
if (rc)
return rc;
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
/* Already in the requested state? */
if (commit && p->state >= CXL_CONFIG_COMMIT)
goto out;
if (!commit && p->state < CXL_CONFIG_COMMIT)
goto out;
/* Not ready to commit? */
if (commit && p->state < CXL_CONFIG_ACTIVE) {
rc = -ENXIO;
goto out;
}
/*
* Invalidate caches before region setup to drop any speculative
* consumption of this address space
*/
rc = cxl_region_invalidate_memregion(cxlr);
if (rc)
goto out;
if (commit) {
rc = cxl_region_decode_commit(cxlr);
if (rc == 0)
p->state = CXL_CONFIG_COMMIT;
} else {
p->state = CXL_CONFIG_RESET_PENDING;
up_write(&cxl_region_rwsem);
device_release_driver(&cxlr->dev);
down_write(&cxl_region_rwsem);
/*
* The lock was dropped, so need to revalidate that the reset is
* still pending.
*/
if (p->state == CXL_CONFIG_RESET_PENDING) {
rc = cxl_region_decode_reset(cxlr, p->interleave_ways);
/*
* Revert to committed since there may still be active
* decoders associated with this region, or move forward
* to active to mark the reset successful
*/
if (rc)
p->state = CXL_CONFIG_COMMIT;
else
p->state = CXL_CONFIG_ACTIVE;
}
}
out:
up_write(&cxl_region_rwsem);
if (rc)
return rc;
return len;
}
static ssize_t commit_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
rc = sysfs_emit(buf, "%d\n", p->state >= CXL_CONFIG_COMMIT);
up_read(&cxl_region_rwsem);
return rc;
}
static DEVICE_ATTR_RW(commit);
static umode_t cxl_region_visible(struct kobject *kobj, struct attribute *a,
int n)
{
struct device *dev = kobj_to_dev(kobj);
struct cxl_region *cxlr = to_cxl_region(dev);
/*
* Support tooling that expects to find a 'uuid' attribute for all
* regions regardless of mode.
*/
if (a == &dev_attr_uuid.attr && cxlr->mode != CXL_DECODER_PMEM)
return 0444;
return a->mode;
}
static ssize_t interleave_ways_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
rc = sysfs_emit(buf, "%d\n", p->interleave_ways);
up_read(&cxl_region_rwsem);
return rc;
}
static const struct attribute_group *get_cxl_region_target_group(void);
static ssize_t interleave_ways_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
unsigned int val, save;
int rc;
u8 iw;
rc = kstrtouint(buf, 0, &val);
if (rc)
return rc;
rc = ways_to_eiw(val, &iw);
if (rc)
return rc;
/*
* Even for x3, x6, and x12 interleaves the region interleave must be a
* power of 2 multiple of the host bridge interleave.
*/
if (!is_power_of_2(val / cxld->interleave_ways) ||
(val % cxld->interleave_ways)) {
dev_dbg(&cxlr->dev, "invalid interleave: %d\n", val);
return -EINVAL;
}
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
rc = -EBUSY;
goto out;
}
save = p->interleave_ways;
p->interleave_ways = val;
rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
if (rc)
p->interleave_ways = save;
out:
up_write(&cxl_region_rwsem);
if (rc)
return rc;
return len;
}
static DEVICE_ATTR_RW(interleave_ways);
static ssize_t interleave_granularity_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
rc = sysfs_emit(buf, "%d\n", p->interleave_granularity);
up_read(&cxl_region_rwsem);
return rc;
}
static ssize_t interleave_granularity_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
int rc, val;
u16 ig;
rc = kstrtoint(buf, 0, &val);
if (rc)
return rc;
rc = granularity_to_eig(val, &ig);
if (rc)
return rc;
/*
* When the host-bridge is interleaved, disallow region granularity !=
* root granularity. Regions with a granularity less than the root
* interleave result in needing multiple endpoints to support a single
* slot in the interleave (possible to support in the future). Regions
* with a granularity greater than the root interleave result in invalid
* DPA translations (invalid to support).
*/
if (cxld->interleave_ways > 1 && val != cxld->interleave_granularity)
return -EINVAL;
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
rc = -EBUSY;
goto out;
}
p->interleave_granularity = val;
out:
up_write(&cxl_region_rwsem);
if (rc)
return rc;
return len;
}
static DEVICE_ATTR_RW(interleave_granularity);
static ssize_t resource_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
u64 resource = -1ULL;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
if (p->res)
resource = p->res->start;
rc = sysfs_emit(buf, "%#llx\n", resource);
up_read(&cxl_region_rwsem);
return rc;
}
static DEVICE_ATTR_RO(resource);
static ssize_t mode_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
return sysfs_emit(buf, "%s\n", cxl_decoder_mode_name(cxlr->mode));
}
static DEVICE_ATTR_RO(mode);
static int alloc_hpa(struct cxl_region *cxlr, resource_size_t size)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
struct cxl_region_params *p = &cxlr->params;
struct resource *res;
u64 remainder = 0;
lockdep_assert_held_write(&cxl_region_rwsem);
/* Nothing to do... */
if (p->res && resource_size(p->res) == size)
return 0;
/* To change size the old size must be freed first */
if (p->res)
return -EBUSY;
if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
return -EBUSY;
/* ways, granularity and uuid (if PMEM) need to be set before HPA */
if (!p->interleave_ways || !p->interleave_granularity ||
(cxlr->mode == CXL_DECODER_PMEM && uuid_is_null(&p->uuid)))
return -ENXIO;
div64_u64_rem(size, (u64)SZ_256M * p->interleave_ways, &remainder);
if (remainder)
return -EINVAL;
res = alloc_free_mem_region(cxlrd->res, size, SZ_256M,
dev_name(&cxlr->dev));
if (IS_ERR(res)) {
dev_dbg(&cxlr->dev,
"HPA allocation error (%ld) for size:%pap in %s %pr\n",
PTR_ERR(res), &size, cxlrd->res->name, cxlrd->res);
return PTR_ERR(res);
}
p->res = res;
p->state = CXL_CONFIG_INTERLEAVE_ACTIVE;
return 0;
}
static void cxl_region_iomem_release(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
if (device_is_registered(&cxlr->dev))
lockdep_assert_held_write(&cxl_region_rwsem);
if (p->res) {
/*
* Autodiscovered regions may not have been able to insert their
* resource.
*/
if (p->res->parent)
remove_resource(p->res);
kfree(p->res);
p->res = NULL;
}
}
static int free_hpa(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
lockdep_assert_held_write(&cxl_region_rwsem);
if (!p->res)
return 0;
if (p->state >= CXL_CONFIG_ACTIVE)
return -EBUSY;
cxl_region_iomem_release(cxlr);
p->state = CXL_CONFIG_IDLE;
return 0;
}
static ssize_t size_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_region *cxlr = to_cxl_region(dev);
u64 val;
int rc;
rc = kstrtou64(buf, 0, &val);
if (rc)
return rc;
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
if (val)
rc = alloc_hpa(cxlr, val);
else
rc = free_hpa(cxlr);
up_write(&cxl_region_rwsem);
if (rc)
return rc;
return len;
}
static ssize_t size_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
u64 size = 0;
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
if (p->res)
size = resource_size(p->res);
rc = sysfs_emit(buf, "%#llx\n", size);
up_read(&cxl_region_rwsem);
return rc;
}
static DEVICE_ATTR_RW(size);
static struct attribute *cxl_region_attrs[] = {
&dev_attr_uuid.attr,
&dev_attr_commit.attr,
&dev_attr_interleave_ways.attr,
&dev_attr_interleave_granularity.attr,
&dev_attr_resource.attr,
&dev_attr_size.attr,
&dev_attr_mode.attr,
NULL,
};
static const struct attribute_group cxl_region_group = {
.attrs = cxl_region_attrs,
.is_visible = cxl_region_visible,
};
static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_endpoint_decoder *cxled;
int rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
if (pos >= p->interleave_ways) {
dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
p->interleave_ways);
rc = -ENXIO;
goto out;
}
cxled = p->targets[pos];
if (!cxled)
rc = sysfs_emit(buf, "\n");
else
rc = sysfs_emit(buf, "%s\n", dev_name(&cxled->cxld.dev));
out:
up_read(&cxl_region_rwsem);
return rc;
}
static int match_free_decoder(struct device *dev, void *data)
{
struct cxl_decoder *cxld;
int *id = data;
if (!is_switch_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
/* enforce ordered allocation */
if (cxld->id != *id)
return 0;
if (!cxld->region)
return 1;
(*id)++;
return 0;
}
static int match_auto_decoder(struct device *dev, void *data)
{
struct cxl_region_params *p = data;
struct cxl_decoder *cxld;
struct range *r;
if (!is_switch_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
r = &cxld->hpa_range;
if (p->res && p->res->start == r->start && p->res->end == r->end)
return 1;
return 0;
}
static struct cxl_decoder *
cxl_region_find_decoder(struct cxl_port *port,
struct cxl_endpoint_decoder *cxled,
struct cxl_region *cxlr)
{
struct device *dev;
int id = 0;
if (port == cxled_to_port(cxled))
return &cxled->cxld;
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags))
dev = device_find_child(&port->dev, &cxlr->params,
match_auto_decoder);
else
dev = device_find_child(&port->dev, &id, match_free_decoder);
if (!dev)
return NULL;
/*
* This decoder is pinned registered as long as the endpoint decoder is
* registered, and endpoint decoder unregistration holds the
* cxl_region_rwsem over unregister events, so no need to hold on to
* this extra reference.
*/
put_device(dev);
return to_cxl_decoder(dev);
}
static bool auto_order_ok(struct cxl_port *port, struct cxl_region *cxlr_iter,
struct cxl_decoder *cxld)
{
struct cxl_region_ref *rr = cxl_rr_load(port, cxlr_iter);
struct cxl_decoder *cxld_iter = rr->decoder;
/*
* Allow the out of order assembly of auto-discovered regions.
* Per CXL Spec 3.1 8.2.4.20.12 software must commit decoders
* in HPA order. Confirm that the decoder with the lesser HPA
* starting address has the lesser id.
*/
dev_dbg(&cxld->dev, "check for HPA violation %s:%d < %s:%d\n",
dev_name(&cxld->dev), cxld->id,
dev_name(&cxld_iter->dev), cxld_iter->id);
if (cxld_iter->id > cxld->id)
return true;
return false;
}
static struct cxl_region_ref *
alloc_region_ref(struct cxl_port *port, struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_region_ref *cxl_rr, *iter;
unsigned long index;
int rc;
xa_for_each(&port->regions, index, iter) {
struct cxl_region_params *ip = &iter->region->params;
if (!ip->res || ip->res->start < p->res->start)
continue;
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
struct cxl_decoder *cxld;
cxld = cxl_region_find_decoder(port, cxled, cxlr);
if (auto_order_ok(port, iter->region, cxld))
continue;
}
dev_dbg(&cxlr->dev, "%s: HPA order violation %s:%pr vs %pr\n",
dev_name(&port->dev),
dev_name(&iter->region->dev), ip->res, p->res);
return ERR_PTR(-EBUSY);
}
cxl_rr = kzalloc(sizeof(*cxl_rr), GFP_KERNEL);
if (!cxl_rr)
return ERR_PTR(-ENOMEM);
cxl_rr->port = port;
cxl_rr->region = cxlr;
cxl_rr->nr_targets = 1;
xa_init(&cxl_rr->endpoints);
rc = xa_insert(&port->regions, (unsigned long)cxlr, cxl_rr, GFP_KERNEL);
if (rc) {
dev_dbg(&cxlr->dev,
"%s: failed to track region reference: %d\n",
dev_name(&port->dev), rc);
kfree(cxl_rr);
return ERR_PTR(rc);
}
return cxl_rr;
}
static void cxl_rr_free_decoder(struct cxl_region_ref *cxl_rr)
{
struct cxl_region *cxlr = cxl_rr->region;
struct cxl_decoder *cxld = cxl_rr->decoder;
if (!cxld)
return;
dev_WARN_ONCE(&cxlr->dev, cxld->region != cxlr, "region mismatch\n");
if (cxld->region == cxlr) {
cxld->region = NULL;
put_device(&cxlr->dev);
}
}
static void free_region_ref(struct cxl_region_ref *cxl_rr)
{
struct cxl_port *port = cxl_rr->port;
struct cxl_region *cxlr = cxl_rr->region;
cxl_rr_free_decoder(cxl_rr);
xa_erase(&port->regions, (unsigned long)cxlr);
xa_destroy(&cxl_rr->endpoints);
kfree(cxl_rr);
}
static int cxl_rr_ep_add(struct cxl_region_ref *cxl_rr,
struct cxl_endpoint_decoder *cxled)
{
int rc;
struct cxl_port *port = cxl_rr->port;
struct cxl_region *cxlr = cxl_rr->region;
struct cxl_decoder *cxld = cxl_rr->decoder;
struct cxl_ep *ep = cxl_ep_load(port, cxled_to_memdev(cxled));
if (ep) {
rc = xa_insert(&cxl_rr->endpoints, (unsigned long)cxled, ep,
GFP_KERNEL);
if (rc)
return rc;
}
cxl_rr->nr_eps++;
if (!cxld->region) {
cxld->region = cxlr;
get_device(&cxlr->dev);
}
return 0;
}
static int cxl_rr_alloc_decoder(struct cxl_port *port, struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled,
struct cxl_region_ref *cxl_rr)
{
struct cxl_decoder *cxld;
cxld = cxl_region_find_decoder(port, cxled, cxlr);
if (!cxld) {
dev_dbg(&cxlr->dev, "%s: no decoder available\n",
dev_name(&port->dev));
return -EBUSY;
}
if (cxld->region) {
dev_dbg(&cxlr->dev, "%s: %s already attached to %s\n",
dev_name(&port->dev), dev_name(&cxld->dev),
dev_name(&cxld->region->dev));
return -EBUSY;
}
/*
* Endpoints should already match the region type, but backstop that
* assumption with an assertion. Switch-decoders change mapping-type
* based on what is mapped when they are assigned to a region.
*/
dev_WARN_ONCE(&cxlr->dev,
port == cxled_to_port(cxled) &&
cxld->target_type != cxlr->type,
"%s:%s mismatch decoder type %d -> %d\n",
dev_name(&cxled_to_memdev(cxled)->dev),
dev_name(&cxld->dev), cxld->target_type, cxlr->type);
cxld->target_type = cxlr->type;
cxl_rr->decoder = cxld;
return 0;
}
/**
* cxl_port_attach_region() - track a region's interest in a port by endpoint
* @port: port to add a new region reference 'struct cxl_region_ref'
* @cxlr: region to attach to @port
* @cxled: endpoint decoder used to create or further pin a region reference
* @pos: interleave position of @cxled in @cxlr
*
* The attach event is an opportunity to validate CXL decode setup
* constraints and record metadata needed for programming HDM decoders,
* in particular decoder target lists.
*
* The steps are:
*
* - validate that there are no other regions with a higher HPA already
* associated with @port
* - establish a region reference if one is not already present
*
* - additionally allocate a decoder instance that will host @cxlr on
* @port
*
* - pin the region reference by the endpoint
* - account for how many entries in @port's target list are needed to
* cover all of the added endpoints.
*/
static int cxl_port_attach_region(struct cxl_port *port,
struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled, int pos)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_ep *ep = cxl_ep_load(port, cxlmd);
struct cxl_region_ref *cxl_rr;
bool nr_targets_inc = false;
struct cxl_decoder *cxld;
unsigned long index;
int rc = -EBUSY;
lockdep_assert_held_write(&cxl_region_rwsem);
cxl_rr = cxl_rr_load(port, cxlr);
if (cxl_rr) {
struct cxl_ep *ep_iter;
int found = 0;
/*
* Walk the existing endpoints that have been attached to
* @cxlr at @port and see if they share the same 'next' port
* in the downstream direction. I.e. endpoints that share common
* upstream switch.
*/
xa_for_each(&cxl_rr->endpoints, index, ep_iter) {
if (ep_iter == ep)
continue;
if (ep_iter->next == ep->next) {
found++;
break;
}
}
/*
* New target port, or @port is an endpoint port that always
* accounts its own local decode as a target.
*/
if (!found || !ep->next) {
cxl_rr->nr_targets++;
nr_targets_inc = true;
}
} else {
cxl_rr = alloc_region_ref(port, cxlr, cxled);
if (IS_ERR(cxl_rr)) {
dev_dbg(&cxlr->dev,
"%s: failed to allocate region reference\n",
dev_name(&port->dev));
return PTR_ERR(cxl_rr);
}
nr_targets_inc = true;
rc = cxl_rr_alloc_decoder(port, cxlr, cxled, cxl_rr);
if (rc)
goto out_erase;
}
cxld = cxl_rr->decoder;
rc = cxl_rr_ep_add(cxl_rr, cxled);
if (rc) {
dev_dbg(&cxlr->dev,
"%s: failed to track endpoint %s:%s reference\n",
dev_name(&port->dev), dev_name(&cxlmd->dev),
dev_name(&cxld->dev));
goto out_erase;
}
dev_dbg(&cxlr->dev,
"%s:%s %s add: %s:%s @ %d next: %s nr_eps: %d nr_targets: %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxld->dev), dev_name(&cxlmd->dev),
dev_name(&cxled->cxld.dev), pos,
ep ? ep->next ? dev_name(ep->next->uport_dev) :
dev_name(&cxlmd->dev) :
"none",
cxl_rr->nr_eps, cxl_rr->nr_targets);
return 0;
out_erase:
if (nr_targets_inc)
cxl_rr->nr_targets--;
if (cxl_rr->nr_eps == 0)
free_region_ref(cxl_rr);
return rc;
}
static void cxl_port_detach_region(struct cxl_port *port,
struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled)
{
struct cxl_region_ref *cxl_rr;
struct cxl_ep *ep = NULL;
lockdep_assert_held_write(&cxl_region_rwsem);
cxl_rr = cxl_rr_load(port, cxlr);
if (!cxl_rr)
return;
/*
* Endpoint ports do not carry cxl_ep references, and they
* never target more than one endpoint by definition
*/
if (cxl_rr->decoder == &cxled->cxld)
cxl_rr->nr_eps--;
else
ep = xa_erase(&cxl_rr->endpoints, (unsigned long)cxled);
if (ep) {
struct cxl_ep *ep_iter;
unsigned long index;
int found = 0;
cxl_rr->nr_eps--;
xa_for_each(&cxl_rr->endpoints, index, ep_iter) {
if (ep_iter->next == ep->next) {
found++;
break;
}
}
if (!found)
cxl_rr->nr_targets--;
}
if (cxl_rr->nr_eps == 0)
free_region_ref(cxl_rr);
}
static int check_last_peer(struct cxl_endpoint_decoder *cxled,
struct cxl_ep *ep, struct cxl_region_ref *cxl_rr,
int distance)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_region *cxlr = cxl_rr->region;
struct cxl_region_params *p = &cxlr->params;
struct cxl_endpoint_decoder *cxled_peer;
struct cxl_port *port = cxl_rr->port;
struct cxl_memdev *cxlmd_peer;
struct cxl_ep *ep_peer;
int pos = cxled->pos;
/*
* If this position wants to share a dport with the last endpoint mapped
* then that endpoint, at index 'position - distance', must also be
* mapped by this dport.
*/
if (pos < distance) {
dev_dbg(&cxlr->dev, "%s:%s: cannot host %s:%s at %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
return -ENXIO;
}
cxled_peer = p->targets[pos - distance];
cxlmd_peer = cxled_to_memdev(cxled_peer);
ep_peer = cxl_ep_load(port, cxlmd_peer);
if (ep->dport != ep_peer->dport) {
dev_dbg(&cxlr->dev,
"%s:%s: %s:%s pos %d mismatched peer %s:%s\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos,
dev_name(&cxlmd_peer->dev),
dev_name(&cxled_peer->cxld.dev));
return -ENXIO;
}
return 0;
}
static int cxl_port_setup_targets(struct cxl_port *port,
struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
int parent_iw, parent_ig, ig, iw, rc, inc = 0, pos = cxled->pos;
struct cxl_port *parent_port = to_cxl_port(port->dev.parent);
struct cxl_region_ref *cxl_rr = cxl_rr_load(port, cxlr);
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_ep *ep = cxl_ep_load(port, cxlmd);
struct cxl_region_params *p = &cxlr->params;
struct cxl_decoder *cxld = cxl_rr->decoder;
struct cxl_switch_decoder *cxlsd;
u16 eig, peig;
u8 eiw, peiw;
/*
* While root level decoders support x3, x6, x12, switch level
* decoders only support powers of 2 up to x16.
*/
if (!is_power_of_2(cxl_rr->nr_targets)) {
dev_dbg(&cxlr->dev, "%s:%s: invalid target count %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
cxl_rr->nr_targets);
return -EINVAL;
}
cxlsd = to_cxl_switch_decoder(&cxld->dev);
if (cxl_rr->nr_targets_set) {
int i, distance;
/*
* Passthrough decoders impose no distance requirements between
* peers
*/
if (cxl_rr->nr_targets == 1)
distance = 0;
else
distance = p->nr_targets / cxl_rr->nr_targets;
for (i = 0; i < cxl_rr->nr_targets_set; i++)
if (ep->dport == cxlsd->target[i]) {
rc = check_last_peer(cxled, ep, cxl_rr,
distance);
if (rc)
return rc;
goto out_target_set;
}
goto add_target;
}
if (is_cxl_root(parent_port)) {
/*
* Root decoder IG is always set to value in CFMWS which
* may be different than this region's IG. We can use the
* region's IG here since interleave_granularity_store()
* does not allow interleaved host-bridges with
* root IG != region IG.
*/
parent_ig = p->interleave_granularity;
parent_iw = cxlrd->cxlsd.cxld.interleave_ways;
/*
* For purposes of address bit routing, use power-of-2 math for
* switch ports.
*/
if (!is_power_of_2(parent_iw))
parent_iw /= 3;
} else {
struct cxl_region_ref *parent_rr;
struct cxl_decoder *parent_cxld;
parent_rr = cxl_rr_load(parent_port, cxlr);
parent_cxld = parent_rr->decoder;
parent_ig = parent_cxld->interleave_granularity;
parent_iw = parent_cxld->interleave_ways;
}
rc = granularity_to_eig(parent_ig, &peig);
if (rc) {
dev_dbg(&cxlr->dev, "%s:%s: invalid parent granularity: %d\n",
dev_name(parent_port->uport_dev),
dev_name(&parent_port->dev), parent_ig);
return rc;
}
rc = ways_to_eiw(parent_iw, &peiw);
if (rc) {
dev_dbg(&cxlr->dev, "%s:%s: invalid parent interleave: %d\n",
dev_name(parent_port->uport_dev),
dev_name(&parent_port->dev), parent_iw);
return rc;
}
iw = cxl_rr->nr_targets;
rc = ways_to_eiw(iw, &eiw);
if (rc) {
dev_dbg(&cxlr->dev, "%s:%s: invalid port interleave: %d\n",
dev_name(port->uport_dev), dev_name(&port->dev), iw);
return rc;
}
/*
* Interleave granularity is a multiple of @parent_port granularity.
* Multiplier is the parent port interleave ways.
*/
rc = granularity_to_eig(parent_ig * parent_iw, &eig);
if (rc) {
dev_dbg(&cxlr->dev,
"%s: invalid granularity calculation (%d * %d)\n",
dev_name(&parent_port->dev), parent_ig, parent_iw);
return rc;
}
rc = eig_to_granularity(eig, &ig);
if (rc) {
dev_dbg(&cxlr->dev, "%s:%s: invalid interleave: %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
256 << eig);
return rc;
}
if (iw > 8 || iw > cxlsd->nr_targets) {
dev_dbg(&cxlr->dev,
"%s:%s:%s: ways: %d overflows targets: %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxld->dev), iw, cxlsd->nr_targets);
return -ENXIO;
}
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
if (cxld->interleave_ways != iw ||
cxld->interleave_granularity != ig ||
cxld->hpa_range.start != p->res->start ||
cxld->hpa_range.end != p->res->end ||
((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
dev_err(&cxlr->dev,
"%s:%s %s expected iw: %d ig: %d %pr\n",
dev_name(port->uport_dev), dev_name(&port->dev),
__func__, iw, ig, p->res);
dev_err(&cxlr->dev,
"%s:%s %s got iw: %d ig: %d state: %s %#llx:%#llx\n",
dev_name(port->uport_dev), dev_name(&port->dev),
__func__, cxld->interleave_ways,
cxld->interleave_granularity,
(cxld->flags & CXL_DECODER_F_ENABLE) ?
"enabled" :
"disabled",
cxld->hpa_range.start, cxld->hpa_range.end);
return -ENXIO;
}
} else {
cxld->interleave_ways = iw;
cxld->interleave_granularity = ig;
cxld->hpa_range = (struct range) {
.start = p->res->start,
.end = p->res->end,
};
}
dev_dbg(&cxlr->dev, "%s:%s iw: %d ig: %d\n", dev_name(port->uport_dev),
dev_name(&port->dev), iw, ig);
add_target:
if (cxl_rr->nr_targets_set == cxl_rr->nr_targets) {
dev_dbg(&cxlr->dev,
"%s:%s: targets full trying to add %s:%s at %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
return -ENXIO;
}
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
if (cxlsd->target[cxl_rr->nr_targets_set] != ep->dport) {
dev_dbg(&cxlr->dev, "%s:%s: %s expected %s at %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
dev_name(&cxlsd->cxld.dev),
dev_name(ep->dport->dport_dev),
cxl_rr->nr_targets_set);
return -ENXIO;
}
} else
cxlsd->target[cxl_rr->nr_targets_set] = ep->dport;
inc = 1;
out_target_set:
cxl_rr->nr_targets_set += inc;
dev_dbg(&cxlr->dev, "%s:%s target[%d] = %s for %s:%s @ %d\n",
dev_name(port->uport_dev), dev_name(&port->dev),
cxl_rr->nr_targets_set - 1, dev_name(ep->dport->dport_dev),
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
return 0;
}
static void cxl_port_reset_targets(struct cxl_port *port,
struct cxl_region *cxlr)
{
struct cxl_region_ref *cxl_rr = cxl_rr_load(port, cxlr);
struct cxl_decoder *cxld;
/*
* After the last endpoint has been detached the entire cxl_rr may now
* be gone.
*/
if (!cxl_rr)
return;
cxl_rr->nr_targets_set = 0;
cxld = cxl_rr->decoder;
cxld->hpa_range = (struct range) {
.start = 0,
.end = -1,
};
}
static void cxl_region_teardown_targets(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_endpoint_decoder *cxled;
struct cxl_dev_state *cxlds;
struct cxl_memdev *cxlmd;
struct cxl_port *iter;
struct cxl_ep *ep;
int i;
/*
* In the auto-discovery case skip automatic teardown since the
* address space is already active
*/
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags))
return;
for (i = 0; i < p->nr_targets; i++) {
cxled = p->targets[i];
cxlmd = cxled_to_memdev(cxled);
cxlds = cxlmd->cxlds;
if (cxlds->rcd)
continue;
iter = cxled_to_port(cxled);
while (!is_cxl_root(to_cxl_port(iter->dev.parent)))
iter = to_cxl_port(iter->dev.parent);
for (ep = cxl_ep_load(iter, cxlmd); iter;
iter = ep->next, ep = cxl_ep_load(iter, cxlmd))
cxl_port_reset_targets(iter, cxlr);
}
}
static int cxl_region_setup_targets(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_endpoint_decoder *cxled;
struct cxl_dev_state *cxlds;
int i, rc, rch = 0, vh = 0;
struct cxl_memdev *cxlmd;
struct cxl_port *iter;
struct cxl_ep *ep;
for (i = 0; i < p->nr_targets; i++) {
cxled = p->targets[i];
cxlmd = cxled_to_memdev(cxled);
cxlds = cxlmd->cxlds;
/* validate that all targets agree on topology */
if (!cxlds->rcd) {
vh++;
} else {
rch++;
continue;
}
iter = cxled_to_port(cxled);
while (!is_cxl_root(to_cxl_port(iter->dev.parent)))
iter = to_cxl_port(iter->dev.parent);
/*
* Descend the topology tree programming / validating
* targets while looking for conflicts.
*/
for (ep = cxl_ep_load(iter, cxlmd); iter;
iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
rc = cxl_port_setup_targets(iter, cxlr, cxled);
if (rc) {
cxl_region_teardown_targets(cxlr);
return rc;
}
}
}
if (rch && vh) {
dev_err(&cxlr->dev, "mismatched CXL topologies detected\n");
cxl_region_teardown_targets(cxlr);
return -ENXIO;
}
return 0;
}
static int cxl_region_validate_position(struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled,
int pos)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_region_params *p = &cxlr->params;
int i;
if (pos < 0 || pos >= p->interleave_ways) {
dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
p->interleave_ways);
return -ENXIO;
}
if (p->targets[pos] == cxled)
return 0;
if (p->targets[pos]) {
struct cxl_endpoint_decoder *cxled_target = p->targets[pos];
struct cxl_memdev *cxlmd_target = cxled_to_memdev(cxled_target);
dev_dbg(&cxlr->dev, "position %d already assigned to %s:%s\n",
pos, dev_name(&cxlmd_target->dev),
dev_name(&cxled_target->cxld.dev));
return -EBUSY;
}
for (i = 0; i < p->interleave_ways; i++) {
struct cxl_endpoint_decoder *cxled_target;
struct cxl_memdev *cxlmd_target;
cxled_target = p->targets[i];
if (!cxled_target)
continue;
cxlmd_target = cxled_to_memdev(cxled_target);
if (cxlmd_target == cxlmd) {
dev_dbg(&cxlr->dev,
"%s already specified at position %d via: %s\n",
dev_name(&cxlmd->dev), pos,
dev_name(&cxled_target->cxld.dev));
return -EBUSY;
}
}
return 0;
}
static int cxl_region_attach_position(struct cxl_region *cxlr,
struct cxl_root_decoder *cxlrd,
struct cxl_endpoint_decoder *cxled,
const struct cxl_dport *dport, int pos)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_port *iter;
int rc;
if (cxlrd->calc_hb(cxlrd, pos) != dport) {
dev_dbg(&cxlr->dev, "%s:%s invalid target position for %s\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
dev_name(&cxlrd->cxlsd.cxld.dev));
return -ENXIO;
}
for (iter = cxled_to_port(cxled); !is_cxl_root(iter);
iter = to_cxl_port(iter->dev.parent)) {
rc = cxl_port_attach_region(iter, cxlr, cxled, pos);
if (rc)
goto err;
}
return 0;
err:
for (iter = cxled_to_port(cxled); !is_cxl_root(iter);
iter = to_cxl_port(iter->dev.parent))
cxl_port_detach_region(iter, cxlr, cxled);
return rc;
}
static int cxl_region_attach_auto(struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled, int pos)
{
struct cxl_region_params *p = &cxlr->params;
if (cxled->state != CXL_DECODER_STATE_AUTO) {
dev_err(&cxlr->dev,
"%s: unable to add decoder to autodetected region\n",
dev_name(&cxled->cxld.dev));
return -EINVAL;
}
if (pos >= 0) {
dev_dbg(&cxlr->dev, "%s: expected auto position, not %d\n",
dev_name(&cxled->cxld.dev), pos);
return -EINVAL;
}
if (p->nr_targets >= p->interleave_ways) {
dev_err(&cxlr->dev, "%s: no more target slots available\n",
dev_name(&cxled->cxld.dev));
return -ENXIO;
}
/*
* Temporarily record the endpoint decoder into the target array. Yes,
* this means that userspace can view devices in the wrong position
* before the region activates, and must be careful to understand when
* it might be racing region autodiscovery.
*/
pos = p->nr_targets;
p->targets[pos] = cxled;
cxled->pos = pos;
p->nr_targets++;
return 0;
}
static int cmp_interleave_pos(const void *a, const void *b)
{
struct cxl_endpoint_decoder *cxled_a = *(typeof(cxled_a) *)a;
struct cxl_endpoint_decoder *cxled_b = *(typeof(cxled_b) *)b;
return cxled_a->pos - cxled_b->pos;
}
static struct cxl_port *next_port(struct cxl_port *port)
{
if (!port->parent_dport)
return NULL;
return port->parent_dport->port;
}
static int match_switch_decoder_by_range(struct device *dev, void *data)
{
struct cxl_switch_decoder *cxlsd;
struct range *r1, *r2 = data;
if (!is_switch_decoder(dev))
return 0;
cxlsd = to_cxl_switch_decoder(dev);
r1 = &cxlsd->cxld.hpa_range;
if (is_root_decoder(dev))
return range_contains(r1, r2);
return (r1->start == r2->start && r1->end == r2->end);
}
static int find_pos_and_ways(struct cxl_port *port, struct range *range,
int *pos, int *ways)
{
struct cxl_switch_decoder *cxlsd;
struct cxl_port *parent;
struct device *dev;
int rc = -ENXIO;
parent = next_port(port);
if (!parent)
return rc;
dev = device_find_child(&parent->dev, range,
match_switch_decoder_by_range);
if (!dev) {
dev_err(port->uport_dev,
"failed to find decoder mapping %#llx-%#llx\n",
range->start, range->end);
return rc;
}
cxlsd = to_cxl_switch_decoder(dev);
*ways = cxlsd->cxld.interleave_ways;
for (int i = 0; i < *ways; i++) {
if (cxlsd->target[i] == port->parent_dport) {
*pos = i;
rc = 0;
break;
}
}
put_device(dev);
return rc;
}
/**
* cxl_calc_interleave_pos() - calculate an endpoint position in a region
* @cxled: endpoint decoder member of given region
*
* The endpoint position is calculated by traversing the topology from
* the endpoint to the root decoder and iteratively applying this
* calculation:
*
* position = position * parent_ways + parent_pos;
*
* ...where @position is inferred from switch and root decoder target lists.
*
* Return: position >= 0 on success
* -ENXIO on failure
*/
static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
{
struct cxl_port *iter, *port = cxled_to_port(cxled);
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct range *range = &cxled->cxld.hpa_range;
int parent_ways = 0, parent_pos = 0, pos = 0;
int rc;
/*
* Example: the expected interleave order of the 4-way region shown
* below is: mem0, mem2, mem1, mem3
*
* root_port
* / \
* host_bridge_0 host_bridge_1
* | | | |
* mem0 mem1 mem2 mem3
*
* In the example the calculator will iterate twice. The first iteration
* uses the mem position in the host-bridge and the ways of the host-
* bridge to generate the first, or local, position. The second
* iteration uses the host-bridge position in the root_port and the ways
* of the root_port to refine the position.
*
* A trace of the calculation per endpoint looks like this:
* mem0: pos = 0 * 2 + 0 mem2: pos = 0 * 2 + 0
* pos = 0 * 2 + 0 pos = 0 * 2 + 1
* pos: 0 pos: 1
*
* mem1: pos = 0 * 2 + 1 mem3: pos = 0 * 2 + 1
* pos = 1 * 2 + 0 pos = 1 * 2 + 1
* pos: 2 pos = 3
*
* Note that while this example is simple, the method applies to more
* complex topologies, including those with switches.
*/
/* Iterate from endpoint to root_port refining the position */
for (iter = port; iter; iter = next_port(iter)) {
if (is_cxl_root(iter))
break;
rc = find_pos_and_ways(iter, range, &parent_pos, &parent_ways);
if (rc)
return rc;
pos = pos * parent_ways + parent_pos;
}
dev_dbg(&cxlmd->dev,
"decoder:%s parent:%s port:%s range:%#llx-%#llx pos:%d\n",
dev_name(&cxled->cxld.dev), dev_name(cxlmd->dev.parent),
dev_name(&port->dev), range->start, range->end, pos);
return pos;
}
static int cxl_region_sort_targets(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
int i, rc = 0;
for (i = 0; i < p->nr_targets; i++) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
cxled->pos = cxl_calc_interleave_pos(cxled);
/*
* Record that sorting failed, but still continue to calc
* cxled->pos so that follow-on code paths can reliably
* do p->targets[cxled->pos] to self-reference their entry.
*/
if (cxled->pos < 0)
rc = -ENXIO;
}
/* Keep the cxlr target list in interleave position order */
sort(p->targets, p->nr_targets, sizeof(p->targets[0]),
cmp_interleave_pos, NULL);
dev_dbg(&cxlr->dev, "region sort %s\n", rc ? "failed" : "successful");
return rc;
}
static int cxl_region_attach(struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled, int pos)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_region_params *p = &cxlr->params;
struct cxl_port *ep_port, *root_port;
struct cxl_dport *dport;
int rc = -ENXIO;
if (cxled->mode != cxlr->mode) {
dev_dbg(&cxlr->dev, "%s region mode: %d mismatch: %d\n",
dev_name(&cxled->cxld.dev), cxlr->mode, cxled->mode);
return -EINVAL;
}
if (cxled->mode == CXL_DECODER_DEAD) {
dev_dbg(&cxlr->dev, "%s dead\n", dev_name(&cxled->cxld.dev));
return -ENODEV;
}
/* all full of members, or interleave config not established? */
if (p->state > CXL_CONFIG_INTERLEAVE_ACTIVE) {
dev_dbg(&cxlr->dev, "region already active\n");
return -EBUSY;
} else if (p->state < CXL_CONFIG_INTERLEAVE_ACTIVE) {
dev_dbg(&cxlr->dev, "interleave config missing\n");
return -ENXIO;
}
if (p->nr_targets >= p->interleave_ways) {
dev_dbg(&cxlr->dev, "region already has %d endpoints\n",
p->nr_targets);
return -EINVAL;
}
ep_port = cxled_to_port(cxled);
root_port = cxlrd_to_port(cxlrd);
dport = cxl_find_dport_by_dev(root_port, ep_port->host_bridge);
if (!dport) {
dev_dbg(&cxlr->dev, "%s:%s invalid target for %s\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
dev_name(cxlr->dev.parent));
return -ENXIO;
}
if (cxled->cxld.target_type != cxlr->type) {
dev_dbg(&cxlr->dev, "%s:%s type mismatch: %d vs %d\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
cxled->cxld.target_type, cxlr->type);
return -ENXIO;
}
if (!cxled->dpa_res) {
dev_dbg(&cxlr->dev, "%s:%s: missing DPA allocation.\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev));
return -ENXIO;
}
if (resource_size(cxled->dpa_res) * p->interleave_ways !=
resource_size(p->res)) {
dev_dbg(&cxlr->dev,
"%s:%s: decoder-size-%#llx * ways-%d != region-size-%#llx\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
(u64)resource_size(cxled->dpa_res), p->interleave_ways,
(u64)resource_size(p->res));
return -EINVAL;
}
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
int i;
rc = cxl_region_attach_auto(cxlr, cxled, pos);
if (rc)
return rc;
/* await more targets to arrive... */
if (p->nr_targets < p->interleave_ways)
return 0;
/*
* All targets are here, which implies all PCI enumeration that
* affects this region has been completed. Walk the topology to
* sort the devices into their relative region decode position.
*/
rc = cxl_region_sort_targets(cxlr);
if (rc)
return rc;
for (i = 0; i < p->nr_targets; i++) {
cxled = p->targets[i];
ep_port = cxled_to_port(cxled);
dport = cxl_find_dport_by_dev(root_port,
ep_port->host_bridge);
rc = cxl_region_attach_position(cxlr, cxlrd, cxled,
dport, i);
if (rc)
return rc;
}
rc = cxl_region_setup_targets(cxlr);
if (rc)
return rc;
/*
* If target setup succeeds in the autodiscovery case
* then the region is already committed.
*/
p->state = CXL_CONFIG_COMMIT;
return 0;
}
rc = cxl_region_validate_position(cxlr, cxled, pos);
if (rc)
return rc;
rc = cxl_region_attach_position(cxlr, cxlrd, cxled, dport, pos);
if (rc)
return rc;
p->targets[pos] = cxled;
cxled->pos = pos;
p->nr_targets++;
if (p->nr_targets == p->interleave_ways) {
rc = cxl_region_setup_targets(cxlr);
if (rc)
return rc;
p->state = CXL_CONFIG_ACTIVE;
}
cxled->cxld.interleave_ways = p->interleave_ways;
cxled->cxld.interleave_granularity = p->interleave_granularity;
cxled->cxld.hpa_range = (struct range) {
.start = p->res->start,
.end = p->res->end,
};
if (p->nr_targets != p->interleave_ways)
return 0;
/*
* Test the auto-discovery position calculator function
* against this successfully created user-defined region.
* A fail message here means that this interleave config
* will fail when presented as CXL_REGION_F_AUTO.
*/
for (int i = 0; i < p->nr_targets; i++) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
int test_pos;
test_pos = cxl_calc_interleave_pos(cxled);
dev_dbg(&cxled->cxld.dev,
"Test cxl_calc_interleave_pos(): %s test_pos:%d cxled->pos:%d\n",
(test_pos == cxled->pos) ? "success" : "fail",
test_pos, cxled->pos);
}
return 0;
}
static int cxl_region_detach(struct cxl_endpoint_decoder *cxled)
{
struct cxl_port *iter, *ep_port = cxled_to_port(cxled);
struct cxl_region *cxlr = cxled->cxld.region;
struct cxl_region_params *p;
int rc = 0;
lockdep_assert_held_write(&cxl_region_rwsem);
if (!cxlr)
return 0;
p = &cxlr->params;
get_device(&cxlr->dev);
if (p->state > CXL_CONFIG_ACTIVE) {
/*
* TODO: tear down all impacted regions if a device is
* removed out of order
*/
rc = cxl_region_decode_reset(cxlr, p->interleave_ways);
if (rc)
goto out;
p->state = CXL_CONFIG_ACTIVE;
}
for (iter = ep_port; !is_cxl_root(iter);
iter = to_cxl_port(iter->dev.parent))
cxl_port_detach_region(iter, cxlr, cxled);
if (cxled->pos < 0 || cxled->pos >= p->interleave_ways ||
p->targets[cxled->pos] != cxled) {
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
dev_WARN_ONCE(&cxlr->dev, 1, "expected %s:%s at position %d\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
cxled->pos);
goto out;
}
if (p->state == CXL_CONFIG_ACTIVE) {
p->state = CXL_CONFIG_INTERLEAVE_ACTIVE;
cxl_region_teardown_targets(cxlr);
}
p->targets[cxled->pos] = NULL;
p->nr_targets--;
cxled->cxld.hpa_range = (struct range) {
.start = 0,
.end = -1,
};
/* notify the region driver that one of its targets has departed */
up_write(&cxl_region_rwsem);
device_release_driver(&cxlr->dev);
down_write(&cxl_region_rwsem);
out:
put_device(&cxlr->dev);
return rc;
}
void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled)
{
down_write(&cxl_region_rwsem);
cxled->mode = CXL_DECODER_DEAD;
cxl_region_detach(cxled);
up_write(&cxl_region_rwsem);
}
static int attach_target(struct cxl_region *cxlr,
struct cxl_endpoint_decoder *cxled, int pos,
unsigned int state)
{
int rc = 0;
if (state == TASK_INTERRUPTIBLE)
rc = down_write_killable(&cxl_region_rwsem);
else
down_write(&cxl_region_rwsem);
if (rc)
return rc;
down_read(&cxl_dpa_rwsem);
rc = cxl_region_attach(cxlr, cxled, pos);
up_read(&cxl_dpa_rwsem);
up_write(&cxl_region_rwsem);
return rc;
}
static int detach_target(struct cxl_region *cxlr, int pos)
{
struct cxl_region_params *p = &cxlr->params;
int rc;
rc = down_write_killable(&cxl_region_rwsem);
if (rc)
return rc;
if (pos >= p->interleave_ways) {
dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
p->interleave_ways);
rc = -ENXIO;
goto out;
}
if (!p->targets[pos]) {
rc = 0;
goto out;
}
rc = cxl_region_detach(p->targets[pos]);
out:
up_write(&cxl_region_rwsem);
return rc;
}
static size_t store_targetN(struct cxl_region *cxlr, const char *buf, int pos,
size_t len)
{
int rc;
if (sysfs_streq(buf, "\n"))
rc = detach_target(cxlr, pos);
else {
struct device *dev;
dev = bus_find_device_by_name(&cxl_bus_type, NULL, buf);
if (!dev)
return -ENODEV;
if (!is_endpoint_decoder(dev)) {
rc = -EINVAL;
goto out;
}
rc = attach_target(cxlr, to_cxl_endpoint_decoder(dev), pos,
TASK_INTERRUPTIBLE);
out:
put_device(dev);
}
if (rc < 0)
return rc;
return len;
}
#define TARGET_ATTR_RW(n) \
static ssize_t target##n##_show( \
struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return show_targetN(to_cxl_region(dev), buf, (n)); \
} \
static ssize_t target##n##_store(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t len) \
{ \
return store_targetN(to_cxl_region(dev), buf, (n), len); \
} \
static DEVICE_ATTR_RW(target##n)
TARGET_ATTR_RW(0);
TARGET_ATTR_RW(1);
TARGET_ATTR_RW(2);
TARGET_ATTR_RW(3);
TARGET_ATTR_RW(4);
TARGET_ATTR_RW(5);
TARGET_ATTR_RW(6);
TARGET_ATTR_RW(7);
TARGET_ATTR_RW(8);
TARGET_ATTR_RW(9);
TARGET_ATTR_RW(10);
TARGET_ATTR_RW(11);
TARGET_ATTR_RW(12);
TARGET_ATTR_RW(13);
TARGET_ATTR_RW(14);
TARGET_ATTR_RW(15);
static struct attribute *target_attrs[] = {
&dev_attr_target0.attr,
&dev_attr_target1.attr,
&dev_attr_target2.attr,
&dev_attr_target3.attr,
&dev_attr_target4.attr,
&dev_attr_target5.attr,
&dev_attr_target6.attr,
&dev_attr_target7.attr,
&dev_attr_target8.attr,
&dev_attr_target9.attr,
&dev_attr_target10.attr,
&dev_attr_target11.attr,
&dev_attr_target12.attr,
&dev_attr_target13.attr,
&dev_attr_target14.attr,
&dev_attr_target15.attr,
NULL,
};
static umode_t cxl_region_target_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
if (n < p->interleave_ways)
return a->mode;
return 0;
}
static const struct attribute_group cxl_region_target_group = {
.attrs = target_attrs,
.is_visible = cxl_region_target_visible,
};
static const struct attribute_group *get_cxl_region_target_group(void)
{
return &cxl_region_target_group;
}
static const struct attribute_group *region_groups[] = {
&cxl_base_attribute_group,
&cxl_region_group,
&cxl_region_target_group,
NULL,
};
static void cxl_region_release(struct device *dev)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
struct cxl_region *cxlr = to_cxl_region(dev);
int id = atomic_read(&cxlrd->region_id);
/*
* Try to reuse the recently idled id rather than the cached
* next id to prevent the region id space from increasing
* unnecessarily.
*/
if (cxlr->id < id)
if (atomic_try_cmpxchg(&cxlrd->region_id, &id, cxlr->id)) {
memregion_free(id);
goto out;
}
memregion_free(cxlr->id);
out:
put_device(dev->parent);
kfree(cxlr);
}
const struct device_type cxl_region_type = {
.name = "cxl_region",
.release = cxl_region_release,
.groups = region_groups
};
bool is_cxl_region(struct device *dev)
{
return dev->type == &cxl_region_type;
}
EXPORT_SYMBOL_NS_GPL(is_cxl_region, CXL);
static struct cxl_region *to_cxl_region(struct device *dev)
{
if (dev_WARN_ONCE(dev, dev->type != &cxl_region_type,
"not a cxl_region device\n"))
return NULL;
return container_of(dev, struct cxl_region, dev);
}
static void unregister_region(void *_cxlr)
{
struct cxl_region *cxlr = _cxlr;
struct cxl_region_params *p = &cxlr->params;
int i;
device_del(&cxlr->dev);
/*
* Now that region sysfs is shutdown, the parameter block is now
* read-only, so no need to hold the region rwsem to access the
* region parameters.
*/
for (i = 0; i < p->interleave_ways; i++)
detach_target(cxlr, i);
cxl_region_iomem_release(cxlr);
put_device(&cxlr->dev);
}
static struct lock_class_key cxl_region_key;
static struct cxl_region *cxl_region_alloc(struct cxl_root_decoder *cxlrd, int id)
{
struct cxl_region *cxlr;
struct device *dev;
cxlr = kzalloc(sizeof(*cxlr), GFP_KERNEL);
if (!cxlr) {
memregion_free(id);
return ERR_PTR(-ENOMEM);
}
dev = &cxlr->dev;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_region_key);
dev->parent = &cxlrd->cxlsd.cxld.dev;
/*
* Keep root decoder pinned through cxl_region_release to fixup
* region id allocations
*/
get_device(dev->parent);
device_set_pm_not_required(dev);
dev->bus = &cxl_bus_type;
dev->type = &cxl_region_type;
cxlr->id = id;
return cxlr;
}
/**
* devm_cxl_add_region - Adds a region to a decoder
* @cxlrd: root decoder
* @id: memregion id to create, or memregion_free() on failure
* @mode: mode for the endpoint decoders of this region
* @type: select whether this is an expander or accelerator (type-2 or type-3)
*
* This is the second step of region initialization. Regions exist within an
* address space which is mapped by a @cxlrd.
*
* Return: 0 if the region was added to the @cxlrd, else returns negative error
* code. The region will be named "regionZ" where Z is the unique region number.
*/
static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
int id,
enum cxl_decoder_mode mode,
enum cxl_decoder_type type)
{
struct cxl_port *port = to_cxl_port(cxlrd->cxlsd.cxld.dev.parent);
struct cxl_region *cxlr;
struct device *dev;
int rc;
switch (mode) {
case CXL_DECODER_RAM:
case CXL_DECODER_PMEM:
break;
default:
dev_err(&cxlrd->cxlsd.cxld.dev, "unsupported mode %d\n", mode);
return ERR_PTR(-EINVAL);
}
cxlr = cxl_region_alloc(cxlrd, id);
if (IS_ERR(cxlr))
return cxlr;
cxlr->mode = mode;
cxlr->type = type;
dev = &cxlr->dev;
rc = dev_set_name(dev, "region%d", id);
if (rc)
goto err;
rc = device_add(dev);
if (rc)
goto err;
rc = devm_add_action_or_reset(port->uport_dev, unregister_region, cxlr);
if (rc)
return ERR_PTR(rc);
dev_dbg(port->uport_dev, "%s: created %s\n",
dev_name(&cxlrd->cxlsd.cxld.dev), dev_name(dev));
return cxlr;
err:
put_device(dev);
return ERR_PTR(rc);
}
static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
{
return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
}
static ssize_t create_pmem_region_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return __create_region_show(to_cxl_root_decoder(dev), buf);
}
static ssize_t create_ram_region_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return __create_region_show(to_cxl_root_decoder(dev), buf);
}
static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
enum cxl_decoder_mode mode, int id)
{
int rc;
rc = memregion_alloc(GFP_KERNEL);
if (rc < 0)
return ERR_PTR(rc);
if (atomic_cmpxchg(&cxlrd->region_id, id, rc) != id) {
memregion_free(rc);
return ERR_PTR(-EBUSY);
}
return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_HOSTONLYMEM);
}
static ssize_t create_pmem_region_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
struct cxl_region *cxlr;
int rc, id;
rc = sscanf(buf, "region%d\n", &id);
if (rc != 1)
return -EINVAL;
cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id);
if (IS_ERR(cxlr))
return PTR_ERR(cxlr);
return len;
}
DEVICE_ATTR_RW(create_pmem_region);
static ssize_t create_ram_region_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
struct cxl_region *cxlr;
int rc, id;
rc = sscanf(buf, "region%d\n", &id);
if (rc != 1)
return -EINVAL;
cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id);
if (IS_ERR(cxlr))
return PTR_ERR(cxlr);
return len;
}
DEVICE_ATTR_RW(create_ram_region);
static ssize_t region_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
ssize_t rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc)
return rc;
if (cxld->region)
rc = sysfs_emit(buf, "%s\n", dev_name(&cxld->region->dev));
else
rc = sysfs_emit(buf, "\n");
up_read(&cxl_region_rwsem);
return rc;
}
DEVICE_ATTR_RO(region);
static struct cxl_region *
cxl_find_region_by_name(struct cxl_root_decoder *cxlrd, const char *name)
{
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct device *region_dev;
region_dev = device_find_child_by_name(&cxld->dev, name);
if (!region_dev)
return ERR_PTR(-ENODEV);
return to_cxl_region(region_dev);
}
static ssize_t delete_region_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
struct cxl_port *port = to_cxl_port(dev->parent);
struct cxl_region *cxlr;
cxlr = cxl_find_region_by_name(cxlrd, buf);
if (IS_ERR(cxlr))
return PTR_ERR(cxlr);
devm_release_action(port->uport_dev, unregister_region, cxlr);
put_device(&cxlr->dev);
return len;
}
DEVICE_ATTR_WO(delete_region);
static void cxl_pmem_region_release(struct device *dev)
{
struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
int i;
for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
struct cxl_memdev *cxlmd = cxlr_pmem->mapping[i].cxlmd;
put_device(&cxlmd->dev);
}
kfree(cxlr_pmem);
}
static const struct attribute_group *cxl_pmem_region_attribute_groups[] = {
&cxl_base_attribute_group,
NULL,
};
const struct device_type cxl_pmem_region_type = {
.name = "cxl_pmem_region",
.release = cxl_pmem_region_release,
.groups = cxl_pmem_region_attribute_groups,
};
bool is_cxl_pmem_region(struct device *dev)
{
return dev->type == &cxl_pmem_region_type;
}
EXPORT_SYMBOL_NS_GPL(is_cxl_pmem_region, CXL);
struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
{
if (dev_WARN_ONCE(dev, !is_cxl_pmem_region(dev),
"not a cxl_pmem_region device\n"))
return NULL;
return container_of(dev, struct cxl_pmem_region, dev);
}
EXPORT_SYMBOL_NS_GPL(to_cxl_pmem_region, CXL);
struct cxl_poison_context {
struct cxl_port *port;
enum cxl_decoder_mode mode;
u64 offset;
};
static int cxl_get_poison_unmapped(struct cxl_memdev *cxlmd,
struct cxl_poison_context *ctx)
{
struct cxl_dev_state *cxlds = cxlmd->cxlds;
u64 offset, length;
int rc = 0;
/*
* Collect poison for the remaining unmapped resources
* after poison is collected by committed endpoints.
*
* Knowing that PMEM must always follow RAM, get poison
* for unmapped resources based on the last decoder's mode:
* ram: scan remains of ram range, then any pmem range
* pmem: scan remains of pmem range
*/
if (ctx->mode == CXL_DECODER_RAM) {
offset = ctx->offset;
length = resource_size(&cxlds->ram_res) - offset;
rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
if (rc == -EFAULT)
rc = 0;
if (rc)
return rc;
}
if (ctx->mode == CXL_DECODER_PMEM) {
offset = ctx->offset;
length = resource_size(&cxlds->dpa_res) - offset;
if (!length)
return 0;
} else if (resource_size(&cxlds->pmem_res)) {
offset = cxlds->pmem_res.start;
length = resource_size(&cxlds->pmem_res);
} else {
return 0;
}
return cxl_mem_get_poison(cxlmd, offset, length, NULL);
}
static int poison_by_decoder(struct device *dev, void *arg)
{
struct cxl_poison_context *ctx = arg;
struct cxl_endpoint_decoder *cxled;
struct cxl_memdev *cxlmd;
u64 offset, length;
int rc = 0;
if (!is_endpoint_decoder(dev))
return rc;
cxled = to_cxl_endpoint_decoder(dev);
if (!cxled->dpa_res || !resource_size(cxled->dpa_res))
return rc;
/*
* Regions are only created with single mode decoders: pmem or ram.
* Linux does not support mixed mode decoders. This means that
* reading poison per endpoint decoder adheres to the requirement
* that poison reads of pmem and ram must be separated.
* CXL 3.0 Spec 8.2.9.8.4.1
*/
if (cxled->mode == CXL_DECODER_MIXED) {
dev_dbg(dev, "poison list read unsupported in mixed mode\n");
return rc;
}
cxlmd = cxled_to_memdev(cxled);
if (cxled->skip) {
offset = cxled->dpa_res->start - cxled->skip;
length = cxled->skip;
rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM)
rc = 0;
if (rc)
return rc;
}
offset = cxled->dpa_res->start;
length = cxled->dpa_res->end - offset + 1;
rc = cxl_mem_get_poison(cxlmd, offset, length, cxled->cxld.region);
if (rc == -EFAULT && cxled->mode == CXL_DECODER_RAM)
rc = 0;
if (rc)
return rc;
/* Iterate until commit_end is reached */
if (cxled->cxld.id == ctx->port->commit_end) {
ctx->offset = cxled->dpa_res->end + 1;
ctx->mode = cxled->mode;
return 1;
}
return 0;
}
int cxl_get_poison_by_endpoint(struct cxl_port *port)
{
struct cxl_poison_context ctx;
int rc = 0;
ctx = (struct cxl_poison_context) {
.port = port
};
rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder);
if (rc == 1)
rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport_dev),
&ctx);
return rc;
}
static struct lock_class_key cxl_pmem_region_key;
static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_nvdimm_bridge *cxl_nvb;
struct cxl_pmem_region *cxlr_pmem;
struct device *dev;
int i;
down_read(&cxl_region_rwsem);
if (p->state != CXL_CONFIG_COMMIT) {
cxlr_pmem = ERR_PTR(-ENXIO);
goto out;
}
cxlr_pmem = kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets),
GFP_KERNEL);
if (!cxlr_pmem) {
cxlr_pmem = ERR_PTR(-ENOMEM);
goto out;
}
cxlr_pmem->hpa_range.start = p->res->start;
cxlr_pmem->hpa_range.end = p->res->end;
/* Snapshot the region configuration underneath the cxl_region_rwsem */
cxlr_pmem->nr_mappings = p->nr_targets;
for (i = 0; i < p->nr_targets; i++) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
/*
* Regions never span CXL root devices, so by definition the
* bridge for one device is the same for all.
*/
if (i == 0) {
cxl_nvb = cxl_find_nvdimm_bridge(cxlmd);
if (!cxl_nvb) {
cxlr_pmem = ERR_PTR(-ENODEV);
goto out;
}
cxlr->cxl_nvb = cxl_nvb;
}
m->cxlmd = cxlmd;
get_device(&cxlmd->dev);
m->start = cxled->dpa_res->start;
m->size = resource_size(cxled->dpa_res);
m->position = i;
}
dev = &cxlr_pmem->dev;
cxlr_pmem->cxlr = cxlr;
cxlr->cxlr_pmem = cxlr_pmem;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_pmem_region_key);
device_set_pm_not_required(dev);
dev->parent = &cxlr->dev;
dev->bus = &cxl_bus_type;
dev->type = &cxl_pmem_region_type;
out:
up_read(&cxl_region_rwsem);
return cxlr_pmem;
}
static void cxl_dax_region_release(struct device *dev)
{
struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev);
kfree(cxlr_dax);
}
static const struct attribute_group *cxl_dax_region_attribute_groups[] = {
&cxl_base_attribute_group,
NULL,
};
const struct device_type cxl_dax_region_type = {
.name = "cxl_dax_region",
.release = cxl_dax_region_release,
.groups = cxl_dax_region_attribute_groups,
};
static bool is_cxl_dax_region(struct device *dev)
{
return dev->type == &cxl_dax_region_type;
}
struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
{
if (dev_WARN_ONCE(dev, !is_cxl_dax_region(dev),
"not a cxl_dax_region device\n"))
return NULL;
return container_of(dev, struct cxl_dax_region, dev);
}
EXPORT_SYMBOL_NS_GPL(to_cxl_dax_region, CXL);
static struct lock_class_key cxl_dax_region_key;
static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_dax_region *cxlr_dax;
struct device *dev;
down_read(&cxl_region_rwsem);
if (p->state != CXL_CONFIG_COMMIT) {
cxlr_dax = ERR_PTR(-ENXIO);
goto out;
}
cxlr_dax = kzalloc(sizeof(*cxlr_dax), GFP_KERNEL);
if (!cxlr_dax) {
cxlr_dax = ERR_PTR(-ENOMEM);
goto out;
}
cxlr_dax->hpa_range.start = p->res->start;
cxlr_dax->hpa_range.end = p->res->end;
dev = &cxlr_dax->dev;
cxlr_dax->cxlr = cxlr;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_dax_region_key);
device_set_pm_not_required(dev);
dev->parent = &cxlr->dev;
dev->bus = &cxl_bus_type;
dev->type = &cxl_dax_region_type;
out:
up_read(&cxl_region_rwsem);
return cxlr_dax;
}
static void cxlr_pmem_unregister(void *_cxlr_pmem)
{
struct cxl_pmem_region *cxlr_pmem = _cxlr_pmem;
struct cxl_region *cxlr = cxlr_pmem->cxlr;
struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
/*
* Either the bridge is in ->remove() context under the device_lock(),
* or cxlr_release_nvdimm() is cancelling the bridge's release action
* for @cxlr_pmem and doing it itself (while manually holding the bridge
* lock).
*/
device_lock_assert(&cxl_nvb->dev);
cxlr->cxlr_pmem = NULL;
cxlr_pmem->cxlr = NULL;
device_unregister(&cxlr_pmem->dev);
}
static void cxlr_release_nvdimm(void *_cxlr)
{
struct cxl_region *cxlr = _cxlr;
struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
device_lock(&cxl_nvb->dev);
if (cxlr->cxlr_pmem)
devm_release_action(&cxl_nvb->dev, cxlr_pmem_unregister,
cxlr->cxlr_pmem);
device_unlock(&cxl_nvb->dev);
cxlr->cxl_nvb = NULL;
put_device(&cxl_nvb->dev);
}
/**
* devm_cxl_add_pmem_region() - add a cxl_region-to-nd_region bridge
* @cxlr: parent CXL region for this pmem region bridge device
*
* Return: 0 on success negative error code on failure.
*/
static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
{
struct cxl_pmem_region *cxlr_pmem;
struct cxl_nvdimm_bridge *cxl_nvb;
struct device *dev;
int rc;
cxlr_pmem = cxl_pmem_region_alloc(cxlr);
if (IS_ERR(cxlr_pmem))
return PTR_ERR(cxlr_pmem);
cxl_nvb = cxlr->cxl_nvb;
dev = &cxlr_pmem->dev;
rc = dev_set_name(dev, "pmem_region%d", cxlr->id);
if (rc)
goto err;
rc = device_add(dev);
if (rc)
goto err;
dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
dev_name(dev));
device_lock(&cxl_nvb->dev);
if (cxl_nvb->dev.driver)
rc = devm_add_action_or_reset(&cxl_nvb->dev,
cxlr_pmem_unregister, cxlr_pmem);
else
rc = -ENXIO;
device_unlock(&cxl_nvb->dev);
if (rc)
goto err_bridge;
/* @cxlr carries a reference on @cxl_nvb until cxlr_release_nvdimm */
return devm_add_action_or_reset(&cxlr->dev, cxlr_release_nvdimm, cxlr);
err:
put_device(dev);
err_bridge:
put_device(&cxl_nvb->dev);
cxlr->cxl_nvb = NULL;
return rc;
}
static void cxlr_dax_unregister(void *_cxlr_dax)
{
struct cxl_dax_region *cxlr_dax = _cxlr_dax;
device_unregister(&cxlr_dax->dev);
}
static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
{
struct cxl_dax_region *cxlr_dax;
struct device *dev;
int rc;
cxlr_dax = cxl_dax_region_alloc(cxlr);
if (IS_ERR(cxlr_dax))
return PTR_ERR(cxlr_dax);
dev = &cxlr_dax->dev;
rc = dev_set_name(dev, "dax_region%d", cxlr->id);
if (rc)
goto err;
rc = device_add(dev);
if (rc)
goto err;
dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
dev_name(dev));
return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister,
cxlr_dax);
err:
put_device(dev);
return rc;
}
static int match_root_decoder_by_range(struct device *dev, void *data)
{
struct range *r1, *r2 = data;
struct cxl_root_decoder *cxlrd;
if (!is_root_decoder(dev))
return 0;
cxlrd = to_cxl_root_decoder(dev);
r1 = &cxlrd->cxlsd.cxld.hpa_range;
return range_contains(r1, r2);
}
static int match_region_by_range(struct device *dev, void *data)
{
struct cxl_region_params *p;
struct cxl_region *cxlr;
struct range *r = data;
int rc = 0;
if (!is_cxl_region(dev))
return 0;
cxlr = to_cxl_region(dev);
p = &cxlr->params;
down_read(&cxl_region_rwsem);
if (p->res && p->res->start == r->start && p->res->end == r->end)
rc = 1;
up_read(&cxl_region_rwsem);
return rc;
}
/* Establish an empty region covering the given HPA range */
static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
struct cxl_endpoint_decoder *cxled)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct cxl_port *port = cxlrd_to_port(cxlrd);
struct range *hpa = &cxled->cxld.hpa_range;
struct cxl_region_params *p;
struct cxl_region *cxlr;
struct resource *res;
int rc;
do {
cxlr = __create_region(cxlrd, cxled->mode,
atomic_read(&cxlrd->region_id));
} while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY);
if (IS_ERR(cxlr)) {
dev_err(cxlmd->dev.parent,
"%s:%s: %s failed assign region: %ld\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
__func__, PTR_ERR(cxlr));
return cxlr;
}
down_write(&cxl_region_rwsem);
p = &cxlr->params;
if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
dev_err(cxlmd->dev.parent,
"%s:%s: %s autodiscovery interrupted\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
__func__);
rc = -EBUSY;
goto err;
}
set_bit(CXL_REGION_F_AUTO, &cxlr->flags);
res = kmalloc(sizeof(*res), GFP_KERNEL);
if (!res) {
rc = -ENOMEM;
goto err;
}
*res = DEFINE_RES_MEM_NAMED(hpa->start, range_len(hpa),
dev_name(&cxlr->dev));
rc = insert_resource(cxlrd->res, res);
if (rc) {
/*
* Platform-firmware may not have split resources like "System
* RAM" on CXL window boundaries see cxl_region_iomem_release()
*/
dev_warn(cxlmd->dev.parent,
"%s:%s: %s %s cannot insert resource\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
__func__, dev_name(&cxlr->dev));
}
p->res = res;
p->interleave_ways = cxled->cxld.interleave_ways;
p->interleave_granularity = cxled->cxld.interleave_granularity;
p->state = CXL_CONFIG_INTERLEAVE_ACTIVE;
rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
if (rc)
goto err;
dev_dbg(cxlmd->dev.parent, "%s:%s: %s %s res: %pr iw: %d ig: %d\n",
dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__,
dev_name(&cxlr->dev), p->res, p->interleave_ways,
p->interleave_granularity);
/* ...to match put_device() in cxl_add_to_region() */
get_device(&cxlr->dev);
up_write(&cxl_region_rwsem);
return cxlr;
err:
up_write(&cxl_region_rwsem);
devm_release_action(port->uport_dev, unregister_region, cxlr);
return ERR_PTR(rc);
}
int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
struct range *hpa = &cxled->cxld.hpa_range;
struct cxl_decoder *cxld = &cxled->cxld;
struct device *cxlrd_dev, *region_dev;
struct cxl_root_decoder *cxlrd;
struct cxl_region_params *p;
struct cxl_region *cxlr;
bool attach = false;
int rc;
cxlrd_dev = device_find_child(&root->dev, &cxld->hpa_range,
match_root_decoder_by_range);
if (!cxlrd_dev) {
dev_err(cxlmd->dev.parent,
"%s:%s no CXL window for range %#llx:%#llx\n",
dev_name(&cxlmd->dev), dev_name(&cxld->dev),
cxld->hpa_range.start, cxld->hpa_range.end);
return -ENXIO;
}
cxlrd = to_cxl_root_decoder(cxlrd_dev);
/*
* Ensure that if multiple threads race to construct_region() for @hpa
* one does the construction and the others add to that.
*/
mutex_lock(&cxlrd->range_lock);
region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, hpa,
match_region_by_range);
if (!region_dev) {
cxlr = construct_region(cxlrd, cxled);
region_dev = &cxlr->dev;
} else
cxlr = to_cxl_region(region_dev);
mutex_unlock(&cxlrd->range_lock);
rc = PTR_ERR_OR_ZERO(cxlr);
if (rc)
goto out;
attach_target(cxlr, cxled, -1, TASK_UNINTERRUPTIBLE);
down_read(&cxl_region_rwsem);
p = &cxlr->params;
attach = p->state == CXL_CONFIG_COMMIT;
up_read(&cxl_region_rwsem);
if (attach) {
/*
* If device_attach() fails the range may still be active via
* the platform-firmware memory map, otherwise the driver for
* regions is local to this file, so driver matching can't fail.
*/
if (device_attach(&cxlr->dev) < 0)
dev_err(&cxlr->dev, "failed to enable, range: %pr\n",
p->res);
}
put_device(region_dev);
out:
put_device(cxlrd_dev);
return rc;
}
EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, CXL);
static int is_system_ram(struct resource *res, void *arg)
{
struct cxl_region *cxlr = arg;
struct cxl_region_params *p = &cxlr->params;
dev_dbg(&cxlr->dev, "%pr has System RAM: %pr\n", p->res, res);
return 1;
}
static int cxl_region_probe(struct device *dev)
{
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
int rc;
rc = down_read_interruptible(&cxl_region_rwsem);
if (rc) {
dev_dbg(&cxlr->dev, "probe interrupted\n");
return rc;
}
if (p->state < CXL_CONFIG_COMMIT) {
dev_dbg(&cxlr->dev, "config state: %d\n", p->state);
rc = -ENXIO;
goto out;
}
if (test_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags)) {
dev_err(&cxlr->dev,
"failed to activate, re-commit region and retry\n");
rc = -ENXIO;
goto out;
}
/*
* From this point on any path that changes the region's state away from
* CXL_CONFIG_COMMIT is also responsible for releasing the driver.
*/
out:
up_read(&cxl_region_rwsem);
if (rc)
return rc;
switch (cxlr->mode) {
case CXL_DECODER_PMEM:
return devm_cxl_add_pmem_region(cxlr);
case CXL_DECODER_RAM:
/*
* The region can not be manged by CXL if any portion of
* it is already online as 'System RAM'
*/
if (walk_iomem_res_desc(IORES_DESC_NONE,
IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
p->res->start, p->res->end, cxlr,
is_system_ram) > 0)
return 0;
return devm_cxl_add_dax_region(cxlr);
default:
dev_dbg(&cxlr->dev, "unsupported region mode: %d\n",
cxlr->mode);
return -ENXIO;
}
}
static struct cxl_driver cxl_region_driver = {
.name = "cxl_region",
.probe = cxl_region_probe,
.id = CXL_DEVICE_REGION,
};
int cxl_region_init(void)
{
return cxl_driver_register(&cxl_region_driver);
}
void cxl_region_exit(void)
{
cxl_driver_unregister(&cxl_region_driver);
}
MODULE_IMPORT_NS(CXL);
MODULE_IMPORT_NS(DEVMEM);
MODULE_ALIAS_CXL(CXL_DEVICE_REGION);
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