[PATCH v10 04/31] cxl/core: Enforce partition order/simplify partition calls
From: Anisa Su
Date: Sat May 23 2026 - 05:45:42 EST
From: Ira Weiny <ira.weiny@xxxxxxxxx>
Device partitions have an implied order which is made more complex by
the addition of a dynamic partition.
Remove the ram special case information calls in favor of generic calls
with a check ahead of time to ensure the preservation of the implied
partition order.
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
Changes::
[anisa: rebase]
[davidlohr: core/hdm.c: return -EINVAL instead of 0 in cxl_dpa_setup
if partitions are out of order]
---
drivers/cxl/core/hdm.c | 11 ++++++++++-
drivers/cxl/core/memdev.c | 32 +++++++++-----------------------
drivers/cxl/cxlmem.h | 9 +++------
drivers/cxl/mem.c | 2 +-
4 files changed, 23 insertions(+), 31 deletions(-)
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 28974adaab75..7a5812971f8f 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -464,6 +464,7 @@ static const char *cxl_mode_name(enum cxl_partition_mode mode)
int cxl_dpa_setup(struct cxl_dev_state *cxlds, const struct cxl_dpa_info *info)
{
struct device *dev = cxlds->dev;
+ int i;
guard(rwsem_write)(&cxl_rwsem.dpa);
@@ -476,9 +477,17 @@ int cxl_dpa_setup(struct cxl_dev_state *cxlds, const struct cxl_dpa_info *info)
return 0;
}
+ /* Verify partitions are in expected order. */
+ for (i = 1; i < info->nr_partitions; i++) {
+ if (cxlds->part[i].mode < cxlds->part[i-1].mode) {
+ dev_err(dev, "Partition order mismatch\n");
+ return -EINVAL;
+ }
+ }
+
cxlds->dpa_res = DEFINE_RES_MEM(0, info->size);
- for (int i = 0; i < info->nr_partitions; i++) {
+ for (i = 0; i < info->nr_partitions; i++) {
const struct cxl_dpa_part_info *part = &info->part[i];
int rc;
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 80e65690eb77..71602820f896 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -75,20 +75,12 @@ static ssize_t label_storage_size_show(struct device *dev,
}
static DEVICE_ATTR_RO(label_storage_size);
-static resource_size_t cxl_ram_size(struct cxl_dev_state *cxlds)
-{
- /* Static RAM is only expected at partition 0. */
- if (cxlds->part[0].mode != CXL_PARTMODE_RAM)
- return 0;
- return resource_size(&cxlds->part[0].res);
-}
-
static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
- unsigned long long len = cxl_ram_size(cxlds);
+ unsigned long long len = cxl_part_size(cxlds, CXL_PARTMODE_RAM);
return sysfs_emit(buf, "%#llx\n", len);
}
@@ -101,7 +93,7 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr,
{
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
- unsigned long long len = cxl_pmem_size(cxlds);
+ unsigned long long len = cxl_part_size(cxlds, CXL_PARTMODE_PMEM);
return sysfs_emit(buf, "%#llx\n", len);
}
@@ -424,10 +416,11 @@ static struct attribute *cxl_memdev_attributes[] = {
NULL,
};
-static struct cxl_dpa_perf *to_pmem_perf(struct cxl_dev_state *cxlds)
+static struct cxl_dpa_perf *part_perf(struct cxl_dev_state *cxlds,
+ enum cxl_partition_mode mode)
{
for (int i = 0; i < cxlds->nr_partitions; i++)
- if (cxlds->part[i].mode == CXL_PARTMODE_PMEM)
+ if (cxlds->part[i].mode == mode)
return &cxlds->part[i].perf;
return NULL;
}
@@ -438,7 +431,7 @@ static ssize_t pmem_qos_class_show(struct device *dev,
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
- return sysfs_emit(buf, "%d\n", to_pmem_perf(cxlds)->qos_class);
+ return sysfs_emit(buf, "%d\n", part_perf(cxlds, CXL_PARTMODE_PMEM)->qos_class);
}
static struct device_attribute dev_attr_pmem_qos_class =
@@ -450,20 +443,13 @@ static struct attribute *cxl_memdev_pmem_attributes[] = {
NULL,
};
-static struct cxl_dpa_perf *to_ram_perf(struct cxl_dev_state *cxlds)
-{
- if (cxlds->part[0].mode != CXL_PARTMODE_RAM)
- return NULL;
- return &cxlds->part[0].perf;
-}
-
static ssize_t ram_qos_class_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
- return sysfs_emit(buf, "%d\n", to_ram_perf(cxlds)->qos_class);
+ return sysfs_emit(buf, "%d\n", part_perf(cxlds, CXL_PARTMODE_RAM)->qos_class);
}
static struct device_attribute dev_attr_ram_qos_class =
@@ -499,7 +485,7 @@ static umode_t cxl_ram_visible(struct kobject *kobj, struct attribute *a, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
- struct cxl_dpa_perf *perf = to_ram_perf(cxlmd->cxlds);
+ struct cxl_dpa_perf *perf = part_perf(cxlmd->cxlds, CXL_PARTMODE_RAM);
if (a == &dev_attr_ram_qos_class.attr &&
(!perf || perf->qos_class == CXL_QOS_CLASS_INVALID))
@@ -518,7 +504,7 @@ static umode_t cxl_pmem_visible(struct kobject *kobj, struct attribute *a, int n
{
struct device *dev = kobj_to_dev(kobj);
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
- struct cxl_dpa_perf *perf = to_pmem_perf(cxlmd->cxlds);
+ struct cxl_dpa_perf *perf = part_perf(cxlmd->cxlds, CXL_PARTMODE_PMEM);
if (a == &dev_attr_pmem_qos_class.attr &&
(!perf || perf->qos_class == CXL_QOS_CLASS_INVALID))
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index cee936fb3d03..10175ca3b7ee 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -383,14 +383,11 @@ struct cxl_security_state {
#define CXL_MAX_DC_PARTITIONS 8
-static inline resource_size_t cxl_pmem_size(struct cxl_dev_state *cxlds)
+static inline resource_size_t cxl_part_size(struct cxl_dev_state *cxlds,
+ enum cxl_partition_mode mode)
{
- /*
- * Static PMEM may be at partition index 0 when there is no static RAM
- * capacity.
- */
for (int i = 0; i < cxlds->nr_partitions; i++)
- if (cxlds->part[i].mode == CXL_PARTMODE_PMEM)
+ if (cxlds->part[i].mode == mode)
return resource_size(&cxlds->part[i].res);
return 0;
}
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index fcffe24dcb42..f19e08279ec7 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -114,7 +114,7 @@ static int cxl_mem_probe(struct device *dev)
return -ENXIO;
}
- if (cxl_pmem_size(cxlds) && IS_ENABLED(CONFIG_CXL_PMEM)) {
+ if (cxl_part_size(cxlds, CXL_PARTMODE_PMEM) && IS_ENABLED(CONFIG_CXL_PMEM)) {
rc = devm_cxl_add_nvdimm(dev, parent_port, cxlmd);
if (rc) {
if (rc == -ENODEV)
--
2.43.0