On Wed, May 27, 2026 at 04:37:11PM -0700, Dave Jiang wrote:
>
>
> On 5/23/26 2:42 AM, Anisa Su wrote:
> > From: Ira Weiny <[email protected]>
> >
> > 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 <[email protected]>
> >
> > ---
> > 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) {
>
> I think we need to check info->part[i].mode and not cxlds here. cxlds mode is
> assigned later in this function.
>
fixed!
> DJ
>
Thanks,
Anisa
>
> > + 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)
>
