[PATCH v24 03/11] cxl/sfc: Initialize dpa without a mailbox

alejandro.lucero-palau
2026-03-23T11:32:09Z

From: Alejandro Lucero <alucerop@amd.com>

Type3 relies on mailbox CXL_MBOX_OP_IDENTIFY command for initializing
memdev state params which end up being used for DPA initialization.

Allow a Type2 driver to initialize DPA simply by giving the size of its
volatile hardware partition.

Move related functions to memdev.

Add sfc driver as the client.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
---
drivers/cxl/core/core.h | 2 +
drivers/cxl/core/mbox.c | 51 +----------------------
drivers/cxl/core/memdev.c | 66 ++++++++++++++++++++++++++++++
drivers/net/ethernet/sfc/efx_cxl.c | 5 +++
include/cxl/cxl.h | 2 +
5 files changed, 76 insertions(+), 50 deletions(-)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 5539e941782f..77c684744771 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -97,6 +97,8 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
struct dentry *cxl_debugfs_create_dir(const char *dir);
int cxl_dpa_set_part(struct cxl_endpoint_decoder *cxled,
enum cxl_partition_mode mode);
+struct cxl_memdev_state;
+int cxl_mem_get_partition_info(struct cxl_memdev_state *mds);
int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, u64 size);
int cxl_dpa_free(struct cxl_endpoint_decoder *cxled);
resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled);
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 451ff2287b44..cf37676068c2 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1151,7 +1151,7 @@ EXPORT_SYMBOL_NS_GPL(cxl_mem_get_event_records, "CXL");
*
* See CXL @8.2.9.5.2.1 Get Partition Info
*/
-static int cxl_mem_get_partition_info(struct cxl_memdev_state *mds)
+int cxl_mem_get_partition_info(struct cxl_memdev_state *mds)
{
struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
struct cxl_mbox_get_partition_info pi;
@@ -1307,55 +1307,6 @@ int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd)
return -EBUSY;
}

-static void add_part(struct cxl_dpa_info *info, u64 start, u64 size, enum cxl_partition_mode mode)
-{
- int i = info->nr_partitions;
-
- if (size == 0)
- return;
-
- info->part[i].range = (struct range) {
- .start = start,
- .end = start + size - 1,
- };
- info->part[i].mode = mode;
- info->nr_partitions++;
-}
-
-int cxl_mem_dpa_fetch(struct cxl_memdev_state *mds, struct cxl_dpa_info *info)
-{
- struct cxl_dev_state *cxlds = &mds->cxlds;
- struct device *dev = cxlds->dev;
- int rc;
-
- if (!cxlds->media_ready) {
- info->size = 0;
- return 0;
- }
-
- info->size = mds->total_bytes;
-
- if (mds->partition_align_bytes == 0) {
- add_part(info, 0, mds->volatile_only_bytes, CXL_PARTMODE_RAM);
- add_part(info, mds->volatile_only_bytes,
- mds->persistent_only_bytes, CXL_PARTMODE_PMEM);
- return 0;
- }
-
- rc = cxl_mem_get_partition_info(mds);
- if (rc) {
- dev_err(dev, "Failed to query partition information\n");
- return rc;
- }
-
- add_part(info, 0, mds->active_volatile_bytes, CXL_PARTMODE_RAM);
- add_part(info, mds->active_volatile_bytes, mds->active_persistent_bytes,
- CXL_PARTMODE_PMEM);
-
- return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_mem_dpa_fetch, "CXL");
-
int cxl_get_dirty_count(struct cxl_memdev_state *mds, u32 *count)
{
struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 99e422594885..166ec6b7d041 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -582,6 +582,72 @@ bool is_cxl_memdev(const struct device *dev)
}
EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, "CXL");

+static void add_part(struct cxl_dpa_info *info, u64 start, u64 size, enum cxl_partition_mode mode)
+{
+ int i = info->nr_partitions;
+
+ if (size == 0)
+ return;
+
+ info->part[i].range = (struct range) {
+ .start = start,
+ .end = start + size - 1,
+ };
+ info->part[i].mode = mode;
+ info->nr_partitions++;
+}
+
+int cxl_mem_dpa_fetch(struct cxl_memdev_state *mds, struct cxl_dpa_info *info)
+{
+ struct cxl_dev_state *cxlds = &mds->cxlds;
+ struct device *dev = cxlds->dev;
+ int rc;
+
+ if (!cxlds->media_ready) {
+ info->size = 0;
+ return 0;
+ }
+
+ info->size = mds->total_bytes;
+
+ if (mds->partition_align_bytes == 0) {
+ add_part(info, 0, mds->volatile_only_bytes, CXL_PARTMODE_RAM);
+ add_part(info, mds->volatile_only_bytes,
+ mds->persistent_only_bytes, CXL_PARTMODE_PMEM);
+ return 0;
+ }
+
+ rc = cxl_mem_get_partition_info(mds);
+ if (rc) {
+ dev_err(dev, "Failed to query partition information\n");
+ return rc;
+ }
+
+ add_part(info, 0, mds->active_volatile_bytes, CXL_PARTMODE_RAM);
+ add_part(info, mds->active_volatile_bytes, mds->active_persistent_bytes,
+ CXL_PARTMODE_PMEM);
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_dpa_fetch, "CXL");
+
+/**
+ * cxl_set_capacity: initialize dpa by a driver without a mailbox.
+ *
+ * @cxlds: pointer to cxl_dev_state
+ * @capacity: device volatile memory size
+ */
+int cxl_set_capacity(struct cxl_dev_state *cxlds, u64 capacity)
+{
+ struct cxl_dpa_info range_info = {
+ .size = capacity,
+ };
+
+ add_part(&range_info, 0, capacity, CXL_PARTMODE_RAM);
+ return cxl_dpa_setup(cxlds, &range_info);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_set_capacity, "CXL");
+
/**
* set_exclusive_cxl_commands() - atomically disable user cxl commands
* @mds: The device state to operate on
diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
index 7917118e4eba..a52238ac9eaa 100644
--- a/drivers/net/ethernet/sfc/efx_cxl.c
+++ b/drivers/net/ethernet/sfc/efx_cxl.c
@@ -71,6 +71,11 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
*/
cxl->cxlds.media_ready = true;

+ if (cxl_set_capacity(&cxl->cxlds, EFX_CTPIO_BUFFER_SIZE)) {
+ pci_err(pci_dev, "dpa capacity setup failed\n");
+ return -ENODEV;
+ }
+
probe_data->cxl = cxl;

return 0;
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index fa7269154620..1346771edc4e 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -223,4 +223,6 @@ struct cxl_dev_state *_devm_cxl_dev_state_create(struct device *dev,
(drv_struct *)_devm_cxl_dev_state_create(parent, type, serial, dvsec, \
sizeof(drv_struct), mbox); \
})
+
+int cxl_set_capacity(struct cxl_dev_state *cxlds, u64 capacity);
#endif /* __CXL_CXL_H__ */
--
2.34.1