[RFC PATCH v5 02/12] cxl/mbox: Add GET_FEATURE mailbox command

From: shiju.jose
Date: Thu Jan 11 2024 - 08:19:48 EST


From: Shiju Jose <shiju.jose@xxxxxxxxxx>

Add support for GET_FEATURE mailbox command.

CXL spec 3.0 section 8.2.9.6 describes optional device specific features.
The settings of a feature can be retrieved using Get Feature command.

Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
---
drivers/cxl/core/mbox.c | 22 ++++++++++++++++++++++
drivers/cxl/cxlmem.h | 23 +++++++++++++++++++++++
2 files changed, 45 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 6960ce935e73..a50c874edebc 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1326,6 +1326,28 @@ int cxl_get_supported_features(struct cxl_memdev_state *mds,
}
EXPORT_SYMBOL_NS_GPL(cxl_get_supported_features, CXL);

+int cxl_get_feature(struct cxl_memdev_state *mds,
+ struct cxl_mbox_get_feat_in *pi, void *feat_out)
+{
+ struct cxl_mbox_cmd mbox_cmd;
+ int rc;
+
+ mbox_cmd = (struct cxl_mbox_cmd) {
+ .opcode = CXL_MBOX_OP_GET_FEATURE,
+ .size_in = sizeof(*pi),
+ .payload_in = pi,
+ .size_out = le16_to_cpu(pi->count),
+ .payload_out = feat_out,
+ .min_out = le16_to_cpu(pi->count),
+ };
+ rc = cxl_internal_send_cmd(mds, &mbox_cmd);
+ if (rc < 0)
+ return rc;
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_get_feature, CXL);
+
int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
struct cxl_region *cxlr)
{
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index d831dad748f5..92c1f2a44713 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -507,6 +507,7 @@ enum cxl_opcode {
CXL_MBOX_OP_GET_SUPPORTED_LOGS = 0x0400,
CXL_MBOX_OP_GET_LOG = 0x0401,
CXL_MBOX_OP_GET_SUPPORTED_FEATURES = 0x0500,
+ CXL_MBOX_OP_GET_FEATURE = 0x0501,
CXL_MBOX_OP_IDENTIFY = 0x4000,
CXL_MBOX_OP_GET_PARTITION_INFO = 0x4100,
CXL_MBOX_OP_SET_PARTITION_INFO = 0x4101,
@@ -796,6 +797,26 @@ struct cxl_mbox_get_supp_feats_out {
struct cxl_mbox_supp_feat_entry feat_entries[];
} __packed;

+/* Get Feature CXL 3.0 Spec 8.2.9.6.2 */
+/*
+ * Get Feature input payload
+ * CXL rev 3.0 section 8.2.9.6.2; Table 8-79
+ */
+/* Get Feature : Payload in selection */
+enum cxl_get_feat_selection {
+ CXL_GET_FEAT_SEL_CURRENT_VALUE = 0x0,
+ CXL_GET_FEAT_SEL_DEFAULT_VALUE = 0x1,
+ CXL_GET_FEAT_SEL_SAVED_VALUE = 0x2,
+ CXL_GET_FEAT_SEL_MAX
+};
+
+struct cxl_mbox_get_feat_in {
+ uuid_t uuid;
+ __le16 offset;
+ __le16 count;
+ u8 selection;
+} __packed;
+
/* Get Poison List CXL 3.0 Spec 8.2.9.8.4.1 */
struct cxl_mbox_poison_in {
__le64 offset;
@@ -926,6 +947,8 @@ int cxl_set_timestamp(struct cxl_memdev_state *mds);
int cxl_get_supported_features(struct cxl_memdev_state *mds,
struct cxl_mbox_get_supp_feats_in *pi,
void *feats_out);
+int cxl_get_feature(struct cxl_memdev_state *mds,
+ struct cxl_mbox_get_feat_in *pi, void *feat_out);
int cxl_poison_state_init(struct cxl_memdev_state *mds);
int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
struct cxl_region *cxlr);
--
2.34.1