cxl/mbox: Add SET_FEATURE mailbox command

Add support for SET_FEATURE mailbox command.

CXL spec r3.2 section 8.2.9.6 describes optional device specific features.
CXL devices supports features with changeable attributes.
The settings of a feature can be optionally modified using Set Feature
command.
CXL spec r3.2 section 8.2.9.6.3 describes Set Feature command.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250220194438.2281088-6-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 7cd3b98150e612d60cf3e2d05f420a0e3562b38a..17e99a25c29a54724f820d52583f85b4371cc503 100644 (file)
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -122,6 +122,10 @@ size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
                       enum cxl_get_feat_selection selection,
                       void *feat_out, size_t feat_out_size, u16 offset,
                       u16 *return_code);
+int cxl_set_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
+                   u8 feat_version, const void *feat_data,
+                   size_t feat_data_size, u32 feat_flag, u16 offset,
+                   u16 *return_code);
 #endif
 
 #endif /* __CXL_CORE_H__ */

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 3fc6f8415f19129683e3db5d2aa5bf54a73a9574..17a82734a34067acd43226ebf8d6ecd16aa52461 100644 (file)
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -223,3 +223,83 @@ size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
 
        return data_rcvd_size;
 }
+
+/*
+ * FEAT_DATA_MIN_PAYLOAD_SIZE - min extra number of bytes should be
+ * available in the mailbox for storing the actual feature data so that
+ * the feature data transfer would work as expected.
+ */
+#define FEAT_DATA_MIN_PAYLOAD_SIZE 10
+int cxl_set_feature(struct cxl_mailbox *cxl_mbox,
+                   const uuid_t *feat_uuid, u8 feat_version,
+                   const void *feat_data, size_t feat_data_size,
+                   u32 feat_flag, u16 offset, u16 *return_code)
+{
+       size_t data_in_size, data_sent_size = 0;
+       struct cxl_mbox_cmd mbox_cmd;
+       size_t hdr_size;
+
+       if (return_code)
+               *return_code = CXL_MBOX_CMD_RC_INPUT;
+
+       struct cxl_mbox_set_feat_in *pi __free(kfree) =
+                       kzalloc(cxl_mbox->payload_size, GFP_KERNEL);
+       if (!pi)
+               return -ENOMEM;
+
+       uuid_copy(&pi->uuid, feat_uuid);
+       pi->version = feat_version;
+       feat_flag &= ~CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK;
+       feat_flag |= CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET;
+       hdr_size = sizeof(pi->hdr);
+       /*
+        * Check minimum mbox payload size is available for
+        * the feature data transfer.
+        */
+       if (hdr_size + FEAT_DATA_MIN_PAYLOAD_SIZE > cxl_mbox->payload_size)
+               return -ENOMEM;
+
+       if (hdr_size + feat_data_size <= cxl_mbox->payload_size) {
+               pi->flags = cpu_to_le32(feat_flag |
+                                       CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER);
+               data_in_size = feat_data_size;
+       } else {
+               pi->flags = cpu_to_le32(feat_flag |
+                                       CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER);
+               data_in_size = cxl_mbox->payload_size - hdr_size;
+       }
+
+       do {
+               int rc;
+
+               pi->offset = cpu_to_le16(offset + data_sent_size);
+               memcpy(pi->feat_data, feat_data + data_sent_size, data_in_size);
+               mbox_cmd = (struct cxl_mbox_cmd) {
+                       .opcode = CXL_MBOX_OP_SET_FEATURE,
+                       .size_in = hdr_size + data_in_size,
+                       .payload_in = pi,
+               };
+               rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+               if (rc < 0) {
+                       if (return_code)
+                               *return_code = mbox_cmd.return_code;
+                       return rc;
+               }
+
+               data_sent_size += data_in_size;
+               if (data_sent_size >= feat_data_size) {
+                       if (return_code)
+                               *return_code = CXL_MBOX_CMD_RC_SUCCESS;
+                       return 0;
+               }
+
+               if ((feat_data_size - data_sent_size) <= (cxl_mbox->payload_size - hdr_size)) {
+                       data_in_size = feat_data_size - data_sent_size;
+                       pi->flags = cpu_to_le32(feat_flag |
+                                               CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER);
+               } else {
+                       pi->flags = cpu_to_le32(feat_flag |
+                                               CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER);
+               }
+       } while (true);
+}

diff --git a/include/cxl/features.h b/include/cxl/features.h
index 766c09978e5e1fd1545bb249568edddd30570b61..ae56ef7ec9aba62b2f61fc3e4fc4563f14e1182b 100644 (file)
--- a/include/cxl/features.h
+++ b/include/cxl/features.h
@@ -90,6 +90,39 @@ enum cxl_get_feat_selection {
        CXL_GET_FEAT_SEL_MAX
 };
 
+/*
+ * Set Feature CXL spec r3.2  8.2.9.6.3
+ */
+
+/*
+ * Set Feature input payload
+ * CXL spec r3.2 section 8.2.9.6.3 Table 8-101
+ */
+struct cxl_mbox_set_feat_in {
+       __struct_group(cxl_mbox_set_feat_hdr, hdr, /* no attrs */,
+               uuid_t uuid;
+               __le32 flags;
+               __le16 offset;
+               u8 version;
+               u8 rsvd[9];
+       );
+       __u8 feat_data[];
+}  __packed;
+
+/* Set Feature flags field */
+enum cxl_set_feat_flag_data_transfer {
+       CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER = 0,
+       CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER,
+       CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER,
+       CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER,
+       CXL_SET_FEAT_FLAG_ABORT_DATA_TRANSFER,
+       CXL_SET_FEAT_FLAG_DATA_TRANSFER_MAX
+};
+
+#define CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK   GENMASK(2, 0)
+
+#define CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET      BIT(3)
+
 /**
  * struct cxl_features_state - The Features state for the device
  * @cxlds: Pointer to CXL device state