[PATCH v3 13/16] cxl: Add support to handle user feature commands for set feature

[Dave Jiang <dave.jiang@intel.com>]

Add helper function to parse the user data from fwctl RPC ioctl and
send the parsed input parameters to cxl_set_feature() call.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v3:
- Remove duplicate is_cxl_feature_exclusive() prototype. (Jonathan)
---
 drivers/cxl/core/features.c | 18 ++++++++-----
 drivers/cxl/features.h      |  1 +
 drivers/cxl/fwctl.c         | 53 +++++++++++++++++++++++++++++++++++++
 include/uapi/cxl/features.h |  5 ++++
 4 files changed, 71 insertions(+), 6 deletions(-)

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 0ab02c2a94f9..5f64185a5c7a 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -20,6 +20,17 @@ static const uuid_t cxl_exclusive_feats[] = {
 	CXL_FEAT_RANK_SPARING_UUID,
 };
 
+bool is_cxl_feature_exclusive_by_uuid(uuid_t *uuid)
+{
+	for (int i = 0; i < ARRAY_SIZE(cxl_exclusive_feats); i++) {
+		if (uuid_equal(uuid, &cxl_exclusive_feats[i]))
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL_NS_GPL(is_cxl_feature_exclusive_by_uuid, "CXL");
+
 /**
  * is_cxl_feature_exclusive() - Check if a CXL feature is exclusive to kernel
  * @entry: cxl feature entry
@@ -28,12 +39,7 @@ static const uuid_t cxl_exclusive_feats[] = {
  */
 bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry)
 {
-	for (int i = 0; i < ARRAY_SIZE(cxl_exclusive_feats); i++) {
-		if (uuid_equal(&entry->uuid, &cxl_exclusive_feats[i]))
-			return true;
-	}
-
-	return false;
+	return is_cxl_feature_exclusive_by_uuid(&entry->uuid);
 }
 EXPORT_SYMBOL_NS_GPL(is_cxl_feature_exclusive, "CXL");
 
diff --git a/drivers/cxl/features.h b/drivers/cxl/features.h
index a51625774b58..81aabdffb60b 100644
--- a/drivers/cxl/features.h
+++ b/drivers/cxl/features.h
@@ -36,5 +36,6 @@ struct cxl_features_state *devm_cxlfs_allocate(struct cxl_memdev *cxlmd);
 void devm_cxlfs_free(struct cxl_memdev *cxlmd);
 int devm_cxl_add_features(struct cxl_memdev *cxlmd);
 bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry);
+bool is_cxl_feature_exclusive_by_uuid(uuid_t *uuid);
 
 #endif
diff --git a/drivers/cxl/fwctl.c b/drivers/cxl/fwctl.c
index 959845a466ff..db6faccc51fb 100644
--- a/drivers/cxl/fwctl.c
+++ b/drivers/cxl/fwctl.c
@@ -177,6 +177,58 @@ static void *cxlctl_get_feature(struct cxl_features_state *cxlfs,
 	return no_free_ptr(rpc_out);
 }
 
+static void *cxlctl_set_feature(struct cxl_features_state *cxlfs,
+				const struct fwctl_rpc_cxl *rpc_in,
+				size_t *out_len)
+{
+	struct cxl_dev_state *cxlds = cxlfs->cxlmd->cxlds;
+	struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
+	size_t out_size, data_size;
+	u16 offset, return_code;
+	u32 flags;
+	int rc;
+
+	if (rpc_in->op_size <= sizeof(struct cxl_mbox_set_feat_hdr))
+		return ERR_PTR(-EINVAL);
+
+	struct cxl_mbox_set_feat_in *feat_in __free(kvfree) =
+		kvzalloc(rpc_in->op_size, GFP_KERNEL);
+	if (!feat_in)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(feat_in, u64_to_user_ptr(rpc_in->in_payload),
+			   rpc_in->op_size))
+		return ERR_PTR(-EFAULT);
+
+	if (is_cxl_feature_exclusive_by_uuid(&feat_in->hdr.uuid))
+		return ERR_PTR(-EPERM);
+
+	offset = le16_to_cpu(feat_in->hdr.offset);
+	flags = le32_to_cpu(feat_in->hdr.flags);
+	out_size = *out_len;
+
+	struct fwctl_rpc_cxl_out *rpc_out __free(kvfree) =
+		kvzalloc(out_size, GFP_KERNEL);
+	if (!rpc_out)
+		return ERR_PTR(-ENOMEM);
+
+	rpc_out->size = 0;
+
+	data_size = rpc_in->op_size - sizeof(feat_in->hdr);
+	rc = cxl_set_feature(cxl_mbox, &feat_in->hdr.uuid,
+			     feat_in->hdr.version, feat_in->data,
+			     data_size, flags, offset, &return_code);
+	if (rc) {
+		rpc_out->retval = return_code;
+		return no_free_ptr(rpc_out);
+	}
+
+	rpc_out->retval = CXL_MBOX_CMD_RC_SUCCESS;
+	*out_len = sizeof(*rpc_out);
+
+	return no_free_ptr(rpc_out);
+}
+
 static bool cxlctl_validate_set_features(struct cxl_features_state *cxlfs,
 					 const struct fwctl_rpc_cxl *rpc_in,
 					 enum fwctl_rpc_scope scope)
@@ -261,6 +313,7 @@ static void *cxlctl_handle_commands(struct cxl_features_state *cxlfs,
 	case CXL_MBOX_OP_GET_FEATURE:
 		return cxlctl_get_feature(cxlfs, rpc_in, out_len);
 	case CXL_MBOX_OP_SET_FEATURE:
+		return cxlctl_set_feature(cxlfs, rpc_in, out_len);
 	default:
 		return ERR_PTR(-EOPNOTSUPP);
 	}
diff --git a/include/uapi/cxl/features.h b/include/uapi/cxl/features.h
index 05c8a06a5dff..30138506b286 100644
--- a/include/uapi/cxl/features.h
+++ b/include/uapi/cxl/features.h
@@ -107,6 +107,11 @@ struct cxl_mbox_set_feat_hdr {
 	__u8 rsvd[9];
 } __attribute__ ((__packed__));
 
+struct cxl_mbox_set_feat_in {
+	struct cxl_mbox_set_feat_hdr hdr;
+	__u8 data[];
+} __attribute__ ((__packed__));
+
 /* Set Feature flags field */
 enum cxl_set_feat_flag_data_transfer {
 	CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER = 0,
-- 
2.48.1