[PATCH v3 7/9] cxl/mbox: Move cxl_mem_command param to a local variable

[alison.schofield@intel.com]

From: Alison Schofield <alison.schofield@intel.com>

cxl_validate_command_from_user() is now the single point of validation
for mailbox commands coming from user space. Previously, it returned a
a cxl_mem_command, but that was not sufficient when validation of the
actual mailbox command became a requirement. Now, it returns a fully
validated cxl_mbox_cmd.

Remove the extraneous cxl_mem_command parameter. Define and use a
local version only.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/core/mbox.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 0340399c7029..c323d6792405 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -331,10 +331,9 @@ static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
 }
 
 /**
- * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
+ * cxl_validate_cmd_from_user() - Construct a valid cxl_mbox_cmd
  * @cxlds: The device data for the operation
  * @send_cmd: &struct cxl_send_command copied in from userspace.
- * @out_cmd: Sanitized and populated &struct cxl_mem_command.
  * @mbox_cmd: Sanitized and populated &struct cxl_mbox_cmd.
  *
  * Return:
@@ -345,16 +344,14 @@ static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
  *  * %-EPERM	- Attempted to use a protected command.
  *  * %-EBUSY	- Kernel has claimed exclusive access to this opcode
  *
- * The result of this command is a fully validated command in @out_cmd that is
+ * The result of this command is a fully validated command in @mbox_cmd that is
  * safe to send to the hardware.
- *
- * See handle_mailbox_cmd_from_user()
  */
 static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
 				      const struct cxl_send_command *send_cmd,
-				      struct cxl_mem_command *out_cmd,
 				      struct cxl_mbox_cmd *mbox_cmd)
 {
+	struct cxl_mem_command mem_cmd;
 	int rc;
 
 	if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
@@ -370,16 +367,16 @@ static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
 
 	/* Sanitize and construct a cxl_mem_command */
 	if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW)
-		rc = cxl_to_mem_cmd_raw(cxlds, send_cmd, out_cmd);
+		rc = cxl_to_mem_cmd_raw(cxlds, send_cmd, &mem_cmd);
 	else
-		rc = cxl_to_mem_cmd(cxlds, send_cmd, out_cmd);
+		rc = cxl_to_mem_cmd(cxlds, send_cmd, &mem_cmd);
 
 	if (rc)
 		return rc;
 
 	/* Sanitize and construct a cxl_mbox_cmd */
-	rc = cxl_to_mbox_cmd(cxlds, mbox_cmd, out_cmd->opcode,
-			     out_cmd->info.size_in, out_cmd->info.size_out,
+	rc = cxl_to_mbox_cmd(cxlds, mbox_cmd, mem_cmd.opcode,
+			     mem_cmd.info.size_in, mem_cmd.info.size_out,
 			     send_cmd->in.payload);
 
 	return rc;
@@ -490,7 +487,6 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct device *dev = &cxlmd->dev;
 	struct cxl_send_command send;
-	struct cxl_mem_command c;
 	struct cxl_mbox_cmd mbox_cmd;
 	int rc;
 
@@ -499,7 +495,7 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	if (copy_from_user(&send, s, sizeof(send)))
 		return -EFAULT;
 
-	rc = cxl_validate_cmd_from_user(cxlmd->cxlds, &send, &c, &mbox_cmd);
+	rc = cxl_validate_cmd_from_user(cxlmd->cxlds, &send, &mbox_cmd);
 	if (rc)
 		return rc;
 
-- 
2.31.1