[PATCH v3 4/9] cxl/mbox: Construct a users cxl_mbox_cmd in the validation path

[alison.schofield@intel.com]

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

Since the validation of a mailbox command is done as it is built,
move that work out of the dispatch path and into the validation
path.

This is a step in refactoring the handling of user space mailbox
commands. The intent is to have all the validation work originate
in cxl_validate_cmd_from_user().

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/core/mbox.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index d4233cfb2f99..205e671307c3 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -324,6 +324,7 @@ static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
  * @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:
  *  * %0	- @out_cmd is ready to send.
@@ -340,7 +341,8 @@ static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
  */
 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_mem_command *out_cmd,
+				      struct cxl_mbox_cmd *mbox_cmd)
 {
 	int rc;
 
@@ -361,6 +363,14 @@ static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
 	else
 		rc = cxl_to_mem_cmd(cxlds, send_cmd, out_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,
+			     send_cmd->in.payload);
+
 	return rc;
 }
 
@@ -478,6 +488,7 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	struct device *dev = &cxlmd->dev;
 	struct cxl_send_command send;
 	struct cxl_mem_command c;
+	struct cxl_mbox_cmd mbox_cmd;
 	int rc;
 
 	dev_dbg(dev, "Send IOCTL\n");
@@ -485,7 +496,7 @@ 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);
+	rc = cxl_validate_cmd_from_user(cxlmd->cxlds, &send, &c, &mbox_cmd);
 	if (rc)
 		return rc;
 
-- 
2.31.1