cxl/mbox: Construct a users cxl_mbox_cmd in 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().

Move the construction and validation of a mailbox command to the
validation path. Continue to pass both the out_cmd and the mbox_cmd
until handle_mbox_cmd_from_user() learns how to use a mbox_cmd param.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/c9fbdad968a2b619f9108bb6c37cef1a853cdf5a.1648687552.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 99b933f..47f39c6 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -324,6 +324,7 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
 
 /**
  * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
+ * @mbox_cmd: Sanitized and populated &struct 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.
@@ -341,10 +342,13 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
  *
  * See handle_mailbox_cmd_from_user()
  */
-static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
+static int cxl_validate_cmd_from_user(struct cxl_mbox_cmd *mbox_cmd,
+                                     struct cxl_dev_state *cxlds,
                                      const struct cxl_send_command *send_cmd,
                                      struct cxl_mem_command *out_cmd)
 {
+       int rc;
+
        if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
                return -ENOTTY;
 
@@ -358,9 +362,17 @@ 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)
-               return cxl_to_mem_cmd_raw(out_cmd, send_cmd, cxlds);
+               rc = cxl_to_mem_cmd_raw(out_cmd, send_cmd, cxlds);
        else
-               return cxl_to_mem_cmd(out_cmd, send_cmd, cxlds);
+               rc = cxl_to_mem_cmd(out_cmd, send_cmd, cxlds);
+
+       if (rc)
+               return rc;
+
+       /* Sanitize and construct a cxl_mbox_cmd */
+       return cxl_mbox_cmd_ctor(mbox_cmd, cxlds, out_cmd->opcode,
+                                out_cmd->info.size_in, out_cmd->info.size_out,
+                                send_cmd->in.payload);
 }
 
 int cxl_query_cmd(struct cxl_memdev *cxlmd,
@@ -477,6 +489,7 @@ 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");
@@ -484,7 +497,7 @@ 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(&mbox_cmd, cxlmd->cxlds, &send, &c);
        if (rc)
                return rc;