cxl/mbox: Move build of user mailbox cmd to a helper functions

In preparation for moving the construction of a mailbox command
to the validation path, extract the work into a helper functions.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/493d7618a846d787c3ae28778935ca35e2b85eed.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 39c8f6d..99b933f 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -207,6 +207,44 @@ static bool cxl_mem_raw_command_allowed(u16 opcode)
        return true;
 }
 
+static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox,
+                            struct cxl_dev_state *cxlds, u16 opcode,
+                            size_t in_size, size_t out_size, u64 in_payload)
+{
+       *mbox = (struct cxl_mbox_cmd) {
+               .opcode = opcode,
+               .size_in = in_size,
+       };
+
+       if (in_size) {
+               mbox->payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
+                                               in_size);
+               if (!mbox->payload_in)
+                       return PTR_ERR(mbox->payload_in);
+       }
+
+       /* Prepare to handle a full payload for variable sized output */
+       if (out_size < 0)
+               mbox->size_out = cxlds->payload_size;
+       else
+               mbox->size_out = out_size;
+
+       if (mbox->size_out) {
+               mbox->payload_out = kvzalloc(mbox->size_out, GFP_KERNEL);
+               if (!mbox->payload_out) {
+                       kvfree(mbox->payload_in);
+                       return -ENOMEM;
+               }
+       }
+       return 0;
+}
+
+static void cxl_mbox_cmd_dtor(struct cxl_mbox_cmd *mbox)
+{
+       kvfree(mbox->payload_in);
+       kvfree(mbox->payload_out);
+}
+
 static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
                              const struct cxl_send_command *send_cmd,
                              struct cxl_dev_state *cxlds)
@@ -390,27 +428,14 @@ static int handle_mailbox_cmd_from_user(struct cxl_dev_state *cxlds,
                                        s32 *size_out, u32 *retval)
 {
        struct device *dev = cxlds->dev;
-       struct cxl_mbox_cmd mbox_cmd = {
-               .opcode = cmd->opcode,
-               .size_in = cmd->info.size_in,
-               .size_out = cmd->info.size_out,
-       };
+       struct cxl_mbox_cmd mbox_cmd;
        int rc;
 
-       if (cmd->info.size_out) {
-               mbox_cmd.payload_out = kvzalloc(cmd->info.size_out, GFP_KERNEL);
-               if (!mbox_cmd.payload_out)
-                       return -ENOMEM;
-       }
-
-       if (cmd->info.size_in) {
-               mbox_cmd.payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
-                                                  cmd->info.size_in);
-               if (IS_ERR(mbox_cmd.payload_in)) {
-                       kvfree(mbox_cmd.payload_out);
-                       return PTR_ERR(mbox_cmd.payload_in);
-               }
-       }
+       rc = cxl_mbox_cmd_ctor(&mbox_cmd, cxlds, cmd->opcode,
+                              cmd->info.size_in, cmd->info.size_out,
+                              in_payload);
+       if (rc)
+               return rc;
 
        dev_dbg(dev,
                "Submitting %s command for user\n"
@@ -442,8 +467,7 @@ static int handle_mailbox_cmd_from_user(struct cxl_dev_state *cxlds,
        *retval = mbox_cmd.return_code;
 
 out:
-       kvfree(mbox_cmd.payload_in);
-       kvfree(mbox_cmd.payload_out);
+       cxl_mbox_cmd_dtor(&mbox_cmd);
        return rc;
 }
 
@@ -464,10 +488,6 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
        if (rc)
                return rc;
 
-       /* Prepare to handle a full payload for variable sized output */
-       if (c.info.size_out < 0)
-               c.info.size_out = cxlds->payload_size;
-
        rc = handle_mailbox_cmd_from_user(cxlds, &c, send.in.payload,
                                          send.out.payload, &send.out.size,
                                          &send.retval);