cxl/mbox: Fix missing variable payload checks in cmd size validation

The conversion of command sizes to unsigned missed a couple of checks
against variable size payloads during command validation, which made all
variable payload commands unconditionally fail. Add the checks back using
the new CXL_VARIABLE_PAYLOAD scheme.

Fixes: 26f89535a5bb ("cxl/mbox: Use type __u32 for mailbox payload sizes")
Cc: <stable@vger.kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Reported-by: Abhi Cs <abhi.cs@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/20220628220109.633564-1-vishal.l.verma@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 54f434733b5623cc35d18c161479e40d8fc372b4..cbf23beebebefaf89df8bf7055b4ac765d5731b0 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -355,11 +355,13 @@ static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
                return -EBUSY;
 
        /* Check the input buffer is the expected size */
-       if (info->size_in != send_cmd->in.size)
+       if ((info->size_in != CXL_VARIABLE_PAYLOAD) &&
+           (info->size_in != send_cmd->in.size))
                return -ENOMEM;
 
        /* Check the output buffer is at least large enough */
-       if (send_cmd->out.size < info->size_out)
+       if ((info->size_out != CXL_VARIABLE_PAYLOAD) &&
+           (send_cmd->out.size < info->size_out))
                return -ENOMEM;
 
        *mem_cmd = (struct cxl_mem_command) {