[S390] qdio: Sanitize do_QDIO sanity checks

Remove unneeded sanity checks from do_QDIO since this is the hot path.
Change the type of bufnr and count to unsigned int so the check for the
maximum value works.

Reported-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 3 insertions, 8 deletions

diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h
index 402d6dcf0d26..79d849f014f0 100644
--- a/arch/s390/include/asm/qdio.h
+++ b/arch/s390/include/asm/qdio.h
@@ -380,7 +380,7 @@ extern int qdio_establish(struct qdio_initialize *);
 extern int qdio_activate(struct ccw_device *);
 
 extern int do_QDIO(struct ccw_device *cdev, unsigned int callflags,
-                   int q_nr, int bufnr, int count);
+                   int q_nr, unsigned int bufnr, unsigned int count);
 extern int qdio_cleanup(struct ccw_device*, int);
 extern int qdio_shutdown(struct ccw_device*, int);
 extern int qdio_free(struct ccw_device *);
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 75b521963a4e..0038750ad945 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -1497,18 +1497,13 @@ out:
  * @count: how many buffers to process
  */
 int do_QDIO(struct ccw_device *cdev, unsigned int callflags,
-            int q_nr, int bufnr, int count)
+            int q_nr, unsigned int bufnr, unsigned int count)
 {
         struct qdio_irq *irq_ptr;
 
-        if ((bufnr > QDIO_MAX_BUFFERS_PER_Q) ||
-            (count > QDIO_MAX_BUFFERS_PER_Q) ||
-            (q_nr >= QDIO_MAX_QUEUES_PER_IRQ))
+        if (bufnr >= QDIO_MAX_BUFFERS_PER_Q || count > QDIO_MAX_BUFFERS_PER_Q)
                 return -EINVAL;
 
-        if (!count)
-                return 0;
-
         irq_ptr = cdev->private->qdio_data;
         if (!irq_ptr)
                 return -ENODEV;