x86: use WARN_ON in mapping functions

In the very same way i386 do, we use WARN_ON functions
in map_simple and map_sg.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kernel/pci-nommu_64.c b/arch/x86/kernel/pci-nommu_64.c
index c6901e751770..8d036aee2a8d 100644
--- a/arch/x86/kernel/pci-nommu_64.c
+++ b/arch/x86/kernel/pci-nommu_64.c
@@ -30,6 +30,7 @@ nommu_map_single(struct device *hwdev, phys_addr_t paddr, size_t size,
                int direction)
 {
         dma_addr_t bus = paddr;
+        WARN_ON(size == 0);
         if (!check_addr("map_single", hwdev, bus, size))
                                 return bad_dma_address;
         flush_write_buffers();
@@ -58,6 +59,8 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
         struct scatterlist *s;
         int i;
 
+        WARN_ON(nents == 0 || sg[0].length == 0);
+
         for_each_sg(sg, s, nents, i) {
                 BUG_ON(!sg_page(s));
                 s->dma_address = sg_phys(s);