drm/nouveau: Don't pass misaligned offsets to io_mapping_map_atomic_wc().

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index 7369b5e73649..66035283546a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -2083,9 +2083,10 @@ peek_fb(struct drm_device *dev, struct io_mapping *fb,
         uint32_t val = 0;
 
         if (off < pci_resource_len(dev->pdev, 1)) {
-                uint32_t __iomem *p = io_mapping_map_atomic_wc(fb, off, KM_USER0);
+                uint32_t __iomem *p =
+                        io_mapping_map_atomic_wc(fb, off & PAGE_MASK, KM_USER0);
 
-                val = ioread32(p);
+                val = ioread32(p + (off & ~PAGE_MASK));
 
                 io_mapping_unmap_atomic(p, KM_USER0);
         }
@@ -2098,9 +2099,10 @@ poke_fb(struct drm_device *dev, struct io_mapping *fb,
         uint32_t off, uint32_t val)
 {
         if (off < pci_resource_len(dev->pdev, 1)) {
-                uint32_t __iomem *p = io_mapping_map_atomic_wc(fb, off, KM_USER0);
+                uint32_t __iomem *p =
+                        io_mapping_map_atomic_wc(fb, off & PAGE_MASK, KM_USER0);
 
-                iowrite32(val, p);
+                iowrite32(val, p + (off & ~PAGE_MASK));
                 wmb();
 
                 io_mapping_unmap_atomic(p, KM_USER0);