drm/amdgpu: Do not directly dereference pointers to BIOS area.

Use readb() and memcpy_fromio() accessors instead.

Ported from radeon commit:
f2c9e560b406f2f6b14b345c7da33467dee9cdf2

Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
index d7a3ab2624f0..ceb444f6d418 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
@@ -75,7 +75,7 @@ static bool igp_read_bios_from_vram(struct amdgpu_device *adev)
 
 bool amdgpu_read_bios(struct amdgpu_device *adev)
 {
-        uint8_t __iomem *bios;
+        uint8_t __iomem *bios, val1, val2;
         size_t size;
 
         adev->bios = NULL;
@@ -85,15 +85,19 @@ bool amdgpu_read_bios(struct amdgpu_device *adev)
                 return false;
         }
 
-        if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
+        val1 = readb(&bios[0]);
+        val2 = readb(&bios[1]);
+
+        if (size == 0 || val1 != 0x55 || val2 != 0xaa) {
                 pci_unmap_rom(adev->pdev, bios);
                 return false;
         }
-        adev->bios = kmemdup(bios, size, GFP_KERNEL);
+        adev->bios = kzalloc(size, GFP_KERNEL);
         if (adev->bios == NULL) {
                 pci_unmap_rom(adev->pdev, bios);
                 return false;
         }
+        memcpy_fromio(adev->bios, bios, size);
         pci_unmap_rom(adev->pdev, bios);
         return true;
 }