In general I would say yes, but for this particular hardware it's a bit
questionable to do so.
For radeon hardware to work correctly the CPU access to the PCIE BARs
should work even without using the specialized IO macros/functions,
otherwise mapping VRAM CPU accessible isn't really possible.
What's the background of the change? Some problems on a certain CPU
platform? or just general cleanups?
Regards,
Christian.
On 19.03.2015 04:18, David Miller wrote:
> Use readb() and memcpy_fromio() accessors instead.
>
> Signed-off-by: David S. Miller <davem at davemloft.net>
>
> diff --git a/drivers/gpu/drm/radeon/radeon_bios.c
> b/drivers/gpu/drm/radeon/radeon_bios.c
> index 63ccb8f..d27e4cc 100644
> --- a/drivers/gpu/drm/radeon/radeon_bios.c
> +++ b/drivers/gpu/drm/radeon/radeon_bios.c
> @@ -76,7 +76,7 @@ static bool igp_read_bios_from_vram(struct radeon_device
> *rdev)
>
> static bool radeon_read_bios(struct radeon_device *rdev)
> {
> - uint8_t __iomem *bios;
> + uint8_t __iomem *bios, val1, val2;
> size_t size;
>
> rdev->bios = NULL;
> @@ -86,15 +86,19 @@ static bool radeon_read_bios(struct radeon_device *rdev)
> 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(rdev->pdev, bios);
> return false;
> }
> - rdev->bios = kmemdup(bios, size, GFP_KERNEL);
> + rdev->bios = kzalloc(size, GFP_KERNEL);
> if (rdev->bios == NULL) {
> pci_unmap_rom(rdev->pdev, bios);
> return false;
> }
> + memcpy_fromio(rdev->bios, bios, size);
> pci_unmap_rom(rdev->pdev, bios);
> return true;
> }
