[PATCH V2 12/16] drm/radeon: Make radeon card usable for Loongson.

[Alex Deucher]

On Wed, Jun 20, 2012 at 4:28 AM, Huacai Chen <chenhuacai at gmail.com> wrote:
> On Wed, Jun 20, 2012 at 9:26 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
>> On Tue, Jun 19, 2012 at 9:57 AM, j.glisse <j.glisse at gmail.com> wrote:
>>> On Tue, Jun 19, 2012 at 02:50:20PM +0800, Huacai Chen wrote:
>>>> 1, Use 32-bit DMA as a workaround (Loongson has a hardware bug that it
>>>>    doesn't support DMA address above 4GB).
>>>> 2, Read vga bios offered by system firmware.
>>>> 3, Handle io prot correctly for MIPS.
>>>> 4, Don't use swiotlb on Loongson machines (when use swiotlb, GPU reset
>>>>    occurs at resume from suspend).
>>>>
>>>> Signed-off-by: Huacai Chen <chenhc at lemote.com>
>>>> Signed-off-by: Hongliang Tao <taohl at lemote.com>
>>>> Signed-off-by: Hua Yan <yanh at lemote.com>
>>>> Cc: dri-devel at lists.freedesktop.org
>>>> ---
>>>>  drivers/gpu/drm/drm_vm.c               |    2 +-
>>>>  drivers/gpu/drm/radeon/radeon_bios.c   |   32 ++++++++++++++++++++++++++++++++
>>>>  drivers/gpu/drm/radeon/radeon_device.c |    5 +++++
>>>>  drivers/gpu/drm/radeon/radeon_ttm.c    |    6 +++---
>>>>  drivers/gpu/drm/ttm/ttm_bo_util.c      |    2 +-
>>>>  include/drm/drm_sarea.h                |    2 ++
>>>>  6 files changed, 44 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
>>>> index 961ee08..3f06166 100644
>>>> --- a/drivers/gpu/drm/drm_vm.c
>>>> +++ b/drivers/gpu/drm/drm_vm.c
>>>> @@ -62,7 +62,7 @@ static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
>>>>               tmp = pgprot_writecombine(tmp);
>>>>       else
>>>>               tmp = pgprot_noncached(tmp);
>>>> -#elif defined(__sparc__) || defined(__arm__)
>>>> +#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
>>>>       tmp = pgprot_noncached(tmp);
>>>>  #endif
>>>>       return tmp;
>>>> diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
>>>> index 501f488..2630e22 100644
>>>> --- a/drivers/gpu/drm/radeon/radeon_bios.c
>>>> +++ b/drivers/gpu/drm/radeon/radeon_bios.c
>>>> @@ -29,6 +29,7 @@
>>>>  #include "radeon_reg.h"
>>>>  #include "radeon.h"
>>>>  #include "atom.h"
>>>> +#include <asm/bootinfo.h>
>>>>
>>>>  #include <linux/vga_switcheroo.h>
>>>>  #include <linux/slab.h>
>>>> @@ -73,6 +74,32 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
>>>>       return true;
>>>>  }
>>>>
>>>> +#ifdef CONFIG_CPU_LOONGSON3
>>>> +extern u64 vgabios_addr;
>>>
>>> Ugly, is this how platform specific stuff are handled usualy ? I hope not,
>>> i would rather see a platform specific function such as loongson3_get_vga_bios.
>>
>> It could be hooked in as a pci quirk similar to how we read the vbios
>> from the legacy vga location on x86.
> Hi, Alex, the method you said is pci_fixup_video() in arch/x86/pci/fixup.c?

Correct, although you will probably need it in arch/mips/pci for your
platform.  You may want to make your quirk specific to this pci device
unless you need it for all vga chips on your platform.

Alex