[PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access
Christian König
deathsimple at vodafone.de
Wed Mar 15 11:03:12 UTC 2017
No, we resize the BAR on the fly during driver load without help from
the BIOS or VBIOS.
Christian.
Am 15.03.2017 um 11:42 schrieb Ayyappa Ch:
> It also needs any support from VBIOS side ? I mean PCIe large bar support?
>
> Thanks,
> Ayyappa.
>
> On Wed, Mar 15, 2017 at 1:07 PM, Christian König
> <deathsimple at vodafone.de> wrote:
>> Carizzo is an APU and resizing BARs isn't needed nor supported there. The
>> CPU can access the full stolen VRAM directly on that hardware.
>>
>> As far as I know ASICs with support for this are Tonga, Fiji and all Polaris
>> variants.
>>
>> Christian.
>>
>>
>> Am 15.03.2017 um 08:23 schrieb Ayyappa Ch:
>>> Is it possible on Carrizo asics? Or only supports on newer asics?
>>>
>>> On Mon, Mar 13, 2017 at 6:11 PM, Christian König
>>> <deathsimple at vodafone.de> wrote:
>>>> From: Christian König <christian.koenig at amd.com>
>>>>
>>>> Try to resize BAR0 to let CPU access all of VRAM.
>>>>
>>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>>> ---
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 29
>>>> +++++++++++++++++++++++++++++
>>>> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 8 +++++---
>>>> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 8 +++++---
>>>> 4 files changed, 40 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> index 3b81ded..905ded9 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> @@ -1719,6 +1719,7 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct
>>>> amdgpu_device *adev, struct ttm_tt *ttm,
>>>> struct ttm_mem_reg *mem);
>>>> void amdgpu_vram_location(struct amdgpu_device *adev, struct amdgpu_mc
>>>> *mc, u64 base);
>>>> void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc
>>>> *mc);
>>>> +void amdgpu_resize_bar0(struct amdgpu_device *adev);
>>>> void amdgpu_ttm_set_active_vram_size(struct amdgpu_device *adev, u64
>>>> size);
>>>> int amdgpu_ttm_init(struct amdgpu_device *adev);
>>>> void amdgpu_ttm_fini(struct amdgpu_device *adev);
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> index 118f4e6..92955fe 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> @@ -692,6 +692,35 @@ void amdgpu_gtt_location(struct amdgpu_device *adev,
>>>> struct amdgpu_mc *mc)
>>>> mc->gtt_size >> 20, mc->gtt_start, mc->gtt_end);
>>>> }
>>>>
>>>> +/**
>>>> + * amdgpu_resize_bar0 - try to resize BAR0
>>>> + *
>>>> + * @adev: amdgpu_device pointer
>>>> + *
>>>> + * Try to resize BAR0 to make all VRAM CPU accessible.
>>>> + */
>>>> +void amdgpu_resize_bar0(struct amdgpu_device *adev)
>>>> +{
>>>> + u32 size = max(ilog2(adev->mc.real_vram_size - 1) + 1, 20) - 20;
>>>> + int r;
>>>> +
>>>> + r = pci_resize_resource(adev->pdev, 0, size);
>>>> +
>>>> + if (r == -ENOTSUPP) {
>>>> + /* The hardware don't support the extension. */
>>>> + return;
>>>> +
>>>> + } else if (r == -ENOSPC) {
>>>> + DRM_INFO("Not enoigh PCI address space for a large
>>>> BAR.");
>>>> + } else if (r) {
>>>> + DRM_ERROR("Problem resizing BAR0 (%d).", r);
>>>> + }
>>>> +
>>>> + /* Reinit the doorbell mapping, it is most likely moved as well
>>>> */
>>>> + amdgpu_doorbell_fini(adev);
>>>> + BUG_ON(amdgpu_doorbell_init(adev));
>>>> +}
>>>> +
>>>> /*
>>>> * GPU helpers function.
>>>> */
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>> index dc9b6d6..36a7aa5 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>> @@ -367,13 +367,15 @@ static int gmc_v7_0_mc_init(struct amdgpu_device
>>>> *adev)
>>>> break;
>>>> }
>>>> adev->mc.vram_width = numchan * chansize;
>>>> - /* Could aper size report 0 ? */
>>>> - adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
>>>> - adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
>>>> /* size in MB on si */
>>>> adev->mc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL *
>>>> 1024ULL;
>>>> adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL *
>>>> 1024ULL;
>>>>
>>>> + if (!(adev->flags & AMD_IS_APU))
>>>> + amdgpu_resize_bar0(adev);
>>>> + adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
>>>> + adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
>>>> +
>>>> #ifdef CONFIG_X86_64
>>>> if (adev->flags & AMD_IS_APU) {
>>>> adev->mc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) <<
>>>> 22;
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>> index c087b00..7761ad3 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>> @@ -459,13 +459,15 @@ static int gmc_v8_0_mc_init(struct amdgpu_device
>>>> *adev)
>>>> break;
>>>> }
>>>> adev->mc.vram_width = numchan * chansize;
>>>> - /* Could aper size report 0 ? */
>>>> - adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
>>>> - adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
>>>> /* size in MB on si */
>>>> adev->mc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL *
>>>> 1024ULL;
>>>> adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL *
>>>> 1024ULL;
>>>>
>>>> + if (!(adev->flags & AMD_IS_APU))
>>>> + amdgpu_resize_bar0(adev);
>>>> + adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
>>>> + adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
>>>> +
>>>> #ifdef CONFIG_X86_64
>>>> if (adev->flags & AMD_IS_APU) {
>>>> adev->mc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) <<
>>>> 22;
>>>> --
>>>> 2.7.4
>>>>
>>>> _______________________________________________
>>>> dri-devel mailing list
>>>> dri-devel at lists.freedesktop.org
>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>>
More information about the amd-gfx
mailing list