RE: [PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access

From: Zhang, Jerry
Date: Wed Mar 15 2017 - 22:41:41 EST


Thanks for your info.
I see.

Regards,
Jerry (Junwei Zhang)

Linux Base Graphics
SRDC Software Development
_____________________________________


> -----Original Message-----
> From: Alex Deucher [mailto:alexdeucher@xxxxxxxxx]
> Sent: Thursday, March 16, 2017 10:25
> To: Zhang, Jerry
> Cc: Christian KÃnig; Zhou, David(ChunMing); Ayyappa Ch; linux-
> pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dri-
> devel@xxxxxxxxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx;
> helgaas@xxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access
>
> On Wed, Mar 15, 2017 at 10:19 PM, Zhang, Jerry <Jerry.Zhang@xxxxxxx> wrote:
> >> -----Original Message-----
> >> From: dri-devel [mailto:dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx] On
> >> Behalf Of Christian K?nig
> >> Sent: Wednesday, March 15, 2017 17:29
> >> To: Zhou, David(ChunMing); Ayyappa Ch
> >> Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; amd-
> >> gfx@xxxxxxxxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx;
> >> helgaas@xxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> >> Subject: Re: [PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access
> >>
> >> Yes, exactly that.
> >
> > (I'm not familiar with PCI too much.)
> > Is there any restrict for PCI device?
> > I'm concerning if any PCI couldn't support it on some motherboard.
>
> It depends on the PCI root bridge. This patch set only implements support for
> AMD root bridges. Intel and other vendors would need similar code.
>
> Alex
>
> >
> >>
> >> Christian.
> >>
> >> Am 15.03.2017 um 09:25 schrieb Zhou, David(ChunMing):
> >> > Does that means we don't need invisible vram later?
> >> >
> >> > David
> >> >
> >> > -----Original Message-----
> >> > From: dri-devel [mailto:dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx] On
> >> > Behalf Of Christian K?nig
> >> > Sent: Wednesday, March 15, 2017 3:38 PM
> >> > To: Ayyappa Ch <ayyappa.ch.linux@xxxxxxxxx>
> >> > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> >> > amd-gfx@xxxxxxxxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx;
> >> > helgaas@xxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> >> > Subject: Re: [PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access
> >> >
> >> > 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 KÃnig
> >> >> <deathsimple@xxxxxxxxxxx> wrote:
> >> >>> From: Christian KÃnig <christian.koenig@xxxxxxx>
> >> >>>
> >> >>> Try to resize BAR0 to let CPU access all of VRAM.
> >> >>>
> >> >>> Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
> >> >>> ---
> >> >>> 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
> >> >>>
> >> >>> _______________________________________________
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> >> >>> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> >> >>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >> >
> >> > _______________________________________________
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> >> > _______________________________________________
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> >>
> >>
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