Re: [PATCH 4/4] drm/amdgpu: resize VRAM BAR for CPU access v2

From: Alex Deucher
Date: Tue Apr 25 2017 - 11:15:10 EST

On Tue, Apr 25, 2017 at 11:09 AM, Christian KÃnig
<deathsimple@xxxxxxxxxxx> wrote:
> Am 25.04.2017 um 16:34 schrieb Alex Deucher:
>>
>> On Tue, Apr 25, 2017 at 9:19 AM, Christian KÃnig
>> <deathsimple@xxxxxxxxxxx> wrote:
>>>
>>> From: Christian KÃnig <christian.koenig@xxxxxxx>
>>>
>>> Try to resize BAR0 to let CPU access all of VRAM.
>>>
>>> v2: rebased, style cleanups, disable mem decode before resize,
>>> handle gmc_v9 as well, round size up to power of two.
>>>
>>> Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
>>> ---
>>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 37
>>> ++++++++++++++++++++++++++++++
>>> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 8 ++++---
>>> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 8 ++++---
>>> drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 10 ++++----
>>> 5 files changed, 54 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> index 4a16e3c..9484062 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> @@ -1879,6 +1879,7 @@ 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 a09ad3cf..d5ca77a 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -695,6 +695,43 @@ 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)
>>
>> I'd suggest renaming this to amdgpu_device_resize_bar() to try and
>> impose some consistency in this file, but not a big deal either way.
>>
>>> +{
>>> + u64 space_needed = roundup_pow_of_two(adev->mc.real_vram_size);
>>> + u32 rbar_size = order_base_2(((space_needed >> 20) | 1)) -1;
>>> + u16 cmd;
>>> + int r;
>>> +
>>> + /* Free the doorbell mapping, it most likely needs to move as
>>> well */
>>> + amdgpu_doorbell_fini(adev);
>>> + pci_release_resource(adev->pdev, 2);
>>
>> This should check for if (adev->asic_type >= CHIP_BONAIRE) since SI
>> didn't have doorbells.
>>
>>> +
>>> + /* Disable memory decoding while we change the BAR addresses and
>>> size */
>>> + pci_read_config_word(adev->pdev, PCI_COMMAND, &cmd);
>>> + pci_write_config_word(adev->pdev, PCI_COMMAND,
>>> + cmd & ~PCI_COMMAND_MEMORY);
>>> +
>>> + r = pci_resize_resource(adev->pdev, 0, rbar_size);
>>> + if (r == -ENOSPC)
>>> + DRM_INFO("Not enough PCI address space for a large
>>> BAR.");
>>> + else if (r && r != -ENOTSUPP)
>>> + DRM_ERROR("Problem resizing BAR0 (%d).", r);
>>> +
>>> + pci_write_config_word(adev->pdev, PCI_COMMAND, cmd);
>>> +
>>> + /* When the doorbell BAR isn't available we have no chance of
>>> + * using the device.
>>> + */
>>> + BUG_ON(amdgpu_doorbell_init(adev));
>>
>> Same here.
>>
>>> +}
>>> +
>>> /*
>>> * 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 a9083a1..ae71524 100644
>>
>> What about SI (gmc_v6_0.c)?
>
>
> As far as I know there is no SI hardware with resizeable BAR support.
>
> The all VI generation can do this, but I'm not 100% sure if there aren't any
> Bonaires out there which can handle it as well that's why I added gmc_v7
> support.
>
> Still need to double check that.

I think NI or even evergreen supported resizeable bars in theory,
although I'm not sure if any boards were fused to expose it.

Alex


>
> Christian.
>
>
>>
>> Alex
>>
>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>> @@ -372,13 +372,15 @@ static int gmc_v7_0_mc_init(struct amdgpu_device
>>> *adev)
>>> }
>>> 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 4ac9978..1655de2 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>> @@ -534,13 +534,15 @@ static int gmc_v8_0_mc_init(struct amdgpu_device
>>> *adev)
>>> }
>>> 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_v9_0.c
>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
>>> index e5d4dfe..4bbef79 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
>>> @@ -469,16 +469,18 @@ static int gmc_v9_0_mc_init(struct amdgpu_device
>>> *adev)
>>> }
>>> 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 =
>>> nbio_v6_1_get_memsize(adev) * 1024ULL * 1024ULL;
>>> adev->mc.real_vram_size = adev->mc.mc_vram_size;
>>> - adev->mc.visible_vram_size = adev->mc.aper_size;
>>> +
>>> + 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);
>>>
>>> /* In case the PCI BAR is larger than the actual amount of vram
>>> */
>>> + adev->mc.visible_vram_size = adev->mc.aper_size;
>>> if (adev->mc.visible_vram_size > adev->mc.real_vram_size)
>>> adev->mc.visible_vram_size = adev->mc.real_vram_size;
>>>
>>> --
>>> 2.7.4
>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel@xxxxxxxxxxxxxxxxxxxxx
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
>
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