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

From: Alex Deucher
Date: Tue Apr 25 2017 - 12:30:44 EST


On Tue, Apr 25, 2017 at 12:22 PM, Christian KÃnig
<deathsimple@xxxxxxxxxxx> wrote:
> Am 25.04.2017 um 17:14 schrieb Alex Deucher:
>>
>> 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.
>
>
> In theory yes, in practice no.
>
> Their PCIE config space defines the necessary registers, but I haven't found
> any board from Evergreen, NI, SI or CIK generation where that is actually
> validated.
>
> Tonga is the first one I'm 100% sure that it is supported and I have
> hardware to test it.
>
> I would rather drop Bonaire support as well and wait for somebody with the
> hardware to complain so that we can test and enable it.

I may have some workstation CI parts that support it.

Alex

>
> Christian.
>
>
>>
>> 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
>>>
>>>
>>>
>