[PATCH] drm/amdgpu: enable paging queue doorbell support v3

Yang, Philip Philip.Yang at amd.com
Fri Nov 16 22:38:45 UTC 2018


On 2018-11-16 4:35 p.m., Alex Deucher wrote:
> On Fri, Nov 16, 2018 at 2:08 PM Yang, Philip <Philip.Yang at amd.com> wrote:
>> Because increase SDMA_DOORBELL_RANGE to add new SDMA doorbell for paging queue will
>> break SRIOV, instead we can reserve and map two doorbell pages for amdgpu, paging
>> queues doorbell index use same index as SDMA gfx queues index but on second page.
>>
>> For Vega20, after we change doorbell layout to increase SDMA doorbell for 8 SDMA RLC
>> queues later, we could use new doorbell index for paging queue.
>>
>> Change-Id: I9adb965f16ee4089d261d9a22231337739184e49
>> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 13 +++++++++
>>   drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c     | 33 +++++++++++++---------
>>   2 files changed, 33 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 590588a82471..7a54760591ae 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -534,6 +534,19 @@ static int amdgpu_device_doorbell_init(struct amdgpu_device *adev)
>>          if (adev->doorbell.num_doorbells == 0)
>>                  return -EINVAL;
>>
>> +       /* For Vega, reserve and map two pages on doorbell BAR since SDMA
>> +        * paging queue doorbell use the second page
>> +        */
>> +       switch (adev->asic_type) {
>> +       case CHIP_VEGA10:
>> +       case CHIP_VEGA12:
>> +       case CHIP_VEGA20:
>> +               adev->doorbell.num_doorbells *= 2;
>> +               break;
>> +       default:
>> +               break;
>> +       }
>> +
> To future proof this, maybe we should just change this to:
> if (asic_type >= VEGA10)
>    number_doorbells *= 2;
>
OK
>>          adev->doorbell.ptr = ioremap(adev->doorbell.base,
>>                                       adev->doorbell.num_doorbells *
>>                                       sizeof(u32));
>> diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>> index f4490cdd9804..db5a71db9f10 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>> @@ -925,11 +925,9 @@ static void sdma_v4_0_page_resume(struct amdgpu_device *adev, unsigned int i)
>>                                          OFFSET, ring->doorbell_index);
>>          WREG32_SDMA(i, mmSDMA0_PAGE_DOORBELL, doorbell);
>>          WREG32_SDMA(i, mmSDMA0_PAGE_DOORBELL_OFFSET, doorbell_offset);
>> -       /* TODO: enable doorbell support */
>> -       /*adev->nbio_funcs->sdma_doorbell_range(adev, i, ring->use_doorbell,
>> -                                             ring->doorbell_index);*/
>>
>> -       sdma_v4_0_ring_set_wptr(ring);
>> +       /* paging queue doorbell index is already enabled at sdma_v4_0_gfx_resume */
>> +       sdma_v4_0_page_ring_set_wptr(ring);
> This looks like a bug fix that should be a separate patch.
OK
>>          /* set minor_ptr_update to 0 after wptr programed */
>>          WREG32_SDMA(i, mmSDMA0_PAGE_MINOR_PTR_UPDATE, 0);
>> @@ -1504,18 +1502,14 @@ static int sdma_v4_0_sw_init(void *handle)
>>                  ring->ring_obj = NULL;
>>                  ring->use_doorbell = true;
>>
>> -               DRM_INFO("use_doorbell being set to: [%s]\n",
>> -                               ring->use_doorbell?"true":"false");
>> -
>>                  if (adev->asic_type == CHIP_VEGA10)
>>                          ring->doorbell_index = (i == 0) ?
>> -                               (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE0 << 1) //get DWORD offset
>> -                               : (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE1 << 1); // get DWORD offset
>> +                               (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE0 << 1) // doorbell size 2 dwords
>> +                               : (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE1 << 1); // doorbell size 2 dwords
>>                  else
>>                          ring->doorbell_index = (i == 0) ?
>> -                               (AMDGPU_DOORBELL64_sDMA_ENGINE0 << 1) //get DWORD offset
>> -                               : (AMDGPU_DOORBELL64_sDMA_ENGINE1 << 1); // get DWORD offset
>> -
>> +                               (AMDGPU_DOORBELL64_sDMA_ENGINE0 << 1) // doorbell size 2 dwords
>> +                               : (AMDGPU_DOORBELL64_sDMA_ENGINE1 << 1); // doorbell size 2 dwords
>>
>>                  sprintf(ring->name, "sdma%d", i);
>>                  r = amdgpu_ring_init(adev, ring, 1024,
>> @@ -1529,7 +1523,20 @@ static int sdma_v4_0_sw_init(void *handle)
>>                  if (adev->sdma.has_page_queue) {
>>                          ring = &adev->sdma.instance[i].page;
>>                          ring->ring_obj = NULL;
>> -                       ring->use_doorbell = false;
>> +                       ring->use_doorbell = true;
>> +
>> +                       /* paging queue use same doorbell index/routing as gfx queue
>> +                        * with 0x400 (4096 dwords) offset on second doorbell page
>> +                        */
>> +                       if (adev->asic_type == CHIP_VEGA10)
>> +                               ring->doorbell_index = (i == 0) ?
>> +                                       (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE0 << 1)
>> +                                       : (AMDGPU_VEGA10_DOORBELL64_sDMA_ENGINE1 << 1);
>> +                       else
>> +                               ring->doorbell_index = (i == 0) ?
>> +                                       (AMDGPU_DOORBELL64_sDMA_ENGINE0 << 1)
>> +                                       : (AMDGPU_DOORBELL64_sDMA_ENGINE1 << 1);
>> +                       ring->doorbell_index += 0x400;
> I don't quite understand how this works.  Why don't we have to adjust
> the doorbell range registers in the nbio code?
>
> Alex
nbio doorbell routing use low bits (11bits or 12bits?), so doorbell 
index 0x1E0 and 0x5E0 (dwords
address 0x780 and 0x1780) will both route to same SDMA engine0.

Philip
>>                          sprintf(ring->name, "page%d", i);
>>                          r = amdgpu_ring_init(adev, ring, 1024,
>> --
>> 2.17.1
>>
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