Re: [Intel-gfx] [PATCH 10/19] drm/i915/perf: Use gt-specific ggtt for OA and noa-wait buffers

Lionel Landwerlin
2022-09-06T20:33:01Z

On 06/09/2022 23:28, Umesh Nerlige Ramappa wrote:
> On Tue, Sep 06, 2022 at 10:56:13PM +0300, Lionel Landwerlin wrote:
>> On 23/08/2022 23:41, Umesh Nerlige Ramappa wrote:
>>> User passes uabi engine class and instance to the perf OA interface.
>>> Use
>>> gt corresponding to the engine to pin the buffers to the right ggtt.
>>>
>>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
>>
>> I didn't know there was a GGTT per engine.
>>
>> Do I understand this correct?
>
> No, GGTT is still per-gt. We just derive the gt from engine class
> instance passed (as in engine->gt).

Oh thanks I understand now.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

>
>>
>>
>> Thanks,
>>
>> -Lionel
>>
>>
>>> ---
>>>  drivers/gpu/drm/i915/i915_perf.c | 21 +++++++++++++++++++--
>>>  1 file changed, 19 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_perf.c
>>> b/drivers/gpu/drm/i915/i915_perf.c
>>> index 87b92d2946f4..f7621b45966c 100644
>>> --- a/drivers/gpu/drm/i915/i915_perf.c
>>> +++ b/drivers/gpu/drm/i915/i915_perf.c
>>> @@ -1765,6 +1765,7 @@ static void gen12_init_oa_buffer(struct
>>> i915_perf_stream *stream)
>>>  static int alloc_oa_buffer(struct i915_perf_stream *stream)
>>>  {
>>>      struct drm_i915_private *i915 = stream->perf->i915;
>>> +    struct intel_gt *gt = stream->engine->gt;
>>>      struct drm_i915_gem_object *bo;
>>>      struct i915_vma *vma;
>>>      int ret;
>>> @@ -1784,11 +1785,22 @@ static int alloc_oa_buffer(struct
>>> i915_perf_stream *stream)
>>>      i915_gem_object_set_cache_coherency(bo, I915_CACHE_LLC);
>>>      /* PreHSW required 512K alignment, HSW requires 16M */
>>> -    vma = i915_gem_object_ggtt_pin(bo, NULL, 0, SZ_16M, 0);
>>> +    vma = i915_vma_instance(bo, &gt->ggtt->vm, NULL);
>>>      if (IS_ERR(vma)) {
>>>          ret = PTR_ERR(vma);
>>>          goto err_unref;
>>>      }
>>> +
>>> +    /*
>>> +     * PreHSW required 512K alignment.
>>> +     * HSW and onwards, align to requested size of OA buffer.
>>> +     */
>>> +    ret = i915_vma_pin(vma, 0, SZ_16M, PIN_GLOBAL | PIN_HIGH);
>>> +    if (ret) {
>>> +        drm_err(&gt->i915->drm, "Failed to pin OA buffer %d\n", ret);
>>> +        goto err_unref;
>>> +    }
>>> +
>>>      stream->oa_buffer.vma = vma;
>>>      stream->oa_buffer.vaddr =
>>> @@ -1838,6 +1850,7 @@ static u32 *save_restore_register(struct
>>> i915_perf_stream *stream, u32 *cs,
>>>  static int alloc_noa_wait(struct i915_perf_stream *stream)
>>>  {
>>>      struct drm_i915_private *i915 = stream->perf->i915;
>>> +    struct intel_gt *gt = stream->engine->gt;
>>>      struct drm_i915_gem_object *bo;
>>>      struct i915_vma *vma;
>>>      const u64 delay_ticks = 0xffffffffffffffff -
>>> @@ -1878,12 +1891,16 @@ static int alloc_noa_wait(struct
>>> i915_perf_stream *stream)
>>>       * multiple OA config BOs will have a jump to this address and it
>>>       * needs to be fixed during the lifetime of the i915/perf stream.
>>>       */
>>> -    vma = i915_gem_object_ggtt_pin_ww(bo, &ww, NULL, 0, 0, PIN_HIGH);
>>> +    vma = i915_vma_instance(bo, &gt->ggtt->vm, NULL);
>>>      if (IS_ERR(vma)) {
>>>          ret = PTR_ERR(vma);
>>>          goto out_ww;
>>>      }
>>> +    ret = i915_vma_pin_ww(vma, &ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
>>> +    if (ret)
>>> +        goto out_ww;
>>> +
>>>      batch = cs = i915_gem_object_pin_map(bo, I915_MAP_WB);
>>>      if (IS_ERR(batch)) {
>>>          ret = PTR_ERR(batch);
>>
>>