[PATCH v3] drm/amdgpu: Don't flush/invalidate HDP for APUs and A+A

Eric Huang jinhuieric.huang at amd.com
Wed Jun 2 15:26:06 UTC 2021



On 2021-06-02 3:00 a.m., Christian König wrote:
> Am 02.06.21 um 04:04 schrieb Eric Huang:
>> Integrate two macros into two generic functions and add
>> no_flush flag to determine if HDP flush is needed for
>> all Asics.
>
> Yes that starts looks like it should work, just a few comments below.
>
>>
>> Signed-off-by: Eric Huang <jinhuieric.huang at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  9 ++++---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 29 ++++++++++++++++++++++
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_hdp.h    |  1 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c     | 15 ++---------
>>   4 files changed, 37 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> index 1e3cd4ce9e91..224552d38240 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> @@ -1297,10 +1297,6 @@ int emu_soc_asic_init(struct amdgpu_device 
>> *adev);
>>   #define amdgpu_asic_read_bios_from_rom(adev, b, l) 
>> (adev)->asic_funcs->read_bios_from_rom((adev), (b), (l))
>>   #define amdgpu_asic_read_register(adev, se, sh, offset, 
>> v)((adev)->asic_funcs->read_register((adev), (se), (sh), (offset), (v)))
>>   #define amdgpu_asic_get_config_memsize(adev) 
>> (adev)->asic_funcs->get_config_memsize((adev))
>> -#define amdgpu_asic_flush_hdp(adev, r) \
>> -    ((adev)->asic_funcs->flush_hdp ? 
>> (adev)->asic_funcs->flush_hdp((adev), (r)) : 
>> (adev)->hdp.funcs->flush_hdp((adev), (r)))
>> -#define amdgpu_asic_invalidate_hdp(adev, r) \
>> -    ((adev)->asic_funcs->invalidate_hdp ? 
>> (adev)->asic_funcs->invalidate_hdp((adev), (r)) : 
>> (adev)->hdp.funcs->invalidate_hdp((adev), (r)))
>>   #define amdgpu_asic_need_full_reset(adev) 
>> (adev)->asic_funcs->need_full_reset((adev))
>>   #define amdgpu_asic_init_doorbell_index(adev) 
>> (adev)->asic_funcs->init_doorbell_index((adev))
>>   #define amdgpu_asic_get_pcie_usage(adev, cnt0, cnt1) 
>> ((adev)->asic_funcs->get_pcie_usage((adev), (cnt0), (cnt1)))
>> @@ -1314,6 +1310,11 @@ int emu_soc_asic_init(struct amdgpu_device 
>> *adev);
>>     #define amdgpu_inc_vram_lost(adev) 
>> atomic_inc(&((adev)->vram_lost_counter));
>>   +void amdgpu_asic_flush_hdp(struct amdgpu_device *adev,
>> +        struct amdgpu_ring *ring);
>> +void amdgpu_asic_invalidate_hdp(struct amdgpu_device *adev,
>> +        struct amdgpu_ring *ring);
>> +
>>   /* Common functions */
>>   bool amdgpu_device_has_job_running(struct amdgpu_device *adev);
>>   bool amdgpu_device_should_recover_gpu(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 9c4d33f649f7..951feefb5e76 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -3505,6 +3505,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>>       if (r)
>>           goto failed_unmap;
>>   +    if ((adev->flags & AMD_IS_APU) || 
>> adev->gmc.xgmi.connected_to_cpu)
>> +        adev->hdp.no_flush = true;
>> +
>
> This is not correct. We can only skip HDP flush on X86_64, but not on 
> 32bit builds.
>
> Additional to that we might want this somewhere in the GMC code and 
> not here.
>
>>       /* doorbell bar mapping and doorbell index init*/
>>       amdgpu_device_doorbell_init(adev);
>>   @@ -5548,3 +5551,29 @@ bool amdgpu_device_is_headless(struct 
>> amdgpu_device *adev)
>>       /* Check if it is NV's VGA class while VCN is harvest, it is 
>> headless*/
>>       return nv_is_headless_sku(adev->pdev);
>>   }
>> +
>> +void amdgpu_asic_flush_hdp(struct amdgpu_device *adev,
>> +        struct amdgpu_ring *ring)
>
> Please name the functions amdgpu_device_, the amdgpu_asic_ names are 
> for callbacks only.

I was thinking about the naming you mention, then we have to change all 
the caller for amdgpu_asic_flush_hdp(). The idea here is to simplify 
changes. If you think changing name is necessary, I am fine with that.

>
>> +{
>> +    if (adev->hdp.no_flush)
>> +        return;
>
> Since we now have a function to check the different conditions I think 
> we might want to check for X86_64 & APU and XGMI connection separately 
> here.
>
> But that is not a hard requirement, using the no_flush variable is 
> fine with me if you think that this is better.
>
>> +
>> +    if (ring->funcs->emit_hdp_flush)
>> +        amdgpu_ring_emit_hdp_flush(ring);
>> +    else if (adev->asic_funcs->flush_hdp)
>> +        adev->asic_funcs->flush_hdp(adev, ring);
>> +    else
>> +        adev->hdp.funcs->flush_hdp(adev, ring);
>> +}
>> +
>> +void amdgpu_asic_invalidate_hdp(struct amdgpu_device *adev,
>> +        struct amdgpu_ring *ring)
>> +{
>> +    if (adev->hdp.no_flush)
>> +        return;
>> +
>> +    if (adev->asic_funcs->invalidate_hdp)
>> +        adev->asic_funcs->invalidate_hdp(adev, ring);
>> +    else
>> +        adev->hdp.funcs->invalidate_hdp(adev, ring);
>> +}
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hdp.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_hdp.h
>> index 7ec99d591584..1ca23f2f51d2 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hdp.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hdp.h
>> @@ -44,6 +44,7 @@ struct amdgpu_hdp {
>>       struct ras_common_if            *ras_if;
>>       const struct amdgpu_hdp_funcs        *funcs;
>>       const struct amdgpu_hdp_ras_funcs    *ras_funcs;
>> +    bool    no_flush;
>>   };
>>     int amdgpu_hdp_ras_late_init(struct amdgpu_device *adev);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> index aaa2574ce9bc..6db676c4c7e1 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
>> @@ -222,15 +222,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, 
>> unsigned num_ibs,
>>       if (job && ring->funcs->init_cond_exec)
>>           patch_offset = amdgpu_ring_init_cond_exec(ring);
>>   -#ifdef CONFIG_X86_64
>> -    if (!(adev->flags & AMD_IS_APU))
>> -#endif
>> -    {
>> -        if (ring->funcs->emit_hdp_flush)
>> -            amdgpu_ring_emit_hdp_flush(ring);
>> -        else
>> -            amdgpu_asic_flush_hdp(adev, ring);
>> -    }
>> +    amdgpu_asic_flush_hdp(adev, ring);
>
> We also have two more HDP flush cases in the GART code and the CPU 
> based VM code IIRC.

Are there calling amdgpu_asic_flush_hdp() in function 
amdgpu_gart_unbind() and amdgpu_vm_cpu_commit()? if so, keeping the same 
name of amdgpu_asic_flush_hdp() will not need to change. That is the 
reason I don't change the name.

Regards,
Eric
>
> Thanks,
> Christian.
>
>>         if (need_ctx_switch)
>>           status |= AMDGPU_HAVE_CTX_SWITCH;
>> @@ -267,10 +259,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, 
>> unsigned num_ibs,
>>       if (job && ring->funcs->emit_frame_cntl)
>>           amdgpu_ring_emit_frame_cntl(ring, false, secure);
>>   -#ifdef CONFIG_X86_64
>> -    if (!(adev->flags & AMD_IS_APU))
>> -#endif
>> -        amdgpu_asic_invalidate_hdp(adev, ring);
>> +    amdgpu_asic_invalidate_hdp(adev, ring);
>>         if (ib->flags & AMDGPU_IB_FLAG_TC_WB_NOT_INVALIDATE)
>>           fence_flags |= AMDGPU_FENCE_FLAG_TC_WB_ONLY;
>



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