Re: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8
On 28/09/2023 20:53, Felix Kuehling wrote: On 2023-09-28 11:38, Shashank Sharma wrote: Hello Felix, Mukul, On 28/09/2023 17:30, Felix Kuehling wrote: On 2023-09-28 10:30, Joshi, Mukul wrote: [AMD Official Use Only - General] -Original Message- From: Yadav, Arvind Sent: Thursday, September 28, 2023 5:54 AM To: Koenig, Christian ; Deucher, Alexander ; Sharma, Shashank ; Kuehling, Felix ; Joshi, Mukul ; Pan, Xinhui ; airl...@gmail.com; dan...@ffwll.ch Cc: amd-gfx@lists.freedesktop.org; dri-de...@lists.freedesktop.org; linux- ker...@vger.kernel.org; Yadav, Arvind ; Koenig, Christian Subject: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8 This patch is to adjust the absolute doorbell offset against the doorbell id considering the doorbell size of 32/64 bit. v2: - Addressed the review comment from Felix. Cc: Christian Koenig Cc: Alex Deucher Signed-off-by: Shashank Sharma Signed-off-by: Arvind Yadav --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index 0d3d538b64eb..c54c4392d26e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -407,7 +407,14 @@ static int allocate_doorbell(struct qcm_process_device *qpd, q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev- adev, qpd- proc_doorbells, - q- doorbell_id); + 0); + It looks like amdgpu_doorbell_index_on_bar() works only for 64-bit doorbells. Shouldn't it work for both 32-bit and 64-bit doorbells considering this is common doorbell manager code? Yes, You are right that the calculations to find a particular doorbell in the doorbell page considers a doorbell width of 64-bit. I could see this argument going either way. KFD is the only one that cares about managing doorbells for user mode queues on GFXv8 GPUs. This is not a use case that amdgpu cares about. So I'm OK with KFD doing its own address calculations to make sure doorbells continue to work on GFXv8. It may not be worth adding complexity to the common doorbell manager code to support legacy GPUs with 32-bit doorbells. I was thinking about adding an additional input parameter which will indicate if the doorbell width is 32-bit vs 64-bit (like is_doorbell_64_bit), and doorbell manager can alter the multiplier while calculating the final offset. Please let me know if that will work for both the cases. Yes, that would work for KFD because we already have the doorbell size in our device-info structure. Instead of making it a boolean flag, you could make it a doorbell_size parameter, in byte or dword units to simplify the pointer math. Sounds good, will do that and send an update. - Shashank Regards, Felix - Shashank Regards, Felix Thanks, Mukul + /* Adjust the absolute doorbell offset against the doorbell id considering + * the doorbell size of 32/64 bit. + */ + q->properties.doorbell_off += q->doorbell_id * + dev->kfd->device_info.doorbell_size / 4; + return 0; } -- 2.34.1
Re: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8
On 2023-09-28 11:38, Shashank Sharma wrote: Hello Felix, Mukul, On 28/09/2023 17:30, Felix Kuehling wrote: On 2023-09-28 10:30, Joshi, Mukul wrote: [AMD Official Use Only - General] -Original Message- From: Yadav, Arvind Sent: Thursday, September 28, 2023 5:54 AM To: Koenig, Christian ; Deucher, Alexander ; Sharma, Shashank ; Kuehling, Felix ; Joshi, Mukul ; Pan, Xinhui ; airl...@gmail.com; dan...@ffwll.ch Cc: amd-gfx@lists.freedesktop.org; dri-de...@lists.freedesktop.org; linux- ker...@vger.kernel.org; Yadav, Arvind ; Koenig, Christian Subject: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8 This patch is to adjust the absolute doorbell offset against the doorbell id considering the doorbell size of 32/64 bit. v2: - Addressed the review comment from Felix. Cc: Christian Koenig Cc: Alex Deucher Signed-off-by: Shashank Sharma Signed-off-by: Arvind Yadav --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index 0d3d538b64eb..c54c4392d26e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -407,7 +407,14 @@ static int allocate_doorbell(struct qcm_process_device *qpd, q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev- adev, qpd- proc_doorbells, - q- doorbell_id); + 0); + It looks like amdgpu_doorbell_index_on_bar() works only for 64-bit doorbells. Shouldn't it work for both 32-bit and 64-bit doorbells considering this is common doorbell manager code? Yes, You are right that the calculations to find a particular doorbell in the doorbell page considers a doorbell width of 64-bit. I could see this argument going either way. KFD is the only one that cares about managing doorbells for user mode queues on GFXv8 GPUs. This is not a use case that amdgpu cares about. So I'm OK with KFD doing its own address calculations to make sure doorbells continue to work on GFXv8. It may not be worth adding complexity to the common doorbell manager code to support legacy GPUs with 32-bit doorbells. I was thinking about adding an additional input parameter which will indicate if the doorbell width is 32-bit vs 64-bit (like is_doorbell_64_bit), and doorbell manager can alter the multiplier while calculating the final offset. Please let me know if that will work for both the cases. Yes, that would work for KFD because we already have the doorbell size in our device-info structure. Instead of making it a boolean flag, you could make it a doorbell_size parameter, in byte or dword units to simplify the pointer math. Regards, Felix - Shashank Regards, Felix Thanks, Mukul + /* Adjust the absolute doorbell offset against the doorbell id considering + * the doorbell size of 32/64 bit. + */ + q->properties.doorbell_off += q->doorbell_id * + dev->kfd->device_info.doorbell_size / 4; + return 0; } -- 2.34.1
Re: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8
Hello Felix, Mukul, On 28/09/2023 17:30, Felix Kuehling wrote: On 2023-09-28 10:30, Joshi, Mukul wrote: [AMD Official Use Only - General] -Original Message- From: Yadav, Arvind Sent: Thursday, September 28, 2023 5:54 AM To: Koenig, Christian ; Deucher, Alexander ; Sharma, Shashank ; Kuehling, Felix ; Joshi, Mukul ; Pan, Xinhui ; airl...@gmail.com; dan...@ffwll.ch Cc: amd-gfx@lists.freedesktop.org; dri-de...@lists.freedesktop.org; linux- ker...@vger.kernel.org; Yadav, Arvind ; Koenig, Christian Subject: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8 This patch is to adjust the absolute doorbell offset against the doorbell id considering the doorbell size of 32/64 bit. v2: - Addressed the review comment from Felix. Cc: Christian Koenig Cc: Alex Deucher Signed-off-by: Shashank Sharma Signed-off-by: Arvind Yadav --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index 0d3d538b64eb..c54c4392d26e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -407,7 +407,14 @@ static int allocate_doorbell(struct qcm_process_device *qpd, q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev- adev, qpd- proc_doorbells, - q- doorbell_id); + 0); + It looks like amdgpu_doorbell_index_on_bar() works only for 64-bit doorbells. Shouldn't it work for both 32-bit and 64-bit doorbells considering this is common doorbell manager code? Yes, You are right that the calculations to find a particular doorbell in the doorbell page considers a doorbell width of 64-bit. I could see this argument going either way. KFD is the only one that cares about managing doorbells for user mode queues on GFXv8 GPUs. This is not a use case that amdgpu cares about. So I'm OK with KFD doing its own address calculations to make sure doorbells continue to work on GFXv8. It may not be worth adding complexity to the common doorbell manager code to support legacy GPUs with 32-bit doorbells. I was thinking about adding an additional input parameter which will indicate if the doorbell width is 32-bit vs 64-bit (like is_doorbell_64_bit), and doorbell manager can alter the multiplier while calculating the final offset. Please let me know if that will work for both the cases. - Shashank Regards, Felix Thanks, Mukul + /* Adjust the absolute doorbell offset against the doorbell id considering + * the doorbell size of 32/64 bit. + */ + q->properties.doorbell_off += q->doorbell_id * + dev->kfd->device_info.doorbell_size / 4; + return 0; } -- 2.34.1
Re: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8
On 2023-09-28 10:30, Joshi, Mukul wrote: [AMD Official Use Only - General] -Original Message- From: Yadav, Arvind Sent: Thursday, September 28, 2023 5:54 AM To: Koenig, Christian ; Deucher, Alexander ; Sharma, Shashank ; Kuehling, Felix ; Joshi, Mukul ; Pan, Xinhui ; airl...@gmail.com; dan...@ffwll.ch Cc: amd-gfx@lists.freedesktop.org; dri-de...@lists.freedesktop.org; linux- ker...@vger.kernel.org; Yadav, Arvind ; Koenig, Christian Subject: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8 This patch is to adjust the absolute doorbell offset against the doorbell id considering the doorbell size of 32/64 bit. v2: - Addressed the review comment from Felix. Cc: Christian Koenig Cc: Alex Deucher Signed-off-by: Shashank Sharma Signed-off-by: Arvind Yadav --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index 0d3d538b64eb..c54c4392d26e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -407,7 +407,14 @@ static int allocate_doorbell(struct qcm_process_device *qpd, q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev- adev, qpd- proc_doorbells, - q- doorbell_id); + 0); + It looks like amdgpu_doorbell_index_on_bar() works only for 64-bit doorbells. Shouldn't it work for both 32-bit and 64-bit doorbells considering this is common doorbell manager code? I could see this argument going either way. KFD is the only one that cares about managing doorbells for user mode queues on GFXv8 GPUs. This is not a use case that amdgpu cares about. So I'm OK with KFD doing its own address calculations to make sure doorbells continue to work on GFXv8. It may not be worth adding complexity to the common doorbell manager code to support legacy GPUs with 32-bit doorbells. Regards, Felix Thanks, Mukul + /* Adjust the absolute doorbell offset against the doorbell id considering + * the doorbell size of 32/64 bit. + */ + q->properties.doorbell_off += q->doorbell_id * + dev->kfd->device_info.doorbell_size / 4; + return 0; } -- 2.34.1
RE: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8
[AMD Official Use Only - General] > -Original Message- > From: Yadav, Arvind > Sent: Thursday, September 28, 2023 5:54 AM > To: Koenig, Christian ; Deucher, Alexander > ; Sharma, Shashank > ; Kuehling, Felix ; > Joshi, Mukul ; Pan, Xinhui ; > airl...@gmail.com; dan...@ffwll.ch > Cc: amd-gfx@lists.freedesktop.org; dri-de...@lists.freedesktop.org; linux- > ker...@vger.kernel.org; Yadav, Arvind ; Koenig, > Christian > Subject: [PATCH v2 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset > for gfx8 > > This patch is to adjust the absolute doorbell offset against the doorbell id > considering the doorbell size of 32/64 bit. > > v2: > - Addressed the review comment from Felix. > > Cc: Christian Koenig > Cc: Alex Deucher > Signed-off-by: Shashank Sharma > Signed-off-by: Arvind Yadav > --- > drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 - > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > index 0d3d538b64eb..c54c4392d26e 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > @@ -407,7 +407,14 @@ static int allocate_doorbell(struct > qcm_process_device *qpd, > > q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev- > >adev, > qpd- > >proc_doorbells, > - q- > >doorbell_id); > + 0); > + It looks like amdgpu_doorbell_index_on_bar() works only for 64-bit doorbells. Shouldn't it work for both 32-bit and 64-bit doorbells considering this is common doorbell manager code? Thanks, Mukul > + /* Adjust the absolute doorbell offset against the doorbell id > considering > + * the doorbell size of 32/64 bit. > + */ > + q->properties.doorbell_off += q->doorbell_id * > + dev->kfd->device_info.doorbell_size / 4; > + > return 0; > } > > -- > 2.34.1
