Re: [PATCH v2 8/8] drm/amdgpu: start using kernel doorbell bo

[Shashank Sharma <shashank.sharma@xxxxxxx>]

On 14/02/2023 19:40, Christian König wrote:
> Am 14.02.23 um 17:15 schrieb Shashank Sharma:
> > From: Shashank Sharma <contactshashanksharma@xxxxxxxxx>
> >
> > This patch does the following:
> >
> > - Adds new variables like mman.doorbell_bo_size/gpu_addr/cpu_addr.
> >    The cpu_addr ptr will be used now for doorbell read/write from
> >    doorbell BAR.
> > - Adjusts the existing code to use kernel doorbell BO's size and its
> >    cpu_address.
> >
> > Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> > Cc: Christian Koenig <christian.koenig@xxxxxxx>
> > Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> > Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxx>
>
> Maybe squash this one together with the previous patch.

I just split it from the last patch in this series, thought it was too 
scattered and might not be

easy to review :D


> But see below.
>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c   |  5 ++-
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   | 33 +++++++++-----------
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h |  1 -
> >   3 files changed, 16 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> > index 0493c64e9d0a..87f486f522ae 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> > @@ -109,11 +109,10 @@ static void amdgpu_doorbell_get_kfd_info(struct 
> > amdgpu_device *adev,
> >           *aperture_base = adev->doorbell.doorbell_aper_base;
> >           *aperture_size = 0;
> >           *start_offset = 0;
> > -    } else if (adev->doorbell.doorbell_aper_size > 
> > adev->doorbell.num_doorbells *
> > -                        sizeof(u32)) {
> > +    } else if (adev->doorbell.doorbell_aper_size > 
> > adev->mman.doorbell_kernel_bo_size) {
> >           *aperture_base = adev->doorbell.doorbell_aper_base;
> >           *aperture_size = adev->doorbell.doorbell_aper_size;
> > -        *start_offset = adev->doorbell.num_doorbells * sizeof(u32);
> > +        *start_offset = adev->mman.doorbell_kernel_bo_size;
> >       } else {
> >           *aperture_base = 0;
> >           *aperture_size = 0;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > index 43c1b67c2778..fde199434579 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > @@ -596,8 +596,8 @@ u32 amdgpu_mm_rdoorbell(struct amdgpu_device 
> > *adev, u32 index)
> >       if (amdgpu_device_skip_hw_access(adev))
> >           return 0;
> >   -    if (index < adev->doorbell.num_doorbells) {
> > -        return readl(adev->mman.doorbell_aper_base_kaddr + index);
> > +    if (index < adev->mman.num_kernel_doorbells) {
> > +        return readl(adev->mman.doorbell_cpu_addr + index);
> >       } else {
> >           DRM_ERROR("reading beyond doorbell aperture: 0x%08x!\n", 
> > index);
> >           return 0;
> > @@ -619,8 +619,8 @@ void amdgpu_mm_wdoorbell(struct amdgpu_device 
> > *adev, u32 index, u32 v)
> >       if (amdgpu_device_skip_hw_access(adev))
> >           return;
> >   -    if (index < adev->doorbell.num_doorbells) {
> > -        writel(v, adev->mman.doorbell_aper_base_kaddr + index);
> > +    if (index < adev->mman.num_kernel_doorbells) {
> > +        writel(v, adev->mman.doorbell_cpu_addr + index);
> >       } else {
> >           DRM_ERROR("writing beyond doorbell aperture: 0x%08x!\n", 
> > index);
> >       }
> > @@ -640,8 +640,8 @@ u64 amdgpu_mm_rdoorbell64(struct amdgpu_device 
> > *adev, u32 index)
> >       if (amdgpu_device_skip_hw_access(adev))
> >           return 0;
> >   -    if (index < adev->doorbell.num_doorbells) {
> > -        return atomic64_read((atomic64_t 
> > *)(adev->mman.doorbell_aper_base_kaddr + index));
> > +    if (index < adev->mman.num_kernel_doorbells) {
> > +        return atomic64_read((atomic64_t 
> > *)(adev->mman.doorbell_cpu_addr + index));
> >       } else {
> >           DRM_ERROR("reading beyond doorbell aperture: 0x%08x!\n", 
> > index);
> >           return 0;
> > @@ -663,8 +663,8 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device 
> > *adev, u32 index, u64 v)
> >       if (amdgpu_device_skip_hw_access(adev))
> >           return;
> >   -    if (index < adev->doorbell.num_doorbells) {
> > -        atomic64_set((atomic64_t 
> > *)(adev->mman.doorbell_aper_base_kaddr + index), v);
> > +    if (index < adev->mman.num_kernel_doorbells) {
> > +        atomic64_set((atomic64_t *)(adev->mman.doorbell_cpu_addr + 
> > index), v);
> >       } else {
> >           DRM_ERROR("writing beyond doorbell aperture: 0x%08x!\n", 
> > index);
> >       }
> > @@ -1037,7 +1037,7 @@ static int amdgpu_device_doorbell_init(struct 
> > amdgpu_device *adev)
> >       if (adev->asic_type < CHIP_BONAIRE) {
> >           adev->doorbell.doorbell_aper_base = 0;
> >           adev->doorbell.doorbell_aper_size = 0;
> > -        adev->doorbell.num_doorbells = 0;
> > +        adev->mman.num_kernel_doorbells = 0;
> >           adev->mman.doorbell_aper_base_kaddr = NULL;
> >           return 0;
> >       }
> > @@ -1052,13 +1052,13 @@ static int amdgpu_device_doorbell_init(struct 
> > amdgpu_device *adev)
> >       adev->doorbell.doorbell_aper_size = 
> > pci_resource_len(adev->pdev, 2);
> >         if (adev->enable_mes) {
> > -        adev->doorbell.num_doorbells =
> > +        adev->mman.num_kernel_doorbells =
> >               adev->doorbell.doorbell_aper_size / sizeof(u32);
> >       } else {
> > -        adev->doorbell.num_doorbells =
> > +        adev->mman.num_kernel_doorbells =
> >               min_t(u32, adev->doorbell.doorbell_aper_size / 
> > sizeof(u32),
> >                     adev->doorbell_index.max_assignment+1);
> > -        if (adev->doorbell.num_doorbells == 0)
> > +        if (adev->mman.num_kernel_doorbells == 0)
> >               return -EINVAL;
> >             /* For Vega, reserve and map two pages on doorbell BAR 
> > since SDMA
> > @@ -1068,15 +1068,10 @@ static int amdgpu_device_doorbell_init(struct 
> > amdgpu_device *adev)
> >            * the max num_doorbells should + 1 page (0x400 in dword)
> >            */
> >           if (adev->asic_type >= CHIP_VEGA10)
> > -            adev->doorbell.num_doorbells += 0x400;
> > +            adev->mman.num_kernel_doorbells += 0x400;
> >       }
> >   -    adev->mman.doorbell_aper_base_kaddr = 
> > ioremap(adev->doorbell.doorbell_aper_base,
> > -                              adev->doorbell.num_doorbells *
> > -                              sizeof(u32));
> > -    if (adev->mman.doorbell_aper_base_kaddr == NULL)
> > -        return -ENOMEM;
> > -
> > +    adev->mman.doorbell_kernel_bo_size = 
> > adev->mman.num_kernel_doorbells * sizeof(u32);
>
> I would just keep the kernel_bo_size around and make the 
> num_kernel_doorbells a local variable.
Noted,

- Shashank

> Christian.
>
> >       return 0;
> >   }
> >   diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> > index 526b6b4a86dd..7bdff4f926ad 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> > @@ -28,7 +28,6 @@ struct amdgpu_doorbell {
> >       /* doorbell mmio */
> >       resource_size_t        doorbell_aper_base;
> >       resource_size_t        doorbell_aper_size;
> > -    u32            num_doorbells;    /* Number of doorbells actually 
> > reserved for amdgpu. */
> >   };
> >     /* Reserved doorbells for amdgpu (including multimedia).