[PATCH v3 08/12] drm/amdgpu: use doorbell manager for kfd kernel doorbells
Felix Kuehling
felix.kuehling at amd.com
Thu Jul 13 19:04:26 UTC 2023
On 2023-06-20 13:16, Shashank Sharma wrote:
> This patch:
> - adds a doorbell bo in kfd device structure.
> - creates doorbell page for kfd kernel usages.
> - updates the get_kernel_doorbell and free_kernel_doorbell functions
> accordingly
>
> V2: Do not use wrapper API, use direct amdgpu_create_kernel(Alex)
> V3:
> - Move single variable declaration below (Christian)
> - Add a to-do item to reuse the KGD kernel level doorbells for
> KFD for non-MES cases, instead of reserving one page (Felix)
>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Christian Koenig <christian.koenig at amd.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_device.c | 2 -
> drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c | 109 +++++++---------------
> drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 6 ++
> 3 files changed, 39 insertions(+), 78 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
> index 00f528eb9812..36fbe9c840ee 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
> @@ -437,8 +437,6 @@ struct kfd_dev *kgd2kfd_probe(struct amdgpu_device *adev, bool vf)
> atomic_set(&kfd->compute_profile, 0);
>
> mutex_init(&kfd->doorbell_mutex);
> - memset(&kfd->doorbell_available_index, 0,
> - sizeof(kfd->doorbell_available_index));
>
> atomic_set(&kfd->sram_ecc_flag, 0);
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> index 38c9e1ca6691..f7d45057ed32 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> @@ -61,81 +61,46 @@ size_t kfd_doorbell_process_slice(struct kfd_dev *kfd)
> /* Doorbell calculations for device init. */
> int kfd_doorbell_init(struct kfd_dev *kfd)
> {
> - size_t doorbell_start_offset;
> - size_t doorbell_aperture_size;
> - size_t doorbell_process_limit;
> + int size = PAGE_SIZE;
> + int r;
>
> /*
> - * With MES enabled, just set the doorbell base as it is needed
> - * to calculate doorbell physical address.
> - */
> - if (kfd->shared_resources.enable_mes) {
> - kfd->doorbell_base =
> - kfd->shared_resources.doorbell_physical_address;
> - return 0;
> - }
> -
> - /*
> - * We start with calculations in bytes because the input data might
> - * only be byte-aligned.
> - * Only after we have done the rounding can we assume any alignment.
> + * Todo: KFD kernel level operations need only one doorbell for
> + * ring test/HWS. So instead of reserving a whole page here for
> + * kernel, reserve and consume a doorbell from existing KGD kernel
> + * doorbell page.
> */
>
> - doorbell_start_offset =
> - roundup(kfd->shared_resources.doorbell_start_offset,
> - kfd_doorbell_process_slice(kfd));
> -
> - doorbell_aperture_size =
> - rounddown(kfd->shared_resources.doorbell_aperture_size,
> - kfd_doorbell_process_slice(kfd));
> -
> - if (doorbell_aperture_size > doorbell_start_offset)
> - doorbell_process_limit =
> - (doorbell_aperture_size - doorbell_start_offset) /
> - kfd_doorbell_process_slice(kfd);
> - else
> - return -ENOSPC;
> -
> - if (!kfd->max_doorbell_slices ||
> - doorbell_process_limit < kfd->max_doorbell_slices)
> - kfd->max_doorbell_slices = doorbell_process_limit;
> -
> - kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
> - doorbell_start_offset;
> -
> - kfd->doorbell_base_dw_offset = doorbell_start_offset / sizeof(u32);
> -
> - kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
> - kfd_doorbell_process_slice(kfd));
> -
> - if (!kfd->doorbell_kernel_ptr)
> + /* Bitmap to dynamically allocate doorbells from kernel page */
> + kfd->doorbell_bitmap = bitmap_zalloc(size / sizeof(u32), GFP_KERNEL);
> + if (!kfd->doorbell_bitmap) {
> + DRM_ERROR("Failed to allocate kernel doorbell bitmap\n");
> return -ENOMEM;
> + }
>
> - pr_debug("Doorbell initialization:\n");
> - pr_debug("doorbell base == 0x%08lX\n",
> - (uintptr_t)kfd->doorbell_base);
> -
> - pr_debug("doorbell_base_dw_offset == 0x%08lX\n",
> - kfd->doorbell_base_dw_offset);
> -
> - pr_debug("doorbell_process_limit == 0x%08lX\n",
> - doorbell_process_limit);
> -
> - pr_debug("doorbell_kernel_offset == 0x%08lX\n",
> - (uintptr_t)kfd->doorbell_base);
> -
> - pr_debug("doorbell aperture size == 0x%08lX\n",
> - kfd->shared_resources.doorbell_aperture_size);
> -
> - pr_debug("doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr);
> + /* Alloc a doorbell page for KFD kernel usages */
> + r = amdgpu_bo_create_kernel(kfd->adev,
> + size,
> + PAGE_SIZE,
> + AMDGPU_GEM_DOMAIN_DOORBELL,
> + &kfd->doorbells,
> + NULL,
> + (void **)&kfd->doorbell_kernel_ptr);
> + if (r) {
> + pr_err("failed to allocate kernel doorbells\n");
> + bitmap_free(kfd->doorbell_bitmap);
> + return r;
> + }
>
> + pr_debug("Doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr);
> return 0;
> }
>
> void kfd_doorbell_fini(struct kfd_dev *kfd)
> {
> - if (kfd->doorbell_kernel_ptr)
> - iounmap(kfd->doorbell_kernel_ptr);
> + bitmap_free(kfd->doorbell_bitmap);
> + amdgpu_bo_free_kernel(&kfd->doorbells, NULL,
> + (void **)&kfd->doorbell_kernel_ptr);
> }
>
> int kfd_doorbell_mmap(struct kfd_dev *dev, struct kfd_process *process,
> @@ -188,22 +153,15 @@ void __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
> u32 inx;
>
> mutex_lock(&kfd->doorbell_mutex);
> - inx = find_first_zero_bit(kfd->doorbell_available_index,
> - KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
> + inx = find_first_zero_bit(kfd->doorbell_bitmap, PAGE_SIZE / sizeof(u32));
>
> - __set_bit(inx, kfd->doorbell_available_index);
> + __set_bit(inx, kfd->doorbell_bitmap);
> mutex_unlock(&kfd->doorbell_mutex);
>
> if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
> return NULL;
>
> - inx *= kfd->device_info.doorbell_size / sizeof(u32);
> -
> - /*
> - * Calculating the kernel doorbell offset using the first
> - * doorbell page.
> - */
> - *doorbell_off = kfd->doorbell_base_dw_offset + inx;
> + *doorbell_off = amdgpu_doorbell_index_on_bar(kfd->adev, kfd->doorbells, inx);
>
> pr_debug("Get kernel queue doorbell\n"
> " doorbell offset == 0x%08X\n"
> @@ -217,11 +175,10 @@ void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
> {
> unsigned int inx;
>
> - inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr)
> - * sizeof(u32) / kfd->device_info.doorbell_size;
> + inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
>
> mutex_lock(&kfd->doorbell_mutex);
> - __clear_bit(inx, kfd->doorbell_available_index);
> + __clear_bit(inx, kfd->doorbell_bitmap);
> mutex_unlock(&kfd->doorbell_mutex);
> }
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> index 94a438956868..42c215782d72 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> @@ -349,6 +349,12 @@ struct kfd_dev {
>
> /* HMM page migration MEMORY_DEVICE_PRIVATE mapping */
> struct dev_pagemap pgmap;
> +
> + /* Kernel doorbells for KFD device */
> + struct amdgpu_bo *doorbells;
> +
> + /* bitmap for dynamic doorbell allocation from this object */
> + unsigned long *doorbell_bitmap;
> };
>
> enum kfd_mempool {
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