No one else seems to have any thoughts on it, so Reviewed-by: Kent Russell
<kent.russ...@amd.com>
Kent
________________________________
From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> on behalf of Russell,
Kent <kent.russ...@amd.com>
Sent: Monday, August 22, 2022 10:10 AM
To: Kuehling, Felix <felix.kuehl...@amd.com>; amd-gfx@lists.freedesktop.org
<amd-gfx@lists.freedesktop.org>
Subject: RE: [PATCH] drm/amdkfd: Allocate doorbells only when needed
[AMD Official Use Only - General]
I can throw an Acked-by: Kent Russell <kent.russ...@amd.com> since we don't
have an RB yet.
Kent
> -----Original Message-----
> From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> On Behalf Of Felix
> Kuehling
> Sent: Wednesday, August 3, 2022 2:56 PM
> To: amd-gfx@lists.freedesktop.org
> Subject: [PATCH] drm/amdkfd: Allocate doorbells only when needed
>
> Only allocate doorbells when the first queue is created on a GPU or the
> doorbells need to be mapped into CPU or GPU virtual address space. This
> avoids allocating doorbells unnecessarily and can allow more processes
> to use KFD on multi-GPU systems.
>
> Signed-off-by: Felix Kuehling <felix.kuehl...@amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 13 +++++++++++++
> drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c | 9 +++++++++
> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 5 -----
> 3 files changed, 22 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index 2b3d8bc8f0aa..907f4711abce 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -327,6 +327,12 @@ static int kfd_ioctl_create_queue(struct file *filep,
> struct kfd_process *p,
> goto err_bind_process;
> }
>
> + if (!pdd->doorbell_index &&
> + kfd_alloc_process_doorbells(dev, &pdd->doorbell_index) < 0) {
> + err = -ENOMEM;
> + goto err_alloc_doorbells;
> + }
> +
> /* Starting with GFX11, wptr BOs must be mapped to GART for MES to
> determine work
> * on unmapped queues for usermode queue oversubscription (no
> aggregated doorbell)
> */
> @@ -404,6 +410,7 @@ static int kfd_ioctl_create_queue(struct file *filep,
> struct
> kfd_process *p,
> if (wptr_bo)
> amdgpu_amdkfd_free_gtt_mem(dev->adev, wptr_bo);
> err_wptr_map_gart:
> +err_alloc_doorbells:
> err_bind_process:
> err_pdd:
> mutex_unlock(&p->mutex);
> @@ -1092,6 +1099,10 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file
> *filep,
> goto err_unlock;
> }
> offset = kfd_get_process_doorbells(pdd);
> + if (!offset) {
> + err = -ENOMEM;
> + goto err_unlock;
> + }
> } else if (flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP) {
> if (args->size != PAGE_SIZE) {
> err = -EINVAL;
> @@ -2173,6 +2184,8 @@ static int criu_restore_memory_of_gpu(struct
> kfd_process_device *pdd,
> return -EINVAL;
>
> offset = kfd_get_process_doorbells(pdd);
> + if (!offset)
> + return -ENOMEM;
> } else if (bo_bucket->alloc_flags &
> KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP) {
> /* MMIO BOs need remapped bus address */
> if (bo_bucket->size != PAGE_SIZE) {
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> index cb3d2ccc5100..b33798f89ef0 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
> @@ -157,6 +157,8 @@ int kfd_doorbell_mmap(struct kfd_dev *dev, struct
> kfd_process *process,
>
> /* Calculate physical address of doorbell */
> address = kfd_get_process_doorbells(pdd);
> + if (!address)
> + return -ENOMEM;
> vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND |
> VM_NORESERVE |
> VM_DONTDUMP | VM_PFNMAP;
>
> @@ -275,6 +277,13 @@ uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
>
> phys_addr_t kfd_get_process_doorbells(struct kfd_process_device *pdd)
> {
> + if (!pdd->doorbell_index) {
> + int r = kfd_alloc_process_doorbells(pdd->dev,
> + &pdd->doorbell_index);
> + if (r)
> + return 0;
> + }
> +
> return pdd->dev->doorbell_base +
> pdd->doorbell_index * kfd_doorbell_process_slice(pdd->dev);
> }
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index 6c83a519b3a1..951b63677248 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -1499,11 +1499,6 @@ struct kfd_process_device
> *kfd_create_process_device_data(struct kfd_dev *dev,
> if (!pdd)
> return NULL;
>
> - if (kfd_alloc_process_doorbells(dev, &pdd->doorbell_index) < 0) {
> - pr_err("Failed to alloc doorbell for pdd\n");
> - goto err_free_pdd;
> - }
> -
> if (init_doorbell_bitmap(&pdd->qpd, dev)) {
> pr_err("Failed to init doorbell for process\n");
> goto err_free_pdd;
> --
> 2.32.0
