Am 11.03.25 um 09:33 schrieb jesse.zh...@amd.com:
> From: "jesse.zh...@amd.com" <jesse.zh...@amd.com>
>
> This patch introduces two new functions, `amdgpu_sdma_stop_queue` and
> `amdgpu_sdma_start_queue`, to handle the stopping and starting of SDMA queues
> during engine reset operations. The changes include:
>
> 1. **New Functions**:
> - `amdgpu_sdma_stop_queue`: Stops the SDMA queues and the scheduler's work
> queue
> for the GFX and page rings.
> - `amdgpu_sdma_start_queue`: Starts the SDMA queues and restarts the
> scheduler's
> work queue for the GFX and page rings.
>
> 2. **Integration with Ring Functions**:
> - The `stop_queue` and `start_queue` callbacks are added to the
> `amdgpu_ring_funcs`
> structure and implemented for SDMA v4.4.2.
>
> Suggested-by:Jonathan Kim <jonathan....@amd.com>
> Signed-off-by: Jesse Zhang <jesse.zh...@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 1 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 2 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 92 ++++++++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h | 2 +
> 4 files changed, 97 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index d55c8b7fdb59..ff9aacbdf046 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -351,6 +351,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct
> amdgpu_ring *ring,
> 0xffffffffffffffff : ring->buf_mask;
> /* Initialize cached_rptr to 0 */
> ring->cached_rptr = 0;
> + atomic_set(&ring->stop_refcount, 0);
>
> /* Allocate ring buffer */
> if (ring->is_mes_queue) {
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 1c52ff92ea26..7a984dbb48c7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -312,6 +312,8 @@ struct amdgpu_ring {
> unsigned int entry_index;
> /* store the cached rptr to restore after reset */
> uint64_t cached_rptr;
> + /* Reference counter for stop requests */
> + atomic_t stop_refcount;
>
> };
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> index 39669f8788a7..7cd6dcd6e7f0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> @@ -30,6 +30,7 @@
> #define AMDGPU_CSA_SDMA_SIZE 64
> /* SDMA CSA reside in the 3rd page of CSA */
> #define AMDGPU_CSA_SDMA_OFFSET (4096 * 2)
> +DEFINE_MUTEX(sdma_queue_mutex);
Absolutely clear NAK to using a global mutex for this.
Regards,
Christian.
>
> /*
> * GPU SDMA IP block helpers function.
> @@ -504,6 +505,97 @@ void amdgpu_sdma_sysfs_reset_mask_fini(struct
> amdgpu_device *adev)
> }
> }
>
> +int amdgpu_sdma_stop_queue(struct amdgpu_device *adev, uint32_t instance_id)
> +{
> + struct amdgpu_sdma_instance *sdma_instance =
> &adev->sdma.instance[instance_id];
> + struct amdgpu_ring *gfx_ring = &sdma_instance->ring;
> + struct amdgpu_ring *page_ring = &sdma_instance->page;
> + int r;
> +
> + mutex_lock(&sdma_queue_mutex);
> +
> + /* Avoid accidentally unparking the sched thread during GPU reset */
> + r = down_read_killable(&adev->reset_domain->sem);
> + if (r)
> + goto exit;
> +
> + /* Increment the reference counter */
> + atomic_inc(&gfx_ring->stop_refcount);
> + if (adev->sdma.has_page_queue)
> + atomic_inc(&page_ring->stop_refcount);
> +
> + if (atomic_read(&gfx_ring->stop_refcount) != 1 ||
> + (adev->sdma.has_page_queue && atomic_read(&page_ring->stop_refcount)
> != 1)) {
> + up_read(&adev->reset_domain->sem);
> + r = -EBUSY;
> + goto exit;
> + }
> +
> + if (!amdgpu_ring_sched_ready(gfx_ring))
> + drm_sched_wqueue_stop(&gfx_ring->sched);
> +
> + if (adev->sdma.has_page_queue && !amdgpu_ring_sched_ready(page_ring))
> + drm_sched_wqueue_stop(&page_ring->sched);
> +
> + if (gfx_ring->funcs && gfx_ring->funcs->stop_queue)
> + gfx_ring->funcs->stop_queue(adev, instance_id);
> +
> + if (adev->sdma.has_page_queue && page_ring->funcs &&
> page_ring->funcs->stop_queue)
> + page_ring->funcs->stop_queue(adev, instance_id);
> +
> + up_read(&adev->reset_domain->sem);
> +
> +exit:
> + mutex_unlock(&sdma_queue_mutex);
> + return r;
> +}
> +
> +int amdgpu_sdma_start_queue(struct amdgpu_device *adev, uint32_t instance_id)
> +{
> + struct amdgpu_sdma_instance *sdma_instance =
> &adev->sdma.instance[instance_id];
> + struct amdgpu_ring *gfx_ring = &sdma_instance->ring;
> + struct amdgpu_ring *page_ring = &sdma_instance->page;
> + int r;
> +
> + mutex_lock(&sdma_queue_mutex);
> +
> + /* Avoid accidentally unparking the sched thread during GPU reset */
> + r = down_read_killable(&adev->reset_domain->sem);
> + if (r)
> + goto exit;
> +
> + /* Decrement the reference counter */
> + atomic_dec(&gfx_ring->stop_refcount);
> + if (adev->sdma.has_page_queue)
> + atomic_dec(&page_ring->stop_refcount);
> +
> + if (atomic_read(&gfx_ring->stop_refcount) != 0 ||
> + (adev->sdma.has_page_queue && atomic_read(&page_ring->stop_refcount)
> != 0)) {
> + up_read(&adev->reset_domain->sem);
> + r = -EBUSY;
> + goto exit;
> + }
> +
> + if (gfx_ring->funcs && gfx_ring->funcs->start_queue)
> + gfx_ring->funcs->start_queue(adev, instance_id);
> +
> + if (adev->sdma.has_page_queue && page_ring->funcs &&
> page_ring->funcs->start_queue)
> + page_ring->funcs->start_queue(adev, instance_id);
> +
> + /* Restart the scheduler's work queue for the GFX and page rings */
> + if (amdgpu_ring_sched_ready(gfx_ring))
> + drm_sched_wqueue_start(&gfx_ring->sched);
> +
> + if (amdgpu_ring_sched_ready(page_ring))
> + drm_sched_wqueue_start(&page_ring->sched);
> +
> + up_read(&adev->reset_domain->sem);
> +
> +exit:
> + mutex_unlock(&sdma_queue_mutex);
> + return r;
> +}
> +
> /**
> * amdgpu_sdma_register_on_reset_callbacks - Register SDMA reset callbacks
> * @funcs: Pointer to the callback structure containing pre_reset and
> post_reset functions
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> index 965169320065..a91791fa3ecf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> @@ -170,6 +170,8 @@ struct amdgpu_buffer_funcs {
>
> void amdgpu_sdma_register_on_reset_callbacks(struct amdgpu_device *adev,
> struct sdma_on_reset_funcs *funcs);
> int amdgpu_sdma_reset_engine(struct amdgpu_device *adev, uint32_t
> instance_id, bool suspend_user_queues);
> +int amdgpu_sdma_stop_queue(struct amdgpu_device *adev, uint32_t instance_id);
> +int amdgpu_sdma_start_queue(struct amdgpu_device *adev, uint32_t
> instance_id);
>
> #define amdgpu_emit_copy_buffer(adev, ib, s, d, b, t)
> (adev)->mman.buffer_funcs->emit_copy_buffer((ib), (s), (d), (b), (t))
> #define amdgpu_emit_fill_buffer(adev, ib, s, d, b)
> (adev)->mman.buffer_funcs->emit_fill_buffer((ib), (s), (d), (b))
