Re: [PATCH 7/7] drm/lima: Use the drm_gem_fence_array_add helpers for our deps.

From: Qiang Yu
Date: Tue Apr 02 2019 - 06:22:22 EST


On Tue, Apr 2, 2019 at 6:26 AM Eric Anholt <eric@xxxxxxxxxx> wrote:
>
> I haven't tested this, but it's a pretty direct port of what I did for
> v3d.
>
> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> ---
> drivers/gpu/drm/lima/lima_gem.c | 37 +----------------
> drivers/gpu/drm/lima/lima_sched.c | 66 ++++++-------------------------
> drivers/gpu/drm/lima/lima_sched.h | 6 +--
> 3 files changed, 16 insertions(+), 93 deletions(-)
>
> diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
> index 2d3cf96f6c58..8f80286c80b4 100644
> --- a/drivers/gpu/drm/lima/lima_gem.c
> +++ b/drivers/gpu/drm/lima/lima_gem.c
> @@ -144,40 +144,7 @@ static int lima_gem_sync_bo(struct lima_sched_task *task, struct lima_bo *bo,
> if (explicit)
> return 0;
>
> - /* implicit sync use bo fence in resv obj */
> - if (write) {
> - unsigned nr_fences;
> - struct dma_fence **fences;
> - int i;
> -
> - err = reservation_object_get_fences_rcu(
> - bo->gem.resv, NULL, &nr_fences, &fences);
> - if (err || !nr_fences)
> - return err;
> -
> - for (i = 0; i < nr_fences; i++) {
> - err = lima_sched_task_add_dep(task, fences[i]);
> - if (err)
> - break;
> - }
> -
> - /* for error case free remaining fences */
> - for ( ; i < nr_fences; i++)
> - dma_fence_put(fences[i]);
> -
> - kfree(fences);
> - } else {
> - struct dma_fence *fence;
> -
> - fence = reservation_object_get_excl_rcu(bo->gem.resv);
> - if (fence) {
> - err = lima_sched_task_add_dep(task, fence);
> - if (err)
> - dma_fence_put(fence);
> - }
> - }
> -
> - return err;
> + return drm_gem_fence_array_add_implicit(&task->deps, &bo->gem, write);
> }
>
> static int lima_gem_lock_bos(struct lima_bo **bos, u32 nr_bos,
> @@ -250,7 +217,7 @@ static int lima_gem_add_deps(struct drm_file *file, struct lima_submit *submit)
> if (err)
> return err;
>
> - err = lima_sched_task_add_dep(submit->task, fence);
> + err = drm_gem_fence_array_add(&submit->task->deps, fence);
> if (err) {
> dma_fence_put(fence);
> return err;
> diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c
> index 97bd9c1deb87..e253d031fb3d 100644
> --- a/drivers/gpu/drm/lima/lima_sched.c
> +++ b/drivers/gpu/drm/lima/lima_sched.c
> @@ -3,6 +3,7 @@
>
> #include <linux/kthread.h>
> #include <linux/slab.h>
> +#include <linux/xarray.h>
>
> #include "lima_drv.h"
> #include "lima_sched.h"
> @@ -126,19 +127,24 @@ int lima_sched_task_init(struct lima_sched_task *task,
>
> task->num_bos = num_bos;
> task->vm = lima_vm_get(vm);
> +
> + xa_init_flags(&task->deps, XA_FLAGS_ALLOC);
> +
> return 0;
> }
>
> void lima_sched_task_fini(struct lima_sched_task *task)
> {
> + struct dma_fence *fence;
> + unsigned long index;
> int i;
>
> drm_sched_job_cleanup(&task->base);
>
> - for (i = 0; i < task->num_dep; i++)
> - dma_fence_put(task->dep[i]);
> -
> - kfree(task->dep);
> + xa_for_each(&task->deps, index, fence) {
> + dma_fence_put(fence);
> + }
> + xa_destroy(&task->deps);
>
> if (task->bos) {
> for (i = 0; i < task->num_bos; i++)
> @@ -149,42 +155,6 @@ void lima_sched_task_fini(struct lima_sched_task *task)
> lima_vm_put(task->vm);
> }
>
> -int lima_sched_task_add_dep(struct lima_sched_task *task, struct dma_fence *fence)
> -{
> - int i, new_dep = 4;
> -
> - /* same context's fence is definitly earlier then this task */
> - if (fence->context == task->base.s_fence->finished.context) {
> - dma_fence_put(fence);
> - return 0;
> - }

Seems you dropped this check in the drm_gem_fence_array_add, no bug if we
don't have this, but redundant fence will be added in the deps array. Maybe we
can add a context parameter to drm_gem_fence_array_add and
drm_gem_fence_array_add_implicit to filter out fences from same
drm_sched_entity.

Regards,
Qiang


> -
> - if (task->dep && task->num_dep == task->max_dep)
> - new_dep = task->max_dep * 2;
> -
> - if (task->max_dep < new_dep) {
> - void *dep = krealloc(task->dep, sizeof(*task->dep) * new_dep, GFP_KERNEL);
> -
> - if (!dep)
> - return -ENOMEM;
> -
> - task->max_dep = new_dep;
> - task->dep = dep;
> - }
> -
> - for (i = 0; i < task->num_dep; i++) {
> - if (task->dep[i]->context == fence->context &&
> - dma_fence_is_later(fence, task->dep[i])) {
> - dma_fence_put(task->dep[i]);
> - task->dep[i] = fence;
> - return 0;
> - }
> - }
> -
> - task->dep[task->num_dep++] = fence;
> - return 0;
> -}
> -
> int lima_sched_context_init(struct lima_sched_pipe *pipe,
> struct lima_sched_context *context,
> atomic_t *guilty)
> @@ -213,21 +183,9 @@ static struct dma_fence *lima_sched_dependency(struct drm_sched_job *job,
> struct drm_sched_entity *entity)
> {
> struct lima_sched_task *task = to_lima_task(job);
> - int i;
> -
> - for (i = 0; i < task->num_dep; i++) {
> - struct dma_fence *fence = task->dep[i];
> -
> - if (!task->dep[i])
> - continue;
> -
> - task->dep[i] = NULL;
>
> - if (!dma_fence_is_signaled(fence))
> - return fence;
> -
> - dma_fence_put(fence);
> - }
> + if (!xa_empty(&task->deps))
> + return xa_erase(&task->deps, task->last_dep++);
>
> return NULL;
> }
> diff --git a/drivers/gpu/drm/lima/lima_sched.h b/drivers/gpu/drm/lima/lima_sched.h
> index b017cfa7e327..928af91c1118 100644
> --- a/drivers/gpu/drm/lima/lima_sched.h
> +++ b/drivers/gpu/drm/lima/lima_sched.h
> @@ -14,9 +14,8 @@ struct lima_sched_task {
> struct lima_vm *vm;
> void *frame;
>
> - struct dma_fence **dep;
> - int num_dep;
> - int max_dep;
> + struct xarray deps;
> + unsigned long last_dep;
>
> struct lima_bo **bos;
> int num_bos;
> @@ -78,7 +77,6 @@ int lima_sched_task_init(struct lima_sched_task *task,
> struct lima_bo **bos, int num_bos,
> struct lima_vm *vm);
> void lima_sched_task_fini(struct lima_sched_task *task);
> -int lima_sched_task_add_dep(struct lima_sched_task *task, struct dma_fence *fence);
>
> int lima_sched_context_init(struct lima_sched_pipe *pipe,
> struct lima_sched_context *context,
> --
> 2.20.1
>