[PATCH 09/11] drm/msm: Conversion to drm scheduler

Rob Clark
2021-07-17T20:25:59Z

Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/4
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/gpu/drm/msm/Kconfig | 1 +
drivers/gpu/drm/msm/msm_gem.c | 35 ------
drivers/gpu/drm/msm/msm_gem.h | 24 ++++-
drivers/gpu/drm/msm/msm_gem_submit.c | 149 +++++++++++++-------------
drivers/gpu/drm/msm/msm_gpu.c | 4 +-
drivers/gpu/drm/msm/msm_gpu.h | 2 +
drivers/gpu/drm/msm/msm_ringbuffer.c | 66 ++++++++++++
drivers/gpu/drm/msm/msm_ringbuffer.h | 12 +++
drivers/gpu/drm/msm/msm_submitqueue.c | 26 +++++
9 files changed, 204 insertions(+), 115 deletions(-)

diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 10f693ea89d3..896266267ad7 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -12,6 +12,7 @@ config DRM_MSM
select REGULATOR
select DRM_KMS_HELPER
select DRM_PANEL
+ select DRM_SCHED
select SHMEM
select TMPFS
select QCOM_SCM if ARCH_QCOM
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index e24e1591f811..46c02772eb86 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -806,41 +806,6 @@ void msm_gem_vunmap(struct drm_gem_object *obj)
msm_obj->vaddr = NULL;
}

-/* must be called before _move_to_active().. */
-int msm_gem_sync_object(struct drm_gem_object *obj,
- struct msm_fence_context *fctx, bool exclusive)
-{
- struct dma_resv_list *fobj;
- struct dma_fence *fence;
- int i, ret;
-
- fobj = dma_resv_get_list(obj->resv);
- if (!fobj || (fobj->shared_count == 0)) {
- fence = dma_resv_get_excl(obj->resv);
- /* don't need to wait on our own fences, since ring is fifo */
- if (fence && (fence->context != fctx->context)) {
- ret = dma_fence_wait(fence, true);
- if (ret)
- return ret;
- }
- }
-
- if (!exclusive || !fobj)
- return 0;
-
- for (i = 0; i < fobj->shared_count; i++) {
- fence = rcu_dereference_protected(fobj->shared[i],
- dma_resv_held(obj->resv));
- if (fence->context != fctx->context) {
- ret = dma_fence_wait(fence, true);
- if (ret)
- return ret;
- }
- }
-
- return 0;
-}
-
void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index e0579abda5b9..f89793898f1b 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -9,6 +9,7 @@

#include <linux/kref.h>
#include <linux/dma-resv.h>
+#include "drm/gpu_scheduler.h"
#include "msm_drv.h"

/* Make all GEM related WARN_ON()s ratelimited.. when things go wrong they
@@ -143,8 +144,6 @@ void *msm_gem_get_vaddr_active(struct drm_gem_object *obj);
void msm_gem_put_vaddr_locked(struct drm_gem_object *obj);
void msm_gem_put_vaddr(struct drm_gem_object *obj);
int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv);
-int msm_gem_sync_object(struct drm_gem_object *obj,
- struct msm_fence_context *fctx, bool exclusive);
void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu);
void msm_gem_active_put(struct drm_gem_object *obj);
int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout);
@@ -311,6 +310,7 @@ void msm_gem_vunmap(struct drm_gem_object *obj);
* make it easier to unwind when things go wrong, etc).
*/
struct msm_gem_submit {
+ struct drm_sched_job base;
struct kref ref;
struct drm_device *dev;
struct msm_gpu *gpu;
@@ -319,7 +319,22 @@ struct msm_gem_submit {
struct list_head bo_list;
struct ww_acquire_ctx ticket;
uint32_t seqno; /* Sequence number of the submit on the ring */
+
+ /* Array of struct dma_fence * to block on before submitting this job.
+ */
+ struct xarray deps;
+ unsigned long last_dep;
+
+ /* Hw fence, which is created when the scheduler executes the job, and
+ * is signaled when the hw finishes (via seqno write from cmdstream)
+ */
+ struct dma_fence *hw_fence;
+
+ /* Userspace visible fence, which is signaled by the scheduler after
+ * the hw_fence is signaled.
+ */
struct dma_fence *fence;
+
int fence_id; /* key into queue->fence_idr */
struct msm_gpu_submitqueue *queue;
struct pid *pid; /* submitting process */
@@ -350,6 +365,11 @@ struct msm_gem_submit {
} bos[];
};

+static inline struct msm_gem_submit *to_msm_submit(struct drm_sched_job *job)
+{
+ return container_of(job, struct msm_gem_submit, base);
+}
+
void __msm_gem_submit_destroy(struct kref *kref);

static inline void msm_gem_submit_get(struct msm_gem_submit *submit)
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index f570155bc086..66316ea47c18 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -33,6 +33,7 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
{
struct msm_gem_submit *submit;
uint64_t sz;
+ int ret;

sz = struct_size(submit, bos, nr_bos) +
((u64)nr_cmds * sizeof(submit->cmd[0]));
@@ -44,6 +45,14 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
if (!submit)
return ERR_PTR(-ENOMEM);

+ ret = drm_sched_job_init(&submit->base, &queue->entity, queue);
+ if (ret) {
+ kfree(submit);
+ return ERR_PTR(ret);
+ }
+
+ xa_init_flags(&submit->deps, XA_FLAGS_ALLOC);
+
kref_init(&submit->ref);
submit->dev = dev;
submit->aspace = queue->ctx->aspace;
@@ -63,6 +72,8 @@ void __msm_gem_submit_destroy(struct kref *kref)
{
struct msm_gem_submit *submit =
container_of(kref, struct msm_gem_submit, ref);
+ unsigned long index;
+ struct dma_fence *fence;
unsigned i;

if (submit->fence_id) {
@@ -71,7 +82,14 @@ void __msm_gem_submit_destroy(struct kref *kref)
mutex_unlock(&submit->queue->lock);
}

+ xa_for_each (&submit->deps, index, fence) {
+ dma_fence_put(fence);
+ }
+
+ xa_destroy(&submit->deps);
+
dma_fence_put(submit->fence);
+ dma_fence_put(submit->hw_fence);

put_pid(submit->pid);
msm_submitqueue_put(submit->queue);
@@ -307,7 +325,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)
int i, ret = 0;

for (i = 0; i < submit->nr_bos; i++) {
- struct msm_gem_object *msm_obj = submit->bos[i].obj;
+ struct drm_gem_object *obj = &submit->bos[i].obj->base;
bool write = submit->bos[i].flags & MSM_SUBMIT_BO_WRITE;

if (!write) {
@@ -316,8 +334,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)
* strange place to call it. OTOH this is a
* convenient can-fail point to hook it in.
*/
- ret = dma_resv_reserve_shared(msm_obj->base.resv,
- 1);
+ ret = dma_resv_reserve_shared(obj->resv, 1);
if (ret)
return ret;
}
@@ -325,7 +342,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)
if (no_implicit)
continue;

- ret = msm_gem_sync_object(&msm_obj->base, submit->ring->fctx,
+ ret = drm_gem_fence_array_add_implicit(&submit->deps, obj,
write);
if (ret)
break;
@@ -517,12 +534,12 @@ struct msm_submit_post_dep {
struct dma_fence_chain *chain;
};

-static struct drm_syncobj **msm_wait_deps(struct drm_device *dev,
- struct drm_file *file,
- uint64_t in_syncobjs_addr,
- uint32_t nr_in_syncobjs,
- size_t syncobj_stride,
- struct msm_ringbuffer *ring)
+static struct drm_syncobj **msm_parse_deps(struct msm_gem_submit *submit,
+ struct drm_file *file,
+ uint64_t in_syncobjs_addr,
+ uint32_t nr_in_syncobjs,
+ size_t syncobj_stride,
+ struct msm_ringbuffer *ring)
{
struct drm_syncobj **syncobjs = NULL;
struct drm_msm_gem_submit_syncobj syncobj_desc = {0};
@@ -546,7 +563,7 @@ static struct drm_syncobj **msm_wait_deps(struct drm_device *dev,
}

if (syncobj_desc.point &&
- !drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE)) {
+ !drm_core_check_feature(submit->dev, DRIVER_SYNCOBJ_TIMELINE)) {
ret = -EOPNOTSUPP;
break;
}
@@ -561,10 +578,7 @@ static struct drm_syncobj **msm_wait_deps(struct drm_device *dev,
if (ret)
break;

- if (!dma_fence_match_context(fence, ring->fctx->context))
- ret = dma_fence_wait(fence, true);
-
- dma_fence_put(fence);
+ ret = drm_gem_fence_array_add(&submit->deps, fence);
if (ret)
break;

@@ -741,47 +755,6 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
trace_msm_gpu_submit(pid_nr(pid), ring->id, submitid,
args->nr_bos, args->nr_cmds);

- if (args->flags & MSM_SUBMIT_FENCE_FD_IN) {
- struct dma_fence *in_fence;
-
- in_fence = sync_file_get_fence(args->fence_fd);
-
- if (!in_fence)
- return -EINVAL;
-
- /*
- * Wait if the fence is from a foreign context, or if the fence
- * array contains any fence from a foreign context.
- */
- ret = 0;
- if (!dma_fence_match_context(in_fence, ring->fctx->context))
- ret = dma_fence_wait(in_fence, true);
-
- dma_fence_put(in_fence);
- if (ret)
- return ret;
- }
-
- if (args->flags & MSM_SUBMIT_SYNCOBJ_IN) {
- syncobjs_to_reset = msm_wait_deps(dev, file,
- args->in_syncobjs,
- args->nr_in_syncobjs,
- args->syncobj_stride, ring);
- if (IS_ERR(syncobjs_to_reset))
- return PTR_ERR(syncobjs_to_reset);
- }
-
- if (args->flags & MSM_SUBMIT_SYNCOBJ_OUT) {
- post_deps = msm_parse_post_deps(dev, file,
- args->out_syncobjs,
- args->nr_out_syncobjs,
- args->syncobj_stride);
- if (IS_ERR(post_deps)) {
- ret = PTR_ERR(post_deps);
- goto out_post_unlock;
- }
- }
-
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
goto out_post_unlock;
@@ -807,22 +780,50 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
if (args->flags & MSM_SUBMIT_SUDO)
submit->in_rb = true;

+ if (args->flags & MSM_SUBMIT_FENCE_FD_IN) {
+ struct dma_fence *in_fence;
+
+ in_fence = sync_file_get_fence(args->fence_fd);
+
+ if (!in_fence) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ ret = drm_gem_fence_array_add(&submit->deps, in_fence);
+ if (ret)
+ goto out_unlock;
+ }
+
+ if (args->flags & MSM_SUBMIT_SYNCOBJ_IN) {
+ syncobjs_to_reset = msm_parse_deps(submit, file,
+ args->in_syncobjs,
+ args->nr_in_syncobjs,
+ args->syncobj_stride, ring);
+ if (IS_ERR(syncobjs_to_reset)) {
+ ret = PTR_ERR(syncobjs_to_reset);
+ goto out_unlock;
+ }
+ }
+
+ if (args->flags & MSM_SUBMIT_SYNCOBJ_OUT) {
+ post_deps = msm_parse_post_deps(dev, file,
+ args->out_syncobjs,
+ args->nr_out_syncobjs,
+ args->syncobj_stride);
+ if (IS_ERR(post_deps)) {
+ ret = PTR_ERR(post_deps);
+ goto out_unlock;
+ }
+ }
+
ret = submit_lookup_objects(submit, args, file);
if (ret)
- goto out_pre_pm;
+ goto out;

ret = submit_lookup_cmds(submit, args, file);
if (ret)
- goto out_pre_pm;
-
- /*
- * Thanks to dev_pm_opp opp_table_lock interactions with mm->mmap_sem
- * in the resume path, we need to to rpm get before we lock objs.
- * Which unfortunately might involve powering up the GPU sooner than
- * is necessary. But at least in the explicit fencing case, we will
- * have already done all the fence waiting.
- */
- pm_runtime_get_sync(&gpu->pdev->dev);
+ goto out;

/* copy_*_user while holding a ww ticket upsets lockdep */
ww_acquire_init(&submit->ticket, &reservation_ww_class);
@@ -869,12 +870,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,

submit->nr_cmds = i;

- submit->fence = msm_fence_alloc(ring->fctx);
- if (IS_ERR(submit->fence)) {
- ret = PTR_ERR(submit->fence);
- submit->fence = NULL;
- goto out;
- }
+ submit->fence = dma_fence_get(&submit->base.s_fence->finished);

/*
* Allocate an id which can be used by WAIT_FENCE ioctl to map back
@@ -902,7 +898,10 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,

submit_attach_object_fences(submit);

- msm_gpu_submit(gpu, submit);
+ /* The scheduler owns a ref now: */
+ msm_gem_submit_get(submit);
+
+ drm_sched_entity_push_job(&submit->base, &queue->entity);

args->fence = submit->fence_id;

@@ -912,8 +911,6 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,

out:
- pm_runtime_put(&gpu->pdev->dev);
-out_pre_pm:
submit_cleanup(submit, !!ret);
if (has_ww_ticket)
ww_acquire_fini(&submit->ticket);
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index fef5ba51f425..e329b2c0ed08 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -298,7 +298,7 @@ static void update_fences(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
break;

msm_update_fence(submit->ring->fctx,
- submit->fence->seqno);
+ submit->hw_fence->seqno);
}
spin_unlock(&ring->submit_lock);
}
@@ -813,7 +813,7 @@ static void retire_submits(struct msm_gpu *gpu)
* been signalled, then later submits are not signalled
* either, so we are also done.
*/
- if (submit && dma_fence_is_signaled(submit->fence)) {
+ if (submit && dma_fence_is_signaled(submit->hw_fence)) {
retire_submit(gpu, ring, submit);
} else {
break;
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index cc4e4a9ac1c2..e1e65b452c17 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -225,6 +225,7 @@ struct msm_gpu_perfcntr {
* seqno, protected by submitqueue lock
* @lock: submitqueue lock
* @ref: reference count
+ * @entity: the submit job-queue
*/
struct msm_gpu_submitqueue {
int id;
@@ -236,6 +237,7 @@ struct msm_gpu_submitqueue {
struct idr fence_idr;
struct mutex lock;
struct kref ref;
+ struct drm_sched_entity entity;
};

struct msm_gpu_state_bo {
diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c
index a577db054613..02100beae74b 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.c
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
@@ -7,10 +7,64 @@
#include "msm_ringbuffer.h"
#include "msm_gpu.h"

+/**
+ * The max # of jobs to write into the hw ringbuffer.
+ */
+static uint num_hw_submissions = 8;
+MODULE_PARM_DESC(num_hw_submissions, "The max number of HW submissions (default 8)");
+module_param(num_hw_submissions, uint, 0600);
+
+static struct dma_fence *msm_job_dependency(struct drm_sched_job *job,
+ struct drm_sched_entity *s_entity)
+{
+ struct msm_gem_submit *submit = to_msm_submit(job);
+
+ if (!xa_empty(&submit->deps))
+ return xa_erase(&submit->deps, submit->last_dep++);
+
+ return NULL;
+}
+
+static struct dma_fence *msm_job_run(struct drm_sched_job *job)
+{
+ struct msm_gem_submit *submit = to_msm_submit(job);
+ struct msm_gpu *gpu = submit->gpu;
+
+ submit->hw_fence = msm_fence_alloc(submit->ring->fctx);
+
+ pm_runtime_get_sync(&gpu->pdev->dev);
+
+ /* TODO move submit path over to using a per-ring lock.. */
+ mutex_lock(&gpu->dev->struct_mutex);
+
+ msm_gpu_submit(gpu, submit);
+
+ mutex_unlock(&gpu->dev->struct_mutex);
+
+ pm_runtime_put(&gpu->pdev->dev);
+
+ return dma_fence_get(submit->hw_fence);
+}
+
+static void msm_job_free(struct drm_sched_job *job)
+{
+ struct msm_gem_submit *submit = to_msm_submit(job);
+
+ drm_sched_job_cleanup(job);
+ msm_gem_submit_put(submit);
+}
+
+const struct drm_sched_backend_ops msm_sched_ops = {
+ .dependency = msm_job_dependency,
+ .run_job = msm_job_run,
+ .free_job = msm_job_free
+};
+
struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id,
void *memptrs, uint64_t memptrs_iova)
{
struct msm_ringbuffer *ring;
+ long sched_timeout;
char name[32];
int ret;

@@ -45,6 +99,16 @@ struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id,
ring->memptrs = memptrs;
ring->memptrs_iova = memptrs_iova;

+ /* currently managing hangcheck ourselves: */
+ sched_timeout = MAX_SCHEDULE_TIMEOUT;
+
+ ret = drm_sched_init(&ring->sched, &msm_sched_ops,
+ num_hw_submissions, 0, sched_timeout,
+ NULL, to_msm_bo(ring->bo)->name);
+ if (ret) {
+ goto fail;
+ }
+
INIT_LIST_HEAD(&ring->submits);
spin_lock_init(&ring->submit_lock);
spin_lock_init(&ring->preempt_lock);
@@ -65,6 +129,8 @@ void msm_ringbuffer_destroy(struct msm_ringbuffer *ring)
if (IS_ERR_OR_NULL(ring))
return;

+ drm_sched_fini(&ring->sched);
+
msm_fence_context_free(ring->fctx);

msm_gem_kernel_put(ring->bo, ring->gpu->aspace);
diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.h b/drivers/gpu/drm/msm/msm_ringbuffer.h
index fe55d4a1aa16..d8c63df4e9ca 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.h
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.h
@@ -7,6 +7,7 @@
#ifndef __MSM_RINGBUFFER_H__
#define __MSM_RINGBUFFER_H__

+#include "drm/gpu_scheduler.h"
#include "msm_drv.h"

#define rbmemptr(ring, member) \
@@ -40,8 +41,19 @@ struct msm_ringbuffer {
struct drm_gem_object *bo;
uint32_t *start, *end, *cur, *next;

+ /*
+ * The job scheduler for this ring.
+ */
+ struct drm_gpu_scheduler sched;
+
/*
* List of in-flight submits on this ring. Protected by submit_lock.
+ *
+ * Currently just submits that are already written into the ring, not
+ * submits that are still in drm_gpu_scheduler's queues. At a later
+ * step we could probably move to letting drm_gpu_scheduler manage
+ * hangcheck detection and keep track of submit jobs that are in-
+ * flight.
*/
struct list_head submits;
spinlock_t submit_lock;
diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
index 75cded54d571..5c486fa6176b 100644
--- a/drivers/gpu/drm/msm/msm_submitqueue.c
+++ b/drivers/gpu/drm/msm/msm_submitqueue.c
@@ -14,6 +14,8 @@ void msm_submitqueue_destroy(struct kref *kref)

idr_destroy(&queue->fence_idr);

+ drm_sched_entity_destroy(&queue->entity);
+
msm_file_private_put(queue->ctx);

kfree(queue);
@@ -64,6 +66,9 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
{
struct msm_drm_private *priv = drm->dev_private;
struct msm_gpu_submitqueue *queue;
+ struct msm_ringbuffer *ring;
+ struct drm_gpu_scheduler *sched;
+ int ret;

if (!ctx)
return -ENODEV;
@@ -83,6 +88,27 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
queue->flags = flags;
queue->prio = prio;

+ ring = priv->gpu->rb[prio];
+ sched = &ring->sched;
+
+ /*
+ * TODO we can allow more priorities than we have ringbuffers by
+ * mapping:
+ *
+ * ring = prio / 3;
+ * ent_prio = DRM_SCHED_PRIORITY_MIN + (prio % 3);
+ *
+ * Probably avoid using DRM_SCHED_PRIORITY_KERNEL as that is
+ * treated specially in places.
+ */
+ ret = drm_sched_entity_init(&queue->entity,
+ DRM_SCHED_PRIORITY_NORMAL,
+ &sched, 1, NULL);
+ if (ret) {
+ kfree(queue);
+ return ret;
+ }
+
write_lock(&ctx->queuelock);

queue->ctx = msm_file_private_get(ctx);
--
2.31.1