drm/nouveau: implement new VM_BIND uAPI

This commit provides the implementation for the new uapi motivated by the
Vulkan API. It allows user mode drivers (UMDs) to:

1) Initialize a GPU virtual address (VA) space via the new
   DRM_IOCTL_NOUVEAU_VM_INIT ioctl for UMDs to specify the portion of VA
   space managed by the kernel and userspace, respectively.

2) Allocate and free a VA space region as well as bind and unbind memory
   to the GPUs VA space via the new DRM_IOCTL_NOUVEAU_VM_BIND ioctl.
   UMDs can request the named operations to be processed either
   synchronously or asynchronously. It supports DRM syncobjs
   (incl. timelines) as synchronization mechanism. The management of the
   GPU VA mappings is implemented with the DRM GPU VA manager.

3) Execute push buffers with the new DRM_IOCTL_NOUVEAU_EXEC ioctl. The
   execution happens asynchronously. It supports DRM syncobj (incl.
   timelines) as synchronization mechanism. DRM GEM object locking is
   handled with drm_exec.

Both, DRM_IOCTL_NOUVEAU_VM_BIND and DRM_IOCTL_NOUVEAU_EXEC, use the DRM
GPU scheduler for the asynchronous paths.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-12-dakr@redhat.com

1 files changed, 419 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_sched.c b/drivers/gpu/drm/nouveau/nouveau_sched.c
new file mode 100644
index 000000000000..b3b59fbec291
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_sched.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: MIT
+
+#include <linux/slab.h>
+#include <drm/gpu_scheduler.h>
+#include <drm/drm_syncobj.h>
+
+#include "nouveau_drv.h"
+#include "nouveau_gem.h"
+#include "nouveau_mem.h"
+#include "nouveau_dma.h"
+#include "nouveau_exec.h"
+#include "nouveau_abi16.h"
+#include "nouveau_sched.h"
+
+/* FIXME
+ *
+ * We want to make sure that jobs currently executing can't be deferred by
+ * other jobs competing for the hardware. Otherwise we might end up with job
+ * timeouts just because of too many clients submitting too many jobs. We don't
+ * want jobs to time out because of system load, but because of the job being
+ * too bulky.
+ *
+ * For now allow for up to 16 concurrent jobs in flight until we know how many
+ * rings the hardware can process in parallel.
+ */
+#define NOUVEAU_SCHED_HW_SUBMISSIONS		16
+#define NOUVEAU_SCHED_JOB_TIMEOUT_MS		10000
+
+int
+nouveau_job_init(struct nouveau_job *job,
+		 struct nouveau_job_args *args)
+{
+	struct nouveau_sched_entity *entity = args->sched_entity;
+	int ret;
+
+	job->file_priv = args->file_priv;
+	job->cli = nouveau_cli(args->file_priv);
+	job->entity = entity;
+
+	job->sync = args->sync;
+	job->resv_usage = args->resv_usage;
+
+	job->ops = args->ops;
+
+	job->in_sync.count = args->in_sync.count;
+	if (job->in_sync.count) {
+		if (job->sync)
+			return -EINVAL;
+
+		job->in_sync.data = kmemdup(args->in_sync.s,
+					 sizeof(*args->in_sync.s) *
+					 args->in_sync.count,
+					 GFP_KERNEL);
+		if (!job->in_sync.data)
+			return -ENOMEM;
+	}
+
+	job->out_sync.count = args->out_sync.count;
+	if (job->out_sync.count) {
+		if (job->sync) {
+			ret = -EINVAL;
+			goto err_free_in_sync;
+		}
+
+		job->out_sync.data = kmemdup(args->out_sync.s,
+					  sizeof(*args->out_sync.s) *
+					  args->out_sync.count,
+					  GFP_KERNEL);
+		if (!job->out_sync.data) {
+			ret = -ENOMEM;
+			goto err_free_in_sync;
+		}
+
+		job->out_sync.objs = kcalloc(job->out_sync.count,
+					     sizeof(*job->out_sync.objs),
+					     GFP_KERNEL);
+		if (!job->out_sync.objs) {
+			ret = -ENOMEM;
+			goto err_free_out_sync;
+		}
+
+		job->out_sync.chains = kcalloc(job->out_sync.count,
+					       sizeof(*job->out_sync.chains),
+					       GFP_KERNEL);
+		if (!job->out_sync.chains) {
+			ret = -ENOMEM;
+			goto err_free_objs;
+		}
+
+	}
+
+	ret = drm_sched_job_init(&job->base, &entity->base, NULL);
+	if (ret)
+		goto err_free_chains;
+
+	job->state = NOUVEAU_JOB_INITIALIZED;
+
+	return 0;
+
+err_free_chains:
+	kfree(job->out_sync.chains);
+err_free_objs:
+	kfree(job->out_sync.objs);
+err_free_out_sync:
+	kfree(job->out_sync.data);
+err_free_in_sync:
+	kfree(job->in_sync.data);
+return ret;
+}
+
+void
+nouveau_job_free(struct nouveau_job *job)
+{
+	kfree(job->in_sync.data);
+	kfree(job->out_sync.data);
+	kfree(job->out_sync.objs);
+	kfree(job->out_sync.chains);
+}
+
+void nouveau_job_fini(struct nouveau_job *job)
+{
+	dma_fence_put(job->done_fence);
+	drm_sched_job_cleanup(&job->base);
+	job->ops->free(job);
+}
+
+static int
+sync_find_fence(struct nouveau_job *job,
+		struct drm_nouveau_sync *sync,
+		struct dma_fence **fence)
+{
+	u32 stype = sync->flags & DRM_NOUVEAU_SYNC_TYPE_MASK;
+	u64 point = 0;
+	int ret;
+
+	if (stype != DRM_NOUVEAU_SYNC_SYNCOBJ &&
+	    stype != DRM_NOUVEAU_SYNC_TIMELINE_SYNCOBJ)
+		return -EOPNOTSUPP;
+
+	if (stype == DRM_NOUVEAU_SYNC_TIMELINE_SYNCOBJ)
+		point = sync->timeline_value;
+
+	ret = drm_syncobj_find_fence(job->file_priv,
+				     sync->handle, point,
+				     sync->flags, fence);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int
+nouveau_job_add_deps(struct nouveau_job *job)
+{
+	struct dma_fence *in_fence = NULL;
+	int ret, i;
+
+	for (i = 0; i < job->in_sync.count; i++) {
+		struct drm_nouveau_sync *sync = &job->in_sync.data[i];
+
+		ret = sync_find_fence(job, sync, &in_fence);
+		if (ret) {
+			NV_PRINTK(warn, job->cli,
+				  "Failed to find syncobj (-> in): handle=%d\n",
+				  sync->handle);
+			return ret;
+		}
+
+		ret = drm_sched_job_add_dependency(&job->base, in_fence);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void
+nouveau_job_fence_attach_cleanup(struct nouveau_job *job)
+{
+	int i;
+
+	for (i = 0; i < job->out_sync.count; i++) {
+		struct drm_syncobj *obj = job->out_sync.objs[i];
+		struct dma_fence_chain *chain = job->out_sync.chains[i];
+
+		if (obj)
+			drm_syncobj_put(obj);
+
+		if (chain)
+			dma_fence_chain_free(chain);
+	}
+}
+
+static int
+nouveau_job_fence_attach_prepare(struct nouveau_job *job)
+{
+	int i, ret;
+
+	for (i = 0; i < job->out_sync.count; i++) {
+		struct drm_nouveau_sync *sync = &job->out_sync.data[i];
+		struct drm_syncobj **pobj = &job->out_sync.objs[i];
+		struct dma_fence_chain **pchain = &job->out_sync.chains[i];
+		u32 stype = sync->flags & DRM_NOUVEAU_SYNC_TYPE_MASK;
+
+		if (stype != DRM_NOUVEAU_SYNC_SYNCOBJ &&
+		    stype != DRM_NOUVEAU_SYNC_TIMELINE_SYNCOBJ) {
+			ret = -EINVAL;
+			goto err_sync_cleanup;
+		}
+
+		*pobj = drm_syncobj_find(job->file_priv, sync->handle);
+		if (!*pobj) {
+			NV_PRINTK(warn, job->cli,
+				  "Failed to find syncobj (-> out): handle=%d\n",
+				  sync->handle);
+			ret = -ENOENT;
+			goto err_sync_cleanup;
+		}
+
+		if (stype == DRM_NOUVEAU_SYNC_TIMELINE_SYNCOBJ) {
+			*pchain = dma_fence_chain_alloc();
+			if (!*pchain) {
+				ret = -ENOMEM;
+				goto err_sync_cleanup;
+			}
+		}
+	}
+
+	return 0;
+
+err_sync_cleanup:
+	nouveau_job_fence_attach_cleanup(job);
+	return ret;
+}
+
+static void
+nouveau_job_fence_attach(struct nouveau_job *job)
+{
+	struct dma_fence *fence = job->done_fence;
+	int i;
+
+	for (i = 0; i < job->out_sync.count; i++) {
+		struct drm_nouveau_sync *sync = &job->out_sync.data[i];
+		struct drm_syncobj **pobj = &job->out_sync.objs[i];
+		struct dma_fence_chain **pchain = &job->out_sync.chains[i];
+		u32 stype = sync->flags & DRM_NOUVEAU_SYNC_TYPE_MASK;
+
+		if (stype == DRM_NOUVEAU_SYNC_TIMELINE_SYNCOBJ) {
+			drm_syncobj_add_point(*pobj, *pchain, fence,
+					      sync->timeline_value);
+		} else {
+			drm_syncobj_replace_fence(*pobj, fence);
+		}
+
+		drm_syncobj_put(*pobj);
+		*pobj = NULL;
+		*pchain = NULL;
+	}
+}
+
+int
+nouveau_job_submit(struct nouveau_job *job)
+{
+	struct nouveau_sched_entity *entity = to_nouveau_sched_entity(job->base.entity);
+	struct dma_fence *done_fence = NULL;
+	int ret;
+
+	ret = nouveau_job_add_deps(job);
+	if (ret)
+		goto err;
+
+	ret = nouveau_job_fence_attach_prepare(job);
+	if (ret)
+		goto err;
+
+	/* Make sure the job appears on the sched_entity's queue in the same
+	 * order as it was submitted.
+	 */
+	mutex_lock(&entity->mutex);
+
+	/* Guarantee we won't fail after the submit() callback returned
+	 * successfully.
+	 */
+	if (job->ops->submit) {
+		ret = job->ops->submit(job);
+		if (ret)
+			goto err_cleanup;
+	}
+
+	drm_sched_job_arm(&job->base);
+	job->done_fence = dma_fence_get(&job->base.s_fence->finished);
+	if (job->sync)
+		done_fence = dma_fence_get(job->done_fence);
+
+	if (job->ops->armed_submit)
+		job->ops->armed_submit(job);
+
+	nouveau_job_fence_attach(job);
+
+	/* Set job state before pushing the job to the scheduler,
+	 * such that we do not overwrite the job state set in run().
+	 */
+	job->state = NOUVEAU_JOB_SUBMIT_SUCCESS;
+
+	drm_sched_entity_push_job(&job->base);
+
+	mutex_unlock(&entity->mutex);
+
+	if (done_fence) {
+		dma_fence_wait(done_fence, true);
+		dma_fence_put(done_fence);
+	}
+
+	return 0;
+
+err_cleanup:
+	mutex_unlock(&entity->mutex);
+	nouveau_job_fence_attach_cleanup(job);
+err:
+	job->state = NOUVEAU_JOB_SUBMIT_FAILED;
+	return ret;
+}
+
+bool
+nouveau_sched_entity_qwork(struct nouveau_sched_entity *entity,
+			   struct work_struct *work)
+{
+	return queue_work(entity->sched_wq, work);
+}
+
+static struct dma_fence *
+nouveau_job_run(struct nouveau_job *job)
+{
+	struct dma_fence *fence;
+
+	fence = job->ops->run(job);
+	if (IS_ERR(fence))
+		job->state = NOUVEAU_JOB_RUN_FAILED;
+	else
+		job->state = NOUVEAU_JOB_RUN_SUCCESS;
+
+	return fence;
+}
+
+static struct dma_fence *
+nouveau_sched_run_job(struct drm_sched_job *sched_job)
+{
+	struct nouveau_job *job = to_nouveau_job(sched_job);
+
+	return nouveau_job_run(job);
+}
+
+static enum drm_gpu_sched_stat
+nouveau_sched_timedout_job(struct drm_sched_job *sched_job)
+{
+	struct nouveau_job *job = to_nouveau_job(sched_job);
+
+	NV_PRINTK(warn, job->cli, "Job timed out.\n");
+
+	if (job->ops->timeout)
+		return job->ops->timeout(job);
+
+	return DRM_GPU_SCHED_STAT_ENODEV;
+}
+
+static void
+nouveau_sched_free_job(struct drm_sched_job *sched_job)
+{
+	struct nouveau_job *job = to_nouveau_job(sched_job);
+
+	nouveau_job_fini(job);
+}
+
+int nouveau_sched_entity_init(struct nouveau_sched_entity *entity,
+			      struct drm_gpu_scheduler *sched,
+			      struct workqueue_struct *sched_wq)
+{
+	mutex_init(&entity->mutex);
+	spin_lock_init(&entity->job.list.lock);
+	INIT_LIST_HEAD(&entity->job.list.head);
+	init_waitqueue_head(&entity->job.wq);
+
+	entity->sched_wq = sched_wq;
+	return drm_sched_entity_init(&entity->base,
+				     DRM_SCHED_PRIORITY_NORMAL,
+				     &sched, 1, NULL);
+}
+
+void
+nouveau_sched_entity_fini(struct nouveau_sched_entity *entity)
+{
+	drm_sched_entity_destroy(&entity->base);
+}
+
+static const struct drm_sched_backend_ops nouveau_sched_ops = {
+	.run_job = nouveau_sched_run_job,
+	.timedout_job = nouveau_sched_timedout_job,
+	.free_job = nouveau_sched_free_job,
+};
+
+int nouveau_sched_init(struct nouveau_drm *drm)
+{
+	struct drm_gpu_scheduler *sched = &drm->sched;
+	long job_hang_limit = msecs_to_jiffies(NOUVEAU_SCHED_JOB_TIMEOUT_MS);
+
+	drm->sched_wq = create_singlethread_workqueue("nouveau_sched_wq");
+	if (!drm->sched_wq)
+		return -ENOMEM;
+
+	return drm_sched_init(sched, &nouveau_sched_ops,
+			      NOUVEAU_SCHED_HW_SUBMISSIONS, 0, job_hang_limit,
+			      NULL, NULL, "nouveau_sched", drm->dev->dev);
+}
+
+void nouveau_sched_fini(struct nouveau_drm *drm)
+{
+	destroy_workqueue(drm->sched_wq);
+	drm_sched_fini(&drm->sched);
+}