drm/amdgpu: use ref to keep job alive

this is to fix fatal page fault error that occured if:
job is signaled/released after its timeout work is already
put to the global queue (in this case the cancel_delayed_work
will return false), which will lead to NX-protection error
page fault during job_timeout_func.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index ccb2846..2ac07eb 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -750,7 +750,9 @@ int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
                     struct amdgpu_job **job);
 int amdgpu_job_alloc_with_ib(struct amdgpu_device *adev, unsigned size,
                             struct amdgpu_job **job);
+
 void amdgpu_job_free(struct amdgpu_job *job);
+void amdgpu_job_free_func(struct kref *refcount);
 int amdgpu_job_submit(struct amdgpu_job *job, struct amdgpu_ring *ring,
                      struct amd_sched_entity *entity, void *owner,
                      struct fence **f);

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 9025671..d7e0b0b 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -872,6 +872,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
        r = amd_sched_job_init(&job->base, &ring->sched,
                                                &p->ctx->rings[ring->idx].entity,
                                                amdgpu_job_timeout_func,
+                                               amdgpu_job_free_func,
                                                p->filp, &fence);
        if (r) {
                amdgpu_job_free(job);

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index 961cae4..a052ac2 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -31,7 +31,7 @@
 static void amdgpu_job_free_handler(struct work_struct *ws)
 {
        struct amdgpu_job *job = container_of(ws, struct amdgpu_job, base.work_free_job);
-       kfree(job);
+       amd_sched_job_put(&job->base);
 }
 
 void amdgpu_job_timeout_func(struct work_struct *work)
@@ -41,6 +41,8 @@ void amdgpu_job_timeout_func(struct work_struct *work)
                                job->base.sched->name,
                                (uint32_t)atomic_read(&job->ring->fence_drv.last_seq),
                                job->ring->fence_drv.sync_seq);
+
+       amd_sched_job_put(&job->base);
 }
 
 int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
@@ -101,6 +103,12 @@ void amdgpu_job_free(struct amdgpu_job *job)
                kfree(job);
 }
 
+void amdgpu_job_free_func(struct kref *refcount)
+{
+       struct amdgpu_job *job = container_of(refcount, struct amdgpu_job, base.refcount);
+       kfree(job);
+}
+
 int amdgpu_job_submit(struct amdgpu_job *job, struct amdgpu_ring *ring,
                      struct amd_sched_entity *entity, void *owner,
                      struct fence **f)
@@ -113,9 +121,10 @@ int amdgpu_job_submit(struct amdgpu_job *job, struct amdgpu_ring *ring,
                return -EINVAL;
 
        r = amd_sched_job_init(&job->base, &ring->sched,
-                                                       entity, owner,
+                                                       entity,
                                                        amdgpu_job_timeout_func,
-                                                       &fence);
+                                                       amdgpu_job_free_func,
+                                                       owner, &fence);
        if (r)
                return r;
 

diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
index b7e8071..639c70d 100644 (file)
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
@@ -333,7 +333,8 @@ void amd_sched_job_finish(struct amd_sched_job *s_job)
        struct amd_gpu_scheduler *sched = s_job->sched;
 
        if (sched->timeout != MAX_SCHEDULE_TIMEOUT) {
-               cancel_delayed_work(&s_job->work_tdr); /*TODO: how to deal the case that tdr is running */
+               if (cancel_delayed_work(&s_job->work_tdr))
+                       amd_sched_job_put(s_job);
 
                /* queue TDR for next job */
                next = list_first_entry_or_null(&sched->ring_mirror_list,
@@ -341,6 +342,7 @@ void amd_sched_job_finish(struct amd_sched_job *s_job)
 
                if (next) {
                        INIT_DELAYED_WORK(&next->work_tdr, s_job->timeout_callback);
+                       amd_sched_job_get(next);
                        schedule_delayed_work(&next->work_tdr, sched->timeout);
                }
        }
@@ -354,6 +356,7 @@ void amd_sched_job_begin(struct amd_sched_job *s_job)
                list_first_entry_or_null(&sched->ring_mirror_list, struct amd_sched_job, node) == s_job)
        {
                INIT_DELAYED_WORK(&s_job->work_tdr, s_job->timeout_callback);
+               amd_sched_job_get(s_job);
                schedule_delayed_work(&s_job->work_tdr, sched->timeout);
        }
 }
@@ -382,9 +385,11 @@ int amd_sched_job_init(struct amd_sched_job *job,
                                                struct amd_gpu_scheduler *sched,
                                                struct amd_sched_entity *entity,
                                                void (*timeout_cb)(struct work_struct *work),
+                                               void (*free_cb)(struct kref *refcount),
                                                void *owner, struct fence **fence)
 {
        INIT_LIST_HEAD(&job->node);
+       kref_init(&job->refcount);
        job->sched = sched;
        job->s_entity = entity;
        job->s_fence = amd_sched_fence_create(entity, owner);
@@ -393,6 +398,7 @@ int amd_sched_job_init(struct amd_sched_job *job,
 
        job->s_fence->s_job = job;
        job->timeout_callback = timeout_cb;
+       job->free_callback = free_cb;
 
        if (fence)
                *fence = &job->s_fence->base;

diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
index a5700ad..95ebfd0 100644 (file)
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
@@ -78,6 +78,7 @@ struct amd_sched_fence {
 };
 
 struct amd_sched_job {
+       struct kref refcount;
        struct amd_gpu_scheduler        *sched;
        struct amd_sched_entity         *s_entity;
        struct amd_sched_fence          *s_fence;
@@ -87,6 +88,7 @@ struct amd_sched_job {
        struct list_head                           node;
        struct delayed_work work_tdr;
        void (*timeout_callback) (struct work_struct *work);
+       void (*free_callback)(struct kref *refcount);
 };
 
 extern const struct fence_ops amd_sched_fence_ops;
@@ -155,9 +157,20 @@ int amd_sched_job_init(struct amd_sched_job *job,
                                        struct amd_gpu_scheduler *sched,
                                        struct amd_sched_entity *entity,
                                        void (*timeout_cb)(struct work_struct *work),
+                                       void (*free_cb)(struct kref* refcount),
                                        void *owner, struct fence **fence);
 void amd_sched_job_pre_schedule(struct amd_gpu_scheduler *sched ,
                                                                struct amd_sched_job *s_job);
 void amd_sched_job_finish(struct amd_sched_job *s_job);
 void amd_sched_job_begin(struct amd_sched_job *s_job);
+static inline void amd_sched_job_get(struct amd_sched_job *job) {
+       if (job)
+               kref_get(&job->refcount);
+}
+
+static inline void amd_sched_job_put(struct amd_sched_job *job) {
+       if (job)
+               kref_put(&job->refcount, job->free_callback);
+}
+
 #endif