From: Rob Clark <robdclark@xxxxxxxxxxxx>
Pre-allocate the VMA objects that we will need in the vm bind job.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_gem.h | 9 +++++
drivers/gpu/drm/msm/msm_gem_submit.c | 5 +++
drivers/gpu/drm/msm/msm_gem_vma.c | 60 ++++++++++++++++++++++++++++
3 files changed, 74 insertions(+)
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 1622d557ea1f..cb76959fa8a8 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -115,6 +115,9 @@ msm_gem_vm_create(struct drm_device *drm, struct msm_mmu *mmu, const char *name,
void msm_gem_vm_close(struct drm_gpuvm *gpuvm);
+void msm_vma_job_prepare(struct msm_gem_submit *submit);
+void msm_vma_job_cleanup(struct msm_gem_submit *submit);
+
struct msm_fence_context;
/**
@@ -339,6 +342,12 @@ struct msm_gem_submit {
int fence_id; /* key into queue->fence_idr */
struct msm_gpu_submitqueue *queue;
+
+ /* List of pre-allocated msm_gem_vma's, used to avoid memory allocation
+ * in fence signalling path.
+ */
+ struct list_head preallocated_vmas;
+
struct pid *pid; /* submitting process */
bool bos_pinned : 1;
bool fault_dumped:1;/* Limit devcoredump dumping to one per submit */
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 39a6e0418bdf..a9b3e6692db3 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -80,6 +80,7 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
submit->ident = atomic_inc_return(&ident) - 1;
INIT_LIST_HEAD(&submit->node);
+ INIT_LIST_HEAD(&submit->preallocated_vmas);
return submit;
}
@@ -584,6 +585,9 @@ void msm_submit_retire(struct msm_gem_submit *submit)
{
int i;
+ if (submit_is_vmbind(submit))
+ msm_vma_job_cleanup(submit);
+
for (i = 0; i < submit->nr_bos; i++) {
struct drm_gem_object *obj = submit->bos[i].obj;
@@ -912,6 +916,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
}
if (submit_is_vmbind(submit)) {
+ msm_vma_job_prepare(submit);
ret = submit_get_pages(submit);
} else {
ret = submit_pin_vmas(submit);
diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 7d40b151aa95..5c7d44b004fb 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -258,6 +258,66 @@ static const struct drm_sched_backend_ops msm_vm_bind_ops = {
.free_job = msm_vma_job_free
};
+/**
+ * msm_vma_job_prepare() - VM_BIND job setup
+ * @submit: the VM_BIND job
+ *
+ * Prepare for a VM_BIND job by pre-allocating various memory that will
+ * be required once the job runs. Memory allocations cannot happen in
+ * the fence signalling path (ie. from job->run()) as that could recurse
+ * into the shrinker and potentially block waiting on the fence that is
+ * signalled when this job completes (ie. deadlock).
+ *
+ * Called after BOs are locked.
+ */
+void
+msm_vma_job_prepare(struct msm_gem_submit *submit)
+{
+ unsigned num_prealloc_vmas = 0;
+
+ for (int i = 0; i < submit->nr_bos; i++) {
+ unsigned op = submit->bos[i].flags & MSM_SUBMIT_BO_OP_MASK;
+
+ if (submit->bos[i].obj)
+ msm_gem_assert_locked(submit->bos[i].obj);
+
+ /*
+ * OP_MAP/OP_MAP_NULL has one new VMA for the new mapping,
+ * and potentially remaps with a prev and next VMA, for a
+ * total of 3 new VMAs.
+ *
+ * OP_UNMAP could trigger a remap with either a prev or
+ * next VMA, but not both.
+ */
+ num_prealloc_vmas += (op == MSM_SUBMIT_BO_OP_UNMAP) ? 1 : 3;
+ }
+
+ while (num_prealloc_vmas-- > 0) {
+ struct msm_gem_vma *vma = kzalloc(sizeof(*vma), GFP_KERNEL);
+ list_add_tail(&vma->base.rb.entry, &submit->preallocated_vmas);
+ }
+}
+
+/**
+ * msm_vma_job_cleanup() - cleanup after a VM_BIND job
+ * @submit: the VM_BIND job
+ *
+ * The counterpoint to msm_vma_job_prepare().
+ */
+void
+msm_vma_job_cleanup(struct msm_gem_submit *submit)
+{
+ struct drm_gpuva *vma;
+
+ while (!list_empty(&submit->preallocated_vmas)) {
+ vma = list_first_entry(&submit->preallocated_vmas,
+ struct drm_gpuva,
+ rb.entry);
+ list_del(&vma->rb.entry);
+ kfree(to_msm_vma(vma));
+ }
+}
+
/**
* msm_gem_vm_create() - Create and initialize a &msm_gem_vm
* @drm: the drm device
--
2.48.1
