Add basic SVM garbage collector which can destroy an SVM range upon an
MMU UNMAP event.
v2:
- Flush garbage collector in xe_svm_close
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_svm.c | 87 +++++++++++++++++++++++++++++++-
drivers/gpu/drm/xe/xe_svm.h | 1 +
drivers/gpu/drm/xe/xe_vm.c | 4 ++
drivers/gpu/drm/xe/xe_vm_types.h | 5 ++
4 files changed, 95 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index a9addaea316d..9c2f44cba166 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -30,6 +30,7 @@ xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
if (!range)
return ERR_PTR(-ENOMEM);
+ INIT_LIST_HEAD(&range->garbage_collector_link);
xe_vm_get(gpusvm_to_vm(gpusvm));
return &range->base;
@@ -46,6 +47,24 @@ static struct xe_svm_range *to_xe_range(struct drm_gpusvm_range *r)
return container_of(r, struct xe_svm_range, base);
}
+static void
+xe_svm_garbage_collector_add_range(struct xe_vm *vm, struct xe_svm_range *range,
+ const struct mmu_notifier_range *mmu_range)
+{
+ struct xe_device *xe = vm->xe;
+
+ drm_gpusvm_range_set_unmapped(&range->base, mmu_range);
+
+ spin_lock(&vm->svm.garbage_collector.lock);
+ if (list_empty(&range->garbage_collector_link))
+ list_add_tail(&range->garbage_collector_link,
+ &vm->svm.garbage_collector.range_list);
+ spin_unlock(&vm->svm.garbage_collector.lock);
+
+ queue_work(xe_device_get_root_tile(xe)->primary_gt->usm.pf_wq,
+ &vm->svm.garbage_collector.work);
+}
+
static u8
xe_svm_range_notifier_event_begin(struct xe_vm *vm, struct drm_gpusvm_range *r,
const struct mmu_notifier_range *mmu_range,
@@ -88,7 +107,9 @@ xe_svm_range_notifier_event_end(struct xe_vm *vm, struct drm_gpusvm_range *r,
struct drm_gpusvm_ctx ctx = { .in_notifier = true, };
drm_gpusvm_range_unmap_pages(&vm->svm.gpusvm, r, &ctx);
- /* TODO: Add range to garbage collector */
+ if (mmu_range->event == MMU_NOTIFY_UNMAP)
+ xe_svm_garbage_collector_add_range(vm, to_xe_range(r),
+ mmu_range);
}
static void xe_svm_invalidate(struct drm_gpusvm *gpusvm,
@@ -184,6 +205,58 @@ static void xe_svm_invalidate(struct drm_gpusvm *gpusvm,
xe_svm_range_notifier_event_end(vm, r, mmu_range);
}
+static int __xe_svm_garbage_collector(struct xe_vm *vm,
+ struct xe_svm_range *range)
+{
+ /* TODO: Do unbind */
+
+ drm_gpusvm_range_remove(&vm->svm.gpusvm, &range->base);
+
+ return 0;
+}
+
+static int xe_svm_garbage_collector(struct xe_vm *vm)
+{
+ struct xe_svm_range *range, *next;
+ int err;
+
+ lockdep_assert_held_write(&vm->lock);
+
+ if (xe_vm_is_closed_or_banned(vm))
+ return -ENOENT;
+
+ spin_lock(&vm->svm.garbage_collector.lock);
+ list_for_each_entry_safe(range, next,
+ &vm->svm.garbage_collector.range_list,
+ garbage_collector_link) {
+ list_del(&range->garbage_collector_link);
+ spin_unlock(&vm->svm.garbage_collector.lock);
+
+ err = __xe_svm_garbage_collector(vm, range);
+ if (err) {
+ drm_warn(&vm->xe->drm,
+ "Garbage collection failed: %d\n", err);
+ xe_vm_kill(vm, true);
+ return err;
+ }
+
+ spin_lock(&vm->svm.garbage_collector.lock);
+ }
+ spin_unlock(&vm->svm.garbage_collector.lock);
+
+ return 0;
+}
+
+static void xe_svm_garbage_collector_work_func(struct work_struct *w)
+{
+ struct xe_vm *vm = container_of(w, struct xe_vm,
+ svm.garbage_collector.work);
+
+ down_write(&vm->lock);
+ xe_svm_garbage_collector(vm);
+ up_write(&vm->lock);
+}
+
static const struct drm_gpusvm_ops gpusvm_ops = {
.range_alloc = xe_svm_range_alloc,
.range_free = xe_svm_range_free,
@@ -198,6 +271,11 @@ static const u64 fault_chunk_sizes[] = {
int xe_svm_init(struct xe_vm *vm)
{
+ spin_lock_init(&vm->svm.garbage_collector.lock);
+ INIT_LIST_HEAD(&vm->svm.garbage_collector.range_list);
+ INIT_WORK(&vm->svm.garbage_collector.work,
+ xe_svm_garbage_collector_work_func);
+
return drm_gpusvm_init(&vm->svm.gpusvm, "Xe SVM", &vm->xe->drm,
current->mm, NULL, 0, vm->size,
SZ_512M, &gpusvm_ops, fault_chunk_sizes,
@@ -211,6 +289,8 @@ void xe_svm_close(struct xe_vm *vm)
/* Flush running notifiers making xe_vm_close() visable */
xe_svm_notifier_lock(vm);
xe_svm_notifier_unlock(vm);
+
+ flush_work(&vm->svm.garbage_collector.work);
}
void xe_svm_fini(struct xe_vm *vm)
@@ -241,7 +321,10 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
lockdep_assert_held_write(&vm->lock);
retry:
- /* TODO: Run garbage collector */
+ /* Always process UNMAPs first so view SVM ranges is current */
+ err = xe_svm_garbage_collector(vm);
+ if (err)
+ return err;
r = drm_gpusvm_range_find_or_insert(&vm->svm.gpusvm, fault_addr,
xe_vma_start(vma), xe_vma_end(vma),
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index ee0bd1ae655b..06d90d0f71a6 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -17,6 +17,7 @@ struct xe_vma;
struct xe_svm_range {
struct drm_gpusvm_range base;
+ struct list_head garbage_collector_link;
u8 tile_present;
u8 tile_invalidated;
};
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 63aa0a25d3b7..399cbbdbddd5 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3071,6 +3071,10 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
goto put_exec_queue;
}
+ /* Ensure all UNMAPs visable */
+ if (xe_vm_in_fault_mode(vm))
+ flush_work(&vm->svm.garbage_collector.work);
+
err = down_write_killable(&vm->lock);
if (err)
goto put_vm;
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index b736e53779d2..2eae3575c409 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -146,6 +146,11 @@ struct xe_vm {
struct {
/** @svm.gpusvm: base GPUSVM used to track fault allocations */
struct drm_gpusvm gpusvm;
+ struct {
+ spinlock_t lock;
+ struct list_head range_list;
+ struct work_struct work;
+ } garbage_collector;
} svm;
struct xe_device *xe;
--
2.34.1
