gpu: ion: Make ion_free asynchronous
Add the ability for a heap to free buffers asynchrounously. Freed buffers
are placed on a free list and freed from a low priority background thread.
If allocations from a particular heap fail, the free list is drained. This
patch also enable asynchronous frees from the chunk heap.
Change-Id: Id16ad870355a8099be26084b51feb3d622d15ced
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
Git-commit: 4e9ef397ec3cfb04b64f165d40dcf1b501415718
Git-repo: https://android.googlesource.com/kernel/common
[lauraa@codeaurora.org: Fixup context differences due to
addition of CMA heap and delayed unsecure]
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
index 6b11c35..d2700f9 100644
--- a/drivers/gpu/ion/ion.c
+++ b/drivers/gpu/ion/ion.c
@@ -19,15 +19,18 @@
#include <linux/module.h>
#include <linux/device.h>
#include <linux/file.h>
+#include <linux/freezer.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
#include <linux/ion.h>
+#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/memblock.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/mm_types.h>
#include <linux/rbtree.h>
+#include <linux/rtmutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
@@ -147,6 +150,7 @@
static int ion_buffer_alloc_dirty(struct ion_buffer *buffer);
+static bool ion_heap_drain_freelist(struct ion_heap *heap);
/* this function should only be called while dev->lock is held */
static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
struct ion_device *dev,
@@ -168,9 +172,16 @@
kref_init(&buffer->ref);
ret = heap->ops->allocate(heap, buffer, len, align, flags);
+
if (ret) {
- kfree(buffer);
- return ERR_PTR(ret);
+ if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
+ goto err2;
+
+ ion_heap_drain_freelist(heap);
+ ret = heap->ops->allocate(heap, buffer, len, align,
+ flags);
+ if (ret)
+ goto err2;
}
buffer->dev = dev;
@@ -223,6 +234,7 @@
err:
heap->ops->unmap_dma(heap, buffer);
heap->ops->free(buffer);
+err2:
kfree(buffer);
return ERR_PTR(ret);
}
@@ -233,25 +245,39 @@
buffer->heap->ops->unsecure_buffer(buffer, 1);
}
-static void ion_buffer_destroy(struct kref *kref)
+static void _ion_buffer_destroy(struct ion_buffer *buffer)
{
- struct ion_buffer *buffer = container_of(kref, struct ion_buffer, ref);
- struct ion_device *dev = buffer->dev;
-
if (WARN_ON(buffer->kmap_cnt > 0))
buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
buffer->heap->ops->unmap_dma(buffer->heap, buffer);
ion_delayed_unsecure(buffer);
buffer->heap->ops->free(buffer);
- mutex_lock(&dev->buffer_lock);
- rb_erase(&buffer->node, &dev->buffers);
- mutex_unlock(&dev->buffer_lock);
if (buffer->flags & ION_FLAG_CACHED)
kfree(buffer->dirty);
kfree(buffer);
}
+static void ion_buffer_destroy(struct kref *kref)
+{
+ struct ion_buffer *buffer = container_of(kref, struct ion_buffer, ref);
+ struct ion_heap *heap = buffer->heap;
+ struct ion_device *dev = buffer->dev;
+
+ mutex_lock(&dev->buffer_lock);
+ rb_erase(&buffer->node, &dev->buffers);
+ mutex_unlock(&dev->buffer_lock);
+
+ if (heap->flags & ION_HEAP_FLAG_DEFER_FREE) {
+ rt_mutex_lock(&heap->lock);
+ list_add(&buffer->list, &heap->free_list);
+ rt_mutex_unlock(&heap->lock);
+ wake_up(&heap->waitqueue);
+ return;
+ }
+ _ion_buffer_destroy(buffer);
+}
+
static void ion_buffer_get(struct ion_buffer *buffer)
{
kref_get(&buffer->ref);
@@ -1628,13 +1654,81 @@
.release = single_release,
};
+static size_t ion_heap_free_list_is_empty(struct ion_heap *heap)
+{
+ bool is_empty;
+
+ rt_mutex_lock(&heap->lock);
+ is_empty = list_empty(&heap->free_list);
+ rt_mutex_unlock(&heap->lock);
+
+ return is_empty;
+}
+
+static int ion_heap_deferred_free(void *data)
+{
+ struct ion_heap *heap = data;
+
+ while (true) {
+ struct ion_buffer *buffer;
+
+ wait_event_freezable(heap->waitqueue,
+ !ion_heap_free_list_is_empty(heap));
+
+ rt_mutex_lock(&heap->lock);
+ if (list_empty(&heap->free_list)) {
+ rt_mutex_unlock(&heap->lock);
+ continue;
+ }
+ buffer = list_first_entry(&heap->free_list, struct ion_buffer,
+ list);
+ list_del(&buffer->list);
+ rt_mutex_unlock(&heap->lock);
+ _ion_buffer_destroy(buffer);
+ }
+
+ return 0;
+}
+
+static bool ion_heap_drain_freelist(struct ion_heap *heap)
+{
+ struct ion_buffer *buffer, *tmp;
+
+ if (ion_heap_free_list_is_empty(heap))
+ return false;
+ rt_mutex_lock(&heap->lock);
+ list_for_each_entry_safe(buffer, tmp, &heap->free_list, list) {
+ _ion_buffer_destroy(buffer);
+ list_del(&buffer->list);
+ }
+ BUG_ON(!list_empty(&heap->free_list));
+ rt_mutex_unlock(&heap->lock);
+
+
+ return true;
+}
+
void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap)
{
+ struct sched_param param = { .sched_priority = 0 };
+
if (!heap->ops->allocate || !heap->ops->free || !heap->ops->map_dma ||
!heap->ops->unmap_dma)
pr_err("%s: can not add heap with invalid ops struct.\n",
__func__);
+ if (heap->flags & ION_HEAP_FLAG_DEFER_FREE) {
+ INIT_LIST_HEAD(&heap->free_list);
+ rt_mutex_init(&heap->lock);
+ init_waitqueue_head(&heap->waitqueue);
+ heap->task = kthread_run(ion_heap_deferred_free, heap,
+ "%s", heap->name);
+ sched_setscheduler(heap->task, SCHED_IDLE, ¶m);
+ if (IS_ERR(heap->task))
+ pr_err("%s: creating thread for deferred free failed\n",
+ __func__);
+ }
+
heap->dev = dev;
down_write(&dev->lock);
/* use negative heap->id to reverse the priority -- when traversing