Utilize the drm pagepool code to speed up allocation
performance.
This is similar to the ION pagepool usage, but tries to
utilize generic code instead of a custom implementation.
Cc: Daniel Vetter <[email protected]>
Cc: Christian Koenig <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: Liam Mark <[email protected]>
Cc: Chris Goldsworthy <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Brian Starkey <[email protected]>
Cc: Hridya Valsaraju <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sandeep Patil <[email protected]>
Cc: Daniel Mentz <[email protected]>
Cc: Ørjan Eide <[email protected]>
Cc: Robin Murphy <[email protected]>
Cc: Ezequiel Garcia <[email protected]>
Cc: Simon Ser <[email protected]>
Cc: James Jones <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: John Stultz <[email protected]>
---
v2:
* Fix build issue caused by selecting PAGE_POOL w/o NET
as Reported-by: kernel test robot <[email protected]>
v3:
* Simplify the page zeroing logic a bit by using kmap_atomic
instead of vmap as suggested by Daniel Mentz
v5:
* Shift away from networking page pool completely to
dmabuf page pool implementation
v6:
* Switch again to using the drm_page_pool code shared w/
ttm_pool
---
drivers/dma-buf/heaps/Kconfig | 1 +
drivers/dma-buf/heaps/system_heap.c | 56 +++++++++++++++++++++++++++--
2 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index f7aef8bc7119..7e28934e0def 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -4,6 +4,7 @@ config DMABUF_HEAPS_DEFERRED_FREE
config DMABUF_HEAPS_SYSTEM
bool "DMA-BUF System Heap"
depends on DMABUF_HEAPS
+ select DRM_PAGE_POOL
help
Choose this option to enable the system dmabuf heap. The system heap
is backed by pages from the buddy allocator. If in doubt, say Y.
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 17e0e9a68baf..6d39e9f32e36 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -21,6 +21,8 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
+#include <drm/page_pool.h>
+
static struct dma_heap *sys_heap;
struct system_heap_buffer {
@@ -53,6 +55,7 @@ static gfp_t order_flags[] = {HIGH_ORDER_GFP, LOW_ORDER_GFP, LOW_ORDER_GFP};
*/
static const unsigned int orders[] = {8, 4, 0};
#define NUM_ORDERS ARRAY_SIZE(orders)
+struct drm_page_pool *pools[NUM_ORDERS];
static struct sg_table *dup_sg_table(struct sg_table *table)
{
@@ -281,18 +284,49 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
dma_buf_map_clear(map);
}
+static int system_heap_free_pages(struct page *p, unsigned int order)
+{
+ __free_pages(p, order);
+ return 1 << order;
+}
+
+static int system_heap_zero_buffer(struct system_heap_buffer *buffer)
+{
+ struct sg_table *sgt = &buffer->sg_table;
+ struct sg_page_iter piter;
+ struct page *p;
+ void *vaddr;
+ int ret = 0;
+
+ for_each_sgtable_page(sgt, &piter, 0) {
+ p = sg_page_iter_page(&piter);
+ vaddr = kmap_atomic(p);
+ memset(vaddr, 0, PAGE_SIZE);
+ kunmap_atomic(vaddr);
+ }
+
+ return ret;
+}
+
static void system_heap_dma_buf_release(struct dma_buf *dmabuf)
{
struct system_heap_buffer *buffer = dmabuf->priv;
struct sg_table *table;
struct scatterlist *sg;
- int i;
+ int i, j;
+
+ /* Zero the buffer pages before adding back to the pool */
+ system_heap_zero_buffer(buffer);
table = &buffer->sg_table;
for_each_sg(table->sgl, sg, table->nents, i) {
struct page *page = sg_page(sg);
- __free_pages(page, compound_order(page));
+ for (j = 0; j < NUM_ORDERS; j++) {
+ if (compound_order(page) == orders[j])
+ break;
+ }
+ drm_page_pool_add(pools[j], page);
}
sg_free_table(table);
kfree(buffer);
@@ -323,7 +357,9 @@ static struct page *alloc_largest_available(unsigned long size,
if (max_order < orders[i])
continue;
- page = alloc_pages(order_flags[i], orders[i]);
+ page = drm_page_pool_fetch(pools[i]);
+ if (!page)
+ page = alloc_pages(order_flags[i], orders[i]);
if (!page)
continue;
return page;
@@ -428,6 +464,20 @@ static const struct dma_heap_ops system_heap_ops = {
static int system_heap_create(void)
{
struct dma_heap_export_info exp_info;
+ int i;
+
+ for (i = 0; i < NUM_ORDERS; i++) {
+ pools[i] = drm_page_pool_create(orders[i],
+ system_heap_free_pages);
+ if (IS_ERR(pools[i])) {
+ int j;
+
+ pr_err("%s: page pool creation failed!\n", __func__);
+ for (j = 0; j < i; j++)
+ drm_page_pool_destroy(pools[j]);
+ return PTR_ERR(pools[i]);
+ }
+ }
exp_info.name = "system";
exp_info.ops = &system_heap_ops;
--
2.25.1