@@ -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.
@@ -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;
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 <daniel@ffwll.ch> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Liam Mark <lmark@codeaurora.org> Cc: Chris Goldsworthy <cgoldswo@codeaurora.org> Cc: Laura Abbott <labbott@kernel.org> Cc: Brian Starkey <Brian.Starkey@arm.com> Cc: Hridya Valsaraju <hridya@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Daniel Mentz <danielmentz@google.com> Cc: Ørjan Eide <orjan.eide@arm.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Ezequiel Garcia <ezequiel@collabora.com> Cc: Simon Ser <contact@emersion.fr> Cc: James Jones <jajones@nvidia.com> Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz <john.stultz@linaro.org> --- v2: * Fix build issue caused by selecting PAGE_POOL w/o NET as Reported-by: kernel test robot <lkp@intel.com> 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(-) -- 2.25.1