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(-)
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;