Reuse/abuse the pagepool code from the network 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: 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 --- drivers/dma-buf/heaps/Kconfig | 2 ++ drivers/dma-buf/heaps/system_heap.c | 52 ++++++++++++++++++++++++++--- 2 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index f7aef8bc7119..45c7d277448b 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -4,6 +4,8 @@ config DMABUF_HEAPS_DEFERRED_FREE config DMABUF_HEAPS_SYSTEM bool "DMA-BUF System Heap" depends on DMABUF_HEAPS + select NET + select 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..2addb6d832e0 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -20,6 +20,7 @@ #include <linux/scatterlist.h> #include <linux/slab.h> #include <linux/vmalloc.h> +#include <net/page_pool.h>
static struct dma_heap *sys_heap;
@@ -53,6 +54,7 @@ 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 page_pool *pools[NUM_ORDERS];
static struct sg_table *dup_sg_table(struct sg_table *table) { @@ -281,18 +283,43 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) dma_buf_map_clear(map); }
+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; + } + page_pool_put_full_page(pools[j], page, false); } sg_free_table(table); kfree(buffer); @@ -322,8 +349,7 @@ static struct page *alloc_largest_available(unsigned long size, continue; if (max_order < orders[i]) continue; - - page = alloc_pages(order_flags[i], orders[i]); + page = page_pool_alloc_pages(pools[i], order_flags[i]); if (!page) continue; return page; @@ -428,6 +454,24 @@ 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++) { + struct page_pool_params pp; + + memset(&pp, 0, sizeof(pp)); + pp.order = orders[i]; + pools[i] = page_pool_create(&pp); + + if (IS_ERR(pools[i])) { + int j; + + pr_err("%s: page pool creation failed!\n", __func__); + for (j = 0; j < i; j++) + page_pool_destroy(pools[j]); + return PTR_ERR(pools[i]); + } + }
exp_info.name = "system"; exp_info.ops = &system_heap_ops;