On Thu, Dec 17, 2020 at 11:06:11PM +0000, John Stultz wrote:
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: 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
We also have one of these in ttm. I think we should have at most one of these for the gpu ecosystem overall, maybe as a helper that can be plugged into all the places.
Or I'm kinda missing something, which could be since I only glanced at yours for a bit. But it's also called page pool for buffer allocations, and I don't think there's that many ways to implement that really :-) -Daniel
drivers/dma-buf/heaps/Kconfig | 1 + drivers/dma-buf/heaps/system_heap.c | 68 +++++++++++++++++++++++++++-- 2 files changed, 65 insertions(+), 4 deletions(-)
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index ecf65204f714..fa5e1c330cce 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 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..885e30894b77 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 +283,59 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) dma_buf_map_clear(map); }
+static int system_heap_clear_pages(struct page **pages, int num, pgprot_t pgprot) +{
- void *addr = vmap(pages, num, VM_MAP, pgprot);
- if (!addr)
return -ENOMEM;- memset(addr, 0, PAGE_SIZE * num);
- vunmap(addr);
- return 0;
+}
+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 *pages[32];
- int p = 0;
- int ret = 0;
- for_each_sgtable_page(sgt, &piter, 0) {
pages[p++] = sg_page_iter_page(&piter);if (p == ARRAY_SIZE(pages)) {ret = system_heap_clear_pages(pages, p, PAGE_KERNEL);if (ret)return ret;p = 0;}- }
- if (p)
ret = system_heap_clear_pages(pages, p, PAGE_KERNEL);- 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);@@ -322,8 +365,7 @@ 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]);@@ -428,6 +470,24 @@ 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;
-- 2.17.1
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