From: Bing Song bing.song@nxp.com
This adds a heap that allocates CMA buffers that are marked as writecombined, so they are not cached by the CPU.
Cc: Daniel Vetter daniel@ffwll.ch Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@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: Chris Goldsworthy cgoldswo@codeaurora.org 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: Bing Song bing.song@nxp.com Signed-off-by: John Stultz john.stultz@linaro.org --- drivers/dma-buf/heaps/cma_heap.c | 119 +++++++++++++++++++++++++++---- 1 file changed, 107 insertions(+), 12 deletions(-)
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 364fc2f3e499..1b8c6eb0a8ea 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -38,6 +38,7 @@ struct cma_heap_buffer { pgoff_t pagecount; int vmap_cnt; void *vaddr; + bool uncached; };
struct dma_heap_attachment { @@ -45,6 +46,7 @@ struct dma_heap_attachment { struct sg_table table; struct list_head list; bool mapped; + bool uncached; };
static int cma_heap_attach(struct dma_buf *dmabuf, @@ -70,6 +72,7 @@ static int cma_heap_attach(struct dma_buf *dmabuf, a->dev = attachment->dev; INIT_LIST_HEAD(&a->list); a->mapped = false; + a->uncached = buffer->uncached;
attachment->priv = a;
@@ -99,8 +102,12 @@ static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachme { struct dma_heap_attachment *a = attachment->priv; struct sg_table *table = &a->table; + int attr = 0; int ret;
+ if (a->uncached) + attr = DMA_ATTR_SKIP_CPU_SYNC; + ret = dma_map_sgtable(attachment->dev, table, direction, 0); if (ret) return ERR_PTR(-ENOMEM); @@ -113,7 +120,10 @@ static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direction) { struct dma_heap_attachment *a = attachment->priv; + int attr = 0;
+ if (a->uncached) + attr = DMA_ATTR_SKIP_CPU_SYNC; a->mapped = false; dma_unmap_sgtable(attachment->dev, table, direction, 0); } @@ -128,10 +138,12 @@ static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
mutex_lock(&buffer->lock); - list_for_each_entry(a, &buffer->attachments, list) { - if (!a->mapped) - continue; - dma_sync_sgtable_for_cpu(a->dev, &a->table, direction); + if (!buffer->uncached) { + list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; + dma_sync_sgtable_for_cpu(a->dev, &a->table, direction); + } } mutex_unlock(&buffer->lock);
@@ -148,10 +160,12 @@ static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, flush_kernel_vmap_range(buffer->vaddr, buffer->len);
mutex_lock(&buffer->lock); - list_for_each_entry(a, &buffer->attachments, list) { - if (!a->mapped) - continue; - dma_sync_sgtable_for_device(a->dev, &a->table, direction); + if (!buffer->uncached) { + list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; + dma_sync_sgtable_for_device(a->dev, &a->table, direction); + } } mutex_unlock(&buffer->lock);
@@ -183,6 +197,9 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0) return -EINVAL;
+ if (buffer->uncached) + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + vma->vm_ops = &dma_heap_vm_ops; vma->vm_private_data = buffer;
@@ -191,9 +208,13 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer) { + pgprot_t pgprot = PAGE_KERNEL; void *vaddr;
- vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL); + if (buffer->uncached) + pgprot = pgprot_writecombine(PAGE_KERNEL); + + vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, pgprot); if (!vaddr) return ERR_PTR(-ENOMEM);
@@ -271,10 +292,11 @@ static const struct dma_buf_ops cma_heap_buf_ops = { .release = cma_heap_dma_buf_release, };
-static int cma_heap_allocate(struct dma_heap *heap, +static int cma_heap_do_allocate(struct dma_heap *heap, unsigned long len, unsigned long fd_flags, - unsigned long heap_flags) + unsigned long heap_flags, + bool uncached) { struct cma_heap *cma_heap = dma_heap_get_drvdata(heap); struct cma_heap_buffer *buffer; @@ -283,8 +305,9 @@ static int cma_heap_allocate(struct dma_heap *heap, pgoff_t pagecount = size >> PAGE_SHIFT; unsigned long align = get_order(size); struct page *cma_pages; + struct sg_table table; struct dma_buf *dmabuf; - int ret = -ENOMEM; + int ret = -ENOMEM, ret_sg_table; pgoff_t pg;
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); @@ -294,6 +317,7 @@ static int cma_heap_allocate(struct dma_heap *heap, INIT_LIST_HEAD(&buffer->attachments); mutex_init(&buffer->lock); buffer->len = size; + buffer->uncached = uncached;
if (align > CONFIG_CMA_ALIGNMENT) align = CONFIG_CMA_ALIGNMENT; @@ -356,6 +380,18 @@ static int cma_heap_allocate(struct dma_heap *heap, return ret; }
+ if (buffer->uncached) { + ret_sg_table = sg_alloc_table(&table, 1, GFP_KERNEL); + if (ret_sg_table) + return ret_sg_table; + + sg_set_page(table.sgl, cma_pages, size, 0); + + dma_map_sgtable(dma_heap_get_dev(heap), &table, DMA_BIDIRECTIONAL, 0); + dma_unmap_sgtable(dma_heap_get_dev(heap), &table, DMA_BIDIRECTIONAL, 0); + sg_free_table(&table); + } + return ret;
free_pages: @@ -368,14 +404,45 @@ static int cma_heap_allocate(struct dma_heap *heap, return ret; }
+static int cma_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + return cma_heap_do_allocate(heap, len, fd_flags, heap_flags, false); +} + +static int cma_uncached_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + return cma_heap_do_allocate(heap, len, fd_flags, heap_flags, true); +} + +/* Dummy function to be used until we can call coerce_mask_and_coherent */ +static int cma_uncached_heap_not_initialized(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + return -EBUSY; +} + static const struct dma_heap_ops cma_heap_ops = { .allocate = cma_heap_allocate, };
+static struct dma_heap_ops cma_uncached_heap_ops = { + .allocate = cma_uncached_heap_not_initialized, +}; + static int __add_cma_heap(struct cma *cma, void *data) { struct cma_heap *cma_heap; struct dma_heap_export_info exp_info; + const char *postfixed = "-uncached"; + char *cma_name;
cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL); if (!cma_heap) @@ -394,6 +461,34 @@ static int __add_cma_heap(struct cma *cma, void *data) return ret; }
+ cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL); + if (!cma_heap) + return -ENOMEM; + cma_heap->cma = cma; + + cma_name = kzalloc(strlen(cma_get_name(cma)) + strlen(postfixed) + 1, GFP_KERNEL); + if (!cma_name) { + kfree(cma_heap); + return -ENOMEM; + } + + exp_info.name = strcat(strcpy(cma_name, cma_get_name(cma)), postfixed); + exp_info.ops = &cma_uncached_heap_ops; + exp_info.priv = cma_heap; + + cma_heap->heap = dma_heap_add(&exp_info); + if (IS_ERR(cma_heap->heap)) { + int ret = PTR_ERR(cma_heap->heap); + + kfree(cma_heap); + kfree(cma_name); + return ret; + } + + dma_coerce_mask_and_coherent(dma_heap_get_dev(cma_heap->heap), DMA_BIT_MASK(64)); + mb(); /* make sure we only set allocate after dma_mask is set */ + cma_uncached_heap_ops.allocate = cma_uncached_heap_allocate; + return 0; }