Add the dma_ops for this restricted heap. For restricted buffer, 1) cache_ops/mmap are not allowed, thus return EPERM for them. 2) In map_dma_buf, use DMA_ATTR_SKIP_CPU_SYNC to skip cache sync since the buffer is protected. This type buffers are marked by sg_dma_mark_restricted, the user could check if this is a restricted buffer by sg_dma_is_restricted.
Signed-off-by: Yong Wu yong.wu@mediatek.com --- drivers/dma-buf/heaps/restricted_heap.c | 102 ++++++++++++++++++++++++ drivers/dma-buf/heaps/restricted_heap.h | 2 + 2 files changed, 104 insertions(+)
diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c index 8bb3c1876a69..4e45d46a6467 100644 --- a/drivers/dma-buf/heaps/restricted_heap.c +++ b/drivers/dma-buf/heaps/restricted_heap.c @@ -8,10 +8,16 @@ #include <linux/dma-buf.h> #include <linux/dma-heap.h> #include <linux/err.h> +#include <linux/scatterlist.h> #include <linux/slab.h>
#include "restricted_heap.h"
+struct restricted_heap_attachment { + struct sg_table *table; + struct device *dev; +}; + static int restricted_heap_memory_allocate(struct restricted_heap *rheap, struct restricted_buffer *buf) { @@ -45,6 +51,101 @@ restricted_heap_memory_free(struct restricted_heap *rheap, struct restricted_buf ops->free(rheap, buf); }
+static int restricted_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) +{ + struct restricted_buffer *restricted_buf = dmabuf->priv; + struct restricted_heap_attachment *a; + struct sg_table *table; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return -ENOMEM; + + table = sg_dup_table(&restricted_buf->sg_table); + if (!table) { + kfree(a); + return -ENOMEM; + } + + sg_dma_mark_restricted(table->sgl); + a->table = table; + a->dev = attachment->dev; + attachment->priv = a; + + return 0; +} + +static void restricted_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) +{ + struct restricted_heap_attachment *a = attachment->priv; + + sg_free_table(a->table); + kfree(a->table); + kfree(a); +} + +static struct sg_table * +restricted_heap_map_dma_buf(struct dma_buf_attachment *attachment, + enum dma_data_direction direction) +{ + struct restricted_heap_attachment *a = attachment->priv; + struct sg_table *table = a->table; + int ret; + + ret = dma_map_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC); + if (ret) + return ERR_PTR(ret); + return table; +} + +static void +restricted_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, + enum dma_data_direction direction) +{ + struct restricted_heap_attachment *a = attachment->priv; + + WARN_ON(a->table != table); + + dma_unmap_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC); +} + +static int +restricted_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction) +{ + return -EPERM; +} + +static int +restricted_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction) +{ + return -EPERM; +} + +static int restricted_heap_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) +{ + return -EPERM; +} + +static void restricted_heap_free(struct dma_buf *dmabuf) +{ + struct restricted_buffer *restricted_buf = dmabuf->priv; + struct restricted_heap *rheap = dma_heap_get_drvdata(restricted_buf->heap); + + restricted_heap_memory_free(rheap, restricted_buf); + kfree(restricted_buf); +} + +static const struct dma_buf_ops restricted_heap_buf_ops = { + .attach = restricted_heap_attach, + .detach = restricted_heap_detach, + .map_dma_buf = restricted_heap_map_dma_buf, + .unmap_dma_buf = restricted_heap_unmap_dma_buf, + .begin_cpu_access = restricted_heap_dma_buf_begin_cpu_access, + .end_cpu_access = restricted_heap_dma_buf_end_cpu_access, + .mmap = restricted_heap_dma_buf_mmap, + .release = restricted_heap_free, +}; + static struct dma_buf * restricted_heap_allocate(struct dma_heap *heap, unsigned long size, unsigned long fd_flags, unsigned long heap_flags) @@ -66,6 +167,7 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size, if (ret) goto err_free_buf; exp_info.exp_name = dma_heap_get_name(heap); + exp_info.ops = &restricted_heap_buf_ops; exp_info.size = restricted_buf->size; exp_info.flags = fd_flags; exp_info.priv = restricted_buf; diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h index 5783275d5714..6d9599a4a34e 100644 --- a/drivers/dma-buf/heaps/restricted_heap.h +++ b/drivers/dma-buf/heaps/restricted_heap.h @@ -11,6 +11,8 @@ struct restricted_buffer { struct dma_heap *heap; size_t size; + + struct sg_table sg_table; };
struct restricted_heap {