[Linaro-mm-sig] Re: [PATCH v5 5/9] dma-buf: heaps: restricted_heap: Add private heap ops

On Wed, May 15, 2024 at 07:23:04PM GMT, Yong Wu wrote:

Add "struct restricted_heap_ops". For the restricted memory, totally there are two steps: a) alloc: Allocate the buffer in kernel; b) restrict_buf: Restrict/Protect/Secure that buffer. The "alloc" is mandatory while "restrict_buf" is optional since it may be part of "alloc".

Signed-off-by: Yong Wu yong.wu@mediatek.com

drivers/dma-buf/heaps/restricted_heap.c | 41 ++++++++++++++++++++++++- drivers/dma-buf/heaps/restricted_heap.h | 12 ++++++++ 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c index c2ae19ba7d7e..8bb3c1876a69 100644 --- a/drivers/dma-buf/heaps/restricted_heap.c +++ b/drivers/dma-buf/heaps/restricted_heap.c @@ -12,10 +12,44 @@ #include "restricted_heap.h" +static int +restricted_heap_memory_allocate(struct restricted_heap *rheap, struct restricted_buffer *buf) +{

• const struct restricted_heap_ops *ops = rheap->ops;
• int ret;
• ret = ops->alloc(rheap, buf);
• if (ret)

• return ret;
  

• if (ops->restrict_buf) {

• ret = ops->restrict_buf(rheap, buf);
  

• if (ret)
  

• 	goto buf_free;
  

• }
• return 0;

+buf_free:

• ops->free(rheap, buf);
• return ret;

+}

+static void +restricted_heap_memory_free(struct restricted_heap *rheap, struct restricted_buffer *buf) +{

• const struct restricted_heap_ops *ops = rheap->ops;
• if (ops->unrestrict_buf)

• ops->unrestrict_buf(rheap, buf);
  

• ops->free(rheap, buf);

+}

static struct dma_buf * restricted_heap_allocate(struct dma_heap *heap, unsigned long size, unsigned long fd_flags, unsigned long heap_flags) {

• struct restricted_heap *rheap = dma_heap_get_drvdata(heap); struct restricted_buffer *restricted_buf; DEFINE_DMA_BUF_EXPORT_INFO(exp_info); struct dma_buf *dmabuf;

@@ -28,6 +62,9 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size, restricted_buf->size = ALIGN(size, PAGE_SIZE); restricted_buf->heap = heap;

• ret = restricted_heap_memory_allocate(rheap, restricted_buf);
• if (ret)

• goto err_free_buf;
  

  exp_info.exp_name = dma_heap_get_name(heap); exp_info.size = restricted_buf->size; exp_info.flags = fd_flags;

@@ -36,11 +73,13 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size, dmabuf = dma_buf_export(&exp_info); if (IS_ERR(dmabuf)) { ret = PTR_ERR(dmabuf);

• goto err_free_buf;
  

• goto err_free_rstrd_mem;
  

  }

return dmabuf; +err_free_rstrd_mem:

• restricted_heap_memory_free(rheap, restricted_buf);

err_free_buf: kfree(restricted_buf); return ERR_PTR(ret); diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h index b448f77616ac..5783275d5714 100644 --- a/drivers/dma-buf/heaps/restricted_heap.h +++ b/drivers/dma-buf/heaps/restricted_heap.h @@ -15,6 +15,18 @@ struct restricted_buffer { struct restricted_heap { const char *name;

• const struct restricted_heap_ops *ops;

+};

+struct restricted_heap_ops {

• int (*heap_init)(struct restricted_heap *rheap);

It might be worth moving this to a later patch when it's actually getting used.

Thierry