For the secure memory, there are two steps: a) Allocate buffers in kernel side; b) Secure that buffer. Different heaps may have different buffer allocation methods and different memory protection methods. Here abstract the memory allocation and securing operations.
Signed-off-by: Yong Wu yong.wu@mediatek.com --- drivers/dma-buf/heaps/secure_heap.c | 58 ++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c index a634051a0a67..87ac23072e9e 100644 --- a/drivers/dma-buf/heaps/secure_heap.c +++ b/drivers/dma-buf/heaps/secure_heap.c @@ -24,15 +24,66 @@ struct secure_buffer { size_t size; };
+struct secure_heap; + +struct secure_heap_prv_data { + int (*memory_alloc)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf); + void (*memory_free)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf); + + /* Protect/unprotect the memory */ + int (*secure_the_memory)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf); + void (*unsecure_the_memory)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf); +}; + struct secure_heap { const char *name; const enum secure_memory_type mem_type; + + const struct secure_heap_prv_data *data; };
+static int secure_heap_secure_memory_allocate(struct secure_heap *sec_heap, + struct secure_buffer *sec_buf) +{ + const struct secure_heap_prv_data *data = sec_heap->data; + int ret; + + if (data->memory_alloc) { + ret = data->memory_alloc(sec_heap, sec_buf); + if (ret) + return ret; + } + + if (data->secure_the_memory) { + ret = data->secure_the_memory(sec_heap, sec_buf); + if (ret) + goto sec_memory_free; + } + return 0; + +sec_memory_free: + if (data->memory_free) + data->memory_free(sec_heap, sec_buf); + return ret; +} + +static void secure_heap_secure_memory_free(struct secure_heap *sec_heap, + struct secure_buffer *sec_buf) +{ + const struct secure_heap_prv_data *data = sec_heap->data; + + if (data->unsecure_the_memory) + data->unsecure_the_memory(sec_heap, sec_buf); + + if (data->memory_free) + data->memory_free(sec_heap, sec_buf); +} + static struct dma_buf * secure_heap_allocate(struct dma_heap *heap, unsigned long size, unsigned long fd_flags, unsigned long heap_flags) { + struct secure_heap *sec_heap = dma_heap_get_drvdata(heap); struct secure_buffer *sec_buf; DEFINE_DMA_BUF_EXPORT_INFO(exp_info); struct dma_buf *dmabuf; @@ -45,6 +96,9 @@ secure_heap_allocate(struct dma_heap *heap, unsigned long size, sec_buf->size = ALIGN(size, PAGE_SIZE); sec_buf->heap = heap;
+ ret = secure_heap_secure_memory_allocate(sec_heap, sec_buf); + if (ret) + goto err_free_buf; exp_info.exp_name = dma_heap_get_name(heap); exp_info.size = sec_buf->size; exp_info.flags = fd_flags; @@ -53,11 +107,13 @@ secure_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_sec_mem; }
return dmabuf;
+err_free_sec_mem: + secure_heap_secure_memory_free(sec_heap, sec_buf); err_free_buf: kfree(sec_buf); return ERR_PTR(ret);