Add the dma_ops for this secure heap. a) For secure buffer, cache_ops/mmap are not allowed, thus return EPERM for them. b) The secure buffer can't be accessed in kernel, thus it doesn't have va/dma_address for it. Use the dma_address property to save the "secure handle".
Signed-off-by: Yong Wu yong.wu@mediatek.com --- drivers/dma-buf/heaps/secure_heap.c | 120 ++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+)
diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c index 05062c14e7c7..25cc95442c56 100644 --- a/drivers/dma-buf/heaps/secure_heap.c +++ b/drivers/dma-buf/heaps/secure_heap.c @@ -9,6 +9,7 @@ #include <linux/dma-heap.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/scatterlist.h> #include <linux/slab.h> #include <linux/tee_drv.h> #include <linux/uuid.h> @@ -87,6 +88,10 @@ struct secure_heap { const struct secure_heap_prv_data *data; };
+struct secure_heap_attachment { + struct sg_table *table; +}; + static int tee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) { const struct secure_heap_prv_data *d = data; @@ -238,6 +243,120 @@ static void secure_heap_secure_memory_free(struct secure_heap *sec_heap, data->memory_free(sec_heap, sec_buf); }
+static int secure_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) +{ + struct secure_buffer *sec_buf = dmabuf->priv; + struct secure_heap_attachment *a; + struct sg_table *table; + int ret; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return -ENOMEM; + + table = kzalloc(sizeof(*table), GFP_KERNEL); + if (!table) { + ret = -ENOMEM; + goto err_free_attach; + } + + ret = sg_alloc_table(table, 1, GFP_KERNEL); + if (ret) + goto err_free_sgt; + sg_set_page(table->sgl, 0, sec_buf->size, 0); + + a->table = table; + attachment->priv = a; + + return 0; + +err_free_sgt: + kfree(table); +err_free_attach: + kfree(a); + return ret; +} + +static void secure_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) +{ + struct secure_heap_attachment *a = attachment->priv; + + sg_free_table(a->table); + kfree(a->table); + kfree(a); +} + +static struct sg_table * +secure_heap_map_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direction) +{ + struct secure_heap_attachment *a = attachment->priv; + struct dma_buf *dmabuf = attachment->dmabuf; + struct secure_buffer *sec_buf = dmabuf->priv; + struct sg_table *table = a->table; + + /* + * Technically dma_address refers to the address used by HW, But for secure buffer + * we don't know its dma_address in kernel, Instead, we only know its "secure handle". + * Thus use this property to save the "secure handle", and the user will use it to + * obtain the real address in secure world. + * + * Note: CONFIG_DMA_API_DEBUG requires it to be aligned with PAGE_SIZE. + */ + if (sec_buf->sec_handle) { + sg_dma_address(table->sgl) = sec_buf->sec_handle; + sg_dma_len(table->sgl) = sec_buf->size; + } + return table; +} + +static void +secure_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, + enum dma_data_direction direction) +{ + struct secure_heap_attachment *a = attachment->priv; + + WARN_ON(a->table != table); + sg_dma_address(table->sgl) = 0; + sg_dma_len(table->sgl) = 0; +} + +static int +secure_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction) +{ + return -EPERM; +} + +static int +secure_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction) +{ + return -EPERM; +} + +static int secure_heap_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) +{ + return -EPERM; +} + +static void secure_heap_free(struct dma_buf *dmabuf) +{ + struct secure_buffer *sec_buf = dmabuf->priv; + struct secure_heap *sec_heap = dma_heap_get_drvdata(sec_buf->heap); + + secure_heap_secure_memory_free(sec_heap, sec_buf); + kfree(sec_buf); +} + +static const struct dma_buf_ops sec_heap_buf_ops = { + .attach = secure_heap_attach, + .detach = secure_heap_detach, + .map_dma_buf = secure_heap_map_dma_buf, + .unmap_dma_buf = secure_heap_unmap_dma_buf, + .begin_cpu_access = secure_heap_dma_buf_begin_cpu_access, + .end_cpu_access = secure_heap_dma_buf_end_cpu_access, + .mmap = secure_heap_dma_buf_mmap, + .release = secure_heap_free, +}; + static struct dma_buf * secure_heap_allocate(struct dma_heap *heap, unsigned long size, unsigned long fd_flags, unsigned long heap_flags) @@ -271,6 +390,7 @@ secure_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 = &sec_heap_buf_ops; exp_info.size = sec_buf->size; exp_info.flags = fd_flags; exp_info.priv = sec_buf;