Add tee_shm_alloc_dma_mem() to allocate DMA memory. The memory is represented by a tee_shm object using the new flag TEE_SHM_DMA_MEM to identify it as DMA memory. The allocated memory will later be lent to the TEE to be used as protected memory.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- drivers/tee/tee_shm.c | 85 +++++++++++++++++++++++++++++++++++++++- include/linux/tee_core.h | 5 +++ 2 files changed, 88 insertions(+), 2 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index e63095e84644..60b0f3932cee 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -5,6 +5,8 @@ #include <linux/anon_inodes.h> #include <linux/device.h> #include <linux/dma-buf.h> +#include <linux/dma-mapping.h> +#include <linux/highmem.h> #include <linux/idr.h> #include <linux/io.h> #include <linux/mm.h> @@ -13,9 +15,14 @@ #include <linux/tee_core.h> #include <linux/uaccess.h> #include <linux/uio.h> -#include <linux/highmem.h> #include "tee_private.h"
+struct tee_shm_dma_mem { + struct tee_shm shm; + dma_addr_t dma_addr; + struct page *page; +}; + static void shm_put_kernel_pages(struct page **pages, size_t page_count) { size_t n; @@ -48,7 +55,16 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) { void *p = shm;
- if (shm->flags & TEE_SHM_DMA_BUF) { + if (shm->flags & TEE_SHM_DMA_MEM) { +#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS) + struct tee_shm_dma_mem *dma_mem; + + dma_mem = container_of(shm, struct tee_shm_dma_mem, shm); + p = dma_mem; + dma_free_pages(&teedev->dev, shm->size, dma_mem->page, + dma_mem->dma_addr, DMA_BIDIRECTIONAL); +#endif + } else if (shm->flags & TEE_SHM_DMA_BUF) { struct tee_shm_dmabuf_ref *ref;
ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); @@ -303,6 +319,71 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) } EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
+#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS) +/** + * tee_shm_alloc_dma_mem() - Allocate DMA memory as shared memory object + * @ctx: Context that allocates the shared memory + * @page_count: Number of pages + * + * The allocated memory is expected to be lent (made inaccessible to the + * kernel) to the TEE while it's used and returned (accessible to the + * kernel again) before it's freed. + * + * This function should normally only be used internally in the TEE + * drivers. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx, + size_t page_count) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm_dma_mem *dma_mem; + dma_addr_t dma_addr; + struct page *page; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + page = dma_alloc_pages(&teedev->dev, page_count * PAGE_SIZE, + &dma_addr, DMA_BIDIRECTIONAL, GFP_KERNEL); + if (!page) + goto err_put_teedev; + + dma_mem = kzalloc(sizeof(*dma_mem), GFP_KERNEL); + if (!dma_mem) + goto err_free_pages; + + refcount_set(&dma_mem->shm.refcount, 1); + dma_mem->shm.ctx = ctx; + dma_mem->shm.paddr = page_to_phys(page); + dma_mem->dma_addr = dma_addr; + dma_mem->page = page; + dma_mem->shm.size = page_count * PAGE_SIZE; + dma_mem->shm.flags = TEE_SHM_DMA_MEM; + + teedev_ctx_get(ctx); + + return &dma_mem->shm; + +err_free_pages: + dma_free_pages(&teedev->dev, page_count * PAGE_SIZE, page, dma_addr, + DMA_BIDIRECTIONAL); +err_put_teedev: + tee_device_put(teedev); + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem); +#else +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx, + size_t page_count) +{ + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem); +#endif + int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm, diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h index f17710196c4c..e46a53e753af 100644 --- a/include/linux/tee_core.h +++ b/include/linux/tee_core.h @@ -29,6 +29,8 @@ #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */ #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */ #define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */ +#define TEE_SHM_DMA_MEM BIT(5) /* Memory allocated with */ + /* dma_alloc_pages() */
#define TEE_DEVICE_FLAG_REGISTERED 0x1 #define TEE_MAX_DEV_NAME_LEN 32 @@ -310,6 +312,9 @@ void *tee_get_drvdata(struct tee_device *teedev); */ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
+struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx, + size_t page_count); + int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,