On Tue, Jun 17, 2025 at 1:32 PM Sumit Garg sumit.garg@kernel.org wrote:
On Tue, Jun 10, 2025 at 03:13:50PM +0200, Jens Wiklander wrote:
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)
nit: this config check can be merged into the above if check.
No, because dma_free_pages() is only defined if CONFIG_TEE_DMABUF_HEAPS is enabled.
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) {Do we need a similar config check for this flag too?
No, because DMA_SHARED_BUFFER is selected, so the dma_buf functions are defined.
Cheers, Jens
With these addressed, feel free to add:
Reviewed-by: Sumit Garg sumit.garg@oss.qualcomm.com
-Sumit
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, -- 2.43.0