On Tue, May 20, 2025 at 05:16:49PM +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 | 74 ++++++++++++++++++++++++++++++++++++++-- include/linux/tee_core.h | 5 +++ 2 files changed, 77 insertions(+), 2 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index e1ed52ee0a16..92a6a35e1a1e 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; @@ -49,7 +56,14 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) struct tee_shm *parent_shm = NULL; void *p = shm;
- if (shm->flags & TEE_SHM_DMA_BUF) {
- if (shm->flags & TEE_SHM_DMA_MEM) {
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);
Although the kernel bot already found a randconfig issue, it looks like we need to add Kconfig dependencies like HAS_DMA, DMA_CMA etc.
Also, I was thinking if we should rather add a new TEE subsystem specific Kconfig option like: TEE_DMABUF_HEAPS which can then be used to select whatever dependency is needed as well as act as a gating Kconfig for relevant features.
-Sumit
- } else if (shm->flags & TEE_SHM_DMA_BUF) { struct tee_shm_dmabuf_ref *ref;
ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); @@ -306,6 +320,62 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) } EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); +/**
- 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);
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 02c07f661349..925690e1020b 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