Commit ab09dd6d authored by Jens Wiklander's avatar Jens Wiklander
Browse files

tee: add tee_shm_alloc_dma_mem() 



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.

Reviewed-by: default avatarSumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent 146bf4e7

drivers/tee/tee_shm.c

+83 −2
Original line number Diff line number Diff line
@@ -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);
@@ -268,6 +284,71 @@ 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,

include/linux/tee_core.h

+5 −0
Original line number Diff line number Diff line
@@ -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
@@ -298,6 +300,9 @@ 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,