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Subject[PATCH v5 1/2] tee: enable support to register kernel memory
Date
Enable support to register kernel memory reference with TEE. This change
will allow TEE bus drivers to register memory references.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
drivers/tee/tee_shm.c | 28 +++++++++++++++++++++++++---
include/linux/tee_drv.h | 1 +
2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 937ac5a..a6c75a4 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -9,6 +9,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
+#include <linux/uio.h>
#include "tee_private.h"

static void tee_shm_release(struct tee_shm *shm)
@@ -217,14 +218,15 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
size_t length, u32 flags)
{
struct tee_device *teedev = ctx->teedev;
- const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+ const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+ const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
struct tee_shm *shm;
void *ret;
int rc;
int num_pages;
unsigned long start;

- if (flags != req_flags)
+ if (flags != req_user_flags && flags != req_kernel_flags)
return ERR_PTR(-ENOTSUPP);

if (!tee_device_get(teedev))
@@ -259,7 +261,27 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
goto err;
}

- rc = get_user_pages_fast(start, num_pages, FOLL_WRITE, shm->pages);
+ if (flags & TEE_SHM_USER_MAPPED) {
+ rc = get_user_pages_fast(start, num_pages, FOLL_WRITE,
+ shm->pages);
+ } else {
+ struct kvec *kiov;
+ int i;
+
+ kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
+ if (!kiov) {
+ ret = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+
+ for (i = 0; i < num_pages; i++) {
+ kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
+ kiov[i].iov_len = PAGE_SIZE;
+ }
+
+ rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
+ kfree(kiov);
+ }
if (rc > 0)
shm->num_pages = rc;
if (rc != num_pages) {
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index 7a03f68..dedf8fa 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -26,6 +26,7 @@
#define TEE_SHM_REGISTER BIT(3) /* Memory registered in secure world */
#define TEE_SHM_USER_MAPPED BIT(4) /* Memory mapped in user space */
#define TEE_SHM_POOL BIT(5) /* Memory allocated from pool */
+#define TEE_SHM_KERNEL_MAPPED BIT(6) /* Memory mapped in kernel space */

struct device;
struct tee_device;
--
2.7.4
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