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authorJohn Hubbard <jhubbard@nvidia.com>2020-08-24 23:11:25 +0200
committerJens Wiklander <jens.wiklander@linaro.org>2020-08-25 11:01:06 +0200
commit4300cd6374a5192a2c8122a4a48ed647bdcb0214 (patch)
tree885e9e54c2eb2cfb1cec51c65776cb61f5e5d17f /drivers/tee
parentLinux 5.9-rc1 (diff)
downloadlinux-4300cd6374a5192a2c8122a4a48ed647bdcb0214.tar.xz
linux-4300cd6374a5192a2c8122a4a48ed647bdcb0214.zip
tee: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. Factor out a new, small release_registered_pages() function, in order to consolidate the logic for discerning between TEE_SHM_USER_MAPPED and TEE_SHM_KERNEL_MAPPED pages. This also absorbs the kfree() call that is also required there. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Jens Wiklander <jens.wiklander@linaro.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: tee-dev@lists.linaro.org Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee')
-rw-r--r--drivers/tee/tee_shm.c32
1 files changed, 19 insertions, 13 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 827ac3d0fea9..00472f5ce22e 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -12,6 +12,22 @@
#include <linux/uio.h>
#include "tee_private.h"
+static void release_registered_pages(struct tee_shm *shm)
+{
+ if (shm->pages) {
+ if (shm->flags & TEE_SHM_USER_MAPPED) {
+ unpin_user_pages(shm->pages, shm->num_pages);
+ } else {
+ size_t n;
+
+ for (n = 0; n < shm->num_pages; n++)
+ put_page(shm->pages[n]);
+ }
+
+ kfree(shm->pages);
+ }
+}
+
static void tee_shm_release(struct tee_shm *shm)
{
struct tee_device *teedev = shm->ctx->teedev;
@@ -32,17 +48,13 @@ static void tee_shm_release(struct tee_shm *shm)
poolm->ops->free(poolm, shm);
} else if (shm->flags & TEE_SHM_REGISTER) {
- size_t n;
int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
if (rc)
dev_err(teedev->dev.parent,
"unregister shm %p failed: %d", shm, rc);
- for (n = 0; n < shm->num_pages; n++)
- put_page(shm->pages[n]);
-
- kfree(shm->pages);
+ release_registered_pages(shm);
}
teedev_ctx_put(shm->ctx);
@@ -228,7 +240,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
}
if (flags & TEE_SHM_USER_MAPPED) {
- rc = get_user_pages_fast(start, num_pages, FOLL_WRITE,
+ rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
shm->pages);
} else {
struct kvec *kiov;
@@ -292,18 +304,12 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
return shm;
err:
if (shm) {
- size_t n;
-
if (shm->id >= 0) {
mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
mutex_unlock(&teedev->mutex);
}
- if (shm->pages) {
- for (n = 0; n < shm->num_pages; n++)
- put_page(shm->pages[n]);
- kfree(shm->pages);
- }
+ release_registered_pages(shm);
}
kfree(shm);
teedev_ctx_put(ctx);