[PATCH v3 11/12] tee: replace tee_shm_register()

From: Jens Wiklander
Date: Tue Jan 25 2022 - 11:43:53 EST


tee_shm_register() is replaced by the previously introduced functions
tee_shm_register_user_buf() and tee_shm_register_kernel_buf().

Since there are not external callers left we can remove tee_shm_register()
and refactor the remains.

Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
drivers/tee/tee_shm.c | 156 +++++++++++++++++++++++-----------------
include/linux/tee_drv.h | 11 ---
2 files changed, 90 insertions(+), 77 deletions(-)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 0b6f7aabbf88..c3a29022ec72 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -12,17 +12,43 @@
#include <linux/uio.h>
#include "tee_private.h"

+static void shm_put_kernel_pages(struct page **pages, size_t page_count)
+{
+ size_t n;
+
+ for (n = 0; n < page_count; n++)
+ put_page(pages[n]);
+}
+
+static int shm_get_kernel_pages(unsigned long start, size_t page_count,
+ struct page **pages)
+{
+ struct kvec *kiov;
+ size_t n;
+ int rc;
+
+ kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
+ if (!kiov)
+ return -ENOMEM;
+
+ for (n = 0; n < page_count; n++) {
+ kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
+ kiov[n].iov_len = PAGE_SIZE;
+ }
+
+ rc = get_kernel_pages(kiov, page_count, 0, pages);
+ kfree(kiov);
+
+ return rc;
+}
+
static void release_registered_pages(struct tee_shm *shm)
{
if (shm->pages) {
- if (shm->flags & TEE_SHM_USER_MAPPED) {
+ 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]);
- }
+ else
+ shm_put_kernel_pages(shm->pages, shm->num_pages);

kfree(shm->pages);
}
@@ -189,28 +215,24 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
}
EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);

-struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
- size_t length, u32 flags)
+static struct tee_shm *
+register_shm_helper(struct tee_context *ctx, unsigned long addr,
+ size_t length, u32 flags, int id)
{
struct tee_device *teedev = ctx->teedev;
- 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;
+ unsigned long start;
+ int num_pages;
void *ret;
int rc;
- int num_pages;
- unsigned long start;
-
- if (flags != req_user_flags && flags != req_kernel_flags)
- return ERR_PTR(-ENOTSUPP);

if (!tee_device_get(teedev))
return ERR_PTR(-EINVAL);

if (!teedev->desc->ops->shm_register ||
!teedev->desc->ops->shm_unregister) {
- tee_device_put(teedev);
- return ERR_PTR(-ENOTSUPP);
+ ret = ERR_PTR(-ENOTSUPP);
+ goto err_dev_put;
}

teedev_ctx_get(ctx);
@@ -218,13 +240,13 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
shm = kzalloc(sizeof(*shm), GFP_KERNEL);
if (!shm) {
ret = ERR_PTR(-ENOMEM);
- goto err;
+ goto err_ctx_put;
}

refcount_set(&shm->refcount, 1);
- shm->flags = flags | TEE_SHM_REGISTER;
+ shm->flags = flags;
shm->ctx = ctx;
- shm->id = -1;
+ shm->id = id;
addr = untagged_addr(addr);
start = rounddown(addr, PAGE_SIZE);
shm->offset = addr - start;
@@ -233,71 +255,45 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
if (!shm->pages) {
ret = ERR_PTR(-ENOMEM);
- goto err;
+ goto err_free_shm;
}

- if (flags & TEE_SHM_USER_MAPPED) {
+ if (flags & TEE_SHM_USER_MAPPED)
rc = pin_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);
- }
+ else
+ rc = shm_get_kernel_pages(start, num_pages, shm->pages);
if (rc > 0)
shm->num_pages = rc;
if (rc != num_pages) {
if (rc >= 0)
rc = -ENOMEM;
ret = ERR_PTR(rc);
- goto err;
- }
-
- mutex_lock(&teedev->mutex);
- shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
- mutex_unlock(&teedev->mutex);
-
- if (shm->id < 0) {
- ret = ERR_PTR(shm->id);
- goto err;
+ goto err_put_shm_pages;
}

rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
shm->num_pages, start);
if (rc) {
ret = ERR_PTR(rc);
- goto err;
+ goto err_put_shm_pages;
}

return shm;
-err:
- if (shm) {
- if (shm->id >= 0) {
- mutex_lock(&teedev->mutex);
- idr_remove(&teedev->idr, shm->id);
- mutex_unlock(&teedev->mutex);
- }
- release_registered_pages(shm);
- }
+err_put_shm_pages:
+ if (flags & TEE_SHM_USER_MAPPED)
+ unpin_user_pages(shm->pages, shm->num_pages);
+ else
+ shm_put_kernel_pages(shm->pages, shm->num_pages);
+ kfree(shm->pages);
+err_free_shm:
kfree(shm);
+err_ctx_put:
teedev_ctx_put(ctx);
+err_dev_put:
tee_device_put(teedev);
return ret;
}
-EXPORT_SYMBOL_GPL(tee_shm_register);

/**
* tee_shm_register_user_buf() - Register a userspace shared memory buffer
@@ -310,8 +306,35 @@ EXPORT_SYMBOL_GPL(tee_shm_register);
struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
unsigned long addr, size_t length)
{
- return tee_shm_register(ctx, addr, length,
- TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+ u32 flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED | TEE_SHM_REGISTER;
+ struct tee_device *teedev = ctx->teedev;
+ struct tee_shm *shm;
+ void *ret;
+ int id;
+
+ mutex_lock(&teedev->mutex);
+ id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
+ mutex_unlock(&teedev->mutex);
+ if (id < 0)
+ return ERR_PTR(id);
+
+ shm = register_shm_helper(ctx, addr, length, flags, id);
+ if (IS_ERR(shm)) {
+ mutex_lock(&teedev->mutex);
+ idr_remove(&teedev->idr, id);
+ mutex_unlock(&teedev->mutex);
+ return shm;
+ }
+
+ mutex_lock(&teedev->mutex);
+ ret = idr_replace(&teedev->idr, shm, id);
+ mutex_unlock(&teedev->mutex);
+ if (IS_ERR(ret)) {
+ tee_shm_free(shm);
+ return ret;
+ }
+
+ return shm;
}

/**
@@ -327,8 +350,9 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
void *addr, size_t length)
{
- return tee_shm_register(ctx, (unsigned long)addr, length,
- TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED);
+ u32 flags = TEE_SHM_REGISTER | TEE_SHM_KERNEL_MAPPED;
+
+ return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
}
EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index c9d2cc32a5ed..a3b663ef0694 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -276,17 +276,6 @@ 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_kernel_buf(struct tee_context *ctx, size_t size);

-/**
- * tee_shm_register() - Register shared memory buffer
- * @ctx: Context that registers the shared memory
- * @addr: Address is userspace of the shared buffer
- * @length: Length of the shared buffer
- * @flags: Flags setting properties for the requested shared memory.
- *
- * @returns a pointer to 'struct tee_shm'
- */
-struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
- size_t length, u32 flags);
struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
void *addr, size_t length);

--
2.31.1