[PATCH] tee: make tee_shm_register_kernel_buf vmalloc supported

From: Phil Chang
Date: Sun Feb 13 2022 - 11:21:27 EST


In some low-memory devices, it's hard to aquire large-orders pages,
this patch allowed user using scatter pages to register shm.

Signed-off-by: Phil Chang <phil.chang@xxxxxxxxxxxx>
---
drivers/tee/optee/call.c | 2 +-
drivers/tee/tee_shm.c | 40 ++++++++++++++++++++++++++++------------
2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
index bd49ec934060..2082e632adff 100644
--- a/drivers/tee/optee/call.c
+++ b/drivers/tee/optee/call.c
@@ -362,7 +362,7 @@ int optee_check_mem_type(unsigned long start, size_t num_pages)
* Allow kernel address to register with OP-TEE as kernel
* pages are configured as normal memory only.
*/
- if (virt_addr_valid(start))
+ if (virt_addr_valid(start) || is_vmalloc_addr((void *)start))
return 0;

mmap_read_lock(mm);
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index f31e29e8f1ca..861403588485 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -23,22 +23,38 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count)
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;
+ if (is_vmalloc_addr((void *)start)) {
+ struct page *page;
+ int i;
+
+ for (i = 0; i < page_count; i++) {
+ page = vmalloc_to_page((void *)(start + PAGE_SIZE * i));
+ if (!page)
+ return -ENOMEM;
+
+ get_page(page);
+ pages[i] = page;
+ }
+ rc = page_count;
+ } else {
+ struct kvec *kiov;
+ size_t n;
+
+ 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);
}

- rc = get_kernel_pages(kiov, page_count, 0, pages);
- kfree(kiov);
-
return rc;
}

--
2.25.1