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Commit 9cba6e75 authored by Volodymyr Babchuk's avatar Volodymyr Babchuk Committed by Victor Chong
Browse files

BACKPORT: tee: optee: add page list manipulation functions 



These functions will be used to pass information about shared
buffers to OP-TEE. ABI between Linux and OP-TEE is defined
in optee_msg.h and optee_smc.h.

optee_msg.h defines OPTEE_MSG_ATTR_NONCONTIG attribute
for shared memory references and describes how such references
should be passed. Note that it uses 64-bit page addresses even
on 32 bit systems. This is done to support LPAE and to unify
interface.

Change-Id: I9285315d48979e75c54021163f3e8c7a2772db55
Signed-off-by: default avatarVolodymyr Babchuk <vlad.babchuk@gmail.com>
[jw: replacing uint64_t with u64 in optee_fill_pages_list()]
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
(cherry picked from commit 3bb48ba5cd60f9685aa8f1ccd9b14a72e237c13f)
Signed-off-by: default avatarVictor Chong <victor.chong@linaro.org>
parent f442bb9b

drivers/tee/optee/call.c

+91 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
 * GNU General Public License for more details.

 *

 */

#include <asm/pgtable.h>

#include <linux/arm-smccc.h>

#include <linux/device.h>

#include <linux/err.h>
@@ -442,3 +443,93 @@ void optee_disable_shm_cache(struct optee *optee) 
	}

	optee_cq_wait_final(&optee->call_queue, &w);

}



#define PAGELIST_ENTRIES_PER_PAGE				\

	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)



/**

 * optee_fill_pages_list() - write list of user pages to given shared

 * buffer.

 *

 * @dst: page-aligned buffer where list of pages will be stored

 * @pages: array of pages that represents shared buffer

 * @num_pages: number of entries in @pages

 * @page_offset: offset of user buffer from page start

 *

 * @dst should be big enough to hold list of user page addresses and

 *	links to the next pages of buffer

 */

void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,

			   size_t page_offset)

{

	int n = 0;

	phys_addr_t optee_page;

	/*

	 * Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h

	 * for details.

	 */

	struct {

		u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];

		u64 next_page_data;

	} *pages_data;



	/*

	 * Currently OP-TEE uses 4k page size and it does not looks

	 * like this will change in the future.  On other hand, there are

	 * no know ARM architectures with page size < 4k.

	 * Thus the next built assert looks redundant. But the following

	 * code heavily relies on this assumption, so it is better be

	 * safe than sorry.

	 */

	BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);



	pages_data = (void *)dst;

	/*

	 * If linux page is bigger than 4k, and user buffer offset is

	 * larger than 4k/8k/12k/etc this will skip first 4k pages,

	 * because they bear no value data for OP-TEE.

	 */

	optee_page = page_to_phys(*pages) +

		round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);



	while (true) {

		pages_data->pages_list[n++] = optee_page;



		if (n == PAGELIST_ENTRIES_PER_PAGE) {

			pages_data->next_page_data =

				virt_to_phys(pages_data + 1);

			pages_data++;

			n = 0;

		}



		optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;

		if (!(optee_page & ~PAGE_MASK)) {

			if (!--num_pages)

				break;

			pages++;

			optee_page = page_to_phys(*pages);

		}

	}

}



/*

 * The final entry in each pagelist page is a pointer to the next

 * pagelist page.

 */

static size_t get_pages_list_size(size_t num_entries)

{

	int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);



	return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;

}



u64 *optee_allocate_pages_list(size_t num_entries)

{

	return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);

}



void optee_free_pages_list(void *list, size_t num_entries)

{

	free_pages_exact(list, get_pages_list_size(num_entries));

}

drivers/tee/optee/optee_private.h

+5 −0
Original line number Diff line number Diff line
@@ -154,6 +154,11 @@ int optee_from_msg_param(struct tee_param *params, size_t num_params, 
int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,

		       const struct tee_param *params);



u64 *optee_allocate_pages_list(size_t num_entries);

void optee_free_pages_list(void *array, size_t num_entries);

void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,

			   size_t page_offset);



/*

 * Small helpers

 */