drivers/tee/optee/shm_pool.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, Linaro Limited
   4  * Copyright (c) 2017, EPAM Systems
   5  */
   6 #include <linux/device.h>
   7 #include <linux/dma-buf.h>
   8 #include <linux/genalloc.h>
   9 #include <linux/slab.h>
  10 #include <linux/tee_drv.h>
  11 #include "optee_private.h"
  12 #include "optee_smc.h"
  13 #include "shm_pool.h"
  14
  15 static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
  16                          struct tee_shm *shm, size_t size)
  17 {
  18         unsigned int order = get_order(size);
  19         struct page *page;
  20
  21         page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
  22         if (!page)
  23                 return -ENOMEM;
  24
  25         shm->kaddr = page_address(page);
  26         shm->paddr = page_to_phys(page);
  27         shm->size = PAGE_SIZE << order;
  28
  29         return 0;
  30 }
  31
  32 static void pool_op_free(struct tee_shm_pool_mgr *poolm,
  33                          struct tee_shm *shm)
  34 {
  35         free_pages((unsigned long)shm->kaddr, get_order(shm->size));
  36         shm->kaddr = NULL;
  37 }
  38
  39 static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
  40 {
  41         kfree(poolm);
  42 }
  43
  44 static const struct tee_shm_pool_mgr_ops pool_ops = {
  45         .alloc = pool_op_alloc,
  46         .free = pool_op_free,
  47         .destroy_poolmgr = pool_op_destroy_poolmgr,
  48 };
  49
  50 /**
  51  * optee_shm_pool_alloc_pages() - create page-based allocator pool
  52  *
  53  * This pool is used when OP-TEE supports dymanic SHM. In this case
  54  * command buffers and such are allocated from kernel's own memory.
  55  */
  56 struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
  57 {
  58         struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
  59
  60         if (!mgr)
  61                 return ERR_PTR(-ENOMEM);
  62
  63         mgr->ops = &pool_ops;
  64
  65         return mgr;
  66 }