drivers/tee/optee/shm_pool.c

   1 /*
   2  * Copyright (c) 2015, Linaro Limited
   3  * Copyright (c) 2017, EPAM Systems
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15 #include <linux/device.h>
  16 #include <linux/dma-buf.h>
  17 #include <linux/genalloc.h>
  18 #include <linux/slab.h>
  19 #include <linux/tee_drv.h>
  20 #include "optee_private.h"
  21 #include "optee_smc.h"
  22 #include "shm_pool.h"
  23
  24 static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
  25                          struct tee_shm *shm, size_t size)
  26 {
  27         unsigned int order = get_order(size);
  28         struct page *page;
  29
  30         page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
  31         if (!page)
  32                 return -ENOMEM;
  33
  34         shm->kaddr = page_address(page);
  35         shm->paddr = page_to_phys(page);
  36         shm->size = PAGE_SIZE << order;
  37
  38         return 0;
  39 }
  40
  41 static void pool_op_free(struct tee_shm_pool_mgr *poolm,
  42                          struct tee_shm *shm)
  43 {
  44         free_pages((unsigned long)shm->kaddr, get_order(shm->size));
  45         shm->kaddr = NULL;
  46 }
  47
  48 static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
  49 {
  50         kfree(poolm);
  51 }
  52
  53 static const struct tee_shm_pool_mgr_ops pool_ops = {
  54         .alloc = pool_op_alloc,
  55         .free = pool_op_free,
  56         .destroy_poolmgr = pool_op_destroy_poolmgr,
  57 };
  58
  59 /**
  60  * optee_shm_pool_alloc_pages() - create page-based allocator pool
  61  *
  62  * This pool is used when OP-TEE supports dymanic SHM. In this case
  63  * command buffers and such are allocated from kernel's own memory.
  64  */
  65 struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
  66 {
  67         struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
  68
  69         if (!mgr)
  70                 return ERR_PTR(-ENOMEM);
  71
  72         mgr->ops = &pool_ops;
  73
  74         return mgr;
  75 }