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         int rc = 0;
  21
  22         page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
  23         if (!page)
  24                 return -ENOMEM;
  25
  26         shm->kaddr = page_address(page);
  27         shm->paddr = page_to_phys(page);
  28         shm->size = PAGE_SIZE << order;
  29
  30         if (shm->flags & TEE_SHM_DMA_BUF) {
  31                 unsigned int nr_pages = 1 << order, i;
  32                 struct page **pages;
  33
  34                 pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL);
  35                 if (!pages)
  36                         return -ENOMEM;
  37
  38                 for (i = 0; i < nr_pages; i++) {
  39                         pages[i] = page;
  40                         page++;
  41                 }
  42
  43                 shm->flags |= TEE_SHM_REGISTER;
  44                 rc = optee_shm_register(shm->ctx, shm, pages, nr_pages,
  45                                         (unsigned long)shm->kaddr);
  46                 kfree(pages);
  47         }
  48
  49         return rc;
  50 }
  51
  52 static void pool_op_free(struct tee_shm_pool_mgr *poolm,
  53                          struct tee_shm *shm)
  54 {
  55         if (shm->flags & TEE_SHM_DMA_BUF)
  56                 optee_shm_unregister(shm->ctx, shm);
  57
  58         free_pages((unsigned long)shm->kaddr, get_order(shm->size));
  59         shm->kaddr = NULL;
  60 }
  61
  62 static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
  63 {
  64         kfree(poolm);
  65 }
  66
  67 static const struct tee_shm_pool_mgr_ops pool_ops = {
  68         .alloc = pool_op_alloc,
  69         .free = pool_op_free,
  70         .destroy_poolmgr = pool_op_destroy_poolmgr,
  71 };
  72
  73 /**
  74  * optee_shm_pool_alloc_pages() - create page-based allocator pool
  75  *
  76  * This pool is used when OP-TEE supports dymanic SHM. In this case
  77  * command buffers and such are allocated from kernel's own memory.
  78  */
  79 struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
  80 {
  81         struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
  82
  83         if (!mgr)
  84                 return ERR_PTR(-ENOMEM);
  85
  86         mgr->ops = &pool_ops;
  87
  88         return mgr;
  89 }