LXR linux/drivers/tee/optee/shm

   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
  15static 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        /*
  31         * Shared memory private to the OP-TEE driver doesn't need
  32         * to be registered with OP-TEE.
  33         */
  34        if (!(shm->flags & TEE_SHM_PRIV)) {
  35                unsigned int nr_pages = 1 << order, i;
  36                struct page **pages;
  37
  38                pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL);
  39                if (!pages) {
  40                        rc = -ENOMEM;
  41                        goto err;
  42                }
  43
  44                for (i = 0; i < nr_pages; i++) {
  45                        pages[i] = page;
  46                        page++;
  47                }
  48
  49                shm->flags |= TEE_SHM_REGISTER;
  50                rc = optee_shm_register(shm->ctx, shm, pages, nr_pages,
  51                                        (unsigned long)shm->kaddr);
  52                kfree(pages);
  53                if (rc)
  54                        goto err;
  55        }
  56
  57        return 0;
  58
  59err:
  60        __free_pages(page, order);
  61        return rc;
  62}
  63
  64static void pool_op_free(struct tee_shm_pool_mgr *poolm,
  65                         struct tee_shm *shm)
  66{
  67        if (!(shm->flags & TEE_SHM_PRIV))
  68                optee_shm_unregister(shm->ctx, shm);
  69
  70        free_pages((unsigned long)shm->kaddr, get_order(shm->size));
  71        shm->kaddr = NULL;
  72}
  73
  74static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
  75{
  76        kfree(poolm);
  77}
  78
  79static const struct tee_shm_pool_mgr_ops pool_ops = {
  80        .alloc = pool_op_alloc,
  81        .free = pool_op_free,
  82        .destroy_poolmgr = pool_op_destroy_poolmgr,
  83};
  84
  85/**
  86 * optee_shm_pool_alloc_pages() - create page-based allocator pool
  87 *
  88 * This pool is used when OP-TEE supports dymanic SHM. In this case
  89 * command buffers and such are allocated from kernel's own memory.
  90 */
  91struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
  92{
  93        struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
  94
  95        if (!mgr)
  96                return ERR_PTR(-ENOMEM);
  97
  98        mgr->ops = &pool_ops;
  99
 100        return mgr;
 101}
 102