drivers/tee/tee_shm_pool.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, 2017, 2022 Linaro Limited
   4  */
   5 #include <linux/device.h>
   6 #include <linux/dma-buf.h>
   7 #include <linux/genalloc.h>
   8 #include <linux/slab.h>
   9 #include <linux/tee_core.h>
  10 #include "tee_private.h"
  11
  12 static int pool_op_gen_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
  13                              size_t size, size_t align)
  14 {
  15         unsigned long va;
  16         struct gen_pool *genpool = pool->private_data;
  17         size_t a = max_t(size_t, align, BIT(genpool->min_alloc_order));
  18         struct genpool_data_align data = { .align = a };
  19         size_t s = roundup(size, a);
  20
  21         va = gen_pool_alloc_algo(genpool, s, gen_pool_first_fit_align, &data);
  22         if (!va)
  23                 return -ENOMEM;
  24
  25         memset((void *)va, 0, s);
  26         shm->kaddr = (void *)va;
  27         shm->paddr = gen_pool_virt_to_phys(genpool, va);
  28         shm->size = s;
  29         /*
  30          * This is from a static shared memory pool so no need to register
  31          * each chunk, and no need to unregister later either.
  32          */
  33         shm->flags &= ~TEE_SHM_DYNAMIC;
  34         return 0;
  35 }
  36
  37 static void pool_op_gen_free(struct tee_shm_pool *pool, struct tee_shm *shm)
  38 {
  39         gen_pool_free(pool->private_data, (unsigned long)shm->kaddr,
  40                       shm->size);
  41         shm->kaddr = NULL;
  42 }
  43
  44 static void pool_op_gen_destroy_pool(struct tee_shm_pool *pool)
  45 {
  46         gen_pool_destroy(pool->private_data);
  47         kfree(pool);
  48 }
  49
  50 static const struct tee_shm_pool_ops pool_ops_generic = {
  51         .alloc = pool_op_gen_alloc,
  52         .free = pool_op_gen_free,
  53         .destroy_pool = pool_op_gen_destroy_pool,
  54 };
  55
  56 struct tee_shm_pool *tee_shm_pool_alloc_res_mem(unsigned long vaddr,
  57                                                 phys_addr_t paddr, size_t size,
  58                                                 int min_alloc_order)
  59 {
  60         const size_t page_mask = PAGE_SIZE - 1;
  61         struct tee_shm_pool *pool;
  62         int rc;
  63
  64         /* Start and end must be page aligned */
  65         if (vaddr & page_mask || paddr & page_mask || size & page_mask)
  66                 return ERR_PTR(-EINVAL);
  67
  68         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
  69         if (!pool)
  70                 return ERR_PTR(-ENOMEM);
  71
  72         pool->private_data = gen_pool_create(min_alloc_order, -1);
  73         if (!pool->private_data) {
  74                 rc = -ENOMEM;
  75                 goto err;
  76         }
  77
  78         rc = gen_pool_add_virt(pool->private_data, vaddr, paddr, size, -1);
  79         if (rc) {
  80                 gen_pool_destroy(pool->private_data);
  81                 goto err;
  82         }
  83
  84         pool->ops = &pool_ops_generic;
  85
  86         return pool;
  87 err:
  88         kfree(pool);
  89
  90         return ERR_PTR(rc);
  91 }
  92 EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);