drivers/tee/amdtee/shm_pool.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2019 Advanced Micro Devices, Inc.
   4  */
   5
   6 #include <linux/slab.h>
   7 #include <linux/tee_drv.h>
   8 #include <linux/psp.h>
   9 #include "amdtee_private.h"
  10
  11 static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
  12                          size_t size, size_t align)
  13 {
  14         unsigned int order = get_order(size);
  15         unsigned long va;
  16         int rc;
  17
  18         /*
  19          * Ignore alignment since this is already going to be page aligned
  20          * and there's no need for any larger alignment.
  21          */
  22         va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  23         if (!va)
  24                 return -ENOMEM;
  25
  26         shm->kaddr = (void *)va;
  27         shm->paddr = __psp_pa((void *)va);
  28         shm->size = PAGE_SIZE << order;
  29
  30         /* Map the allocated memory in to TEE */
  31         rc = amdtee_map_shmem(shm);
  32         if (rc) {
  33                 free_pages(va, order);
  34                 shm->kaddr = NULL;
  35                 return rc;
  36         }
  37
  38         return 0;
  39 }
  40
  41 static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
  42 {
  43         /* Unmap the shared memory from TEE */
  44         amdtee_unmap_shmem(shm);
  45         free_pages((unsigned long)shm->kaddr, get_order(shm->size));
  46         shm->kaddr = NULL;
  47 }
  48
  49 static void pool_op_destroy_pool(struct tee_shm_pool *pool)
  50 {
  51         kfree(pool);
  52 }
  53
  54 static const struct tee_shm_pool_ops pool_ops = {
  55         .alloc = pool_op_alloc,
  56         .free = pool_op_free,
  57         .destroy_pool = pool_op_destroy_pool,
  58 };
  59
  60 struct tee_shm_pool *amdtee_config_shm(void)
  61 {
  62         struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
  63
  64         if (!pool)
  65                 return ERR_PTR(-ENOMEM);
  66
  67         pool->ops = &pool_ops;
  68
  69         return pool;
  70 }