xref: /linux/drivers/tee/tee_shm_pool.c (revision fe833e4397fbdc3ae13a60202dfc7c335b032499)
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);
93