xref: /openbmc/linux/drivers/tee/tee_shm_pool.c (revision dea54fba)
1 /*
2  * Copyright (c) 2015, Linaro Limited
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 #include <linux/device.h>
15 #include <linux/dma-buf.h>
16 #include <linux/genalloc.h>
17 #include <linux/slab.h>
18 #include <linux/tee_drv.h>
19 #include "tee_private.h"
20 
21 static int pool_op_gen_alloc(struct tee_shm_pool_mgr *poolm,
22 			     struct tee_shm *shm, size_t size)
23 {
24 	unsigned long va;
25 	struct gen_pool *genpool = poolm->private_data;
26 	size_t s = roundup(size, 1 << genpool->min_alloc_order);
27 
28 	va = gen_pool_alloc(genpool, s);
29 	if (!va)
30 		return -ENOMEM;
31 
32 	memset((void *)va, 0, s);
33 	shm->kaddr = (void *)va;
34 	shm->paddr = gen_pool_virt_to_phys(genpool, va);
35 	shm->size = s;
36 	return 0;
37 }
38 
39 static void pool_op_gen_free(struct tee_shm_pool_mgr *poolm,
40 			     struct tee_shm *shm)
41 {
42 	gen_pool_free(poolm->private_data, (unsigned long)shm->kaddr,
43 		      shm->size);
44 	shm->kaddr = NULL;
45 }
46 
47 static const struct tee_shm_pool_mgr_ops pool_ops_generic = {
48 	.alloc = pool_op_gen_alloc,
49 	.free = pool_op_gen_free,
50 };
51 
52 static void pool_res_mem_destroy(struct tee_shm_pool *pool)
53 {
54 	gen_pool_destroy(pool->private_mgr.private_data);
55 	gen_pool_destroy(pool->dma_buf_mgr.private_data);
56 }
57 
58 static int pool_res_mem_mgr_init(struct tee_shm_pool_mgr *mgr,
59 				 struct tee_shm_pool_mem_info *info,
60 				 int min_alloc_order)
61 {
62 	size_t page_mask = PAGE_SIZE - 1;
63 	struct gen_pool *genpool = NULL;
64 	int rc;
65 
66 	/*
67 	 * Start and end must be page aligned
68 	 */
69 	if ((info->vaddr & page_mask) || (info->paddr & page_mask) ||
70 	    (info->size & page_mask))
71 		return -EINVAL;
72 
73 	genpool = gen_pool_create(min_alloc_order, -1);
74 	if (!genpool)
75 		return -ENOMEM;
76 
77 	gen_pool_set_algo(genpool, gen_pool_best_fit, NULL);
78 	rc = gen_pool_add_virt(genpool, info->vaddr, info->paddr, info->size,
79 			       -1);
80 	if (rc) {
81 		gen_pool_destroy(genpool);
82 		return rc;
83 	}
84 
85 	mgr->private_data = genpool;
86 	mgr->ops = &pool_ops_generic;
87 	return 0;
88 }
89 
90 /**
91  * tee_shm_pool_alloc_res_mem() - Create a shared memory pool from reserved
92  * memory range
93  * @priv_info:	Information for driver private shared memory pool
94  * @dmabuf_info: Information for dma-buf shared memory pool
95  *
96  * Start and end of pools will must be page aligned.
97  *
98  * Allocation with the flag TEE_SHM_DMA_BUF set will use the range supplied
99  * in @dmabuf, others will use the range provided by @priv.
100  *
101  * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
102  */
103 struct tee_shm_pool *
104 tee_shm_pool_alloc_res_mem(struct tee_shm_pool_mem_info *priv_info,
105 			   struct tee_shm_pool_mem_info *dmabuf_info)
106 {
107 	struct tee_shm_pool *pool = NULL;
108 	int ret;
109 
110 	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
111 	if (!pool) {
112 		ret = -ENOMEM;
113 		goto err;
114 	}
115 
116 	/*
117 	 * Create the pool for driver private shared memory
118 	 */
119 	ret = pool_res_mem_mgr_init(&pool->private_mgr, priv_info,
120 				    3 /* 8 byte aligned */);
121 	if (ret)
122 		goto err;
123 
124 	/*
125 	 * Create the pool for dma_buf shared memory
126 	 */
127 	ret = pool_res_mem_mgr_init(&pool->dma_buf_mgr, dmabuf_info,
128 				    PAGE_SHIFT);
129 	if (ret)
130 		goto err;
131 
132 	pool->destroy = pool_res_mem_destroy;
133 	return pool;
134 err:
135 	if (ret == -ENOMEM)
136 		pr_err("%s: can't allocate memory for res_mem shared memory pool\n", __func__);
137 	if (pool && pool->private_mgr.private_data)
138 		gen_pool_destroy(pool->private_mgr.private_data);
139 	kfree(pool);
140 	return ERR_PTR(ret);
141 }
142 EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
143 
144 /**
145  * tee_shm_pool_free() - Free a shared memory pool
146  * @pool:	The shared memory pool to free
147  *
148  * There must be no remaining shared memory allocated from this pool when
149  * this function is called.
150  */
151 void tee_shm_pool_free(struct tee_shm_pool *pool)
152 {
153 	pool->destroy(pool);
154 	kfree(pool);
155 }
156 EXPORT_SYMBOL_GPL(tee_shm_pool_free);
157