xref: /openbmc/linux/drivers/tee/tee_shm_pool.c (revision d0e22329)
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 void pool_op_gen_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
48 {
49 	gen_pool_destroy(poolm->private_data);
50 	kfree(poolm);
51 }
52 
53 static const struct tee_shm_pool_mgr_ops pool_ops_generic = {
54 	.alloc = pool_op_gen_alloc,
55 	.free = pool_op_gen_free,
56 	.destroy_poolmgr = pool_op_gen_destroy_poolmgr,
57 };
58 
59 /**
60  * tee_shm_pool_alloc_res_mem() - Create a shared memory pool from reserved
61  * memory range
62  * @priv_info:	Information for driver private shared memory pool
63  * @dmabuf_info: Information for dma-buf shared memory pool
64  *
65  * Start and end of pools will must be page aligned.
66  *
67  * Allocation with the flag TEE_SHM_DMA_BUF set will use the range supplied
68  * in @dmabuf, others will use the range provided by @priv.
69  *
70  * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
71  */
72 struct tee_shm_pool *
73 tee_shm_pool_alloc_res_mem(struct tee_shm_pool_mem_info *priv_info,
74 			   struct tee_shm_pool_mem_info *dmabuf_info)
75 {
76 	struct tee_shm_pool_mgr *priv_mgr;
77 	struct tee_shm_pool_mgr *dmabuf_mgr;
78 	void *rc;
79 
80 	/*
81 	 * Create the pool for driver private shared memory
82 	 */
83 	rc = tee_shm_pool_mgr_alloc_res_mem(priv_info->vaddr, priv_info->paddr,
84 					    priv_info->size,
85 					    3 /* 8 byte aligned */);
86 	if (IS_ERR(rc))
87 		return rc;
88 	priv_mgr = rc;
89 
90 	/*
91 	 * Create the pool for dma_buf shared memory
92 	 */
93 	rc = tee_shm_pool_mgr_alloc_res_mem(dmabuf_info->vaddr,
94 					    dmabuf_info->paddr,
95 					    dmabuf_info->size, PAGE_SHIFT);
96 	if (IS_ERR(rc))
97 		goto err_free_priv_mgr;
98 	dmabuf_mgr = rc;
99 
100 	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
101 	if (IS_ERR(rc))
102 		goto err_free_dmabuf_mgr;
103 
104 	return rc;
105 
106 err_free_dmabuf_mgr:
107 	tee_shm_pool_mgr_destroy(dmabuf_mgr);
108 err_free_priv_mgr:
109 	tee_shm_pool_mgr_destroy(priv_mgr);
110 
111 	return rc;
112 }
113 EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
114 
115 struct tee_shm_pool_mgr *tee_shm_pool_mgr_alloc_res_mem(unsigned long vaddr,
116 							phys_addr_t paddr,
117 							size_t size,
118 							int min_alloc_order)
119 {
120 	const size_t page_mask = PAGE_SIZE - 1;
121 	struct tee_shm_pool_mgr *mgr;
122 	int rc;
123 
124 	/* Start and end must be page aligned */
125 	if (vaddr & page_mask || paddr & page_mask || size & page_mask)
126 		return ERR_PTR(-EINVAL);
127 
128 	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
129 	if (!mgr)
130 		return ERR_PTR(-ENOMEM);
131 
132 	mgr->private_data = gen_pool_create(min_alloc_order, -1);
133 	if (!mgr->private_data) {
134 		rc = -ENOMEM;
135 		goto err;
136 	}
137 
138 	gen_pool_set_algo(mgr->private_data, gen_pool_best_fit, NULL);
139 	rc = gen_pool_add_virt(mgr->private_data, vaddr, paddr, size, -1);
140 	if (rc) {
141 		gen_pool_destroy(mgr->private_data);
142 		goto err;
143 	}
144 
145 	mgr->ops = &pool_ops_generic;
146 
147 	return mgr;
148 err:
149 	kfree(mgr);
150 
151 	return ERR_PTR(rc);
152 }
153 EXPORT_SYMBOL_GPL(tee_shm_pool_mgr_alloc_res_mem);
154 
155 static bool check_mgr_ops(struct tee_shm_pool_mgr *mgr)
156 {
157 	return mgr && mgr->ops && mgr->ops->alloc && mgr->ops->free &&
158 		mgr->ops->destroy_poolmgr;
159 }
160 
161 struct tee_shm_pool *tee_shm_pool_alloc(struct tee_shm_pool_mgr *priv_mgr,
162 					struct tee_shm_pool_mgr *dmabuf_mgr)
163 {
164 	struct tee_shm_pool *pool;
165 
166 	if (!check_mgr_ops(priv_mgr) || !check_mgr_ops(dmabuf_mgr))
167 		return ERR_PTR(-EINVAL);
168 
169 	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
170 	if (!pool)
171 		return ERR_PTR(-ENOMEM);
172 
173 	pool->private_mgr = priv_mgr;
174 	pool->dma_buf_mgr = dmabuf_mgr;
175 
176 	return pool;
177 }
178 EXPORT_SYMBOL_GPL(tee_shm_pool_alloc);
179 
180 /**
181  * tee_shm_pool_free() - Free a shared memory pool
182  * @pool:	The shared memory pool to free
183  *
184  * There must be no remaining shared memory allocated from this pool when
185  * this function is called.
186  */
187 void tee_shm_pool_free(struct tee_shm_pool *pool)
188 {
189 	if (pool->private_mgr)
190 		tee_shm_pool_mgr_destroy(pool->private_mgr);
191 	if (pool->dma_buf_mgr)
192 		tee_shm_pool_mgr_destroy(pool->dma_buf_mgr);
193 	kfree(pool);
194 }
195 EXPORT_SYMBOL_GPL(tee_shm_pool_free);
196