1 /*
2 * Amlogic Secure Monitor driver
3 *
4 * Copyright (C) 2016 Endless Mobile, Inc.
5 * Author: Carlo Caione <carlo@endlessm.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program. If not, see <http://www.gnu.org/licenses/>.
13 */
14
15 #define pr_fmt(fmt) "meson-sm: " fmt
16
17 #include <linux/arm-smccc.h>
18 #include <linux/bug.h>
19 #include <linux/io.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/printk.h>
23 #include <linux/types.h>
24 #include <linux/sizes.h>
25
26 #include <linux/firmware/meson/meson_sm.h>
27
28 struct meson_sm_cmd {
29 unsigned int index;
30 u32 smc_id;
31 };
32 #define CMD(d, s) { .index = (d), .smc_id = (s), }
33
34 struct meson_sm_chip {
35 unsigned int shmem_size;
36 u32 cmd_shmem_in_base;
37 u32 cmd_shmem_out_base;
38 struct meson_sm_cmd cmd[];
39 };
40
41 struct meson_sm_chip gxbb_chip = {
42 .shmem_size = SZ_4K,
43 .cmd_shmem_in_base = 0x82000020,
44 .cmd_shmem_out_base = 0x82000021,
45 .cmd = {
46 CMD(SM_EFUSE_READ, 0x82000030),
47 CMD(SM_EFUSE_WRITE, 0x82000031),
48 CMD(SM_EFUSE_USER_MAX, 0x82000033),
49 { /* sentinel */ },
50 },
51 };
52
53 struct meson_sm_firmware {
54 const struct meson_sm_chip *chip;
55 void __iomem *sm_shmem_in_base;
56 void __iomem *sm_shmem_out_base;
57 };
58
59 static struct meson_sm_firmware fw;
60
meson_sm_get_cmd(const struct meson_sm_chip * chip,unsigned int cmd_index)61 static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,
62 unsigned int cmd_index)
63 {
64 const struct meson_sm_cmd *cmd = chip->cmd;
65
66 while (cmd->smc_id && cmd->index != cmd_index)
67 cmd++;
68
69 return cmd->smc_id;
70 }
71
__meson_sm_call(u32 cmd,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)72 static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,
73 u32 arg3, u32 arg4)
74 {
75 struct arm_smccc_res res;
76
77 arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
78 return res.a0;
79 }
80
meson_sm_map_shmem(u32 cmd_shmem,unsigned int size)81 static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
82 {
83 u32 sm_phy_base;
84
85 sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
86 if (!sm_phy_base)
87 return 0;
88
89 return ioremap_cache(sm_phy_base, size);
90 }
91
92 /**
93 * meson_sm_call - generic SMC32 call to the secure-monitor
94 *
95 * @cmd_index: Index of the SMC32 function ID
96 * @ret: Returned value
97 * @arg0: SMC32 Argument 0
98 * @arg1: SMC32 Argument 1
99 * @arg2: SMC32 Argument 2
100 * @arg3: SMC32 Argument 3
101 * @arg4: SMC32 Argument 4
102 *
103 * Return: 0 on success, a negative value on error
104 */
meson_sm_call(unsigned int cmd_index,u32 * ret,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)105 int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0,
106 u32 arg1, u32 arg2, u32 arg3, u32 arg4)
107 {
108 u32 cmd, lret;
109
110 if (!fw.chip)
111 return -ENOENT;
112
113 cmd = meson_sm_get_cmd(fw.chip, cmd_index);
114 if (!cmd)
115 return -EINVAL;
116
117 lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
118
119 if (ret)
120 *ret = lret;
121
122 return 0;
123 }
124 EXPORT_SYMBOL(meson_sm_call);
125
126 /**
127 * meson_sm_call_read - retrieve data from secure-monitor
128 *
129 * @buffer: Buffer to store the retrieved data
130 * @bsize: Size of the buffer
131 * @cmd_index: Index of the SMC32 function ID
132 * @arg0: SMC32 Argument 0
133 * @arg1: SMC32 Argument 1
134 * @arg2: SMC32 Argument 2
135 * @arg3: SMC32 Argument 3
136 * @arg4: SMC32 Argument 4
137 *
138 * Return: size of read data on success, a negative value on error
139 * When 0 is returned there is no guarantee about the amount of
140 * data read and bsize bytes are copied in buffer.
141 */
meson_sm_call_read(void * buffer,unsigned int bsize,unsigned int cmd_index,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)142 int meson_sm_call_read(void *buffer, unsigned int bsize, unsigned int cmd_index,
143 u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
144 {
145 u32 size;
146 int ret;
147
148 if (!fw.chip)
149 return -ENOENT;
150
151 if (!fw.chip->cmd_shmem_out_base)
152 return -EINVAL;
153
154 if (bsize > fw.chip->shmem_size)
155 return -EINVAL;
156
157 if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
158 return -EINVAL;
159
160 if (size > bsize)
161 return -EINVAL;
162
163 ret = size;
164
165 if (!size)
166 size = bsize;
167
168 if (buffer)
169 memcpy(buffer, fw.sm_shmem_out_base, size);
170
171 return ret;
172 }
173 EXPORT_SYMBOL(meson_sm_call_read);
174
175 /**
176 * meson_sm_call_write - send data to secure-monitor
177 *
178 * @buffer: Buffer containing data to send
179 * @size: Size of the data to send
180 * @cmd_index: Index of the SMC32 function ID
181 * @arg0: SMC32 Argument 0
182 * @arg1: SMC32 Argument 1
183 * @arg2: SMC32 Argument 2
184 * @arg3: SMC32 Argument 3
185 * @arg4: SMC32 Argument 4
186 *
187 * Return: size of sent data on success, a negative value on error
188 */
meson_sm_call_write(void * buffer,unsigned int size,unsigned int cmd_index,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)189 int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index,
190 u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
191 {
192 u32 written;
193
194 if (!fw.chip)
195 return -ENOENT;
196
197 if (size > fw.chip->shmem_size)
198 return -EINVAL;
199
200 if (!fw.chip->cmd_shmem_in_base)
201 return -EINVAL;
202
203 memcpy(fw.sm_shmem_in_base, buffer, size);
204
205 if (meson_sm_call(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
206 return -EINVAL;
207
208 if (!written)
209 return -EINVAL;
210
211 return written;
212 }
213 EXPORT_SYMBOL(meson_sm_call_write);
214
215 static const struct of_device_id meson_sm_ids[] = {
216 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
217 { /* sentinel */ },
218 };
219
meson_sm_init(void)220 int __init meson_sm_init(void)
221 {
222 const struct meson_sm_chip *chip;
223 const struct of_device_id *matched_np;
224 struct device_node *np;
225
226 np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
227 if (!np)
228 return -ENODEV;
229
230 chip = matched_np->data;
231 if (!chip) {
232 pr_err("unable to setup secure-monitor data\n");
233 goto out;
234 }
235
236 if (chip->cmd_shmem_in_base) {
237 fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
238 chip->shmem_size);
239 if (WARN_ON(!fw.sm_shmem_in_base))
240 goto out;
241 }
242
243 if (chip->cmd_shmem_out_base) {
244 fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
245 chip->shmem_size);
246 if (WARN_ON(!fw.sm_shmem_out_base))
247 goto out_in_base;
248 }
249
250 fw.chip = chip;
251 pr_info("secure-monitor enabled\n");
252
253 return 0;
254
255 out_in_base:
256 iounmap(fw.sm_shmem_in_base);
257 out:
258 return -EINVAL;
259 }
260 device_initcall(meson_sm_init);
261