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 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 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 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 */ 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 */ 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 */ 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 }; 219 220 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