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/module.h> 21 #include <linux/of.h> 22 #include <linux/of_device.h> 23 #include <linux/platform_device.h> 24 #include <linux/printk.h> 25 #include <linux/types.h> 26 #include <linux/sizes.h> 27 28 #include <linux/firmware/meson/meson_sm.h> 29 30 struct meson_sm_cmd { 31 unsigned int index; 32 u32 smc_id; 33 }; 34 #define CMD(d, s) { .index = (d), .smc_id = (s), } 35 36 struct meson_sm_chip { 37 unsigned int shmem_size; 38 u32 cmd_shmem_in_base; 39 u32 cmd_shmem_out_base; 40 struct meson_sm_cmd cmd[]; 41 }; 42 43 struct meson_sm_chip gxbb_chip = { 44 .shmem_size = SZ_4K, 45 .cmd_shmem_in_base = 0x82000020, 46 .cmd_shmem_out_base = 0x82000021, 47 .cmd = { 48 CMD(SM_EFUSE_READ, 0x82000030), 49 CMD(SM_EFUSE_WRITE, 0x82000031), 50 CMD(SM_EFUSE_USER_MAX, 0x82000033), 51 { /* sentinel */ }, 52 }, 53 }; 54 55 struct meson_sm_firmware { 56 const struct meson_sm_chip *chip; 57 void __iomem *sm_shmem_in_base; 58 void __iomem *sm_shmem_out_base; 59 }; 60 61 static struct meson_sm_firmware fw; 62 63 static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip, 64 unsigned int cmd_index) 65 { 66 const struct meson_sm_cmd *cmd = chip->cmd; 67 68 while (cmd->smc_id && cmd->index != cmd_index) 69 cmd++; 70 71 return cmd->smc_id; 72 } 73 74 static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, 75 u32 arg3, u32 arg4) 76 { 77 struct arm_smccc_res res; 78 79 arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res); 80 return res.a0; 81 } 82 83 static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size) 84 { 85 u32 sm_phy_base; 86 87 sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0); 88 if (!sm_phy_base) 89 return 0; 90 91 return ioremap_cache(sm_phy_base, size); 92 } 93 94 /** 95 * meson_sm_call - generic SMC32 call to the secure-monitor 96 * 97 * @cmd_index: Index of the SMC32 function ID 98 * @ret: Returned value 99 * @arg0: SMC32 Argument 0 100 * @arg1: SMC32 Argument 1 101 * @arg2: SMC32 Argument 2 102 * @arg3: SMC32 Argument 3 103 * @arg4: SMC32 Argument 4 104 * 105 * Return: 0 on success, a negative value on error 106 */ 107 int meson_sm_call(unsigned int cmd_index, u32 *ret, u32 arg0, 108 u32 arg1, u32 arg2, u32 arg3, u32 arg4) 109 { 110 u32 cmd, lret; 111 112 if (!fw.chip) 113 return -ENOENT; 114 115 cmd = meson_sm_get_cmd(fw.chip, cmd_index); 116 if (!cmd) 117 return -EINVAL; 118 119 lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4); 120 121 if (ret) 122 *ret = lret; 123 124 return 0; 125 } 126 EXPORT_SYMBOL(meson_sm_call); 127 128 /** 129 * meson_sm_call_read - retrieve data from secure-monitor 130 * 131 * @buffer: Buffer to store the retrieved data 132 * @bsize: Size of the buffer 133 * @cmd_index: Index of the SMC32 function ID 134 * @arg0: SMC32 Argument 0 135 * @arg1: SMC32 Argument 1 136 * @arg2: SMC32 Argument 2 137 * @arg3: SMC32 Argument 3 138 * @arg4: SMC32 Argument 4 139 * 140 * Return: size of read data on success, a negative value on error 141 * When 0 is returned there is no guarantee about the amount of 142 * data read and bsize bytes are copied in buffer. 143 */ 144 int meson_sm_call_read(void *buffer, unsigned int bsize, unsigned int cmd_index, 145 u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4) 146 { 147 u32 size; 148 int ret; 149 150 if (!fw.chip) 151 return -ENOENT; 152 153 if (!fw.chip->cmd_shmem_out_base) 154 return -EINVAL; 155 156 if (bsize > fw.chip->shmem_size) 157 return -EINVAL; 158 159 if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0) 160 return -EINVAL; 161 162 if (size > bsize) 163 return -EINVAL; 164 165 ret = size; 166 167 if (!size) 168 size = bsize; 169 170 if (buffer) 171 memcpy(buffer, fw.sm_shmem_out_base, size); 172 173 return ret; 174 } 175 EXPORT_SYMBOL(meson_sm_call_read); 176 177 /** 178 * meson_sm_call_write - send data to secure-monitor 179 * 180 * @buffer: Buffer containing data to send 181 * @size: Size of the data to send 182 * @cmd_index: Index of the SMC32 function ID 183 * @arg0: SMC32 Argument 0 184 * @arg1: SMC32 Argument 1 185 * @arg2: SMC32 Argument 2 186 * @arg3: SMC32 Argument 3 187 * @arg4: SMC32 Argument 4 188 * 189 * Return: size of sent data on success, a negative value on error 190 */ 191 int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index, 192 u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4) 193 { 194 u32 written; 195 196 if (!fw.chip) 197 return -ENOENT; 198 199 if (size > fw.chip->shmem_size) 200 return -EINVAL; 201 202 if (!fw.chip->cmd_shmem_in_base) 203 return -EINVAL; 204 205 memcpy(fw.sm_shmem_in_base, buffer, size); 206 207 if (meson_sm_call(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0) 208 return -EINVAL; 209 210 if (!written) 211 return -EINVAL; 212 213 return written; 214 } 215 EXPORT_SYMBOL(meson_sm_call_write); 216 217 static const struct of_device_id meson_sm_ids[] = { 218 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip }, 219 { /* sentinel */ }, 220 }; 221 222 static int __init meson_sm_probe(struct platform_device *pdev) 223 { 224 const struct meson_sm_chip *chip; 225 226 chip = of_match_device(meson_sm_ids, &pdev->dev)->data; 227 228 if (chip->cmd_shmem_in_base) { 229 fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base, 230 chip->shmem_size); 231 if (WARN_ON(!fw.sm_shmem_in_base)) 232 goto out; 233 } 234 235 if (chip->cmd_shmem_out_base) { 236 fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base, 237 chip->shmem_size); 238 if (WARN_ON(!fw.sm_shmem_out_base)) 239 goto out_in_base; 240 } 241 242 fw.chip = chip; 243 pr_info("secure-monitor enabled\n"); 244 245 return 0; 246 247 out_in_base: 248 iounmap(fw.sm_shmem_in_base); 249 out: 250 return -EINVAL; 251 } 252 253 static struct platform_driver meson_sm_driver = { 254 .driver = { 255 .name = "meson-sm", 256 .of_match_table = of_match_ptr(meson_sm_ids), 257 }, 258 }; 259 module_platform_driver_probe(meson_sm_driver, meson_sm_probe); 260