1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Amlogic Secure Monitor driver 4 * 5 * Copyright (C) 2016 Endless Mobile, Inc. 6 * Author: Carlo Caione <carlo@endlessm.com> 7 */ 8 9 #define pr_fmt(fmt) "meson-sm: " fmt 10 11 #include <linux/arm-smccc.h> 12 #include <linux/bug.h> 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/of_platform.h> 17 #include <linux/platform_device.h> 18 #include <linux/printk.h> 19 #include <linux/property.h> 20 #include <linux/types.h> 21 #include <linux/sizes.h> 22 #include <linux/slab.h> 23 24 #include <linux/firmware/meson/meson_sm.h> 25 26 struct meson_sm_cmd { 27 unsigned int index; 28 u32 smc_id; 29 }; 30 #define CMD(d, s) { .index = (d), .smc_id = (s), } 31 32 struct meson_sm_chip { 33 unsigned int shmem_size; 34 u32 cmd_shmem_in_base; 35 u32 cmd_shmem_out_base; 36 struct meson_sm_cmd cmd[]; 37 }; 38 39 static const struct meson_sm_chip gxbb_chip = { 40 .shmem_size = SZ_4K, 41 .cmd_shmem_in_base = 0x82000020, 42 .cmd_shmem_out_base = 0x82000021, 43 .cmd = { 44 CMD(SM_EFUSE_READ, 0x82000030), 45 CMD(SM_EFUSE_WRITE, 0x82000031), 46 CMD(SM_EFUSE_USER_MAX, 0x82000033), 47 CMD(SM_GET_CHIP_ID, 0x82000044), 48 CMD(SM_A1_PWRC_SET, 0x82000093), 49 CMD(SM_A1_PWRC_GET, 0x82000095), 50 { /* sentinel */ }, 51 }, 52 }; 53 54 struct meson_sm_firmware { 55 const struct meson_sm_chip *chip; 56 void __iomem *sm_shmem_in_base; 57 void __iomem *sm_shmem_out_base; 58 }; 59 60 static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip, 61 unsigned int cmd_index) 62 { 63 const struct meson_sm_cmd *cmd = chip->cmd; 64 65 while (cmd->smc_id && cmd->index != cmd_index) 66 cmd++; 67 68 return cmd->smc_id; 69 } 70 71 static s32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, 72 u32 arg3, u32 arg4) 73 { 74 struct arm_smccc_res res; 75 76 arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res); 77 return res.a0; 78 } 79 80 static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size) 81 { 82 u32 sm_phy_base; 83 84 sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0); 85 if (!sm_phy_base) 86 return NULL; 87 88 return ioremap_cache(sm_phy_base, size); 89 } 90 91 /** 92 * meson_sm_call - generic SMC32 call to the secure-monitor 93 * 94 * @fw: Pointer to secure-monitor firmware 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(struct meson_sm_firmware *fw, unsigned int cmd_index, 106 s32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4) 107 { 108 u32 cmd; 109 s32 lret; 110 111 if (!fw->chip) 112 return -ENOENT; 113 114 cmd = meson_sm_get_cmd(fw->chip, cmd_index); 115 if (!cmd) 116 return -EINVAL; 117 118 lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4); 119 120 if (ret) 121 *ret = lret; 122 123 return 0; 124 } 125 EXPORT_SYMBOL(meson_sm_call); 126 127 /** 128 * meson_sm_call_read - retrieve data from secure-monitor 129 * 130 * @fw: Pointer to secure-monitor firmware 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(struct meson_sm_firmware *fw, void *buffer, 145 unsigned int bsize, unsigned int cmd_index, u32 arg0, 146 u32 arg1, u32 arg2, u32 arg3, u32 arg4) 147 { 148 s32 size; 149 int ret; 150 151 if (!fw->chip) 152 return -ENOENT; 153 154 if (!fw->chip->cmd_shmem_out_base) 155 return -EINVAL; 156 157 if (bsize > fw->chip->shmem_size) 158 return -EINVAL; 159 160 if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0) 161 return -EINVAL; 162 163 if (size < 0 || size > bsize) 164 return -EINVAL; 165 166 ret = size; 167 168 /* In some cases (for example GET_CHIP_ID command), 169 * SMC doesn't return the number of bytes read, even 170 * though the bytes were actually read into sm_shmem_out. 171 * So this check is needed. 172 */ 173 if (!size) 174 size = bsize; 175 176 if (buffer) 177 memcpy(buffer, fw->sm_shmem_out_base, size); 178 179 return ret; 180 } 181 EXPORT_SYMBOL(meson_sm_call_read); 182 183 /** 184 * meson_sm_call_write - send data to secure-monitor 185 * 186 * @fw: Pointer to secure-monitor firmware 187 * @buffer: Buffer containing data to send 188 * @size: Size of the data to send 189 * @cmd_index: Index of the SMC32 function ID 190 * @arg0: SMC32 Argument 0 191 * @arg1: SMC32 Argument 1 192 * @arg2: SMC32 Argument 2 193 * @arg3: SMC32 Argument 3 194 * @arg4: SMC32 Argument 4 195 * 196 * Return: size of sent data on success, a negative value on error 197 */ 198 int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer, 199 unsigned int size, unsigned int cmd_index, u32 arg0, 200 u32 arg1, u32 arg2, u32 arg3, u32 arg4) 201 { 202 s32 written; 203 204 if (!fw->chip) 205 return -ENOENT; 206 207 if (size > fw->chip->shmem_size) 208 return -EINVAL; 209 210 if (!fw->chip->cmd_shmem_in_base) 211 return -EINVAL; 212 213 memcpy(fw->sm_shmem_in_base, buffer, size); 214 215 if (meson_sm_call(fw, cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0) 216 return -EINVAL; 217 218 if (written <= 0 || written > size) 219 return -EINVAL; 220 221 return written; 222 } 223 EXPORT_SYMBOL(meson_sm_call_write); 224 225 /** 226 * meson_sm_get - get pointer to meson_sm_firmware structure. 227 * 228 * @sm_node: Pointer to the secure-monitor Device Tree node. 229 * 230 * Return: NULL is the secure-monitor device is not ready. 231 */ 232 struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node) 233 { 234 struct platform_device *pdev = of_find_device_by_node(sm_node); 235 236 if (!pdev) 237 return NULL; 238 239 return platform_get_drvdata(pdev); 240 } 241 EXPORT_SYMBOL_GPL(meson_sm_get); 242 243 #define SM_CHIP_ID_LENGTH 119 244 #define SM_CHIP_ID_OFFSET 4 245 #define SM_CHIP_ID_SIZE 12 246 247 static ssize_t serial_show(struct device *dev, struct device_attribute *attr, 248 char *buf) 249 { 250 struct platform_device *pdev = to_platform_device(dev); 251 struct meson_sm_firmware *fw; 252 uint8_t *id_buf; 253 int ret; 254 255 fw = platform_get_drvdata(pdev); 256 257 id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL); 258 if (!id_buf) 259 return -ENOMEM; 260 261 ret = meson_sm_call_read(fw, id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID, 262 0, 0, 0, 0, 0); 263 if (ret < 0) { 264 kfree(id_buf); 265 return ret; 266 } 267 268 ret = sprintf(buf, "%12phN\n", &id_buf[SM_CHIP_ID_OFFSET]); 269 270 kfree(id_buf); 271 272 return ret; 273 } 274 275 static DEVICE_ATTR_RO(serial); 276 277 static struct attribute *meson_sm_sysfs_attrs[] = { 278 &dev_attr_serial.attr, 279 NULL, 280 }; 281 ATTRIBUTE_GROUPS(meson_sm_sysfs); 282 283 static const struct of_device_id meson_sm_ids[] = { 284 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip }, 285 { /* sentinel */ }, 286 }; 287 288 static int __init meson_sm_probe(struct platform_device *pdev) 289 { 290 struct device *dev = &pdev->dev; 291 const struct meson_sm_chip *chip; 292 struct meson_sm_firmware *fw; 293 294 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); 295 if (!fw) 296 return -ENOMEM; 297 298 chip = device_get_match_data(dev); 299 if (!chip) 300 return -EINVAL; 301 302 if (chip->cmd_shmem_in_base) { 303 fw->sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base, 304 chip->shmem_size); 305 if (WARN_ON(!fw->sm_shmem_in_base)) 306 goto out; 307 } 308 309 if (chip->cmd_shmem_out_base) { 310 fw->sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base, 311 chip->shmem_size); 312 if (WARN_ON(!fw->sm_shmem_out_base)) 313 goto unmap_in_base; 314 } 315 316 fw->chip = chip; 317 318 platform_set_drvdata(pdev, fw); 319 320 if (devm_of_platform_populate(dev)) 321 goto unmap_out_base; 322 323 pr_info("secure-monitor enabled\n"); 324 325 return 0; 326 327 unmap_out_base: 328 iounmap(fw->sm_shmem_out_base); 329 unmap_in_base: 330 iounmap(fw->sm_shmem_in_base); 331 out: 332 return -EINVAL; 333 } 334 335 static struct platform_driver meson_sm_driver = { 336 .driver = { 337 .name = "meson-sm", 338 .of_match_table = of_match_ptr(meson_sm_ids), 339 .dev_groups = meson_sm_sysfs_groups, 340 }, 341 }; 342 module_platform_driver_probe(meson_sm_driver, meson_sm_probe); 343 MODULE_DESCRIPTION("Amlogic Secure Monitor driver"); 344 MODULE_LICENSE("GPL v2"); 345