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 * @cmd_index: Index of the SMC32 function ID 131 * @arg0: SMC32 Argument 0 132 * @arg1: SMC32 Argument 1 133 * @arg2: SMC32 Argument 2 134 * @arg3: SMC32 Argument 3 135 * @arg4: SMC32 Argument 4 136 * 137 * Return: size of read data on success, a negative value on error 138 */ 139 int meson_sm_call_read(void *buffer, unsigned int cmd_index, u32 arg0, 140 u32 arg1, u32 arg2, u32 arg3, u32 arg4) 141 { 142 u32 size; 143 144 if (!fw.chip) 145 return -ENOENT; 146 147 if (!fw.chip->cmd_shmem_out_base) 148 return -EINVAL; 149 150 if (meson_sm_call(cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0) 151 return -EINVAL; 152 153 if (!size || size > fw.chip->shmem_size) 154 return -EINVAL; 155 156 if (buffer) 157 memcpy(buffer, fw.sm_shmem_out_base, size); 158 159 return size; 160 } 161 EXPORT_SYMBOL(meson_sm_call_read); 162 163 /** 164 * meson_sm_call_write - send data to secure-monitor 165 * 166 * @buffer: Buffer containing data to send 167 * @size: Size of the data to send 168 * @cmd_index: Index of the SMC32 function ID 169 * @arg0: SMC32 Argument 0 170 * @arg1: SMC32 Argument 1 171 * @arg2: SMC32 Argument 2 172 * @arg3: SMC32 Argument 3 173 * @arg4: SMC32 Argument 4 174 * 175 * Return: size of sent data on success, a negative value on error 176 */ 177 int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index, 178 u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4) 179 { 180 u32 written; 181 182 if (!fw.chip) 183 return -ENOENT; 184 185 if (size > fw.chip->shmem_size) 186 return -EINVAL; 187 188 if (!fw.chip->cmd_shmem_in_base) 189 return -EINVAL; 190 191 memcpy(fw.sm_shmem_in_base, buffer, size); 192 193 if (meson_sm_call(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0) 194 return -EINVAL; 195 196 if (!written) 197 return -EINVAL; 198 199 return written; 200 } 201 EXPORT_SYMBOL(meson_sm_call_write); 202 203 static const struct of_device_id meson_sm_ids[] = { 204 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip }, 205 { /* sentinel */ }, 206 }; 207 208 int __init meson_sm_init(void) 209 { 210 const struct meson_sm_chip *chip; 211 const struct of_device_id *matched_np; 212 struct device_node *np; 213 214 np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np); 215 if (!np) 216 return -ENODEV; 217 218 chip = matched_np->data; 219 if (!chip) { 220 pr_err("unable to setup secure-monitor data\n"); 221 goto out; 222 } 223 224 if (chip->cmd_shmem_in_base) { 225 fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base, 226 chip->shmem_size); 227 if (WARN_ON(!fw.sm_shmem_in_base)) 228 goto out; 229 } 230 231 if (chip->cmd_shmem_out_base) { 232 fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base, 233 chip->shmem_size); 234 if (WARN_ON(!fw.sm_shmem_out_base)) 235 goto out_in_base; 236 } 237 238 fw.chip = chip; 239 pr_info("secure-monitor enabled\n"); 240 241 return 0; 242 243 out_in_base: 244 iounmap(fw.sm_shmem_in_base); 245 out: 246 return -EINVAL; 247 } 248 device_initcall(meson_sm_init); 249