arch/arm/kernel/psci.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * Copyright (C) 2012 ARM Limited
  12  *
  13  * Author: Will Deacon <will.deacon@arm.com>
  14  */
  15
  16 #define pr_fmt(fmt) "psci: " fmt
  17
  18 #include <linux/init.h>
  19 #include <linux/of.h>
  20 #include <linux/reboot.h>
  21 #include <linux/pm.h>
  22 #include <uapi/linux/psci.h>
  23
  24 #include <asm/compiler.h>
  25 #include <asm/errno.h>
  26 #include <asm/opcodes-sec.h>
  27 #include <asm/opcodes-virt.h>
  28 #include <asm/psci.h>
  29 #include <asm/system_misc.h>
  30
  31 struct psci_operations psci_ops;
  32
  33 static int (*invoke_psci_fn)(u32, u32, u32, u32);
  34 typedef int (*psci_initcall_t)(const struct device_node *);
  35
  36 enum psci_function {
  37         PSCI_FN_CPU_SUSPEND,
  38         PSCI_FN_CPU_ON,
  39         PSCI_FN_CPU_OFF,
  40         PSCI_FN_MIGRATE,
  41         PSCI_FN_AFFINITY_INFO,
  42         PSCI_FN_MIGRATE_INFO_TYPE,
  43         PSCI_FN_MAX,
  44 };
  45
  46 static u32 psci_function_id[PSCI_FN_MAX];
  47
  48 static int psci_to_linux_errno(int errno)
  49 {
  50         switch (errno) {
  51         case PSCI_RET_SUCCESS:
  52                 return 0;
  53         case PSCI_RET_NOT_SUPPORTED:
  54                 return -EOPNOTSUPP;
  55         case PSCI_RET_INVALID_PARAMS:
  56                 return -EINVAL;
  57         case PSCI_RET_DENIED:
  58                 return -EPERM;
  59         };
  60
  61         return -EINVAL;
  62 }
  63
  64 static u32 psci_power_state_pack(struct psci_power_state state)
  65 {
  66         return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
  67                         & PSCI_0_2_POWER_STATE_ID_MASK) |
  68                 ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
  69                  & PSCI_0_2_POWER_STATE_TYPE_MASK) |
  70                 ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
  71                  & PSCI_0_2_POWER_STATE_AFFL_MASK);
  72 }
  73
  74 /*
  75  * The following two functions are invoked via the invoke_psci_fn pointer
  76  * and will not be inlined, allowing us to piggyback on the AAPCS.
  77  */
  78 static noinline int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1,
  79                                          u32 arg2)
  80 {
  81         asm volatile(
  82                         __asmeq("%0", "r0")
  83                         __asmeq("%1", "r1")
  84                         __asmeq("%2", "r2")
  85                         __asmeq("%3", "r3")
  86                         __HVC(0)
  87                 : "+r" (function_id)
  88                 : "r" (arg0), "r" (arg1), "r" (arg2));
  89
  90         return function_id;
  91 }
  92
  93 static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
  94                                          u32 arg2)
  95 {
  96         asm volatile(
  97                         __asmeq("%0", "r0")
  98                         __asmeq("%1", "r1")
  99                         __asmeq("%2", "r2")
 100                         __asmeq("%3", "r3")
 101                         __SMC(0)
 102                 : "+r" (function_id)
 103                 : "r" (arg0), "r" (arg1), "r" (arg2));
 104
 105         return function_id;
 106 }
 107
 108 #define PSCI_VER_MAJOR_MASK             0xffff0000
 109 #define PSCI_VER_MINOR_MASK             0x0000ffff
 110 #define PSCI_VER_MAJOR_SHIFT    16
 111 #define PSCI_VER_MAJOR(ver)             \
 112         ((ver & PSCI_VER_MAJOR_MASK) >> PSCI_VER_MAJOR_SHIFT)
 113 #define PSCI_VER_MINOR(ver)             (ver & PSCI_VER_MINOR_MASK)
 114
 115 static int psci_get_version(void)
 116 {
 117         int err;
 118
 119         err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 120         return err;
 121 }
 122
 123 static int psci_cpu_suspend(struct psci_power_state state,
 124                             unsigned long entry_point)
 125 {
 126         int err;
 127         u32 fn, power_state;
 128
 129         fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
 130         power_state = psci_power_state_pack(state);
 131         err = invoke_psci_fn(fn, power_state, entry_point, 0);
 132         return psci_to_linux_errno(err);
 133 }
 134
 135 static int psci_cpu_off(struct psci_power_state state)
 136 {
 137         int err;
 138         u32 fn, power_state;
 139
 140         fn = psci_function_id[PSCI_FN_CPU_OFF];
 141         power_state = psci_power_state_pack(state);
 142         err = invoke_psci_fn(fn, power_state, 0, 0);
 143         return psci_to_linux_errno(err);
 144 }
 145
 146 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
 147 {
 148         int err;
 149         u32 fn;
 150
 151         fn = psci_function_id[PSCI_FN_CPU_ON];
 152         err = invoke_psci_fn(fn, cpuid, entry_point, 0);
 153         return psci_to_linux_errno(err);
 154 }
 155
 156 static int psci_migrate(unsigned long cpuid)
 157 {
 158         int err;
 159         u32 fn;
 160
 161         fn = psci_function_id[PSCI_FN_MIGRATE];
 162         err = invoke_psci_fn(fn, cpuid, 0, 0);
 163         return psci_to_linux_errno(err);
 164 }
 165
 166 static int psci_affinity_info(unsigned long target_affinity,
 167                 unsigned long lowest_affinity_level)
 168 {
 169         int err;
 170         u32 fn;
 171
 172         fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
 173         err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
 174         return err;
 175 }
 176
 177 static int psci_migrate_info_type(void)
 178 {
 179         int err;
 180         u32 fn;
 181
 182         fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
 183         err = invoke_psci_fn(fn, 0, 0, 0);
 184         return err;
 185 }
 186
 187 static int get_set_conduit_method(struct device_node *np)
 188 {
 189         const char *method;
 190
 191         pr_info("probing for conduit method from DT.\n");
 192
 193         if (of_property_read_string(np, "method", &method)) {
 194                 pr_warn("missing \"method\" property\n");
 195                 return -ENXIO;
 196         }
 197
 198         if (!strcmp("hvc", method)) {
 199                 invoke_psci_fn = __invoke_psci_fn_hvc;
 200         } else if (!strcmp("smc", method)) {
 201                 invoke_psci_fn = __invoke_psci_fn_smc;
 202         } else {
 203                 pr_warn("invalid \"method\" property: %s\n", method);
 204                 return -EINVAL;
 205         }
 206         return 0;
 207 }
 208
 209 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
 210 {
 211         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
 212 }
 213
 214 static void psci_sys_poweroff(void)
 215 {
 216         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
 217 }
 218
 219 /*
 220  * PSCI Function IDs for v0.2+ are well defined so use
 221  * standard values.
 222  */
 223 static int psci_0_2_init(struct device_node *np)
 224 {
 225         int err, ver;
 226
 227         err = get_set_conduit_method(np);
 228
 229         if (err)
 230                 goto out_put_node;
 231
 232         ver = psci_get_version();
 233
 234         if (ver == PSCI_RET_NOT_SUPPORTED) {
 235                 /* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
 236                 pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
 237                 err = -EOPNOTSUPP;
 238                 goto out_put_node;
 239         } else {
 240                 pr_info("PSCIv%d.%d detected in firmware.\n",
 241                                 PSCI_VERSION_MAJOR(ver),
 242                                 PSCI_VERSION_MINOR(ver));
 243
 244                 if (PSCI_VERSION_MAJOR(ver) == 0 &&
 245                                 PSCI_VERSION_MINOR(ver) < 2) {
 246                         err = -EINVAL;
 247                         pr_err("Conflicting PSCI version detected.\n");
 248                         goto out_put_node;
 249                 }
 250         }
 251
 252         pr_info("Using standard PSCI v0.2 function IDs\n");
 253         psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_CPU_SUSPEND;
 254         psci_ops.cpu_suspend = psci_cpu_suspend;
 255
 256         psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
 257         psci_ops.cpu_off = psci_cpu_off;
 258
 259         psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_CPU_ON;
 260         psci_ops.cpu_on = psci_cpu_on;
 261
 262         psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_MIGRATE;
 263         psci_ops.migrate = psci_migrate;
 264
 265         psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN_AFFINITY_INFO;
 266         psci_ops.affinity_info = psci_affinity_info;
 267
 268         psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
 269                 PSCI_0_2_FN_MIGRATE_INFO_TYPE;
 270         psci_ops.migrate_info_type = psci_migrate_info_type;
 271
 272         //TODO: verify how arm_pm_restart and pm_power_off works with atf
 273         //arm_pm_restart = psci_sys_reset;
 274
 275         //pm_power_off = psci_sys_poweroff;
 276
 277 out_put_node:
 278         of_node_put(np);
 279         return err;
 280 }
 281
 282 /*
 283  * PSCI < v0.2 get PSCI Function IDs via DT.
 284  */
 285 static int psci_0_1_init(struct device_node *np)
 286 {
 287         u32 id;
 288         int err;
 289
 290         err = get_set_conduit_method(np);
 291
 292         if (err)
 293                 goto out_put_node;
 294
 295         pr_info("Using PSCI v0.1 Function IDs from DT\n");
 296
 297         if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 298                 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 299                 psci_ops.cpu_suspend = psci_cpu_suspend;
 300         }
 301
 302         if (!of_property_read_u32(np, "cpu_off", &id)) {
 303                 psci_function_id[PSCI_FN_CPU_OFF] = id;
 304                 psci_ops.cpu_off = psci_cpu_off;
 305         }
 306
 307         if (!of_property_read_u32(np, "cpu_on", &id)) {
 308                 psci_function_id[PSCI_FN_CPU_ON] = id;
 309                 psci_ops.cpu_on = psci_cpu_on;
 310         }
 311
 312         if (!of_property_read_u32(np, "migrate", &id)) {
 313                 psci_function_id[PSCI_FN_MIGRATE] = id;
 314                 psci_ops.migrate = psci_migrate;
 315         }
 316
 317 out_put_node:
 318         of_node_put(np);
 319         return err;
 320 }
 321
 322 static const struct of_device_id psci_of_match[] __initconst = {
 323         { .compatible = "arm,psci", .data = psci_0_1_init},
 324         { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
 325         {},
 326 };
 327
 328 int __init psci_init(void)
 329 {
 330         struct device_node *np;
 331         const struct of_device_id *matched_np;
 332         psci_initcall_t init_fn;
 333
 334         np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
 335         if (!np)
 336                 return -ENODEV;
 337
 338         init_fn = (psci_initcall_t)matched_np->data;
 339         return init_fn(np);
 340 }