root/arch/arm/mach-exynos/platsmp.c

DEFINITIONS

1. cpu_leave_lowpower
2. platform_do_lowpower
3. exynos_cpu_power_down
4. exynos_cpu_power_up
5. exynos_cpu_power_state
6. exynos_cluster_power_down
7. exynos_cluster_power_up
8. exynos_cluster_power_state
9. exynos_scu_enable
10. cpu_boot_reg_base
11. cpu_boot_reg
12. exynos_core_restart
13. exynos_write_pen_release
14. exynos_secondary_init
15. exynos_set_boot_addr
16. exynos_get_boot_addr
17. exynos_boot_secondary
18. exynos_smp_prepare_cpus
19. exynos_cpu_die

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
   3 //              http://www.samsung.com
   4 //
   5 // Cloned from linux/arch/arm/mach-vexpress/platsmp.c
   6 //
   7 //  Copyright (C) 2002 ARM Ltd.
   8 //  All Rights Reserved
   9 
  10 #include <linux/init.h>
  11 #include <linux/errno.h>
  12 #include <linux/delay.h>
  13 #include <linux/jiffies.h>
  14 #include <linux/smp.h>
  15 #include <linux/io.h>
  16 #include <linux/of_address.h>
  17 #include <linux/soc/samsung/exynos-regs-pmu.h>
  18 
  19 #include <asm/cacheflush.h>
  20 #include <asm/cp15.h>
  21 #include <asm/smp_plat.h>
  22 #include <asm/smp_scu.h>
  23 #include <asm/firmware.h>
  24 
  25 #include <mach/map.h>
  26 
  27 #include "common.h"
  28 
  29 extern void exynos4_secondary_startup(void);
  30 
  31 /* XXX exynos_pen_release is cargo culted code - DO NOT COPY XXX */
  32 volatile int exynos_pen_release = -1;
  33 
  34 #ifdef CONFIG_HOTPLUG_CPU
  35 static inline void cpu_leave_lowpower(u32 core_id)
  36 {
  37         unsigned int v;
  38 
  39         asm volatile(
  40         "mrc    p15, 0, %0, c1, c0, 0\n"
  41         "       orr     %0, %0, %1\n"
  42         "       mcr     p15, 0, %0, c1, c0, 0\n"
  43         "       mrc     p15, 0, %0, c1, c0, 1\n"
  44         "       orr     %0, %0, %2\n"
  45         "       mcr     p15, 0, %0, c1, c0, 1\n"
  46           : "=&r" (v)
  47           : "Ir" (CR_C), "Ir" (0x40)
  48           : "cc");
  49 }
  50 
  51 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
  52 {
  53         u32 mpidr = cpu_logical_map(cpu);
  54         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  55 
  56         for (;;) {
  57 
  58                 /* Turn the CPU off on next WFI instruction. */
  59                 exynos_cpu_power_down(core_id);
  60 
  61                 wfi();
  62 
  63                 if (exynos_pen_release == core_id) {
  64                         /*
  65                          * OK, proper wakeup, we're done
  66                          */
  67                         break;
  68                 }
  69 
  70                 /*
  71                  * Getting here, means that we have come out of WFI without
  72                  * having been woken up - this shouldn't happen
  73                  *
  74                  * Just note it happening - when we're woken, we can report
  75                  * its occurrence.
  76                  */
  77                 (*spurious)++;
  78         }
  79 }
  80 #endif /* CONFIG_HOTPLUG_CPU */
  81 
  82 /**
  83  * exynos_core_power_down : power down the specified cpu
  84  * @cpu : the cpu to power down
  85  *
  86  * Power down the specified cpu. The sequence must be finished by a
  87  * call to cpu_do_idle()
  88  *
  89  */
  90 void exynos_cpu_power_down(int cpu)
  91 {
  92         u32 core_conf;
  93 
  94         if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
  95                 /*
  96                  * Bypass power down for CPU0 during suspend. Check for
  97                  * the SYS_PWR_REG value to decide if we are suspending
  98                  * the system.
  99                  */
 100                 int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);
 101 
 102                 if (!(val & S5P_CORE_LOCAL_PWR_EN))
 103                         return;
 104         }
 105 
 106         core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 107         core_conf &= ~S5P_CORE_LOCAL_PWR_EN;
 108         pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 109 }
 110 
 111 /**
 112  * exynos_cpu_power_up : power up the specified cpu
 113  * @cpu : the cpu to power up
 114  *
 115  * Power up the specified cpu
 116  */
 117 void exynos_cpu_power_up(int cpu)
 118 {
 119         u32 core_conf = S5P_CORE_LOCAL_PWR_EN;
 120 
 121         if (soc_is_exynos3250())
 122                 core_conf |= S5P_CORE_AUTOWAKEUP_EN;
 123 
 124         pmu_raw_writel(core_conf,
 125                         EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 126 }
 127 
 128 /**
 129  * exynos_cpu_power_state : returns the power state of the cpu
 130  * @cpu : the cpu to retrieve the power state from
 131  *
 132  */
 133 int exynos_cpu_power_state(int cpu)
 134 {
 135         return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
 136                         S5P_CORE_LOCAL_PWR_EN);
 137 }
 138 
 139 /**
 140  * exynos_cluster_power_down : power down the specified cluster
 141  * @cluster : the cluster to power down
 142  */
 143 void exynos_cluster_power_down(int cluster)
 144 {
 145         pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
 146 }
 147 
 148 /**
 149  * exynos_cluster_power_up : power up the specified cluster
 150  * @cluster : the cluster to power up
 151  */
 152 void exynos_cluster_power_up(int cluster)
 153 {
 154         pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
 155                         EXYNOS_COMMON_CONFIGURATION(cluster));
 156 }
 157 
 158 /**
 159  * exynos_cluster_power_state : returns the power state of the cluster
 160  * @cluster : the cluster to retrieve the power state from
 161  *
 162  */
 163 int exynos_cluster_power_state(int cluster)
 164 {
 165         return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
 166                 S5P_CORE_LOCAL_PWR_EN);
 167 }
 168 
 169 /**
 170  * exynos_scu_enable : enables SCU for Cortex-A9 based system
 171  */
 172 void exynos_scu_enable(void)
 173 {
 174         struct device_node *np;
 175         static void __iomem *scu_base;
 176 
 177         if (!scu_base) {
 178                 np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
 179                 if (np) {
 180                         scu_base = of_iomap(np, 0);
 181                         of_node_put(np);
 182                 } else {
 183                         scu_base = ioremap(scu_a9_get_base(), SZ_4K);
 184                 }
 185         }
 186         scu_enable(scu_base);
 187 }
 188 
 189 static void __iomem *cpu_boot_reg_base(void)
 190 {
 191         if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
 192                 return pmu_base_addr + S5P_INFORM5;
 193         return sysram_base_addr;
 194 }
 195 
 196 static inline void __iomem *cpu_boot_reg(int cpu)
 197 {
 198         void __iomem *boot_reg;
 199 
 200         boot_reg = cpu_boot_reg_base();
 201         if (!boot_reg)
 202                 return IOMEM_ERR_PTR(-ENODEV);
 203         if (soc_is_exynos4412())
 204                 boot_reg += 4*cpu;
 205         else if (soc_is_exynos5420() || soc_is_exynos5800())
 206                 boot_reg += 4;
 207         return boot_reg;
 208 }
 209 
 210 /*
 211  * Set wake up by local power mode and execute software reset for given core.
 212  *
 213  * Currently this is needed only when booting secondary CPU on Exynos3250.
 214  */
 215 void exynos_core_restart(u32 core_id)
 216 {
 217         unsigned int timeout = 16;
 218         u32 val;
 219 
 220         if (!of_machine_is_compatible("samsung,exynos3250"))
 221                 return;
 222 
 223         while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
 224                 timeout--;
 225                 udelay(10);
 226         }
 227         if (timeout == 0) {
 228                 pr_err("cpu core %u restart failed\n", core_id);
 229                 return;
 230         }
 231         udelay(10);
 232 
 233         val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
 234         val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
 235         pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
 236 
 237         pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
 238 }
 239 
 240 /*
 241  * XXX CARGO CULTED CODE - DO NOT COPY XXX
 242  *
 243  * Write exynos_pen_release in a way that is guaranteed to be visible to
 244  * all observers, irrespective of whether they're taking part in coherency
 245  * or not.  This is necessary for the hotplug code to work reliably.
 246  */
 247 static void exynos_write_pen_release(int val)
 248 {
 249         exynos_pen_release = val;
 250         smp_wmb();
 251         sync_cache_w(&exynos_pen_release);
 252 }
 253 
 254 static DEFINE_SPINLOCK(boot_lock);
 255 
 256 static void exynos_secondary_init(unsigned int cpu)
 257 {
 258         /*
 259          * let the primary processor know we're out of the
 260          * pen, then head off into the C entry point
 261          */
 262         exynos_write_pen_release(-1);
 263 
 264         /*
 265          * Synchronise with the boot thread.
 266          */
 267         spin_lock(&boot_lock);
 268         spin_unlock(&boot_lock);
 269 }
 270 
 271 int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
 272 {
 273         int ret;
 274 
 275         /*
 276          * Try to set boot address using firmware first
 277          * and fall back to boot register if it fails.
 278          */
 279         ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
 280         if (ret && ret != -ENOSYS)
 281                 goto fail;
 282         if (ret == -ENOSYS) {
 283                 void __iomem *boot_reg = cpu_boot_reg(core_id);
 284 
 285                 if (IS_ERR(boot_reg)) {
 286                         ret = PTR_ERR(boot_reg);
 287                         goto fail;
 288                 }
 289                 writel_relaxed(boot_addr, boot_reg);
 290                 ret = 0;
 291         }
 292 fail:
 293         return ret;
 294 }
 295 
 296 int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
 297 {
 298         int ret;
 299 
 300         /*
 301          * Try to get boot address using firmware first
 302          * and fall back to boot register if it fails.
 303          */
 304         ret = call_firmware_op(get_cpu_boot_addr, core_id, boot_addr);
 305         if (ret && ret != -ENOSYS)
 306                 goto fail;
 307         if (ret == -ENOSYS) {
 308                 void __iomem *boot_reg = cpu_boot_reg(core_id);
 309 
 310                 if (IS_ERR(boot_reg)) {
 311                         ret = PTR_ERR(boot_reg);
 312                         goto fail;
 313                 }
 314                 *boot_addr = readl_relaxed(boot_reg);
 315                 ret = 0;
 316         }
 317 fail:
 318         return ret;
 319 }
 320 
 321 static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
 322 {
 323         unsigned long timeout;
 324         u32 mpidr = cpu_logical_map(cpu);
 325         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 326         int ret = -ENOSYS;
 327 
 328         /*
 329          * Set synchronisation state between this boot processor
 330          * and the secondary one
 331          */
 332         spin_lock(&boot_lock);
 333 
 334         /*
 335          * The secondary processor is waiting to be released from
 336          * the holding pen - release it, then wait for it to flag
 337          * that it has been released by resetting exynos_pen_release.
 338          *
 339          * Note that "exynos_pen_release" is the hardware CPU core ID, whereas
 340          * "cpu" is Linux's internal ID.
 341          */
 342         exynos_write_pen_release(core_id);
 343 
 344         if (!exynos_cpu_power_state(core_id)) {
 345                 exynos_cpu_power_up(core_id);
 346                 timeout = 10;
 347 
 348                 /* wait max 10 ms until cpu1 is on */
 349                 while (exynos_cpu_power_state(core_id)
 350                        != S5P_CORE_LOCAL_PWR_EN) {
 351                         if (timeout == 0)
 352                                 break;
 353                         timeout--;
 354                         mdelay(1);
 355                 }
 356 
 357                 if (timeout == 0) {
 358                         printk(KERN_ERR "cpu1 power enable failed");
 359                         spin_unlock(&boot_lock);
 360                         return -ETIMEDOUT;
 361                 }
 362         }
 363 
 364         exynos_core_restart(core_id);
 365 
 366         /*
 367          * Send the secondary CPU a soft interrupt, thereby causing
 368          * the boot monitor to read the system wide flags register,
 369          * and branch to the address found there.
 370          */
 371 
 372         timeout = jiffies + (1 * HZ);
 373         while (time_before(jiffies, timeout)) {
 374                 unsigned long boot_addr;
 375 
 376                 smp_rmb();
 377 
 378                 boot_addr = __pa_symbol(exynos4_secondary_startup);
 379 
 380                 ret = exynos_set_boot_addr(core_id, boot_addr);
 381                 if (ret)
 382                         goto fail;
 383 
 384                 call_firmware_op(cpu_boot, core_id);
 385 
 386                 if (soc_is_exynos3250())
 387                         dsb_sev();
 388                 else
 389                         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 390 
 391                 if (exynos_pen_release == -1)
 392                         break;
 393 
 394                 udelay(10);
 395         }
 396 
 397         if (exynos_pen_release != -1)
 398                 ret = -ETIMEDOUT;
 399 
 400         /*
 401          * now the secondary core is starting up let it run its
 402          * calibrations, then wait for it to finish
 403          */
 404 fail:
 405         spin_unlock(&boot_lock);
 406 
 407         return exynos_pen_release != -1 ? ret : 0;
 408 }
 409 
 410 static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
 411 {
 412         exynos_sysram_init();
 413 
 414         exynos_set_delayed_reset_assertion(true);
 415 
 416         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
 417                 exynos_scu_enable();
 418 }
 419 
 420 #ifdef CONFIG_HOTPLUG_CPU
 421 /*
 422  * platform-specific code to shutdown a CPU
 423  *
 424  * Called with IRQs disabled
 425  */
 426 static void exynos_cpu_die(unsigned int cpu)
 427 {
 428         int spurious = 0;
 429         u32 mpidr = cpu_logical_map(cpu);
 430         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 431 
 432         v7_exit_coherency_flush(louis);
 433 
 434         platform_do_lowpower(cpu, &spurious);
 435 
 436         /*
 437          * bring this CPU back into the world of cache
 438          * coherency, and then restore interrupts
 439          */
 440         cpu_leave_lowpower(core_id);
 441 
 442         if (spurious)
 443                 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
 444 }
 445 #endif /* CONFIG_HOTPLUG_CPU */
 446 
 447 const struct smp_operations exynos_smp_ops __initconst = {
 448         .smp_prepare_cpus       = exynos_smp_prepare_cpus,
 449         .smp_secondary_init     = exynos_secondary_init,
 450         .smp_boot_secondary     = exynos_boot_secondary,
 451 #ifdef CONFIG_HOTPLUG_CPU
 452         .cpu_die                = exynos_cpu_die,
 453 #endif
 454 };