arch/arm/mach-exynos/platsmp.c

   1  /*
   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  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #include <linux/init.h>
  16 #include <linux/errno.h>
  17 #include <linux/delay.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/smp.h>
  20 #include <linux/io.h>
  21 #include <linux/of_address.h>
  22 #include <linux/soc/samsung/exynos-regs-pmu.h>
  23
  24 #include <asm/cacheflush.h>
  25 #include <asm/cp15.h>
  26 #include <asm/smp_plat.h>
  27 #include <asm/smp_scu.h>
  28 #include <asm/firmware.h>
  29
  30 #include <mach/map.h>
  31
  32 #include "common.h"
  33
  34 extern void exynos4_secondary_startup(void);
  35
  36 #ifdef CONFIG_HOTPLUG_CPU
  37 static inline void cpu_leave_lowpower(u32 core_id)
  38 {
  39         unsigned int v;
  40
  41         asm volatile(
  42         "mrc    p15, 0, %0, c1, c0, 0\n"
  43         "       orr     %0, %0, %1\n"
  44         "       mcr     p15, 0, %0, c1, c0, 0\n"
  45         "       mrc     p15, 0, %0, c1, c0, 1\n"
  46         "       orr     %0, %0, %2\n"
  47         "       mcr     p15, 0, %0, c1, c0, 1\n"
  48           : "=&r" (v)
  49           : "Ir" (CR_C), "Ir" (0x40)
  50           : "cc");
  51 }
  52
  53 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
  54 {
  55         u32 mpidr = cpu_logical_map(cpu);
  56         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  57
  58         for (;;) {
  59
  60                 /* Turn the CPU off on next WFI instruction. */
  61                 exynos_cpu_power_down(core_id);
  62
  63                 wfi();
  64
  65                 if (pen_release == core_id) {
  66                         /*
  67                          * OK, proper wakeup, we're done
  68                          */
  69                         break;
  70                 }
  71
  72                 /*
  73                  * Getting here, means that we have come out of WFI without
  74                  * having been woken up - this shouldn't happen
  75                  *
  76                  * Just note it happening - when we're woken, we can report
  77                  * its occurrence.
  78                  */
  79                 (*spurious)++;
  80         }
  81 }
  82 #endif /* CONFIG_HOTPLUG_CPU */
  83
  84 /**
  85  * exynos_core_power_down : power down the specified cpu
  86  * @cpu : the cpu to power down
  87  *
  88  * Power down the specified cpu. The sequence must be finished by a
  89  * call to cpu_do_idle()
  90  *
  91  */
  92 void exynos_cpu_power_down(int cpu)
  93 {
  94         u32 core_conf;
  95
  96         if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
  97                 /*
  98                  * Bypass power down for CPU0 during suspend. Check for
  99                  * the SYS_PWR_REG value to decide if we are suspending
 100                  * the system.
 101                  */
 102                 int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);
 103
 104                 if (!(val & S5P_CORE_LOCAL_PWR_EN))
 105                         return;
 106         }
 107
 108         core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 109         core_conf &= ~S5P_CORE_LOCAL_PWR_EN;
 110         pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 111 }
 112
 113 /**
 114  * exynos_cpu_power_up : power up the specified cpu
 115  * @cpu : the cpu to power up
 116  *
 117  * Power up the specified cpu
 118  */
 119 void exynos_cpu_power_up(int cpu)
 120 {
 121         u32 core_conf = S5P_CORE_LOCAL_PWR_EN;
 122
 123         if (soc_is_exynos3250())
 124                 core_conf |= S5P_CORE_AUTOWAKEUP_EN;
 125
 126         pmu_raw_writel(core_conf,
 127                         EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 128 }
 129
 130 /**
 131  * exynos_cpu_power_state : returns the power state of the cpu
 132  * @cpu : the cpu to retrieve the power state from
 133  *
 134  */
 135 int exynos_cpu_power_state(int cpu)
 136 {
 137         return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
 138                         S5P_CORE_LOCAL_PWR_EN);
 139 }
 140
 141 /**
 142  * exynos_cluster_power_down : power down the specified cluster
 143  * @cluster : the cluster to power down
 144  */
 145 void exynos_cluster_power_down(int cluster)
 146 {
 147         pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
 148 }
 149
 150 /**
 151  * exynos_cluster_power_up : power up the specified cluster
 152  * @cluster : the cluster to power up
 153  */
 154 void exynos_cluster_power_up(int cluster)
 155 {
 156         pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
 157                         EXYNOS_COMMON_CONFIGURATION(cluster));
 158 }
 159
 160 /**
 161  * exynos_cluster_power_state : returns the power state of the cluster
 162  * @cluster : the cluster to retrieve the power state from
 163  *
 164  */
 165 int exynos_cluster_power_state(int cluster)
 166 {
 167         return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
 168                 S5P_CORE_LOCAL_PWR_EN);
 169 }
 170
 171 static void __iomem *cpu_boot_reg_base(void)
 172 {
 173         if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
 174                 return pmu_base_addr + S5P_INFORM5;
 175         return sysram_base_addr;
 176 }
 177
 178 static inline void __iomem *cpu_boot_reg(int cpu)
 179 {
 180         void __iomem *boot_reg;
 181
 182         boot_reg = cpu_boot_reg_base();
 183         if (!boot_reg)
 184                 return IOMEM_ERR_PTR(-ENODEV);
 185         if (soc_is_exynos4412())
 186                 boot_reg += 4*cpu;
 187         else if (soc_is_exynos5420() || soc_is_exynos5800())
 188                 boot_reg += 4;
 189         return boot_reg;
 190 }
 191
 192 /*
 193  * Set wake up by local power mode and execute software reset for given core.
 194  *
 195  * Currently this is needed only when booting secondary CPU on Exynos3250.
 196  */
 197 void exynos_core_restart(u32 core_id)
 198 {
 199         u32 val;
 200
 201         if (!of_machine_is_compatible("samsung,exynos3250"))
 202                 return;
 203
 204         while (!pmu_raw_readl(S5P_PMU_SPARE2))
 205                 udelay(10);
 206         udelay(10);
 207
 208         val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
 209         val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
 210         pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
 211
 212         pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
 213 }
 214
 215 /*
 216  * Write pen_release in a way that is guaranteed to be visible to all
 217  * observers, irrespective of whether they're taking part in coherency
 218  * or not.  This is necessary for the hotplug code to work reliably.
 219  */
 220 static void write_pen_release(int val)
 221 {
 222         pen_release = val;
 223         smp_wmb();
 224         sync_cache_w(&pen_release);
 225 }
 226
 227 static void __iomem *scu_base_addr(void)
 228 {
 229         return (void __iomem *)(S5P_VA_SCU);
 230 }
 231
 232 static DEFINE_SPINLOCK(boot_lock);
 233
 234 static void exynos_secondary_init(unsigned int cpu)
 235 {
 236         /*
 237          * let the primary processor know we're out of the
 238          * pen, then head off into the C entry point
 239          */
 240         write_pen_release(-1);
 241
 242         /*
 243          * Synchronise with the boot thread.
 244          */
 245         spin_lock(&boot_lock);
 246         spin_unlock(&boot_lock);
 247 }
 248
 249 int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
 250 {
 251         int ret;
 252
 253         /*
 254          * Try to set boot address using firmware first
 255          * and fall back to boot register if it fails.
 256          */
 257         ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
 258         if (ret && ret != -ENOSYS)
 259                 goto fail;
 260         if (ret == -ENOSYS) {
 261                 void __iomem *boot_reg = cpu_boot_reg(core_id);
 262
 263                 if (IS_ERR(boot_reg)) {
 264                         ret = PTR_ERR(boot_reg);
 265                         goto fail;
 266                 }
 267                 writel_relaxed(boot_addr, boot_reg);
 268                 ret = 0;
 269         }
 270 fail:
 271         return ret;
 272 }
 273
 274 int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
 275 {
 276         int ret;
 277
 278         /*
 279          * Try to get boot address using firmware first
 280          * and fall back to boot register if it fails.
 281          */
 282         ret = call_firmware_op(get_cpu_boot_addr, core_id, boot_addr);
 283         if (ret && ret != -ENOSYS)
 284                 goto fail;
 285         if (ret == -ENOSYS) {
 286                 void __iomem *boot_reg = cpu_boot_reg(core_id);
 287
 288                 if (IS_ERR(boot_reg)) {
 289                         ret = PTR_ERR(boot_reg);
 290                         goto fail;
 291                 }
 292                 *boot_addr = readl_relaxed(boot_reg);
 293                 ret = 0;
 294         }
 295 fail:
 296         return ret;
 297 }
 298
 299 static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
 300 {
 301         unsigned long timeout;
 302         u32 mpidr = cpu_logical_map(cpu);
 303         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 304         int ret = -ENOSYS;
 305
 306         /*
 307          * Set synchronisation state between this boot processor
 308          * and the secondary one
 309          */
 310         spin_lock(&boot_lock);
 311
 312         /*
 313          * The secondary processor is waiting to be released from
 314          * the holding pen - release it, then wait for it to flag
 315          * that it has been released by resetting pen_release.
 316          *
 317          * Note that "pen_release" is the hardware CPU core ID, whereas
 318          * "cpu" is Linux's internal ID.
 319          */
 320         write_pen_release(core_id);
 321
 322         if (!exynos_cpu_power_state(core_id)) {
 323                 exynos_cpu_power_up(core_id);
 324                 timeout = 10;
 325
 326                 /* wait max 10 ms until cpu1 is on */
 327                 while (exynos_cpu_power_state(core_id)
 328                        != S5P_CORE_LOCAL_PWR_EN) {
 329                         if (timeout-- == 0)
 330                                 break;
 331
 332                         mdelay(1);
 333                 }
 334
 335                 if (timeout == 0) {
 336                         printk(KERN_ERR "cpu1 power enable failed");
 337                         spin_unlock(&boot_lock);
 338                         return -ETIMEDOUT;
 339                 }
 340         }
 341
 342         exynos_core_restart(core_id);
 343
 344         /*
 345          * Send the secondary CPU a soft interrupt, thereby causing
 346          * the boot monitor to read the system wide flags register,
 347          * and branch to the address found there.
 348          */
 349
 350         timeout = jiffies + (1 * HZ);
 351         while (time_before(jiffies, timeout)) {
 352                 unsigned long boot_addr;
 353
 354                 smp_rmb();
 355
 356                 boot_addr = virt_to_phys(exynos4_secondary_startup);
 357
 358                 ret = exynos_set_boot_addr(core_id, boot_addr);
 359                 if (ret)
 360                         goto fail;
 361
 362                 call_firmware_op(cpu_boot, core_id);
 363
 364                 if (soc_is_exynos3250())
 365                         dsb_sev();
 366                 else
 367                         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 368
 369                 if (pen_release == -1)
 370                         break;
 371
 372                 udelay(10);
 373         }
 374
 375         if (pen_release != -1)
 376                 ret = -ETIMEDOUT;
 377
 378         /*
 379          * now the secondary core is starting up let it run its
 380          * calibrations, then wait for it to finish
 381          */
 382 fail:
 383         spin_unlock(&boot_lock);
 384
 385         return pen_release != -1 ? ret : 0;
 386 }
 387
 388 /*
 389  * Initialise the CPU possible map early - this describes the CPUs
 390  * which may be present or become present in the system.
 391  */
 392
 393 static void __init exynos_smp_init_cpus(void)
 394 {
 395         void __iomem *scu_base = scu_base_addr();
 396         unsigned int i, ncores;
 397
 398         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
 399                 ncores = scu_base ? scu_get_core_count(scu_base) : 1;
 400         else
 401                 /*
 402                  * CPU Nodes are passed thru DT and set_cpu_possible
 403                  * is set by "arm_dt_init_cpu_maps".
 404                  */
 405                 return;
 406
 407         /* sanity check */
 408         if (ncores > nr_cpu_ids) {
 409                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 410                         ncores, nr_cpu_ids);
 411                 ncores = nr_cpu_ids;
 412         }
 413
 414         for (i = 0; i < ncores; i++)
 415                 set_cpu_possible(i, true);
 416 }
 417
 418 static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
 419 {
 420         int i;
 421
 422         exynos_sysram_init();
 423
 424         exynos_set_delayed_reset_assertion(true);
 425
 426         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
 427                 scu_enable(scu_base_addr());
 428
 429         /*
 430          * Write the address of secondary startup into the
 431          * system-wide flags register. The boot monitor waits
 432          * until it receives a soft interrupt, and then the
 433          * secondary CPU branches to this address.
 434          *
 435          * Try using firmware operation first and fall back to
 436          * boot register if it fails.
 437          */
 438         for (i = 1; i < max_cpus; ++i) {
 439                 unsigned long boot_addr;
 440                 u32 mpidr;
 441                 u32 core_id;
 442                 int ret;
 443
 444                 mpidr = cpu_logical_map(i);
 445                 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 446                 boot_addr = virt_to_phys(exynos4_secondary_startup);
 447
 448                 ret = exynos_set_boot_addr(core_id, boot_addr);
 449                 if (ret)
 450                         break;
 451         }
 452 }
 453
 454 #ifdef CONFIG_HOTPLUG_CPU
 455 /*
 456  * platform-specific code to shutdown a CPU
 457  *
 458  * Called with IRQs disabled
 459  */
 460 static void exynos_cpu_die(unsigned int cpu)
 461 {
 462         int spurious = 0;
 463         u32 mpidr = cpu_logical_map(cpu);
 464         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 465
 466         v7_exit_coherency_flush(louis);
 467
 468         platform_do_lowpower(cpu, &spurious);
 469
 470         /*
 471          * bring this CPU back into the world of cache
 472          * coherency, and then restore interrupts
 473          */
 474         cpu_leave_lowpower(core_id);
 475
 476         if (spurious)
 477                 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
 478 }
 479 #endif /* CONFIG_HOTPLUG_CPU */
 480
 481 const struct smp_operations exynos_smp_ops __initconst = {
 482         .smp_init_cpus          = exynos_smp_init_cpus,
 483         .smp_prepare_cpus       = exynos_smp_prepare_cpus,
 484         .smp_secondary_init     = exynos_secondary_init,
 485         .smp_boot_secondary     = exynos_boot_secondary,
 486 #ifdef CONFIG_HOTPLUG_CPU
 487         .cpu_die                = exynos_cpu_die,
 488 #endif
 489 };