arch/arm/mach-exynos/mcpm-exynos.c

   1 /*
   2  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com
   4  *
   5  * arch/arm/mach-exynos/mcpm-exynos.c
   6  *
   7  * Based on arch/arm/mach-vexpress/dcscb.c
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/arm-cci.h>
  15 #include <linux/delay.h>
  16 #include <linux/io.h>
  17 #include <linux/of_address.h>
  18 #include <linux/syscore_ops.h>
  19
  20 #include <asm/cputype.h>
  21 #include <asm/cp15.h>
  22 #include <asm/mcpm.h>
  23 #include <asm/smp_plat.h>
  24
  25 #include "regs-pmu.h"
  26 #include "common.h"
  27
  28 #define EXYNOS5420_CPUS_PER_CLUSTER     4
  29 #define EXYNOS5420_NR_CLUSTERS          2
  30
  31 #define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN   BIT(9)
  32 #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE      BIT(29)
  33 #define EXYNOS5420_USE_L2_COMMON_UP_STATE       BIT(30)
  34
  35 static void __iomem *ns_sram_base_addr;
  36
  37 /*
  38  * The common v7_exit_coherency_flush API could not be used because of the
  39  * Erratum 799270 workaround. This macro is the same as the common one (in
  40  * arch/arm/include/asm/cacheflush.h) except for the erratum handling.
  41  */
  42 #define exynos_v7_exit_coherency_flush(level) \
  43         asm volatile( \
  44         "stmfd  sp!, {fp, ip}\n\t"\
  45         "mrc    p15, 0, r0, c1, c0, 0   @ get SCTLR\n\t" \
  46         "bic    r0, r0, #"__stringify(CR_C)"\n\t" \
  47         "mcr    p15, 0, r0, c1, c0, 0   @ set SCTLR\n\t" \
  48         "isb\n\t"\
  49         "bl     v7_flush_dcache_"__stringify(level)"\n\t" \
  50         "mrc    p15, 0, r0, c1, c0, 1   @ get ACTLR\n\t" \
  51         "bic    r0, r0, #(1 << 6)       @ disable local coherency\n\t" \
  52         /* Dummy Load of a device register to avoid Erratum 799270 */ \
  53         "ldr    r4, [%0]\n\t" \
  54         "and    r4, r4, #0\n\t" \
  55         "orr    r0, r0, r4\n\t" \
  56         "mcr    p15, 0, r0, c1, c0, 1   @ set ACTLR\n\t" \
  57         "isb\n\t" \
  58         "dsb\n\t" \
  59         "ldmfd  sp!, {fp, ip}" \
  60         : \
  61         : "Ir" (pmu_base_addr + S5P_INFORM0) \
  62         : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
  63           "r9", "r10", "lr", "memory")
  64
  65 static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
  66 {
  67         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
  68
  69         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
  70         if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
  71                 cluster >= EXYNOS5420_NR_CLUSTERS)
  72                 return -EINVAL;
  73
  74         if (!exynos_cpu_power_state(cpunr)) {
  75                 exynos_cpu_power_up(cpunr);
  76
  77                 /*
  78                  * This assumes the cluster number of the big cores(Cortex A15)
  79                  * is 0 and the Little cores(Cortex A7) is 1.
  80                  * When the system was booted from the Little core,
  81                  * they should be reset during power up cpu.
  82                  */
  83                 if (cluster &&
  84                     cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
  85                         /*
  86                          * Before we reset the Little cores, we should wait
  87                          * the SPARE2 register is set to 1 because the init
  88                          * codes of the iROM will set the register after
  89                          * initialization.
  90                          */
  91                         while (!pmu_raw_readl(S5P_PMU_SPARE2))
  92                                 udelay(10);
  93
  94                         pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
  95                                         EXYNOS_SWRESET);
  96                 }
  97         }
  98
  99         return 0;
 100 }
 101
 102 static int exynos_cluster_powerup(unsigned int cluster)
 103 {
 104         pr_debug("%s: cluster %u\n", __func__, cluster);
 105         if (cluster >= EXYNOS5420_NR_CLUSTERS)
 106                 return -EINVAL;
 107
 108         exynos_cluster_power_up(cluster);
 109         return 0;
 110 }
 111
 112 static void exynos_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
 113 {
 114         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
 115
 116         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 117         BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 118                         cluster >= EXYNOS5420_NR_CLUSTERS);
 119         exynos_cpu_power_down(cpunr);
 120 }
 121
 122 static void exynos_cluster_powerdown_prepare(unsigned int cluster)
 123 {
 124         pr_debug("%s: cluster %u\n", __func__, cluster);
 125         BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
 126         exynos_cluster_power_down(cluster);
 127 }
 128
 129 static void exynos_cpu_cache_disable(void)
 130 {
 131         /* Disable and flush the local CPU cache. */
 132         exynos_v7_exit_coherency_flush(louis);
 133 }
 134
 135 static void exynos_cluster_cache_disable(void)
 136 {
 137         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
 138                 /*
 139                  * On the Cortex-A15 we need to disable
 140                  * L2 prefetching before flushing the cache.
 141                  */
 142                 asm volatile(
 143                 "mcr    p15, 1, %0, c15, c0, 3\n\t"
 144                 "isb\n\t"
 145                 "dsb"
 146                 : : "r" (0x400));
 147         }
 148
 149         /* Flush all cache levels for this cluster. */
 150         exynos_v7_exit_coherency_flush(all);
 151
 152         /*
 153          * Disable cluster-level coherency by masking
 154          * incoming snoops and DVM messages:
 155          */
 156         cci_disable_port_by_cpu(read_cpuid_mpidr());
 157 }
 158
 159 static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
 160 {
 161         unsigned int tries = 100;
 162         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
 163
 164         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 165         BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 166                         cluster >= EXYNOS5420_NR_CLUSTERS);
 167
 168         /* Wait for the core state to be OFF */
 169         while (tries--) {
 170                 if ((exynos_cpu_power_state(cpunr) == 0))
 171                         return 0; /* success: the CPU is halted */
 172
 173                 /* Otherwise, wait and retry: */
 174                 msleep(1);
 175         }
 176
 177         return -ETIMEDOUT; /* timeout */
 178 }
 179
 180 static void exynos_cpu_is_up(unsigned int cpu, unsigned int cluster)
 181 {
 182         /* especially when resuming: make sure power control is set */
 183         exynos_cpu_powerup(cpu, cluster);
 184 }
 185
 186 static const struct mcpm_platform_ops exynos_power_ops = {
 187         .cpu_powerup            = exynos_cpu_powerup,
 188         .cluster_powerup        = exynos_cluster_powerup,
 189         .cpu_powerdown_prepare  = exynos_cpu_powerdown_prepare,
 190         .cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
 191         .cpu_cache_disable      = exynos_cpu_cache_disable,
 192         .cluster_cache_disable  = exynos_cluster_cache_disable,
 193         .wait_for_powerdown     = exynos_wait_for_powerdown,
 194         .cpu_is_up              = exynos_cpu_is_up,
 195 };
 196
 197 /*
 198  * Enable cluster-level coherency, in preparation for turning on the MMU.
 199  */
 200 static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
 201 {
 202         asm volatile ("\n"
 203         "cmp    r0, #1\n"
 204         "bxne   lr\n"
 205         "b      cci_enable_port_for_self");
 206 }
 207
 208 static const struct of_device_id exynos_dt_mcpm_match[] = {
 209         { .compatible = "samsung,exynos5420" },
 210         { .compatible = "samsung,exynos5800" },
 211         {},
 212 };
 213
 214 static void exynos_mcpm_setup_entry_point(void)
 215 {
 216         /*
 217          * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
 218          * as part of secondary_cpu_start().  Let's redirect it to the
 219          * mcpm_entry_point(). This is done during both secondary boot-up as
 220          * well as system resume.
 221          */
 222         __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
 223         __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
 224         __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
 225 }
 226
 227 static struct syscore_ops exynos_mcpm_syscore_ops = {
 228         .resume = exynos_mcpm_setup_entry_point,
 229 };
 230
 231 static int __init exynos_mcpm_init(void)
 232 {
 233         struct device_node *node;
 234         unsigned int value, i;
 235         int ret;
 236
 237         node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
 238         if (!node)
 239                 return -ENODEV;
 240         of_node_put(node);
 241
 242         if (!cci_probed())
 243                 return -ENODEV;
 244
 245         node = of_find_compatible_node(NULL, NULL,
 246                         "samsung,exynos4210-sysram-ns");
 247         if (!node)
 248                 return -ENODEV;
 249
 250         ns_sram_base_addr = of_iomap(node, 0);
 251         of_node_put(node);
 252         if (!ns_sram_base_addr) {
 253                 pr_err("failed to map non-secure iRAM base address\n");
 254                 return -ENOMEM;
 255         }
 256
 257         /*
 258          * To increase the stability of KFC reset we need to program
 259          * the PMU SPARE3 register
 260          */
 261         pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
 262
 263         ret = mcpm_platform_register(&exynos_power_ops);
 264         if (!ret)
 265                 ret = mcpm_sync_init(exynos_pm_power_up_setup);
 266         if (!ret)
 267                 ret = mcpm_loopback(exynos_cluster_cache_disable); /* turn on the CCI */
 268         if (ret) {
 269                 iounmap(ns_sram_base_addr);
 270                 return ret;
 271         }
 272
 273         mcpm_smp_set_ops();
 274
 275         pr_info("Exynos MCPM support installed\n");
 276
 277         /*
 278          * On Exynos5420/5800 for the A15 and A7 clusters:
 279          *
 280          * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
 281          * in a cluster are turned off before turning off the cluster L2.
 282          *
 283          * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
 284          * off before waking it up.
 285          *
 286          * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
 287          * turned on before the first man is powered up.
 288          */
 289         for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
 290                 value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
 291                 value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN |
 292                          EXYNOS5420_USE_ARM_CORE_DOWN_STATE    |
 293                          EXYNOS5420_USE_L2_COMMON_UP_STATE;
 294                 pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
 295         }
 296
 297         exynos_mcpm_setup_entry_point();
 298
 299         register_syscore_ops(&exynos_mcpm_syscore_ops);
 300
 301         return ret;
 302 }
 303
 304 early_initcall(exynos_mcpm_init);