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

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3 //              http://www.samsung.com
   4 //
   5 // Based on arch/arm/mach-vexpress/dcscb.c
   6
   7 #include <linux/arm-cci.h>
   8 #include <linux/delay.h>
   9 #include <linux/io.h>
  10 #include <linux/of_address.h>
  11 #include <linux/syscore_ops.h>
  12 #include <linux/soc/samsung/exynos-regs-pmu.h>
  13
  14 #include <asm/cputype.h>
  15 #include <asm/cp15.h>
  16 #include <asm/mcpm.h>
  17 #include <asm/smp_plat.h>
  18
  19 #include "common.h"
  20
  21 #define EXYNOS5420_CPUS_PER_CLUSTER     4
  22 #define EXYNOS5420_NR_CLUSTERS          2
  23
  24 #define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN   BIT(9)
  25 #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE      BIT(29)
  26 #define EXYNOS5420_USE_L2_COMMON_UP_STATE       BIT(30)
  27
  28 static void __iomem *ns_sram_base_addr __ro_after_init;
  29
  30 /*
  31  * The common v7_exit_coherency_flush API could not be used because of the
  32  * Erratum 799270 workaround. This macro is the same as the common one (in
  33  * arch/arm/include/asm/cacheflush.h) except for the erratum handling.
  34  */
  35 #define exynos_v7_exit_coherency_flush(level) \
  36         asm volatile( \
  37         "stmfd  sp!, {fp, ip}\n\t"\
  38         "mrc    p15, 0, r0, c1, c0, 0   @ get SCTLR\n\t" \
  39         "bic    r0, r0, #"__stringify(CR_C)"\n\t" \
  40         "mcr    p15, 0, r0, c1, c0, 0   @ set SCTLR\n\t" \
  41         "isb\n\t"\
  42         "bl     v7_flush_dcache_"__stringify(level)"\n\t" \
  43         "mrc    p15, 0, r0, c1, c0, 1   @ get ACTLR\n\t" \
  44         "bic    r0, r0, #(1 << 6)       @ disable local coherency\n\t" \
  45         /* Dummy Load of a device register to avoid Erratum 799270 */ \
  46         "ldr    r4, [%0]\n\t" \
  47         "and    r4, r4, #0\n\t" \
  48         "orr    r0, r0, r4\n\t" \
  49         "mcr    p15, 0, r0, c1, c0, 1   @ set ACTLR\n\t" \
  50         "isb\n\t" \
  51         "dsb\n\t" \
  52         "ldmfd  sp!, {fp, ip}" \
  53         : \
  54         : "Ir" (pmu_base_addr + S5P_INFORM0) \
  55         : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
  56           "r9", "r10", "lr", "memory")
  57
  58 static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
  59 {
  60         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
  61
  62         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
  63         if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
  64                 cluster >= EXYNOS5420_NR_CLUSTERS)
  65                 return -EINVAL;
  66
  67         if (!exynos_cpu_power_state(cpunr)) {
  68                 exynos_cpu_power_up(cpunr);
  69
  70                 /*
  71                  * This assumes the cluster number of the big cores(Cortex A15)
  72                  * is 0 and the Little cores(Cortex A7) is 1.
  73                  * When the system was booted from the Little core,
  74                  * they should be reset during power up cpu.
  75                  */
  76                 if (cluster &&
  77                     cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
  78                         /*
  79                          * Before we reset the Little cores, we should wait
  80                          * the SPARE2 register is set to 1 because the init
  81                          * codes of the iROM will set the register after
  82                          * initialization.
  83                          */
  84                         while (!pmu_raw_readl(S5P_PMU_SPARE2))
  85                                 udelay(10);
  86
  87                         pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
  88                                         EXYNOS_SWRESET);
  89                 }
  90         }
  91
  92         return 0;
  93 }
  94
  95 static int exynos_cluster_powerup(unsigned int cluster)
  96 {
  97         pr_debug("%s: cluster %u\n", __func__, cluster);
  98         if (cluster >= EXYNOS5420_NR_CLUSTERS)
  99                 return -EINVAL;
 100
 101         exynos_cluster_power_up(cluster);
 102         return 0;
 103 }
 104
 105 static void exynos_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
 106 {
 107         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
 108
 109         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 110         BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 111                         cluster >= EXYNOS5420_NR_CLUSTERS);
 112         exynos_cpu_power_down(cpunr);
 113 }
 114
 115 static void exynos_cluster_powerdown_prepare(unsigned int cluster)
 116 {
 117         pr_debug("%s: cluster %u\n", __func__, cluster);
 118         BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
 119         exynos_cluster_power_down(cluster);
 120 }
 121
 122 static void exynos_cpu_cache_disable(void)
 123 {
 124         /* Disable and flush the local CPU cache. */
 125         exynos_v7_exit_coherency_flush(louis);
 126 }
 127
 128 static void exynos_cluster_cache_disable(void)
 129 {
 130         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
 131                 /*
 132                  * On the Cortex-A15 we need to disable
 133                  * L2 prefetching before flushing the cache.
 134                  */
 135                 asm volatile(
 136                 "mcr    p15, 1, %0, c15, c0, 3\n\t"
 137                 "isb\n\t"
 138                 "dsb"
 139                 : : "r" (0x400));
 140         }
 141
 142         /* Flush all cache levels for this cluster. */
 143         exynos_v7_exit_coherency_flush(all);
 144
 145         /*
 146          * Disable cluster-level coherency by masking
 147          * incoming snoops and DVM messages:
 148          */
 149         cci_disable_port_by_cpu(read_cpuid_mpidr());
 150 }
 151
 152 static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
 153 {
 154         unsigned int tries = 100;
 155         unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
 156
 157         pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 158         BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 159                         cluster >= EXYNOS5420_NR_CLUSTERS);
 160
 161         /* Wait for the core state to be OFF */
 162         while (tries--) {
 163                 if ((exynos_cpu_power_state(cpunr) == 0))
 164                         return 0; /* success: the CPU is halted */
 165
 166                 /* Otherwise, wait and retry: */
 167                 msleep(1);
 168         }
 169
 170         return -ETIMEDOUT; /* timeout */
 171 }
 172
 173 static void exynos_cpu_is_up(unsigned int cpu, unsigned int cluster)
 174 {
 175         /* especially when resuming: make sure power control is set */
 176         exynos_cpu_powerup(cpu, cluster);
 177 }
 178
 179 static const struct mcpm_platform_ops exynos_power_ops = {
 180         .cpu_powerup            = exynos_cpu_powerup,
 181         .cluster_powerup        = exynos_cluster_powerup,
 182         .cpu_powerdown_prepare  = exynos_cpu_powerdown_prepare,
 183         .cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
 184         .cpu_cache_disable      = exynos_cpu_cache_disable,
 185         .cluster_cache_disable  = exynos_cluster_cache_disable,
 186         .wait_for_powerdown     = exynos_wait_for_powerdown,
 187         .cpu_is_up              = exynos_cpu_is_up,
 188 };
 189
 190 /*
 191  * Enable cluster-level coherency, in preparation for turning on the MMU.
 192  */
 193 static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
 194 {
 195         asm volatile ("\n"
 196         "cmp    r0, #1\n"
 197         "bxne   lr\n"
 198         "b      cci_enable_port_for_self");
 199 }
 200
 201 static const struct of_device_id exynos_dt_mcpm_match[] = {
 202         { .compatible = "samsung,exynos5420" },
 203         { .compatible = "samsung,exynos5800" },
 204         {},
 205 };
 206
 207 static void exynos_mcpm_setup_entry_point(void)
 208 {
 209         /*
 210          * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
 211          * as part of secondary_cpu_start().  Let's redirect it to the
 212          * mcpm_entry_point(). This is done during both secondary boot-up as
 213          * well as system resume.
 214          */
 215         __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
 216         __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
 217         __raw_writel(__pa_symbol(mcpm_entry_point), ns_sram_base_addr + 8);
 218 }
 219
 220 static struct syscore_ops exynos_mcpm_syscore_ops = {
 221         .resume = exynos_mcpm_setup_entry_point,
 222 };
 223
 224 static int __init exynos_mcpm_init(void)
 225 {
 226         struct device_node *node;
 227         unsigned int value, i;
 228         int ret;
 229
 230         node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
 231         if (!node)
 232                 return -ENODEV;
 233         of_node_put(node);
 234
 235         if (!cci_probed())
 236                 return -ENODEV;
 237
 238         node = of_find_compatible_node(NULL, NULL,
 239                         "samsung,exynos4210-sysram-ns");
 240         if (!node)
 241                 return -ENODEV;
 242
 243         ns_sram_base_addr = of_iomap(node, 0);
 244         of_node_put(node);
 245         if (!ns_sram_base_addr) {
 246                 pr_err("failed to map non-secure iRAM base address\n");
 247                 return -ENOMEM;
 248         }
 249
 250         /*
 251          * To increase the stability of KFC reset we need to program
 252          * the PMU SPARE3 register
 253          */
 254         pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
 255
 256         ret = mcpm_platform_register(&exynos_power_ops);
 257         if (!ret)
 258                 ret = mcpm_sync_init(exynos_pm_power_up_setup);
 259         if (!ret)
 260                 ret = mcpm_loopback(exynos_cluster_cache_disable); /* turn on the CCI */
 261         if (ret) {
 262                 iounmap(ns_sram_base_addr);
 263                 return ret;
 264         }
 265
 266         mcpm_smp_set_ops();
 267
 268         pr_info("Exynos MCPM support installed\n");
 269
 270         /*
 271          * On Exynos5420/5800 for the A15 and A7 clusters:
 272          *
 273          * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
 274          * in a cluster are turned off before turning off the cluster L2.
 275          *
 276          * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
 277          * off before waking it up.
 278          *
 279          * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
 280          * turned on before the first man is powered up.
 281          */
 282         for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
 283                 value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
 284                 value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN |
 285                          EXYNOS5420_USE_ARM_CORE_DOWN_STATE    |
 286                          EXYNOS5420_USE_L2_COMMON_UP_STATE;
 287                 pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
 288         }
 289
 290         exynos_mcpm_setup_entry_point();
 291
 292         register_syscore_ops(&exynos_mcpm_syscore_ops);
 293
 294         return ret;
 295 }
 296
 297 early_initcall(exynos_mcpm_init);