/* * Copyright (c) 2014 Samsung Electronics Co., Ltd. * http://www.samsung.com * * arch/arm/mach-exynos/mcpm-exynos.c * * Based on arch/arm/mach-vexpress/dcscb.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/arm-cci.h> #include <linux/delay.h> #include <linux/io.h> #include <linux/of_address.h> #include <linux/syscore_ops.h> #include <asm/cputype.h> #include <asm/cp15.h> #include <asm/mcpm.h> #include "regs-pmu.h" #include "common.h" #define EXYNOS5420_CPUS_PER_CLUSTER 4 #define EXYNOS5420_NR_CLUSTERS 2 #define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN BIT(9) #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE BIT(29) #define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30) static void __iomem *ns_sram_base_addr; /* * The common v7_exit_coherency_flush API could not be used because of the * Erratum 799270 workaround. This macro is the same as the common one (in * arch/arm/include/asm/cacheflush.h) except for the erratum handling. */ #define exynos_v7_exit_coherency_flush(level) \ asm volatile( \ "stmfd sp!, {fp, ip}\n\t"\ "mrc p15, 0, r0, c1, c0, 0 @ get SCTLR\n\t" \ "bic r0, r0, #"__stringify(CR_C)"\n\t" \ "mcr p15, 0, r0, c1, c0, 0 @ set SCTLR\n\t" \ "isb\n\t"\ "bl v7_flush_dcache_"__stringify(level)"\n\t" \ "mrc p15, 0, r0, c1, c0, 1 @ get ACTLR\n\t" \ "bic r0, r0, #(1 << 6) @ disable local coherency\n\t" \ /* Dummy Load of a device register to avoid Erratum 799270 */ \ "ldr r4, [%0]\n\t" \ "and r4, r4, #0\n\t" \ "orr r0, r0, r4\n\t" \ "mcr p15, 0, r0, c1, c0, 1 @ set ACTLR\n\t" \ "isb\n\t" \ "dsb\n\t" \ "ldmfd sp!, {fp, ip}" \ : \ : "Ir" (pmu_base_addr + S5P_INFORM0) \ : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \ "r9", "r10", "lr", "memory") /* * We can't use regular spinlocks. In the switcher case, it is possible * for an outbound CPU to call power_down() after its inbound counterpart * is already live using the same logical CPU number which trips lockdep * debugging. */ static arch_spinlock_t exynos_mcpm_lock = __ARCH_SPIN_LOCK_UNLOCKED; static int cpu_use_count[EXYNOS5420_CPUS_PER_CLUSTER][EXYNOS5420_NR_CLUSTERS]; #define exynos_cluster_usecnt(cluster) \ (cpu_use_count[0][cluster] + \ cpu_use_count[1][cluster] + \ cpu_use_count[2][cluster] + \ cpu_use_count[3][cluster]) #define exynos_cluster_unused(cluster) !exynos_cluster_usecnt(cluster) static int exynos_power_up(unsigned int cpu, unsigned int cluster) { unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER); pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER || cluster >= EXYNOS5420_NR_CLUSTERS) return -EINVAL; /* * Since this is called with IRQs enabled, and no arch_spin_lock_irq * variant exists, we need to disable IRQs manually here. */ local_irq_disable(); arch_spin_lock(&exynos_mcpm_lock); cpu_use_count[cpu][cluster]++; if (cpu_use_count[cpu][cluster] == 1) { bool was_cluster_down = (exynos_cluster_usecnt(cluster) == 1); /* * Turn on the cluster (L2/COMMON) and then power on the * cores. */ if (was_cluster_down) exynos_cluster_power_up(cluster); exynos_cpu_power_up(cpunr); } else if (cpu_use_count[cpu][cluster] != 2) { /* * The only possible values are: * 0 = CPU down * 1 = CPU (still) up * 2 = CPU requested to be up before it had a chance * to actually make itself down. * Any other value is a bug. */ BUG(); } arch_spin_unlock(&exynos_mcpm_lock); local_irq_enable(); return 0; } /* * NOTE: This function requires the stack data to be visible through power down * and can only be executed on processors like A15 and A7 that hit the cache * with the C bit clear in the SCTLR register. */ static void exynos_power_down(void) { unsigned int mpidr, cpu, cluster; bool last_man = false, skip_wfi = false; unsigned int cpunr; mpidr = read_cpuid_mpidr(); cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER); pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER || cluster >= EXYNOS5420_NR_CLUSTERS); __mcpm_cpu_going_down(cpu, cluster); arch_spin_lock(&exynos_mcpm_lock); BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP); cpu_use_count[cpu][cluster]--; if (cpu_use_count[cpu][cluster] == 0) { exynos_cpu_power_down(cpunr); if (exynos_cluster_unused(cluster)) { exynos_cluster_power_down(cluster); last_man = true; } } else if (cpu_use_count[cpu][cluster] == 1) { /* * A power_up request went ahead of us. * Even if we do not want to shut this CPU down, * the caller expects a certain state as if the WFI * was aborted. So let's continue with cache cleaning. */ skip_wfi = true; } else { BUG(); } if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) { arch_spin_unlock(&exynos_mcpm_lock); if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) { /* * On the Cortex-A15 we need to disable * L2 prefetching before flushing the cache. */ asm volatile( "mcr p15, 1, %0, c15, c0, 3\n\t" "isb\n\t" "dsb" : : "r" (0x400)); } /* Flush all cache levels for this cluster. */ exynos_v7_exit_coherency_flush(all); /* * Disable cluster-level coherency by masking * incoming snoops and DVM messages: */ cci_disable_port_by_cpu(mpidr); __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN); } else { arch_spin_unlock(&exynos_mcpm_lock); /* Disable and flush the local CPU cache. */ exynos_v7_exit_coherency_flush(louis); } __mcpm_cpu_down(cpu, cluster); /* Now we are prepared for power-down, do it: */ if (!skip_wfi) wfi(); /* Not dead at this point? Let our caller cope. */ } static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster) { unsigned int tries = 100; unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER); pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER || cluster >= EXYNOS5420_NR_CLUSTERS); /* Wait for the core state to be OFF */ while (tries--) { if (ACCESS_ONCE(cpu_use_count[cpu][cluster]) == 0) { if ((exynos_cpu_power_state(cpunr) == 0)) return 0; /* success: the CPU is halted */ } /* Otherwise, wait and retry: */ msleep(1); } return -ETIMEDOUT; /* timeout */ } static void exynos_powered_up(void) { unsigned int mpidr, cpu, cluster; mpidr = read_cpuid_mpidr(); cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); arch_spin_lock(&exynos_mcpm_lock); if (cpu_use_count[cpu][cluster] == 0) cpu_use_count[cpu][cluster] = 1; arch_spin_unlock(&exynos_mcpm_lock); } static void exynos_suspend(u64 residency) { unsigned int mpidr, cpunr; exynos_power_down(); /* * Execution reaches here only if cpu did not power down. * Hence roll back the changes done in exynos_power_down function. * * CAUTION: "This function requires the stack data to be visible through * power down and can only be executed on processors like A15 and A7 * that hit the cache with the C bit clear in the SCTLR register." */ mpidr = read_cpuid_mpidr(); cpunr = exynos_pmu_cpunr(mpidr); exynos_cpu_power_up(cpunr); } static const struct mcpm_platform_ops exynos_power_ops = { .power_up = exynos_power_up, .power_down = exynos_power_down, .wait_for_powerdown = exynos_wait_for_powerdown, .suspend = exynos_suspend, .powered_up = exynos_powered_up, }; static void __init exynos_mcpm_usage_count_init(void) { unsigned int mpidr, cpu, cluster; mpidr = read_cpuid_mpidr(); cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER || cluster >= EXYNOS5420_NR_CLUSTERS); cpu_use_count[cpu][cluster] = 1; } /* * Enable cluster-level coherency, in preparation for turning on the MMU. */ static void __naked exynos_pm_power_up_setup(unsigned int affinity_level) { asm volatile ("\n" "cmp r0, #1\n" "bxne lr\n" "b cci_enable_port_for_self"); } static void __init exynos_cache_off(void) { if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) { /* disable L2 prefetching on the Cortex-A15 */ asm volatile( "mcr p15, 1, %0, c15, c0, 3\n\t" "isb\n\t" "dsb" : : "r" (0x400)); } exynos_v7_exit_coherency_flush(all); } static const struct of_device_id exynos_dt_mcpm_match[] = { { .compatible = "samsung,exynos5420" }, { .compatible = "samsung,exynos5800" }, {}, }; static void exynos_mcpm_setup_entry_point(void) { /* * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr * as part of secondary_cpu_start(). Let's redirect it to the * mcpm_entry_point(). This is done during both secondary boot-up as * well as system resume. */ __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */ __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */ __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8); } static struct syscore_ops exynos_mcpm_syscore_ops = { .resume = exynos_mcpm_setup_entry_point, }; static int __init exynos_mcpm_init(void) { struct device_node *node; unsigned int value, i; int ret; node = of_find_matching_node(NULL, exynos_dt_mcpm_match); if (!node) return -ENODEV; of_node_put(node); if (!cci_probed()) return -ENODEV; node = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-sysram-ns"); if (!node) return -ENODEV; ns_sram_base_addr = of_iomap(node, 0); of_node_put(node); if (!ns_sram_base_addr) { pr_err("failed to map non-secure iRAM base address\n"); return -ENOMEM; } /* * To increase the stability of KFC reset we need to program * the PMU SPARE3 register */ pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3); exynos_mcpm_usage_count_init(); ret = mcpm_platform_register(&exynos_power_ops); if (!ret) ret = mcpm_sync_init(exynos_pm_power_up_setup); if (!ret) ret = mcpm_loopback(exynos_cache_off); /* turn on the CCI */ if (ret) { iounmap(ns_sram_base_addr); return ret; } mcpm_smp_set_ops(); pr_info("Exynos MCPM support installed\n"); /* * On Exynos5420/5800 for the A15 and A7 clusters: * * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores * in a cluster are turned off before turning off the cluster L2. * * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered * off before waking it up. * * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be * turned on before the first man is powered up. */ for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) { value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i)); value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN | EXYNOS5420_USE_ARM_CORE_DOWN_STATE | EXYNOS5420_USE_L2_COMMON_UP_STATE; pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i)); } exynos_mcpm_setup_entry_point(); register_syscore_ops(&exynos_mcpm_syscore_ops); return ret; } early_initcall(exynos_mcpm_init);