diff options
Diffstat (limited to 'arch/arm/mach-exynos/mcpm-exynos.c')
| -rw-r--r-- | arch/arm/mach-exynos/mcpm-exynos.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c new file mode 100644 index 000000000..cd861c57d --- /dev/null +++ b/arch/arm/mach-exynos/mcpm-exynos.c @@ -0,0 +1,312 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2014 Samsung Electronics Co., Ltd. +// http://www.samsung.com +// +// Based on arch/arm/mach-vexpress/dcscb.c + +#include <linux/arm-cci.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/syscore_ops.h> +#include <linux/soc/samsung/exynos-regs-pmu.h> + +#include <asm/cputype.h> +#include <asm/cp15.h> +#include <asm/mcpm.h> +#include <asm/smp_plat.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 __ro_after_init; +static bool secure_firmware __ro_after_init; + +/* + * 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") + +static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster) +{ + unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER); + bool state; + + pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster); + if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER || + cluster >= EXYNOS5420_NR_CLUSTERS) + return -EINVAL; + + state = exynos_cpu_power_state(cpunr); + exynos_cpu_power_up(cpunr); + if (!state && secure_firmware) { + /* + * This assumes the cluster number of the big cores(Cortex A15) + * is 0 and the Little cores(Cortex A7) is 1. + * When the system was booted from the Little core, + * they should be reset during power up cpu. + */ + if (cluster && + cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) { + unsigned int timeout = 16; + + /* + * Before we reset the Little cores, we should wait + * the SPARE2 register is set to 1 because the init + * codes of the iROM will set the register after + * initialization. + */ + while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) { + timeout--; + udelay(10); + } + + if (timeout == 0) { + pr_err("cpu %u cluster %u powerup failed\n", + cpu, cluster); + exynos_cpu_power_down(cpunr); + return -ETIMEDOUT; + } + + pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu), + EXYNOS_SWRESET); + } + } + + return 0; +} + +static int exynos_cluster_powerup(unsigned int cluster) +{ + pr_debug("%s: cluster %u\n", __func__, cluster); + if (cluster >= EXYNOS5420_NR_CLUSTERS) + return -EINVAL; + + exynos_cluster_power_up(cluster); + return 0; +} + +static void exynos_cpu_powerdown_prepare(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); + BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER || + cluster >= EXYNOS5420_NR_CLUSTERS); + exynos_cpu_power_down(cpunr); +} + +static void exynos_cluster_powerdown_prepare(unsigned int cluster) +{ + pr_debug("%s: cluster %u\n", __func__, cluster); + BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS); + exynos_cluster_power_down(cluster); +} + +static void exynos_cpu_cache_disable(void) +{ + /* Disable and flush the local CPU cache. */ + exynos_v7_exit_coherency_flush(louis); +} + +static void exynos_cluster_cache_disable(void) +{ + 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(read_cpuid_mpidr()); +} + +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 ((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_cpu_is_up(unsigned int cpu, unsigned int cluster) +{ + /* especially when resuming: make sure power control is set */ + exynos_cpu_powerup(cpu, cluster); +} + +static const struct mcpm_platform_ops exynos_power_ops = { + .cpu_powerup = exynos_cpu_powerup, + .cluster_powerup = exynos_cluster_powerup, + .cpu_powerdown_prepare = exynos_cpu_powerdown_prepare, + .cluster_powerdown_prepare = exynos_cluster_powerdown_prepare, + .cpu_cache_disable = exynos_cpu_cache_disable, + .cluster_cache_disable = exynos_cluster_cache_disable, + .wait_for_powerdown = exynos_wait_for_powerdown, + .cpu_is_up = exynos_cpu_is_up, +}; + +/* + * 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 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(__pa_symbol(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; + } + + secure_firmware = exynos_secure_firmware_available(); + + /* + * 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); + + ret = mcpm_platform_register(&exynos_power_ops); + if (!ret) + ret = mcpm_sync_init(exynos_pm_power_up_setup); + if (!ret) + ret = mcpm_loopback(exynos_cluster_cache_disable); /* 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); |