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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/mach-exynos/platsmp.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mach-exynos/platsmp.c')
-rw-r--r-- | arch/arm/mach-exynos/platsmp.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c new file mode 100644 index 000000000..fb4a394ec --- /dev/null +++ b/arch/arm/mach-exynos/platsmp.c @@ -0,0 +1,450 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. +// http://www.samsung.com +// +// Cloned from linux/arch/arm/mach-vexpress/platsmp.c +// +// Copyright (C) 2002 ARM Ltd. +// All Rights Reserved + +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/smp.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/soc/samsung/exynos-regs-pmu.h> + +#include <asm/cacheflush.h> +#include <asm/cp15.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> +#include <asm/firmware.h> + +#include "common.h" + +extern void exynos4_secondary_startup(void); + +/* XXX exynos_pen_release is cargo culted code - DO NOT COPY XXX */ +volatile int exynos_pen_release = -1; + +#ifdef CONFIG_HOTPLUG_CPU +static inline void cpu_leave_lowpower(u32 core_id) +{ + unsigned int v; + + asm volatile( + "mrc p15, 0, %0, c1, c0, 0\n" + " orr %0, %0, %1\n" + " mcr p15, 0, %0, c1, c0, 0\n" + " mrc p15, 0, %0, c1, c0, 1\n" + " orr %0, %0, %2\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : "Ir" (CR_C), "Ir" (0x40) + : "cc"); +} + +static inline void platform_do_lowpower(unsigned int cpu, int *spurious) +{ + u32 mpidr = cpu_logical_map(cpu); + u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + + for (;;) { + + /* Turn the CPU off on next WFI instruction. */ + exynos_cpu_power_down(core_id); + + wfi(); + + if (exynos_pen_release == core_id) { + /* + * OK, proper wakeup, we're done + */ + break; + } + + /* + * Getting here, means that we have come out of WFI without + * having been woken up - this shouldn't happen + * + * Just note it happening - when we're woken, we can report + * its occurrence. + */ + (*spurious)++; + } +} +#endif /* CONFIG_HOTPLUG_CPU */ + +/** + * exynos_cpu_power_down() - power down the specified cpu + * @cpu: the cpu to power down + * + * Power down the specified cpu. The sequence must be finished by a + * call to cpu_do_idle() + */ +void exynos_cpu_power_down(int cpu) +{ + u32 core_conf; + + if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) { + /* + * Bypass power down for CPU0 during suspend. Check for + * the SYS_PWR_REG value to decide if we are suspending + * the system. + */ + int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG); + + if (!(val & S5P_CORE_LOCAL_PWR_EN)) + return; + } + + core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu)); + core_conf &= ~S5P_CORE_LOCAL_PWR_EN; + pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu)); +} + +/** + * exynos_cpu_power_up() - power up the specified cpu + * @cpu: the cpu to power up + * + * Power up the specified cpu + */ +void exynos_cpu_power_up(int cpu) +{ + u32 core_conf = S5P_CORE_LOCAL_PWR_EN; + + if (soc_is_exynos3250()) + core_conf |= S5P_CORE_AUTOWAKEUP_EN; + + pmu_raw_writel(core_conf, + EXYNOS_ARM_CORE_CONFIGURATION(cpu)); +} + +/** + * exynos_cpu_power_state() - returns the power state of the cpu + * @cpu: the cpu to retrieve the power state from + */ +int exynos_cpu_power_state(int cpu) +{ + return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) & + S5P_CORE_LOCAL_PWR_EN); +} + +/** + * exynos_cluster_power_down() - power down the specified cluster + * @cluster: the cluster to power down + */ +void exynos_cluster_power_down(int cluster) +{ + pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster)); +} + +/** + * exynos_cluster_power_up() - power up the specified cluster + * @cluster: the cluster to power up + */ +void exynos_cluster_power_up(int cluster) +{ + pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN, + EXYNOS_COMMON_CONFIGURATION(cluster)); +} + +/** + * exynos_cluster_power_state() - returns the power state of the cluster + * @cluster: the cluster to retrieve the power state from + * + */ +int exynos_cluster_power_state(int cluster) +{ + return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) & + S5P_CORE_LOCAL_PWR_EN); +} + +/** + * exynos_scu_enable() - enables SCU for Cortex-A9 based system + */ +void exynos_scu_enable(void) +{ + struct device_node *np; + static void __iomem *scu_base; + + if (!scu_base) { + np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); + if (np) { + scu_base = of_iomap(np, 0); + of_node_put(np); + } else { + scu_base = ioremap(scu_a9_get_base(), SZ_4K); + } + } + scu_enable(scu_base); +} + +static void __iomem *cpu_boot_reg_base(void) +{ + if (soc_is_exynos4210() && exynos_rev() == EXYNOS4210_REV_1_1) + return pmu_base_addr + S5P_INFORM5; + return sysram_base_addr; +} + +static inline void __iomem *cpu_boot_reg(int cpu) +{ + void __iomem *boot_reg; + + boot_reg = cpu_boot_reg_base(); + if (!boot_reg) + return IOMEM_ERR_PTR(-ENODEV); + if (soc_is_exynos4412()) + boot_reg += 4*cpu; + else if (soc_is_exynos5420() || soc_is_exynos5800()) + boot_reg += 4; + return boot_reg; +} + +/* + * Set wake up by local power mode and execute software reset for given core. + * + * Currently this is needed only when booting secondary CPU on Exynos3250. + */ +void exynos_core_restart(u32 core_id) +{ + unsigned int timeout = 16; + u32 val; + + if (!soc_is_exynos3250()) + return; + + while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) { + timeout--; + udelay(10); + } + if (timeout == 0) { + pr_err("cpu core %u restart failed\n", core_id); + return; + } + udelay(10); + + val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id)); + val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG; + pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id)); + + pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET); +} + +/* + * XXX CARGO CULTED CODE - DO NOT COPY XXX + * + * Write exynos_pen_release in a way that is guaranteed to be visible to + * all observers, irrespective of whether they're taking part in coherency + * or not. This is necessary for the hotplug code to work reliably. + */ +static void exynos_write_pen_release(int val) +{ + exynos_pen_release = val; + smp_wmb(); + sync_cache_w(&exynos_pen_release); +} + +static DEFINE_SPINLOCK(boot_lock); + +static void exynos_secondary_init(unsigned int cpu) +{ + /* + * let the primary processor know we're out of the + * pen, then head off into the C entry point + */ + exynos_write_pen_release(-1); + + /* + * Synchronise with the boot thread. + */ + spin_lock(&boot_lock); + spin_unlock(&boot_lock); +} + +int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr) +{ + int ret; + + /* + * Try to set boot address using firmware first + * and fall back to boot register if it fails. + */ + ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr); + if (ret && ret != -ENOSYS) + goto fail; + if (ret == -ENOSYS) { + void __iomem *boot_reg = cpu_boot_reg(core_id); + + if (IS_ERR(boot_reg)) { + ret = PTR_ERR(boot_reg); + goto fail; + } + writel_relaxed(boot_addr, boot_reg); + ret = 0; + } +fail: + return ret; +} + +int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr) +{ + int ret; + + /* + * Try to get boot address using firmware first + * and fall back to boot register if it fails. + */ + ret = call_firmware_op(get_cpu_boot_addr, core_id, boot_addr); + if (ret && ret != -ENOSYS) + goto fail; + if (ret == -ENOSYS) { + void __iomem *boot_reg = cpu_boot_reg(core_id); + + if (IS_ERR(boot_reg)) { + ret = PTR_ERR(boot_reg); + goto fail; + } + *boot_addr = readl_relaxed(boot_reg); + ret = 0; + } +fail: + return ret; +} + +static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + unsigned long timeout; + u32 mpidr = cpu_logical_map(cpu); + u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + int ret = -ENOSYS; + + /* + * Set synchronisation state between this boot processor + * and the secondary one + */ + spin_lock(&boot_lock); + + /* + * The secondary processor is waiting to be released from + * the holding pen - release it, then wait for it to flag + * that it has been released by resetting exynos_pen_release. + * + * Note that "exynos_pen_release" is the hardware CPU core ID, whereas + * "cpu" is Linux's internal ID. + */ + exynos_write_pen_release(core_id); + + if (!exynos_cpu_power_state(core_id)) { + exynos_cpu_power_up(core_id); + timeout = 10; + + /* wait max 10 ms until cpu1 is on */ + while (exynos_cpu_power_state(core_id) + != S5P_CORE_LOCAL_PWR_EN) { + if (timeout == 0) + break; + timeout--; + mdelay(1); + } + + if (timeout == 0) { + printk(KERN_ERR "cpu1 power enable failed"); + spin_unlock(&boot_lock); + return -ETIMEDOUT; + } + } + + exynos_core_restart(core_id); + + /* + * Send the secondary CPU a soft interrupt, thereby causing + * the boot monitor to read the system wide flags register, + * and branch to the address found there. + */ + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + unsigned long boot_addr; + + smp_rmb(); + + boot_addr = __pa_symbol(exynos4_secondary_startup); + + ret = exynos_set_boot_addr(core_id, boot_addr); + if (ret) + goto fail; + + call_firmware_op(cpu_boot, core_id); + + if (soc_is_exynos3250()) + dsb_sev(); + else + arch_send_wakeup_ipi_mask(cpumask_of(cpu)); + + if (exynos_pen_release == -1) + break; + + udelay(10); + } + + if (exynos_pen_release != -1) + ret = -ETIMEDOUT; + + /* + * now the secondary core is starting up let it run its + * calibrations, then wait for it to finish + */ +fail: + spin_unlock(&boot_lock); + + return exynos_pen_release != -1 ? ret : 0; +} + +static void __init exynos_smp_prepare_cpus(unsigned int max_cpus) +{ + exynos_sysram_init(); + + exynos_set_delayed_reset_assertion(true); + + if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) + exynos_scu_enable(); +} + +#ifdef CONFIG_HOTPLUG_CPU +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +static void exynos_cpu_die(unsigned int cpu) +{ + int spurious = 0; + u32 mpidr = cpu_logical_map(cpu); + u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + + v7_exit_coherency_flush(louis); + + platform_do_lowpower(cpu, &spurious); + + /* + * bring this CPU back into the world of cache + * coherency, and then restore interrupts + */ + cpu_leave_lowpower(core_id); + + if (spurious) + pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); +} +#endif /* CONFIG_HOTPLUG_CPU */ + +const struct smp_operations exynos_smp_ops __initconst = { + .smp_prepare_cpus = exynos_smp_prepare_cpus, + .smp_secondary_init = exynos_secondary_init, + .smp_boot_secondary = exynos_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = exynos_cpu_die, +#endif +}; |