diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/common/mcpm_entry.c | 52 | ||||
| -rw-r--r-- | arch/arm/include/asm/mcpm.h | 16 |
2 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c index f91136ab447..3c165fc2dce 100644 --- a/arch/arm/common/mcpm_entry.c +++ b/arch/arm/common/mcpm_entry.c @@ -12,11 +12,13 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/irqflags.h> +#include <linux/cpu_pm.h> #include <asm/mcpm.h> #include <asm/cacheflush.h> #include <asm/idmap.h> #include <asm/cputype.h> +#include <asm/suspend.h> extern unsigned long mcpm_entry_vectors[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER]; @@ -146,6 +148,56 @@ int mcpm_cpu_powered_up(void) return 0; } +#ifdef CONFIG_ARM_CPU_SUSPEND + +static int __init nocache_trampoline(unsigned long _arg) +{ + void (*cache_disable)(void) = (void *)_arg; + unsigned int mpidr = read_cpuid_mpidr(); + unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + phys_reset_t phys_reset; + + mcpm_set_entry_vector(cpu, cluster, cpu_resume); + setup_mm_for_reboot(); + + __mcpm_cpu_going_down(cpu, cluster); + BUG_ON(!__mcpm_outbound_enter_critical(cpu, cluster)); + cache_disable(); + __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN); + __mcpm_cpu_down(cpu, cluster); + + phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset); + phys_reset(virt_to_phys(mcpm_entry_point)); + BUG(); +} + +int __init mcpm_loopback(void (*cache_disable)(void)) +{ + int ret; + + /* + * We're going to soft-restart the current CPU through the + * low-level MCPM code by leveraging the suspend/resume + * infrastructure. Let's play it safe by using cpu_pm_enter() + * in case the CPU init code path resets the VFP or similar. + */ + local_irq_disable(); + local_fiq_disable(); + ret = cpu_pm_enter(); + if (!ret) { + ret = cpu_suspend((unsigned long)cache_disable, nocache_trampoline); + cpu_pm_exit(); + } + local_fiq_enable(); + local_irq_enable(); + if (ret) + pr_err("%s returned %d\n", __func__, ret); + return ret; +} + +#endif + struct sync_struct mcpm_sync; /* diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h index 94060adba17..57ff7f2a308 100644 --- a/arch/arm/include/asm/mcpm.h +++ b/arch/arm/include/asm/mcpm.h @@ -217,6 +217,22 @@ int __mcpm_cluster_state(unsigned int cluster); int __init mcpm_sync_init( void (*power_up_setup)(unsigned int affinity_level)); +/** + * mcpm_loopback - make a run through the MCPM low-level code + * + * @cache_disable: pointer to function performing cache disabling + * + * This exercises the MCPM machinery by soft resetting the CPU and branching + * to the MCPM low-level entry code before returning to the caller. + * The @cache_disable function must do the necessary cache disabling to + * let the regular kernel init code turn it back on as if the CPU was + * hotplugged in. The MCPM state machine is set as if the cluster was + * initialized meaning the power_up_setup callback passed to mcpm_sync_init() + * will be invoked for all affinity levels. This may be useful to initialize + * some resources such as enabling the CCI that requires the cache to be off, or simply for testing purposes. + */ +int __init mcpm_loopback(void (*cache_disable)(void)); + void __init mcpm_smp_set_ops(void); #else |