diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 158 |
1 files changed, 89 insertions, 69 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index cb0956bc96e..43b7c34f92c 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -20,6 +20,7 @@ #include <stdarg.h> +#include <linux/compat.h> #include <linux/export.h> #include <linux/sched.h> #include <linux/kernel.h> @@ -45,9 +46,10 @@ #include <asm/compat.h> #include <asm/cacheflush.h> +#include <asm/fpsimd.h> +#include <asm/mmu_context.h> #include <asm/processor.h> #include <asm/stacktrace.h> -#include <asm/fpsimd.h> static void setup_restart(void) { @@ -70,8 +72,17 @@ static void setup_restart(void) void soft_restart(unsigned long addr) { + typedef void (*phys_reset_t)(unsigned long); + phys_reset_t phys_reset; + setup_restart(); - cpu_reset(addr); + + /* Switch to the identity mapping */ + phys_reset = (phys_reset_t)virt_to_phys(cpu_reset); + phys_reset(addr); + + /* Should never get here */ + BUG(); } /* @@ -80,14 +91,13 @@ void soft_restart(unsigned long addr) void (*pm_power_off)(void); EXPORT_SYMBOL_GPL(pm_power_off); -void (*pm_restart)(const char *cmd); -EXPORT_SYMBOL_GPL(pm_restart); - +void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); +EXPORT_SYMBOL_GPL(arm_pm_restart); /* * This is our default idle handler. */ -static void default_idle(void) +void arch_cpu_idle(void) { /* * This should do all the clock switching and wait for interrupt @@ -97,79 +107,73 @@ static void default_idle(void) local_irq_enable(); } -void (*pm_idle)(void) = default_idle; -EXPORT_SYMBOL_GPL(pm_idle); - -/* - * The idle thread, has rather strange semantics for calling pm_idle, - * but this is what x86 does and we need to do the same, so that - * things like cpuidle get called in the same way. The only difference - * is that we always respect 'hlt_counter' to prevent low power idle. - */ -void cpu_idle(void) +#ifdef CONFIG_HOTPLUG_CPU +void arch_cpu_idle_dead(void) { - local_fiq_enable(); - - /* endless idle loop with no priority at all */ - while (1) { - tick_nohz_idle_enter(); - rcu_idle_enter(); - while (!need_resched()) { - /* - * We need to disable interrupts here to ensure - * we don't miss a wakeup call. - */ - local_irq_disable(); - if (!need_resched()) { - stop_critical_timings(); - pm_idle(); - start_critical_timings(); - /* - * pm_idle functions should always return - * with IRQs enabled. - */ - WARN_ON(irqs_disabled()); - } else { - local_irq_enable(); - } - } - rcu_idle_exit(); - tick_nohz_idle_exit(); - schedule_preempt_disabled(); - } + cpu_die(); } +#endif +/* + * Called by kexec, immediately prior to machine_kexec(). + * + * This must completely disable all secondary CPUs; simply causing those CPUs + * to execute e.g. a RAM-based pin loop is not sufficient. This allows the + * kexec'd kernel to use any and all RAM as it sees fit, without having to + * avoid any code or data used by any SW CPU pin loop. The CPU hotplug + * functionality embodied in disable_nonboot_cpus() to achieve this. + */ void machine_shutdown(void) { -#ifdef CONFIG_SMP - smp_send_stop(); -#endif + disable_nonboot_cpus(); } +/* + * Halting simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. + */ void machine_halt(void) { - machine_shutdown(); + local_irq_disable(); + smp_send_stop(); while (1); } +/* + * Power-off simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. When the system power is turned off, it will take all CPUs + * with it. + */ void machine_power_off(void) { - machine_shutdown(); + local_irq_disable(); + smp_send_stop(); if (pm_power_off) pm_power_off(); } +/* + * Restart requires that the secondary CPUs stop performing any activity + * while the primary CPU resets the system. Systems with a single CPU can + * use soft_restart() as their machine descriptor's .restart hook, since that + * will cause the only available CPU to reset. Systems with multiple CPUs must + * provide a HW restart implementation, to ensure that all CPUs reset at once. + * This is required so that any code running after reset on the primary CPU + * doesn't have to co-ordinate with other CPUs to ensure they aren't still + * executing pre-reset code, and using RAM that the primary CPU's code wishes + * to use. Implementing such co-ordination would be essentially impossible. + */ void machine_restart(char *cmd) { - machine_shutdown(); - /* Disable interrupts first */ local_irq_disable(); - local_fiq_disable(); + smp_send_stop(); /* Now call the architecture specific reboot code. */ - if (pm_restart) - pm_restart(cmd); + if (arm_pm_restart) + arm_pm_restart(reboot_mode, cmd); /* * Whoops - the architecture was unable to reboot. @@ -180,19 +184,26 @@ void machine_restart(char *cmd) void __show_regs(struct pt_regs *regs) { - int i; + int i, top_reg; + u64 lr, sp; - printk("CPU: %d %s (%s %.*s)\n", - raw_smp_processor_id(), print_tainted(), - init_utsname()->release, - (int)strcspn(init_utsname()->version, " "), - init_utsname()->version); + if (compat_user_mode(regs)) { + lr = regs->compat_lr; + sp = regs->compat_sp; + top_reg = 12; + } else { + lr = regs->regs[30]; + sp = regs->sp; + top_reg = 29; + } + + show_regs_print_info(KERN_DEFAULT); print_symbol("PC is at %s\n", instruction_pointer(regs)); - print_symbol("LR is at %s\n", regs->regs[30]); + print_symbol("LR is at %s\n", lr); printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n", - regs->pc, regs->regs[30], regs->pstate); - printk("sp : %016llx\n", regs->sp); - for (i = 29; i >= 0; i--) { + regs->pc, lr, regs->pstate); + printk("sp : %016llx\n", sp); + for (i = top_reg; i >= 0; i--) { printk("x%-2d: %016llx ", i, regs->regs[i]); if (i % 2 == 0) printk("\n"); @@ -203,7 +214,6 @@ void __show_regs(struct pt_regs *regs) void show_regs(struct pt_regs * regs) { printk("\n"); - printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); __show_regs(regs); } @@ -226,7 +236,7 @@ void release_thread(struct task_struct *dead_task) int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { - fpsimd_save_state(¤t->thread.fpsimd_state); + fpsimd_preserve_current_state(); *dst = *src; return 0; } @@ -315,6 +325,13 @@ struct task_struct *__switch_to(struct task_struct *prev, fpsimd_thread_switch(next); tls_thread_switch(next); hw_breakpoint_thread_switch(next); + contextidr_thread_switch(next); + + /* + * Complete any pending TLB or cache maintenance on this CPU in case + * the thread migrates to a different CPU. + */ + dsb(ish); /* the actual thread switch */ last = cpu_switch_to(prev, next); @@ -325,6 +342,7 @@ struct task_struct *__switch_to(struct task_struct *prev, unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; + unsigned long stack_page; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; @@ -332,9 +350,11 @@ unsigned long get_wchan(struct task_struct *p) frame.fp = thread_saved_fp(p); frame.sp = thread_saved_sp(p); frame.pc = thread_saved_pc(p); + stack_page = (unsigned long)task_stack_page(p); do { - int ret = unwind_frame(&frame); - if (ret < 0) + if (frame.sp < stack_page || + frame.sp >= stack_page + THREAD_SIZE || + unwind_frame(&frame)) return 0; if (!in_sched_functions(frame.pc)) return frame.pc; |