--- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1888,7 +1888,7 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL && (!SMP || HOTPLUG_CPU) help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot --- /dev/null +++ b/arch/arm/include/asm/idmap.h @@ -0,0 +1,11 @@ +#ifndef __ASM_IDMAP_H +#define __ASM_IDMAP_H + +#include + +/* Tag a function as requiring to be executed via an identity mapping. */ +#define __idmap __section(.idmap.text) noinline notrace + +void setup_mm_for_reboot(void); + +#endif /* __ASM_IDMAP_H */ --- a/arch/arm/include/asm/mach/arch.h +++ b/arch/arm/include/asm/mach/arch.h @@ -30,10 +30,10 @@ struct machine_desc { unsigned int video_start; /* start of video RAM */ unsigned int video_end; /* end of video RAM */ - unsigned int reserve_lp0 :1; /* never has lp0 */ - unsigned int reserve_lp1 :1; /* never has lp1 */ - unsigned int reserve_lp2 :1; /* never has lp2 */ - unsigned int soft_reboot :1; /* soft reboot */ + unsigned char reserve_lp0 :1; /* never has lp0 */ + unsigned char reserve_lp1 :1; /* never has lp1 */ + unsigned char reserve_lp2 :1; /* never has lp2 */ + char restart_mode; /* default restart mode */ void (*fixup)(struct machine_desc *, struct tag *, char **, struct meminfo *); @@ -46,6 +46,7 @@ struct machine_desc { #ifdef CONFIG_MULTI_IRQ_HANDLER void (*handle_irq)(struct pt_regs *); #endif + void (*restart)(char, const char *); }; /* --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -107,7 +107,7 @@ extern void __show_regs(struct pt_regs * extern int cpu_architecture(void); extern void cpu_init(void); -void arm_machine_restart(char mode, const char *cmd); +void soft_restart(unsigned long); extern void (*arm_pm_restart)(char str, const char *cmd); #define UDBG_UNDEFINED (1 << 0) --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -12,12 +12,11 @@ #include #include #include +#include extern const unsigned char relocate_new_kernel[]; extern const unsigned int relocate_new_kernel_size; -extern void setup_mm_for_reboot(char mode); - extern unsigned long kexec_start_address; extern unsigned long kexec_indirection_page; extern unsigned long kexec_mach_type; @@ -111,14 +110,6 @@ void machine_kexec(struct kimage *image) if (kexec_reinit) kexec_reinit(); - local_irq_disable(); - local_fiq_disable(); - setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/ - flush_cache_all(); - outer_flush_all(); - outer_disable(); - cpu_proc_fin(); - outer_inv_all(); - flush_cache_all(); - cpu_reset(reboot_code_buffer_phys); + + soft_restart(reboot_code_buffer_phys); } --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -57,7 +57,7 @@ static const char *isa_modes[] = { "ARM" , "Thumb" , "Jazelle", "ThumbEE" }; -extern void setup_mm_for_reboot(char mode); +extern void setup_mm_for_reboot(void); static volatile int hlt_counter; @@ -92,40 +92,64 @@ static int __init hlt_setup(char *__unus __setup("nohlt", nohlt_setup); __setup("hlt", hlt_setup); -void arm_machine_restart(char mode, const char *cmd) +extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); +typedef void (*phys_reset_t)(unsigned long); + +/* + * A temporary stack to use for CPU reset. This is static so that we + * don't clobber it with the identity mapping. When running with this + * stack, any references to the current task *will not work* so you + * should really do as little as possible before jumping to your reset + * code. + */ +#define SOFT_RESTART_STACK_WORDS 32 +static u32 soft_restart_stack[SOFT_RESTART_STACK_WORDS]; + +static void __soft_restart(void *addr) { - /* Disable interrupts first */ - local_irq_disable(); - local_fiq_disable(); + phys_reset_t phys_reset; - /* - * Tell the mm system that we are going to reboot - - * we may need it to insert some 1:1 mappings so that - * soft boot works. - */ - setup_mm_for_reboot(mode); + /* Take out a flat memory mapping. */ + setup_mm_for_reboot(); - /* Clean and invalidate caches */ + /* Clean and invalidate caches. */ flush_cache_all(); - /* Turn off caching */ + /* Turn off caching. */ cpu_proc_fin(); /* Push out any further dirty data, and ensure cache is empty */ flush_cache_all(); - /* - * Now call the architecture specific reboot code. - */ - arch_reset(mode, cmd); - - /* - * Whoops - the architecture was unable to reboot. - * Tell the user! - */ - mdelay(1000); - printk("Reboot failed -- System halted\n"); - while (1); + /* Switch to the identity mapping. */ + phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset); + phys_reset((unsigned long)addr); + + /* Should never get here. */ + BUG(); +} + +void soft_restart(unsigned long addr) +{ + u32 *stack = soft_restart_stack + SOFT_RESTART_STACK_WORDS; + + /* Disable interrupts first */ + local_irq_disable(); + local_fiq_disable(); + + /* Disable the L2 if we're the last man standing. */ + if (num_online_cpus() == 1) + outer_disable(); + + /* Change to the new stack and continue with the reset. */ + call_with_stack(__soft_restart, (void *)addr, (void *)stack); + + /* Should never get here. */ + BUG(); +} + +static void null_restart(char mode, const char *cmd) +{ } /* @@ -134,7 +158,7 @@ void arm_machine_restart(char mode, cons void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); -void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart; +void (*arm_pm_restart)(char str, const char *cmd) = null_restart; EXPORT_SYMBOL_GPL(arm_pm_restart); static void do_nothing(void *unused) @@ -253,7 +277,15 @@ void machine_power_off(void) void machine_restart(char *cmd) { machine_shutdown(); + arm_pm_restart(reboot_mode, cmd); + + /* Give a grace period for failure to restart of 1s */ + mdelay(1000); + + /* Whoops - the platform was unable to reboot. Tell the user! */ + printk("Reboot failed -- System halted\n"); + while (1); } void __show_regs(struct pt_regs *regs) --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -896,8 +896,8 @@ void __init setup_arch(char **cmdline_p) arm_dma_zone_size = mdesc->dma_zone_size; } #endif - if (mdesc->soft_reboot) - reboot_setup("s"); + if (mdesc->restart_mode) + reboot_setup(&mdesc->restart_mode); init_mm.start_code = (unsigned long) _text; init_mm.end_code = (unsigned long) _etext; @@ -916,6 +916,9 @@ void __init setup_arch(char **cmdline_p) paging_init(mdesc); request_standard_resources(mdesc); + if (mdesc->restart) + arm_pm_restart = mdesc->restart; + unflatten_device_tree(); #ifdef CONFIG_SMP --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -558,6 +558,10 @@ static void ipi_cpu_stop(unsigned int cp local_fiq_disable(); local_irq_disable(); +#ifdef CONFIG_HOTPLUG_CPU + platform_cpu_kill(cpu); +#endif + while (1) cpu_relax(); } --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -91,6 +91,7 @@ SECTIONS SCHED_TEXT LOCK_TEXT KPROBES_TEXT + IDMAP_TEXT #ifdef CONFIG_MMU *(.fixup) #endif --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -13,7 +13,8 @@ lib-y := backtrace.o changebit.o csumip testchangebit.o testclearbit.o testsetbit.o \ ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ ucmpdi2.o lib1funcs.o div64.o \ - io-readsb.o io-writesb.o io-readsl.o io-writesl.o + io-readsb.o io-writesb.o io-readsl.o io-writesl.o \ + call_with_stack.o mmu-y := clear_user.o copy_page.o getuser.o putuser.o --- /dev/null +++ b/arch/arm/lib/call_with_stack.S @@ -0,0 +1,44 @@ +/* + * arch/arm/lib/call_with_stack.S + * + * Copyright (C) 2011 ARM Ltd. + * Written by Will Deacon + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include + +/* + * void call_with_stack(void (*fn)(void *), void *arg, void *sp) + * + * Change the stack to that pointed at by sp, then invoke fn(arg) with + * the new stack. + */ +ENTRY(call_with_stack) + str sp, [r2, #-4]! + str lr, [r2, #-4]! + + mov sp, r2 + mov r2, r0 + mov r0, r1 + + adr lr, BSYM(1f) + mov pc, r2 + +1: ldr lr, [sp] + ldr sp, [sp, #4] + mov pc, lr +ENDPROC(call_with_stack) --- a/arch/arm/mach-omap2/board-2430sdp.c +++ b/arch/arm/mach-omap2/board-2430sdp.c @@ -34,7 +34,7 @@ #include #include -#include +#include "common.h" #include #include #include @@ -264,4 +264,5 @@ MACHINE_START(OMAP_2430SDP, "OMAP2430 sd .init_irq = omap2_init_irq, .init_machine = omap_2430sdp_init, .timer = &omap2_timer, + .restart = omap_prcm_restart, MACHINE_END --- a/arch/arm/mach-omap2/board-3430sdp.c +++ b/arch/arm/mach-omap2/board-3430sdp.c @@ -33,7 +33,7 @@ #include #include #include -#include +#include "common.h" #include #include #include