diff options
| -rw-r--r-- | arch/arm64/include/asm/smp.h | 28 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 34 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 45 |
4 files changed, 107 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h index 51913be35a0a..817a067ba058 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -16,6 +16,19 @@ #ifndef __ASM_SMP_H #define __ASM_SMP_H +/* Values for secondary_data.status */ + +#define CPU_MMU_OFF (-1) +#define CPU_BOOT_SUCCESS (0) +/* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */ +#define CPU_KILL_ME (1) +/* The cpu couldn't die gracefully and is looping in the kernel */ +#define CPU_STUCK_IN_KERNEL (2) +/* Fatal system error detected by secondary CPU, crash the system */ +#define CPU_PANIC_KERNEL (3) + +#ifndef __ASSEMBLY__ + #include <linux/threads.h> #include <linux/cpumask.h> #include <linux/thread_info.h> @@ -54,11 +67,17 @@ asmlinkage void secondary_start_kernel(void); /* * Initial data for bringing up a secondary CPU. + * @stack - sp for the secondary CPU + * @status - Result passed back from the secondary CPU to + * indicate failure. */ struct secondary_data { void *stack; + long status; }; + extern struct secondary_data secondary_data; +extern long __early_cpu_boot_status; extern void secondary_entry(void); extern void arch_send_call_function_single_ipi(int cpu); @@ -87,4 +106,13 @@ static inline void cpu_park_loop(void) } } +static inline void update_cpu_boot_status(int val) +{ + WRITE_ONCE(secondary_data.status, val); + /* Ensure the visibility of the status update */ + dsb(ishst); +} + +#endif /* ifndef __ASSEMBLY__ */ + #endif /* ifndef __ASM_SMP_H */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 2bb17bd556f8..a506ddc270c0 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -117,6 +117,8 @@ int main(void) DEFINE(TZ_MINWEST, offsetof(struct timezone, tz_minuteswest)); DEFINE(TZ_DSTTIME, offsetof(struct timezone, tz_dsttime)); BLANK(); + DEFINE(CPU_BOOT_STACK, offsetof(struct secondary_data, stack)); + BLANK(); #ifdef CONFIG_KVM_ARM_HOST DEFINE(VCPU_CONTEXT, offsetof(struct kvm_vcpu, arch.ctxt)); DEFINE(CPU_GP_REGS, offsetof(struct kvm_cpu_context, gp_regs)); diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 0ea9a97467a6..6c5595928169 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -36,6 +36,7 @@ #include <asm/pgtable-hwdef.h> #include <asm/pgtable.h> #include <asm/page.h> +#include <asm/smp.h> #include <asm/sysreg.h> #include <asm/thread_info.h> #include <asm/virt.h> @@ -643,7 +644,8 @@ __secondary_switched: msr vbar_el1, x5 isb - ldr_l x0, secondary_data // get secondary_data.stack + adr_l x0, secondary_data + ldr x0, [x0, #CPU_BOOT_STACK] // get secondary_data.stack mov sp, x0 and x0, x0, #~(THREAD_SIZE - 1) msr sp_el0, x0 // save thread_info @@ -652,6 +654,29 @@ __secondary_switched: ENDPROC(__secondary_switched) /* + * The booting CPU updates the failed status @__early_cpu_boot_status, + * with MMU turned off. + * + * update_early_cpu_boot_status tmp, status + * - Corrupts tmp1, tmp2 + * - Writes 'status' to __early_cpu_boot_status and makes sure + * it is committed to memory. + */ + + .macro update_early_cpu_boot_status status, tmp1, tmp2 + mov \tmp2, #\status + str_l \tmp2, __early_cpu_boot_status, \tmp1 + dmb sy + dc ivac, \tmp1 // Invalidate potentially stale cache line + .endm + + .pushsection .data..cacheline_aligned + .align L1_CACHE_SHIFT +ENTRY(__early_cpu_boot_status) + .long 0 + .popsection + +/* * Enable the MMU. * * x0 = SCTLR_EL1 value for turning on the MMU. @@ -669,6 +694,7 @@ ENTRY(__enable_mmu) ubfx x2, x1, #ID_AA64MMFR0_TGRAN_SHIFT, 4 cmp x2, #ID_AA64MMFR0_TGRAN_SUPPORTED b.ne __no_granule_support + update_early_cpu_boot_status 0, x1, x2 msr ttbr0_el1, x25 // load TTBR0 msr ttbr1_el1, x26 // load TTBR1 isb @@ -708,8 +734,12 @@ ENTRY(__enable_mmu) ENDPROC(__enable_mmu) __no_granule_support: + /* Indicate that this CPU can't boot and is stuck in the kernel */ + update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x1, x2 +1: wfe - b __no_granule_support + wfi + b 1b ENDPROC(__no_granule_support) __primary_switch: diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index ee247d441d38..acabb9b99766 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -63,6 +63,8 @@ * where to place its SVC stack */ struct secondary_data secondary_data; +/* Number of CPUs which aren't online, but looping in kernel text. */ +int cpus_stuck_in_kernel; enum ipi_msg_type { IPI_RESCHEDULE, @@ -73,6 +75,16 @@ enum ipi_msg_type { IPI_WAKEUP }; +#ifdef CONFIG_HOTPLUG_CPU +static int op_cpu_kill(unsigned int cpu); +#else +static inline int op_cpu_kill(unsigned int cpu) +{ + return -ENOSYS; +} +#endif + + /* * Boot a secondary CPU, and assign it the specified idle task. * This also gives us the initial stack to use for this CPU. @@ -90,12 +102,14 @@ static DECLARE_COMPLETION(cpu_running); int __cpu_up(unsigned int cpu, struct task_struct *idle) { int ret; + long status; /* * We need to tell the secondary core where to find its stack and the * page tables. */ secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; + update_cpu_boot_status(CPU_MMU_OFF); __flush_dcache_area(&secondary_data, sizeof(secondary_data)); /* @@ -119,6 +133,32 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) } secondary_data.stack = NULL; + status = READ_ONCE(secondary_data.status); + if (ret && status) { + + if (status == CPU_MMU_OFF) + status = READ_ONCE(__early_cpu_boot_status); + + switch (status) { + default: + pr_err("CPU%u: failed in unknown state : 0x%lx\n", + cpu, status); + break; + case CPU_KILL_ME: + if (!op_cpu_kill(cpu)) { + pr_crit("CPU%u: died during early boot\n", cpu); + break; + } + /* Fall through */ + pr_crit("CPU%u: may not have shut down cleanly\n", cpu); + case CPU_STUCK_IN_KERNEL: + pr_crit("CPU%u: is stuck in kernel\n", cpu); + cpus_stuck_in_kernel++; + break; + case CPU_PANIC_KERNEL: + panic("CPU%u detected unsupported configuration\n", cpu); + } + } return ret; } @@ -184,6 +224,9 @@ asmlinkage void secondary_start_kernel(void) */ pr_info("CPU%u: Booted secondary processor [%08x]\n", cpu, read_cpuid_id()); + update_cpu_boot_status(CPU_BOOT_SUCCESS); + /* Make sure the status update is visible before we complete */ + smp_wmb(); set_cpu_online(cpu, true); complete(&cpu_running); @@ -325,10 +368,12 @@ void cpu_die_early(void) set_cpu_present(cpu, 0); #ifdef CONFIG_HOTPLUG_CPU + update_cpu_boot_status(CPU_KILL_ME); /* Check if we can park ourselves */ if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die) cpu_ops[cpu]->cpu_die(cpu); #endif + update_cpu_boot_status(CPU_STUCK_IN_KERNEL); cpu_park_loop(); } |