diff options
Diffstat (limited to 'arch/tile/kernel')
| -rw-r--r-- | arch/tile/kernel/hvglue.S | 3 | ||||
| -rw-r--r-- | arch/tile/kernel/hvglue_trace.c | 4 | ||||
| -rw-r--r-- | arch/tile/kernel/intvec_64.S | 6 | ||||
| -rw-r--r-- | arch/tile/kernel/process.c | 101 | ||||
| -rw-r--r-- | arch/tile/kernel/traps.c | 12 |
5 files changed, 125 insertions, 1 deletions
diff --git a/arch/tile/kernel/hvglue.S b/arch/tile/kernel/hvglue.S index 2ab456622391..d78ee2ad610c 100644 --- a/arch/tile/kernel/hvglue.S +++ b/arch/tile/kernel/hvglue.S @@ -71,4 +71,5 @@ gensym hv_flush_all, 0x6e0, 32 gensym hv_get_ipi_pte, 0x700, 32 gensym hv_set_pte_super_shift, 0x720, 32 gensym hv_console_set_ipi, 0x7e0, 32 -gensym hv_glue_internals, 0x800, 30720 +gensym hv_send_nmi, 0x820, 32 +gensym hv_glue_internals, 0x820, 30688 diff --git a/arch/tile/kernel/hvglue_trace.c b/arch/tile/kernel/hvglue_trace.c index 85c74ad29312..add0d71395c6 100644 --- a/arch/tile/kernel/hvglue_trace.c +++ b/arch/tile/kernel/hvglue_trace.c @@ -75,6 +75,7 @@ #define hv_get_ipi_pte _hv_get_ipi_pte #define hv_set_pte_super_shift _hv_set_pte_super_shift #define hv_console_set_ipi _hv_console_set_ipi +#define hv_send_nmi _hv_send_nmi #include <hv/hypervisor.h> #undef hv_init #undef hv_install_context @@ -134,6 +135,7 @@ #undef hv_get_ipi_pte #undef hv_set_pte_super_shift #undef hv_console_set_ipi +#undef hv_send_nmi /* * Provide macros based on <linux/syscalls.h> to provide a wrapper @@ -264,3 +266,5 @@ HV_WRAP9(int, hv_flush_remote, HV_PhysAddr, cache_pa, HV_VirtAddr, tlb_va, unsigned long, tlb_length, unsigned long, tlb_pgsize, unsigned long*, tlb_cpumask, HV_Remote_ASID*, asids, int, asidcount) +HV_WRAP3(HV_NMI_Info, hv_send_nmi, HV_Coord, tile, unsigned long, info, + __hv64, flags) diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 5b67efcecabd..800b91d3f9dc 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -515,6 +515,10 @@ intvec_\vecname: .ifc \c_routine, handle_perf_interrupt mfspr r2, AUX_PERF_COUNT_STS .endif + .ifc \c_routine, do_nmi + mfspr r2, SPR_SYSTEM_SAVE_K_2 /* nmi type */ + .else + .endif .endif .endif .endif @@ -1571,3 +1575,5 @@ intrpt_start: /* Synthetic interrupt delivered only by the simulator */ int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint + /* Synthetic interrupt delivered by hv */ + int_hand INT_NMI_DWNCL, NMI_DWNCL, do_nmi, handle_nmi diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index b403c2e3e263..0dddcf7e5bfa 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -27,6 +27,7 @@ #include <linux/kernel.h> #include <linux/tracehook.h> #include <linux/signal.h> +#include <linux/delay.h> #include <linux/context_tracking.h> #include <asm/stack.h> #include <asm/switch_to.h> @@ -574,3 +575,103 @@ void show_regs(struct pt_regs *regs) dump_stack_regs(regs); } + +/* To ensure stack dump on tiles occurs one by one. */ +static DEFINE_SPINLOCK(backtrace_lock); +/* To ensure no backtrace occurs before all of the stack dump are done. */ +static atomic_t backtrace_cpus; +/* The cpu mask to avoid reentrance. */ +static struct cpumask backtrace_mask; + +void do_nmi_dump_stack(struct pt_regs *regs) +{ + int is_idle = is_idle_task(current) && !in_interrupt(); + int cpu; + + nmi_enter(); + cpu = smp_processor_id(); + if (WARN_ON_ONCE(!cpumask_test_and_clear_cpu(cpu, &backtrace_mask))) + goto done; + + spin_lock(&backtrace_lock); + if (is_idle) + pr_info("CPU: %d idle\n", cpu); + else + show_regs(regs); + spin_unlock(&backtrace_lock); + atomic_dec(&backtrace_cpus); +done: + nmi_exit(); +} + +#ifdef __tilegx__ +void arch_trigger_all_cpu_backtrace(bool self) +{ + struct cpumask mask; + HV_Coord tile; + unsigned int timeout; + int cpu; + int ongoing; + HV_NMI_Info info[NR_CPUS]; + + ongoing = atomic_cmpxchg(&backtrace_cpus, 0, num_online_cpus() - 1); + if (ongoing != 0) { + pr_err("Trying to do all-cpu backtrace.\n"); + pr_err("But another all-cpu backtrace is ongoing (%d cpus left)\n", + ongoing); + if (self) { + pr_err("Reporting the stack on this cpu only.\n"); + dump_stack(); + } + return; + } + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + cpumask_copy(&backtrace_mask, &mask); + + /* Backtrace for myself first. */ + if (self) + dump_stack(); + + /* Tentatively dump stack on remote tiles via NMI. */ + timeout = 100; + while (!cpumask_empty(&mask) && timeout) { + for_each_cpu(cpu, &mask) { + tile.x = cpu_x(cpu); + tile.y = cpu_y(cpu); + info[cpu] = hv_send_nmi(tile, TILE_NMI_DUMP_STACK, 0); + if (info[cpu].result == HV_NMI_RESULT_OK) + cpumask_clear_cpu(cpu, &mask); + } + + mdelay(10); + timeout--; + } + + /* Warn about cpus stuck in ICS and decrement their counts here. */ + if (!cpumask_empty(&mask)) { + for_each_cpu(cpu, &mask) { + switch (info[cpu].result) { + case HV_NMI_RESULT_FAIL_ICS: + pr_warn("Skipping stack dump of cpu %d in ICS at pc %#llx\n", + cpu, info[cpu].pc); + break; + case HV_NMI_RESULT_FAIL_HV: + pr_warn("Skipping stack dump of cpu %d in hypervisor\n", + cpu); + break; + case HV_ENOSYS: + pr_warn("Hypervisor too old to allow remote stack dumps.\n"); + goto skip_for_each; + default: /* should not happen */ + pr_warn("Skipping stack dump of cpu %d [%d,%#llx]\n", + cpu, info[cpu].result, info[cpu].pc); + break; + } + } +skip_for_each: + atomic_sub(cpumask_weight(&mask), &backtrace_cpus); + } +} +#endif /* __tilegx_ */ diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c index 312fc134c1cb..855f7316f1ee 100644 --- a/arch/tile/kernel/traps.c +++ b/arch/tile/kernel/traps.c @@ -395,6 +395,18 @@ done: exception_exit(prev_state); } +void do_nmi(struct pt_regs *regs, int fault_num, unsigned long reason) +{ + switch (reason) { + case TILE_NMI_DUMP_STACK: + do_nmi_dump_stack(regs); + break; + default: + panic("Unexpected do_nmi type %ld", reason); + return; + } +} + void kernel_double_fault(int dummy, ulong pc, ulong lr, ulong sp, ulong r52) { _dump_stack(dummy, pc, lr, sp, r52); 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