diff options
| -rw-r--r-- | arch/tile/include/asm/irq.h | 5 | ||||
| -rw-r--r-- | arch/tile/include/asm/traps.h | 8 | ||||
| -rw-r--r-- | arch/tile/include/hv/hypervisor.h | 60 | ||||
| -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 |
8 files changed, 197 insertions, 2 deletions
diff --git a/arch/tile/include/asm/irq.h b/arch/tile/include/asm/irq.h index 1fe86911838b..84a924034bdb 100644 --- a/arch/tile/include/asm/irq.h +++ b/arch/tile/include/asm/irq.h @@ -78,4 +78,9 @@ void tile_irq_activate(unsigned int irq, int tile_irq_type); void setup_irq_regs(void); +#ifdef __tilegx__ +void arch_trigger_all_cpu_backtrace(bool self); +#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace +#endif + #endif /* _ASM_TILE_IRQ_H */ diff --git a/arch/tile/include/asm/traps.h b/arch/tile/include/asm/traps.h index 4b99a1c3aab2..11c82270c1f5 100644 --- a/arch/tile/include/asm/traps.h +++ b/arch/tile/include/asm/traps.h @@ -52,6 +52,14 @@ void do_timer_interrupt(struct pt_regs *, int fault_num); /* kernel/messaging.c */ void hv_message_intr(struct pt_regs *, int intnum); +#define TILE_NMI_DUMP_STACK 1 /* Dump stack for sysrq+'l' */ + +/* kernel/process.c */ +void do_nmi_dump_stack(struct pt_regs *regs); + +/* kernel/traps.c */ +void do_nmi(struct pt_regs *, int fault_num, unsigned long reason); + /* kernel/irq.c */ void tile_dev_intr(struct pt_regs *, int intnum); diff --git a/arch/tile/include/hv/hypervisor.h b/arch/tile/include/hv/hypervisor.h index e0e6af4e783b..f10b332b3b65 100644 --- a/arch/tile/include/hv/hypervisor.h +++ b/arch/tile/include/hv/hypervisor.h @@ -321,8 +321,11 @@ /** hv_console_set_ipi */ #define HV_DISPATCH_CONSOLE_SET_IPI 63 +/** hv_send_nmi */ +#define HV_DISPATCH_SEND_NMI 65 + /** One more than the largest dispatch value */ -#define _HV_DISPATCH_END 64 +#define _HV_DISPATCH_END 66 #ifndef __ASSEMBLER__ @@ -1253,6 +1256,11 @@ void hv_downcall_dispatch(void); #define INT_DMATLB_ACCESS_DWNCL INT_DMA_CPL /** Device interrupt downcall interrupt vector */ #define INT_DEV_INTR_DWNCL INT_WORLD_ACCESS +/** NMI downcall interrupt vector */ +#define INT_NMI_DWNCL 64 + +#define HV_NMI_FLAG_FORCE 0x1 /**< Force an NMI downcall regardless of + the ICS bit of the client. */ #ifndef __ASSEMBLER__ @@ -1780,6 +1788,56 @@ int hv_dev_poll(int devhdl, __hv32 events, HV_IntArg intarg); int hv_dev_poll_cancel(int devhdl); +/** NMI information */ +typedef struct +{ + /** Result: negative error, or HV_NMI_RESULT_xxx. */ + int result; + + /** PC from interrupted remote core (if result != HV_NMI_RESULT_FAIL_HV). */ + HV_VirtAddr pc; + +} HV_NMI_Info; + +/** NMI issued successfully. */ +#define HV_NMI_RESULT_OK 0 + +/** NMI not issued: remote tile running at client PL with ICS set. */ +#define HV_NMI_RESULT_FAIL_ICS 1 + +/** NMI not issued: remote tile waiting in hypervisor. */ +#define HV_NMI_RESULT_FAIL_HV 2 + +/** Force an NMI downcall regardless of the ICS bit of the client. */ +#define HV_NMI_FLAG_FORCE 0x1 + +/** Send an NMI interrupt request to a particular tile. + * + * This will cause the NMI to be issued on the remote tile regardless + * of the state of the client interrupt mask. However, if the remote + * tile is in the hypervisor, it will not execute the NMI, and + * HV_NMI_RESULT_FAIL_HV will be returned. Similarly, if the remote + * tile is in a client interrupt critical section at the time of the + * NMI, it will not execute the NMI, and HV_NMI_RESULT_FAIL_ICS will + * be returned. In this second case, however, if HV_NMI_FLAG_FORCE + * is set in flags, then the remote tile will enter its NMI interrupt + * vector regardless. Forcing the NMI vector during an interrupt + * critical section will mean that the client can not safely continue + * execution after handling the interrupt. + * + * @param tile Tile to which the NMI request is sent. + * @param info NMI information which is defined by and interpreted by the + * supervisor, is passed to the specified tile, and is + * stored in the SPR register SYSTEM_SAVE_{CLIENT_PL}_2 on the + * specified tile when entering the NMI handler routine. + * Typically, this parameter stores the NMI type, or an aligned + * VA plus some special bits, etc. + * @param flags Flags (HV_NMI_FLAG_xxx). + * @return Information about the requested NMI. + */ +HV_NMI_Info hv_send_nmi(HV_Coord tile, unsigned long info, __hv64 flags); + + /** Scatter-gather list for preada/pwritea calls. */ typedef struct #if CHIP_VA_WIDTH() <= 32 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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