// SPDX-License-Identifier: GPL-2.0-or-later /* * SGI NMI support routines * * (C) Copyright 2020 Hewlett Packard Enterprise Development LP * Copyright (C) 2007-2017 Silicon Graphics, Inc. All rights reserved. * Copyright (c) Mike Travis */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * UV handler for NMI * * Handle system-wide NMI events generated by the global 'power nmi' command. * * Basic operation is to field the NMI interrupt on each CPU and wait * until all CPU's have arrived into the nmi handler. If some CPU's do not * make it into the handler, try and force them in with the IPI(NMI) signal. * * We also have to lessen UV Hub MMR accesses as much as possible as this * disrupts the UV Hub's primary mission of directing NumaLink traffic and * can cause system problems to occur. * * To do this we register our primary NMI notifier on the NMI_UNKNOWN * chain. This reduces the number of false NMI calls when the perf * tools are running which generate an enormous number of NMIs per * second (~4M/s for 1024 CPU threads). Our secondary NMI handler is * very short as it only checks that if it has been "pinged" with the * IPI(NMI) signal as mentioned above, and does not read the UV Hub's MMR. * */ static struct uv_hub_nmi_s **uv_hub_nmi_list; DEFINE_PER_CPU(struct uv_cpu_nmi_s, uv_cpu_nmi); /* Newer SMM NMI handler, not present in all systems */ static unsigned long uvh_nmi_mmrx; /* UVH_EVENT_OCCURRED0/1 */ static unsigned long uvh_nmi_mmrx_clear; /* UVH_EVENT_OCCURRED0/1_ALIAS */ static int uvh_nmi_mmrx_shift; /* UVH_EVENT_OCCURRED0/1_EXTIO_INT0_SHFT */ static char *uvh_nmi_mmrx_type; /* "EXTIO_INT0" */ /* Non-zero indicates newer SMM NMI handler present */ static unsigned long uvh_nmi_mmrx_supported; /* UVH_EXTIO_INT0_BROADCAST */ /* Indicates to BIOS that we want to use the newer SMM NMI handler */ static unsigned long uvh_nmi_mmrx_req; /* UVH_BIOS_KERNEL_MMR_ALIAS_2 */ static int uvh_nmi_mmrx_req_shift; /* 62 */ /* UV hubless values */ #define NMI_CONTROL_PORT 0x70 #define NMI_DUMMY_PORT 0x71 #define PAD_OWN_GPP_D_0 0x2c #define GPI_NMI_STS_GPP_D_0 0x164 #define GPI_NMI_ENA_GPP_D_0 0x174 #define STS_GPP_D_0_MASK 0x1 #define PAD_CFG_DW0_GPP_D_0 0x4c0 #define GPIROUTNMI (1ul << 17) #define PCH_PCR_GPIO_1_BASE 0xfdae0000ul #define PCH_PCR_GPIO_ADDRESS(offset) (int *)((u64)(pch_base) | (u64)(offset)) static u64 *pch_base; static unsigned long nmi_mmr; static unsigned long nmi_mmr_clear; static unsigned long nmi_mmr_pending; static atomic_t uv_in_nmi; static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1); static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1); static atomic_t uv_nmi_slave_continue; static cpumask_var_t uv_nmi_cpu_mask; static atomic_t uv_nmi_kexec_failed; /* Values for uv_nmi_slave_continue */ #define SLAVE_CLEAR 0 #define SLAVE_CONTINUE 1 #define SLAVE_EXIT 2 /* * Default is all stack dumps go to the console and buffer. * Lower level to send to log buffer only. */ static int uv_nmi_loglevel = CONSOLE_LOGLEVEL_DEFAULT; module_param_named(dump_loglevel, uv_nmi_loglevel, int, 0644); /* * The following values show statistics on how perf events are affecting * this system. */ static int param_get_local64(char *buffer, const struct kernel_param *kp) { return sprintf(buffer, "%lu\n", local64_read((local64_t *)kp->arg)); } static int param_set_local64(const char *val, const struct kernel_param *kp) { /* Clear on any write */ local64_set((local64_t *)kp->arg, 0); return 0; } static const struct kernel_param_ops param_ops_local64 = { .get = param_get_local64, .set = param_set_local64, }; #define param_check_local64(name, p) __param_check(name, p, local64_t) static local64_t uv_nmi_count; module_param_named(nmi_count, uv_nmi_count, local64, 0644); static local64_t uv_nmi_misses; module_param_named(nmi_misses, uv_nmi_misses, local64, 0644); static local64_t uv_nmi_ping_count; module_param_named(ping_count, uv_nmi_ping_count, local64, 0644); static local64_t uv_nmi_ping_misses; module_param_named(ping_misses, uv_nmi_ping_misses, local64, 0644); /* * Following values allow tuning for large systems under heavy loading */ static int uv_nmi_initial_delay = 100; module_param_named(initial_delay, uv_nmi_initial_delay, int, 0644); static int uv_nmi_slave_delay = 100; module_param_named(slave_delay, uv_nmi_slave_delay, int, 0644); static int uv_nmi_loop_delay = 100; module_param_named(loop_delay, uv_nmi_loop_delay, int, 0644); static int uv_nmi_trigger_delay = 10000; module_param_named(trigger_delay, uv_nmi_trigger_delay, int, 0644); static int uv_nmi_wait_count = 100; module_param_named(wait_count, uv_nmi_wait_count, int, 0644); static int uv_nmi_retry_count = 500; module_param_named(retry_count, uv_nmi_retry_count, int, 0644); static bool uv_pch_intr_enable = true; static bool uv_pch_intr_now_enabled; module_param_named(pch_intr_enable, uv_pch_intr_enable, bool, 0644); static bool uv_pch_init_enable = true; module_param_named(pch_init_enable, uv_pch_init_enable, bool, 0644); static int uv_nmi_debug; module_param_named(debug, uv_nmi_debug, int, 0644); #define nmi_debug(fmt, ...) \ do { \ if (uv_nmi_debug) \ pr_info(fmt, ##__VA_ARGS__); \ } while (0) /* Valid NMI Actions */ #define ACTION_LEN 16 static struct nmi_action { char *action; char *desc; } valid_acts[] = { { "kdump", "do kernel crash dump" }, { "dump", "dump process stack for each cpu" }, { "ips", "dump Inst Ptr info for each cpu" }, { "kdb", "enter KDB (needs kgdboc= assignment)" }, { "kgdb", "enter KGDB (needs gdb target remote)" }, { "health", "check if CPUs respond to NMI" }, }; typedef char action_t[ACTION_LEN]; static action_t uv_nmi_action = { "dump" }; static int param_get_action(char *buffer, const struct kernel_param *kp) { return sprintf(buffer, "%s\n", uv_nmi_action); } static int param_set_action(const char *val, const struct kernel_param *kp) { int i; int n = ARRAY_SIZE(valid_acts); char arg[ACTION_LEN]; /* (remove possible '\n') */ strscpy(arg, val, strnchrnul(val, sizeof(arg)-1, '\n') - val + 1); for (i = 0; i < n; i++) if (!strcmp(arg, valid_acts[i].action)) break; if (i < n) { strscpy(uv_nmi_action, arg, sizeof(uv_nmi_action)); pr_info("UV: New NMI action:%s\n", uv_nmi_action); return 0; } pr_err("UV: Invalid NMI action:%s, valid actions are:\n", arg); for (i = 0; i < n; i++) pr_err("UV: %-8s - %s\n", valid_acts[i].action, valid_acts[i].desc); return -EINVAL; } static const struct kernel_param_ops param_ops_action = { .get = param_get_action, .set = param_set_action, }; #define param_check_action(name, p) __param_check(name, p, action_t) module_param_named(action, uv_nmi_action, action, 0644); static inline bool uv_nmi_action_is(const char *action) { return (strncmp(uv_nmi_action, action, strlen(action)) == 0); } /* Setup which NMI support is present in system */ static void uv_nmi_setup_mmrs(void) { bool new_nmi_method_only = false; /* First determine arch specific MMRs to handshake with BIOS */ if (UVH_EVENT_OCCURRED0_EXTIO_INT0_MASK) { /* UV2,3,4 setup */ uvh_nmi_mmrx = UVH_EVENT_OCCURRED0; uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED0_ALIAS; uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED0_EXTIO_INT0_SHFT; uvh_nmi_mmrx_type = "OCRD0-EXTIO_INT0"; uvh_nmi_mmrx_supported = UVH_EXTIO_INT0_BROADCAST; uvh_nmi_mmrx_req = UVH_BIOS_KERNEL_MMR_ALIAS_2; uvh_nmi_mmrx_req_shift = 62; } else if (UVH_EVENT_OCCURRED1_EXTIO_INT0_MASK) { /* UV5+ setup */ uvh_nmi_mmrx = UVH_EVENT_OCCURRED1; uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED1_ALIAS; uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED1_EXTIO_INT0_SHFT; uvh_nmi_mmrx_type = "OCRD1-EXTIO_INT0"; new_nmi_method_only = true; /* Newer nmi always valid on UV5+ */ uvh_nmi_mmrx_req = 0; /* no request bit to clear */ } else { pr_err("UV:%s:NMI support not available on this system\n", __func__); return; } /* Then find out if new NMI is supported */ if (new_nmi_method_only || uv_read_local_mmr(uvh_nmi_mmrx_supported)) { if (uvh_nmi_mmrx_req) uv_write_local_mmr(uvh_nmi_mmrx_req, 1UL << uvh_nmi_mmrx_req_shift); nmi_mmr = uvh_nmi_mmrx; nmi_mmr_clear = uvh_nmi_mmrx_clear; nmi_mmr_pending = 1UL << uvh_nmi_mmrx_shift; pr_info("UV: SMI NMI support: %s\n", uvh_nmi_mmrx_type); } else { nmi_mmr = UVH_NMI_MMR; nmi_mmr_clear = UVH_NMI_MMR_CLEAR; nmi_mmr_pending = 1UL << UVH_NMI_MMR_SHIFT; pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMR_TYPE); } } /* Read NMI MMR and check if NMI flag was set by BMC. */ static inline int uv_nmi_test_mmr(struct uv_hub_nmi_s *hub_nmi) { hub_nmi->nmi_value = uv_read_local_mmr(nmi_mmr); atomic_inc(&hub_nmi->read_mmr_count); return !!(hub_nmi->nmi_value & nmi_mmr_pending); } static inline void uv_local_mmr_clear_nmi(void) { uv_write_local_mmr(nmi_mmr_clear, nmi_mmr_pending); } /* * UV hubless NMI handler functions */ static inline void uv_reassert_nmi(void) { /* (from arch/x86/include/asm/mach_traps.h) */ outb(0x8f, NMI_CONTROL_PORT); inb(NMI_DUMMY_PORT); /* dummy read */ outb(0x0f, NMI_CONTROL_PORT); inb(NMI_DUMMY_PORT); /* dummy read */ } static void uv_init_hubless_pch_io(int offset, int mask, int data) { int *addr = PCH_PCR_GPIO_ADDRESS(offset); int readd = readl(addr); if (mask) { /* OR in new data */ int writed = (readd & ~mask) | data; nmi_debug("UV:PCH: %p = %x & %x | %x (%x)\n", addr, readd, ~mask, data, writed); writel(writed, addr); } else if (readd & data) { /* clear status bit */ nmi_debug("UV:PCH: %p = %x\n", addr, data); writel(data, addr); } (void)readl(addr); /* flush write data */ } static void uv_nmi_setup_hubless_intr(void) { uv_pch_intr_now_enabled = uv_pch_intr_enable; uv_init_hubless_pch_io( PAD_CFG_DW0_GPP_D_0, GPIROUTNMI, uv_pch_intr_now_enabled ? GPIROUTNMI : 0); nmi_debug("UV:NMI: GPP_D_0 interrupt %s\n", uv_pch_intr_now_enabled ? "enabled" : "disabled"); } static struct init_nmi { unsigned int offset; unsigned int mask; unsigned int data; } init_nmi[] = { { /* HOSTSW_OWN_GPP_D_0 */ .offset = 0x84, .mask = 0x1, .data = 0x0, /* ACPI Mode */ }, /* Clear status: */ { /* GPI_INT_STS_GPP_D_0 */ .offset = 0x104, .mask = 0x0, .data = 0x1, /* Clear Status */ }, { /* GPI_GPE_STS_GPP_D_0 */ .offset = 0x124, .mask = 0x0, .data = 0x1, /* Clear Status */ }, { /* GPI_SMI_STS_GPP_D_0 */ .offset = 0x144, .mask = 0x0, .data = 0x1, /* Clear Status */ }, { /* GPI_NMI_STS_GPP_D_0 */ .offset = 0x164, .mask = 0x0, .data = 0x1, /* Clear Status */ }, /* Disable interrupts: */ { /* GPI_INT_EN_GPP_D_0 */ .offset = 0x114, .mask = 0x1, .data = 0x0, /* Disable interrupt generation */ }, { /* GPI_GPE_EN_GPP_D_0 */ .offset = 0x134, .mask = 0x1, .data = 0x0, /* Disable interrupt generation */ }, { /* GPI_SMI_EN_GPP_D_0 */ .offset = 0x154, .mask = 0x1, .data = 0x0, /* Disable interrupt generation */ }, { /* GPI_NMI_EN_GPP_D_0 */ .offset = 0x174, .mask = 0x1, .data = 0x0, /* Disable interrupt generation */ }, /* Setup GPP_D_0 Pad Config: */ { /* PAD_CFG_DW0_GPP_D_0 */ .offset = 0x4c0, .mask = 0xffffffff, .data = 0x82020100, /* * 31:30 Pad Reset Config (PADRSTCFG): = 2h # PLTRST# (default) * * 29 RX Pad State Select (RXPADSTSEL): = 0 # Raw RX pad state directly * from RX buffer (default) * * 28 RX Raw Override to '1' (RXRAW1): = 0 # No Override * * 26:25 RX Level/Edge Configuration (RXEVCFG): * = 0h # Level * = 1h # Edge * * 23 RX Invert (RXINV): = 0 # No Inversion (signal active high) * * 20 GPIO Input Route IOxAPIC (GPIROUTIOXAPIC): * = 0 # Routing does not cause peripheral IRQ... * # (we want an NMI not an IRQ) * * 19 GPIO Input Route SCI (GPIROUTSCI): = 0 # Routing does not cause SCI. * 18 GPIO Input Route SMI (GPIROUTSMI): = 0 # Routing does not cause SMI. * 17 GPIO Input Route NMI (GPIROUTNMI): = 1 # Routing can cause NMI. * * 11:10 Pad Mode (PMODE1/0): = 0h = GPIO control the Pad. * 9 GPIO RX Disable (GPIORXDIS): * = 0 # Enable the input buffer (active low enable) * * 8 GPIO TX Disable (GPIOTXDIS): * = 1 # Disable the output buffer; i.e. Hi-Z * * 1 GPIO RX State (GPIORXSTATE): This is the current internal RX pad state.. * 0 GPIO TX State (GPIOTXSTATE): * = 0 # (Leave at default) */ }, /* Pad Config DW1 */ { /* PAD_CFG_DW1_GPP_D_0 */ .offset = 0x4c4, .mask = 0x3c00, .data = 0, /* Termination = none (default) */ }, }; static void uv_init_hubless_pch_d0(void) { int i, read; read = *PCH_PCR_GPIO_ADDRESS(PAD_OWN_GPP_D_0); if (read != 0) { pr_info("UV: Hubless NMI already configured\n"); return; } nmi_debug("UV: Initializing UV Hubless NMI on PCH\n"); for (i = 0; i < ARRAY_SIZE(init_nmi); i++) { uv_init_hubless_pch_io(init_nmi[i].offset, init_nmi[i].mask, init_nmi[i].data); } } static int uv_nmi_test_hubless(struct uv_hub_nmi_s *hub_nmi) { int *pstat = PCH_PCR_GPIO_ADDRESS(GPI_NMI_STS_GPP_D_0); int status = *pstat; hub_nmi->nmi_value = status; atomic_inc(&hub_nmi->read_mmr_count); if (!(status & STS_GPP_D_0_MASK)) /* Not a UV external NMI */ return 0; *pstat = STS_GPP_D_0_MASK; /* Is a UV NMI: clear GPP_D_0 status */ (void)*pstat; /* Flush write */ return 1; } static int uv_test_nmi(struct uv_hub_nmi_s *hub_nmi) { if (hub_nmi->hub_present) return uv_nmi_test_mmr(hub_nmi); if (hub_nmi->pch_owner) /* Only PCH owner can check status */ return uv_nmi_test_hubless(hub_nmi); return -1; } /* * If first CPU in on this hub, set hub_nmi "in_nmi" and "owner" values and * return true. If first CPU in on the system, set global "in_nmi" flag. */ static int uv_set_in_nmi(int cpu, struct uv_hub_nmi_s *hub_nmi) { int first = atomic_add_unless(&hub_nmi->in_nmi, 1, 1); if (first) { atomic_set(&hub_nmi->cpu_owner, cpu); if (atomic_add_unless(&uv_in_nmi, 1, 1)) atomic_set(&uv_nmi_cpu, cpu); atomic_inc(&hub_nmi->nmi_count); } return first; } /* Check if this is a system NMI event */ static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi) { int cpu = smp_processor_id(); int nmi = 0; int nmi_detected = 0; local64_inc(&uv_nmi_count); this_cpu_inc(uv_cpu_nmi.queries); do { nmi = atomic_read(&hub_nmi->in_nmi); if (nmi) break; if (raw_spin_trylock(&hub_nmi->nmi_lock)) { nmi_detected = uv_test_nmi(hub_nmi); /* Check flag for UV external NMI */ if (nmi_detected > 0) { uv_set_in_nmi(cpu, hub_nmi); nmi = 1; break; } /* A non-PCH node in a hubless system waits for NMI */ else if (nmi_detected < 0) goto slave_wait; /* MMR/PCH NMI flag is clear */ raw_spin_unlock(&hub_nmi->nmi_lock); } else { /* Wait a moment for the HUB NMI locker to set flag */ slave_wait: cpu_relax(); udelay(uv_nmi_slave_delay); /* Re-check hub in_nmi flag */ nmi = atomic_read(&hub_nmi->in_nmi); if (nmi) break; } /* * Check if this BMC missed setting the MMR NMI flag (or) * UV hubless system where only PCH owner can check flag */ if (!nmi) { nmi = atomic_read(&uv_in_nmi); if (nmi) uv_set_in_nmi(cpu, hub_nmi); } /* If we're holding the hub lock, release it now */ if (nmi_detected < 0) raw_spin_unlock(&hub_nmi->nmi_lock); } while (0); if (!nmi) local64_inc(&uv_nmi_misses); return nmi; } /* Need to reset the NMI MMR register, but only once per hub. */ static inline void uv_clear_nmi(int cpu) { struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; if (cpu == atomic_read(&hub_nmi->cpu_owner)) { atomic_set(&hub_nmi->cpu_owner, -1); atomic_set(&hub_nmi->in_nmi, 0); if (hub_nmi->hub_present) uv_local_mmr_clear_nmi(); else uv_reassert_nmi(); raw_spin_unlock(&hub_nmi->nmi_lock); } } /* Ping non-responding CPU's attempting to force them into the NMI handler */ static void uv_nmi_nr_cpus_ping(void) { int cpu; for_each_cpu(cpu, uv_nmi_cpu_mask) uv_cpu_nmi_per(cpu).pinging = 1; __apic_send_IPI_mask(uv_nmi_cpu_mask, APIC_DM_NMI); } /* Clean up flags for CPU's that ignored both NMI and ping */ static void uv_nmi_cleanup_mask(void) { int cpu; for_each_cpu(cpu, uv_nmi_cpu_mask) { uv_cpu_nmi_per(cpu).pinging = 0; uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_OUT; cpumask_clear_cpu(cpu, uv_nmi_cpu_mask); } } /* Loop waiting as CPU's enter NMI handler */ static int uv_nmi_wait_cpus(int first) { int i, j, k, n = num_online_cpus(); int last_k = 0, waiting = 0; int cpu = smp_processor_id(); if (first) { cpumask_copy(uv_nmi_cpu_mask, cpu_online_mask); k = 0; } else { k = n - cpumask_weight(uv_nmi_cpu_mask); } /* PCH NMI causes only one CPU to respond */ if (first && uv_pch_intr_now_enabled) { cpumask_clear_cpu(cpu, uv_nmi_cpu_mask); return n - k - 1; } udelay(uv_nmi_initial_delay); for (i = 0; i < uv_nmi_retry_count; i++) { int loop_delay = uv_nmi_loop_delay; for_each_cpu(j, uv_nmi_cpu_mask) { if (uv_cpu_nmi_per(j).state) { cpumask_clear_cpu(j, uv_nmi_cpu_mask); if (++k >= n) break; } } if (k >= n) { /* all in? */ k = n; break; } if (last_k != k) { /* abort if no new CPU's coming in */ last_k = k; waiting = 0; } else if (++waiting > uv_nmi_wait_count) break; /* Extend delay if waiting only for CPU 0: */ if (waiting && (n - k) == 1 && cpumask_test_cpu(0, uv_nmi_cpu_mask)) loop_delay *= 100; udelay(loop_delay); } atomic_set(&uv_nmi_cpus_in_nmi, k); return n - k; } /* Wait until all slave CPU's have entered UV NMI handler */ static void uv_nmi_wait(int master) { /* Indicate this CPU is in: */ this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_IN); /* If not the first CPU in (the master), then we are a slave CPU */ if (!master) return; do { /* Wait for all other CPU's to gather here */ if (!uv_nmi_wait_cpus(1)) break; /* If not all made it in, send IPI NMI to them */ pr_alert("UV: Sending NMI IPI to %d CPUs: %*pbl\n", cpumask_weight(uv_nmi_cpu_mask), cpumask_pr_args(uv_nmi_cpu_mask)); uv_nmi_nr_cpus_ping(); /* If all CPU's are in, then done */ if (!uv_nmi_wait_cpus(0)) break; pr_alert("UV: %d CPUs not in NMI loop: %*pbl\n", cpumask_weight(uv_nmi_cpu_mask), cpumask_pr_args(uv_nmi_cpu_mask)); } while (0); pr_alert("UV: %d of %d CPUs in NMI\n", atomic_read(&uv_nmi_cpus_in_nmi), num_online_cpus()); } /* Dump Instruction Pointer header */ static void uv_nmi_dump_cpu_ip_hdr(void) { pr_info("\nUV: %4s %6s %-32s %s (Note: PID 0 not listed)\n", "CPU", "PID", "COMMAND", "IP"); } /* Dump Instruction Pointer info */ static void uv_nmi_dump_cpu_ip(int cpu, struct pt_regs *regs) { pr_info("UV: %4d %6d %-32.32s %pS", cpu, current->pid, current->comm, (void *)regs->ip); } /* * Dump this CPU's state. If action was set to "kdump" and the crash_kexec * failed, then we provide "dump" as an alternate action. Action "dump" now * also includes the show "ips" (instruction pointers) action whereas the * action "ips" only displays instruction pointers for the non-idle CPU's. * This is an abbreviated form of the "ps" command. */ static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs) { const char *dots = " ................................. "; if (cpu == 0) uv_nmi_dump_cpu_ip_hdr(); if (current->pid != 0 || !uv_nmi_action_is("ips")) uv_nmi_dump_cpu_ip(cpu, regs); if (uv_nmi_action_is("dump")) { pr_info("UV:%sNMI process trace for CPU %d\n", dots, cpu); show_regs(regs); } this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_DUMP_DONE); } /* Trigger a slave CPU to dump it's state */ static void uv_nmi_trigger_dump(int cpu) { int retry = uv_nmi_trigger_delay; if (uv_cpu_nmi_per(cpu).state != UV_NMI_STATE_IN) return; uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP; do { cpu_relax(); udelay(10); if (uv_cpu_nmi_per(cpu).state != UV_NMI_STATE_DUMP) return; } while (--retry > 0); pr_crit("UV: CPU %d stuck in process dump function\n", cpu); uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP_DONE; } /* Wait until all CPU's ready to exit */ static void uv_nmi_sync_exit(int master) { atomic_dec(&uv_nmi_cpus_in_nmi); if (master) { while (atomic_read(&uv_nmi_cpus_in_nmi) > 0) cpu_relax(); atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR); } else { while (atomic_read(&uv_nmi_slave_continue)) cpu_relax(); } } /* Current "health" check is to check which CPU's are responsive */ static void uv_nmi_action_health(int cpu, struct pt_regs *regs, int master) { if (master) { int in = atomic_read(&uv_nmi_cpus_in_nmi); int out = num_online_cpus() - in; pr_alert("UV: NMI CPU health check (non-responding:%d)\n", out); atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); } else { while (!atomic_read(&uv_nmi_slave_continue)) cpu_relax(); } uv_nmi_sync_exit(master); } /* Walk through CPU list and dump state of each */ static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master) { if (master) { int tcpu; int ignored = 0; int saved_console_loglevel = console_loglevel; pr_alert("UV: tracing %s for %d CPUs from CPU %d\n", uv_nmi_action_is("ips") ? "IPs" : "processes", atomic_read(&uv_nmi_cpus_in_nmi), cpu); console_loglevel = uv_nmi_loglevel; atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); for_each_online_cpu(tcpu) { if (cpumask_test_cpu(tcpu, uv_nmi_cpu_mask)) ignored++; else if (tcpu == cpu) uv_nmi_dump_state_cpu(tcpu, regs); else uv_nmi_trigger_dump(tcpu); } if (ignored) pr_alert("UV: %d CPUs ignored NMI\n", ignored); console_loglevel = saved_console_loglevel; pr_alert("UV: process trace complete\n"); } else { while (!atomic_read(&uv_nmi_slave_continue)) cpu_relax(); while (this_cpu_read(uv_cpu_nmi.state) != UV_NMI_STATE_DUMP) cpu_relax(); uv_nmi_dump_state_cpu(cpu, regs); } uv_nmi_sync_exit(master); } static void uv_nmi_touch_watchdogs(void) { touch_softlockup_watchdog_sync(); clocksource_touch_watchdog(); rcu_cpu_stall_reset(); touch_nmi_watchdog(); } static void uv_nmi_kdump(int cpu, int main, struct pt_regs *regs) { /* Check if kdump kernel loaded for both main and secondary CPUs */ if (!kexec_crash_image) { if (main) pr_err("UV: NMI error: kdump kernel not loaded\n"); return; } /* Call crash to dump system state */ if (main) { pr_emerg("UV: NMI executing crash_kexec on CPU%d\n", cpu); crash_kexec(regs); pr_emerg("UV: crash_kexec unexpectedly returned\n"); atomic_set(&uv_nmi_kexec_failed, 1); } else { /* secondary */ /* If kdump kernel fails, secondaries will exit this loop */ while (atomic_read(&uv_nmi_kexec_failed) == 0) { /* Once shootdown cpus starts, they do not return */ run_crash_ipi_callback(regs); mdelay(10); } } } #ifdef CONFIG_KGDB #ifdef CONFIG_KGDB_KDB static inline int uv_nmi_kdb_reason(void) { return KDB_REASON_SYSTEM_NMI; } #else /* !CONFIG_KGDB_KDB */ static inline int uv_nmi_kdb_reason(void) { /* Ensure user is expecting to attach gdb remote */ if (uv_nmi_action_is("kgdb")) return 0; pr_err("UV: NMI error: KDB is not enabled in this kernel\n"); return -1; } #endif /* CONFIG_KGDB_KDB */ /* * Call KGDB/KDB from NMI handler * * Note that if both KGDB and KDB are configured, then the action of 'kgdb' or * 'kdb' has no affect on which is used. See the KGDB documentation for further * information. */ static void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) { if (master) { int reason = uv_nmi_kdb_reason(); int ret; if (reason < 0) return; /* Call KGDB NMI handler as MASTER */ ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs, reason, &uv_nmi_slave_continue); if (ret) { pr_alert("KGDB returned error, is kgdboc set?\n"); atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); } } else { /* Wait for KGDB signal that it's ready for slaves to enter */ int sig; do { cpu_relax(); sig = atomic_read(&uv_nmi_slave_continue); } while (!sig); /* Call KGDB as slave */ if (sig == SLAVE_CONTINUE) kgdb_nmicallback(cpu, regs); } uv_nmi_sync_exit(master); } #else /* !CONFIG_KGDB */ static inline void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) { pr_err("UV: NMI error: KGDB is not enabled in this kernel\n"); } #endif /* !CONFIG_KGDB */ /* * UV NMI handler */ static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) { struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; int cpu = smp_processor_id(); int master = 0; unsigned long flags; local_irq_save(flags); /* If not a UV System NMI, ignore */ if (!this_cpu_read(uv_cpu_nmi.pinging) && !uv_check_nmi(hub_nmi)) { local_irq_restore(flags); return NMI_DONE; } /* Indicate we are the first CPU into the NMI handler */ master = (atomic_read(&uv_nmi_cpu) == cpu); /* If NMI action is "kdump", then attempt to do it */ if (uv_nmi_action_is("kdump")) { uv_nmi_kdump(cpu, master, regs); /* Unexpected return, revert action to "dump" */ if (master) strscpy(uv_nmi_action, "dump", sizeof(uv_nmi_action)); } /* Pause as all CPU's enter the NMI handler */ uv_nmi_wait(master); /* Process actions other than "kdump": */ if (uv_nmi_action_is("health")) { uv_nmi_action_health(cpu, regs, master); } else if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) { uv_nmi_dump_state(cpu, regs, master); } else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb")) { uv_call_kgdb_kdb(cpu, regs, master); } else { if (master) pr_alert("UV: unknown NMI action: %s\n", uv_nmi_action); uv_nmi_sync_exit(master); } /* Clear per_cpu "in_nmi" flag */ this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_OUT); /* Clear MMR NMI flag on each hub */ uv_clear_nmi(cpu); /* Clear global flags */ if (master) { if (!cpumask_empty(uv_nmi_cpu_mask)) uv_nmi_cleanup_mask(); atomic_set(&uv_nmi_cpus_in_nmi, -1); atomic_set(&uv_nmi_cpu, -1); atomic_set(&uv_in_nmi, 0); atomic_set(&uv_nmi_kexec_failed, 0); atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR); } uv_nmi_touch_watchdogs(); local_irq_restore(flags); return NMI_HANDLED; } /* * NMI handler for pulling in CPU's when perf events are grabbing our NMI */ static int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs) { int ret; this_cpu_inc(uv_cpu_nmi.queries); if (!this_cpu_read(uv_cpu_nmi.pinging)) { local64_inc(&uv_nmi_ping_misses); return NMI_DONE; } this_cpu_inc(uv_cpu_nmi.pings); local64_inc(&uv_nmi_ping_count); ret = uv_handle_nmi(reason, regs); this_cpu_write(uv_cpu_nmi.pinging, 0); return ret; } static void uv_register_nmi_notifier(void) { if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv")) pr_warn("UV: NMI handler failed to register\n"); if (register_nmi_handler(NMI_LOCAL, uv_handle_nmi_ping, 0, "uvping")) pr_warn("UV: PING NMI handler failed to register\n"); } void uv_nmi_init(void) { unsigned int value; /* * Unmask NMI on all CPU's */ value = apic_read(APIC_LVT1) | APIC_DM_NMI; value &= ~APIC_LVT_MASKED; apic_write(APIC_LVT1, value); } /* Setup HUB NMI info */ static void __init uv_nmi_setup_common(bool hubbed) { int size = sizeof(void *) * (1 << NODES_SHIFT); int cpu; uv_hub_nmi_list = kzalloc(size, GFP_KERNEL); nmi_debug("UV: NMI hub list @ 0x%p (%d)\n", uv_hub_nmi_list, size); BUG_ON(!uv_hub_nmi_list); size = sizeof(struct uv_hub_nmi_s); for_each_present_cpu(cpu) { int nid = cpu_to_node(cpu); if (uv_hub_nmi_list[nid] == NULL) { uv_hub_nmi_list[nid] = kzalloc_node(size, GFP_KERNEL, nid); BUG_ON(!uv_hub_nmi_list[nid]); raw_spin_lock_init(&(uv_hub_nmi_list[nid]->nmi_lock)); atomic_set(&uv_hub_nmi_list[nid]->cpu_owner, -1); uv_hub_nmi_list[nid]->hub_present = hubbed; uv_hub_nmi_list[nid]->pch_owner = (nid == 0); } uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid]; } BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL)); } /* Setup for UV Hub systems */ void __init uv_nmi_setup(void) { uv_nmi_setup_mmrs(); uv_nmi_setup_common(true); uv_register_nmi_notifier(); pr_info("UV: Hub NMI enabled\n"); } /* Setup for UV Hubless systems */ void __init uv_nmi_setup_hubless(void) { uv_nmi_setup_common(false); pch_base = xlate_dev_mem_ptr(PCH_PCR_GPIO_1_BASE); nmi_debug("UV: PCH base:%p from 0x%lx, GPP_D_0\n", pch_base, PCH_PCR_GPIO_1_BASE); if (uv_pch_init_enable) uv_init_hubless_pch_d0(); uv_init_hubless_pch_io(GPI_NMI_ENA_GPP_D_0, STS_GPP_D_0_MASK, STS_GPP_D_0_MASK); uv_nmi_setup_hubless_intr(); /* Ensure NMI enabled in Processor Interface Reg: */ uv_reassert_nmi(); uv_register_nmi_notifier(); pr_info("UV: PCH NMI enabled\n"); }