3  * SGI NMI support routines
16 #include <linux/nmi.h>
26 #include <asm/nmi.h>
34  * UV handler for NMI
36  * Handle system-wide NMI events generated by the global 'power nmi' command.
38  * Basic operation is to field the NMI interrupt on each CPU and wait
39  * until all CPU's have arrived into the nmi handler.  If some CPU's do not
40  * make it into the handler, try and force them in with the IPI(NMI) signal.
46  * To do this we register our primary NMI notifier on the NMI_UNKNOWN
47  * chain.  This reduces the number of false NMI calls when the perf
49  * second (~4M/s for 1024 CPU threads).  Our secondary NMI handler is
51  * IPI(NMI) signal as mentioned above, and does not read the UV Hub's MMR.
59 /* Newer SMM NMI handler, not present in all systems */
65 /* Non-zero indicates newer SMM NMI handler present */
68 /* Indicates to BIOS that we want to use the newer SMM NMI handler */
180 /* Valid NMI Actions */
191 	{	"health",	"check if CPUs respond to NMI"		},
220 		pr_info("UV: New NMI action:%s\n", uv_nmi_action);  in param_set_action()
224 	pr_err("UV: Invalid NMI action:%s, valid actions are:\n", arg);  in param_set_action()
244 /* Setup which NMI support is present in system */
266 		new_nmi_method_only = true;		/* Newer nmi always valid on UV5+ */  in uv_nmi_setup_mmrs()
270 		pr_err("UV:%s:NMI support not available on this system\n", __func__);  in uv_nmi_setup_mmrs()
274 	/* Then find out if new NMI is supported */  in uv_nmi_setup_mmrs()
282 		pr_info("UV: SMI NMI support: %s\n", uvh_nmi_mmrx_type);  in uv_nmi_setup_mmrs()
287 		pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMR_TYPE);  in uv_nmi_setup_mmrs()
291 /* Read NMI MMR and check if NMI flag was set by BMC. */
305  * UV hubless NMI handler functions
343 	nmi_debug("UV:NMI: GPP_D_0 interrupt %s\n",  in uv_nmi_setup_hubless_intr()
423  *     # (we want an NMI not an IRQ)
427  *  17    GPIO Input Route NMI (GPIROUTNMI): = 1 # Routing can cause NMI.
456 		pr_info("UV: Hubless NMI already configured\n");  in uv_init_hubless_pch_d0()
460 	nmi_debug("UV: Initializing UV Hubless NMI on PCH\n");  in uv_init_hubless_pch_d0()
476 	if (!(status & STS_GPP_D_0_MASK))	/* Not a UV external NMI */  in uv_nmi_test_hubless()
479 	*pstat = STS_GPP_D_0_MASK;	/* Is a UV NMI: clear GPP_D_0 status */  in uv_nmi_test_hubless()
514 /* Check if this is a system NMI event */
518 	int nmi = 0;  in uv_check_nmi()  local
525 		nmi = atomic_read(&hub_nmi->in_nmi);  in uv_check_nmi()
526 		if (nmi)  in uv_check_nmi()
532 			/* Check flag for UV external NMI */  in uv_check_nmi()
535 				nmi = 1;  in uv_check_nmi()
539 			/* A non-PCH node in a hubless system waits for NMI */  in uv_check_nmi()
543 			/* MMR/PCH NMI flag is clear */  in uv_check_nmi()
548 			/* Wait a moment for the HUB NMI locker to set flag */  in uv_check_nmi()
553 			nmi = atomic_read(&hub_nmi->in_nmi);  in uv_check_nmi()
554 			if (nmi)  in uv_check_nmi()
559 		 * Check if this BMC missed setting the MMR NMI flag (or)  in uv_check_nmi()
562 		if (!nmi) {  in uv_check_nmi()
563 			nmi = atomic_read(&uv_in_nmi);  in uv_check_nmi()
564 			if (nmi)  in uv_check_nmi()
574 	if (!nmi)  in uv_check_nmi()
577 	return nmi;  in uv_check_nmi()
580 /* Need to reset the NMI MMR register, but only once per hub. */
596 /* Ping non-responding CPU's attempting to force them into the NMI handler */
607 /* Clean up flags for CPU's that ignored both NMI and ping */
619 /* Loop waiting as CPU's enter NMI handler */
633 	/* PCH NMI causes only one CPU to respond */  in uv_nmi_wait_cpus()
671 /* Wait until all slave CPU's have entered UV NMI handler */
686 		/* If not all made it in, send IPI NMI to them */  in uv_nmi_wait()
687 		pr_alert("UV: Sending NMI IPI to %d CPUs: %*pbl\n",  in uv_nmi_wait()
697 		pr_alert("UV: %d CPUs not in NMI loop: %*pbl\n",  in uv_nmi_wait()
702 	pr_alert("UV: %d of %d CPUs in NMI\n",  in uv_nmi_wait()
787 		pr_alert("UV: NMI CPU health check (non-responding:%d)\n", out);  in uv_nmi_action_health()
819 			pr_alert("UV: %d CPUs ignored NMI\n", ignored);  in uv_nmi_dump_state()
846 			pr_err("UV: NMI error: kdump kernel not loaded\n");  in uv_nmi_kdump()
852 		pr_emerg("UV: NMI executing crash_kexec on CPU%d\n", cpu);  in uv_nmi_kdump()
884 	pr_err("UV: NMI error: KDB is not enabled in this kernel\n");  in uv_nmi_kdb_reason()
890  * Call KGDB/KDB from NMI handler
905 		/* Call KGDB NMI handler as MASTER */  in uv_call_kgdb_kdb()
931 	pr_err("UV: NMI error: KGDB is not enabled in this kernel\n");  in uv_call_kgdb_kdb()
936  * UV NMI handler
947 	/* If not a UV System NMI, ignore */  in uv_handle_nmi()
953 	/* Indicate we are the first CPU into the NMI handler */  in uv_handle_nmi()
956 	/* If NMI action is "kdump", then attempt to do it */  in uv_handle_nmi()
965 	/* Pause as all CPU's enter the NMI handler */  in uv_handle_nmi()
977 			pr_alert("UV: unknown NMI action: %s\n", uv_nmi_action);  in uv_handle_nmi()
984 	/* Clear MMR NMI flag on each hub */  in uv_handle_nmi()
1005  * NMI handler for pulling in CPU's when perf events are grabbing our NMI
1027 		pr_warn("UV: NMI handler failed to register\n");  in uv_register_nmi_notifier()
1030 		pr_warn("UV: PING NMI handler failed to register\n");  in uv_register_nmi_notifier()
1038 	 * Unmask NMI on all CPU's  in uv_nmi_init()
1045 /* Setup HUB NMI info */
1052 	nmi_debug("UV: NMI hub list @ 0x%p (%d)\n", uv_hub_nmi_list, size);  in uv_nmi_setup_common()
1077 	pr_info("UV: Hub NMI enabled\n");  in uv_nmi_setup()
1092 	/* Ensure NMI enabled in Processor Interface Reg: */  in uv_nmi_setup_hubless()
1095 	pr_info("UV: PCH NMI enabled\n");  in uv_nmi_setup_hubless()