Rudimentary nmi support to be able to do simple debugging on SMP

machines.

3 files changed, 169 insertions, 1 deletions

diff --git a/arch/mips64/sgi-ip27/Makefile b/arch/mips64/sgi-ip27/Makefile
index 514beaa81..c15231c93 100644
--- a/arch/mips64/sgi-ip27/Makefile
+++ b/arch/mips64/sgi-ip27/Makefile
@@ -11,6 +11,6 @@
 L_TARGET = ip27.a
 L_OBJS  = ip27-berr.o ip27-irq.o ip27-irq-glue.o ip27-klconfig.o \
 	  ip27-memory.o ip27-pci.o ip27-pci-dma.o ip27-reset.o ip27-setup.o \
-	  ip27-timer.o ip27-init.o
+	  ip27-timer.o ip27-init.o ip27-nmi.o
 
 include $(TOPDIR)/Rules.make
diff --git a/arch/mips64/sgi-ip27/ip27-init.c b/arch/mips64/sgi-ip27/ip27-init.c
index 253022f37..9e2df3662 100644
--- a/arch/mips64/sgi-ip27/ip27-init.c
+++ b/arch/mips64/sgi-ip27/ip27-init.c
@@ -314,6 +314,7 @@ cpuid_t getcpuid(void)
 
 void per_cpu_init(void)
 {
+	extern void install_cpu_nmi_handler(int slice);
 	extern void load_mmu(void);
 	static int is_slave = 0;
 	cpuid_t cpu = getcpuid();
@@ -328,6 +329,8 @@ void per_cpu_init(void)
 	cpu_time_init();
 	if (smp_processor_id())	/* master can't do this early, no kmalloc */
 		install_cpuintr(cpu);
+	/* Install our NMI handler if symmon hasn't installed one. */
+	install_cpu_nmi_handler(cputoslice(smp_processor_id()));
 #if 0
 	install_tlbintr(cpu);
 #endif
diff --git a/arch/mips64/sgi-ip27/ip27-nmi.c b/arch/mips64/sgi-ip27/ip27-nmi.c
new file mode 100644
index 000000000..3511c62e7
--- /dev/null
+++ b/arch/mips64/sgi-ip27/ip27-nmi.c
@@ -0,0 +1,165 @@
+#include <linux/kernel.h>
+#include <linux/mmzone.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <asm/atomic.h>
+#include <asm/sn/types.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/nmi.h>
+#include <asm/sn/arch.h>
+#include <asm/sn/sn0/hub.h>
+
+#if 0
+#define NODE_NUM_CPUS(n)	CNODE_NUM_CPUS(n)
+#else
+#define NODE_NUM_CPUS(n)	CPUS_PER_NODE
+#endif
+
+#define CNODEID_NONE (cnodeid_t)-1
+#define enter_panic_mode()	spin_lock(&nmi_lock)
+
+typedef unsigned long machreg_t;
+
+spinlock_t nmi_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Lets see what else we need to do here. Set up sp, gp?
+ */
+void nmi_dump(void)
+{
+	void cont_nmi_dump(void);
+
+	cont_nmi_dump();
+}
+
+void install_cpu_nmi_handler(int slice)
+{
+	nmi_t *nmi_addr;
+
+	nmi_addr = (nmi_t *)NMI_ADDR(get_nasid(), slice);
+	if (nmi_addr->call_addr)
+		return;
+	nmi_addr->magic = NMI_MAGIC;
+	nmi_addr->call_addr = (void *)nmi_dump;
+	nmi_addr->call_addr_c =
+		(void *)(~((unsigned long)(nmi_addr->call_addr)));
+	nmi_addr->call_parm = 0;
+}
+
+/*
+ * Copy the cpu registers which have been saved in the IP27prom format
+ * into the eframe format for the node under consideration.
+ */
+
+void
+nmi_cpu_eframe_save(nasid_t nasid,
+		    int	    slice)
+{
+	int 		i, numberof_nmi_cpu_regs;
+	machreg_t	*prom_format;
+	
+	/* Get the total number of registers being saved by the prom */
+	numberof_nmi_cpu_regs = sizeof(struct reg_struct) / sizeof(machreg_t);
+	
+	/* Get the pointer to the current cpu's register set. */
+	prom_format = 
+	    (machreg_t *)(TO_UNCAC(TO_NODE(nasid, IP27_NMI_KREGS_OFFSET)) +
+			  slice * IP27_NMI_KREGS_CPU_SIZE);
+
+	printk("NMI nasid %d: slice %d\n", nasid, slice);
+	for (i = 0; i < numberof_nmi_cpu_regs; i++)
+		printk("0x%lx  ", prom_format[i]);
+	printk("\n\n");
+}	
+
+/*
+ * Copy the cpu registers which have been saved in the IP27prom format
+ * into the eframe format for the node under consideration.
+ */
+void
+nmi_node_eframe_save(cnodeid_t  cnode)
+{
+	int		cpu;
+	nasid_t		nasid;
+
+	/* Make sure that we have a valid node */
+	if (cnode == CNODEID_NONE)
+		return;
+
+	nasid = COMPACT_TO_NASID_NODEID(cnode);
+	if (nasid == INVALID_NASID)
+		return;
+
+	/* Save the registers into eframe for each cpu */
+	for(cpu = 0; cpu < NODE_NUM_CPUS(cnode); cpu++) 
+		nmi_cpu_eframe_save(nasid, cpu);
+}
+
+/*
+ * Save the nmi cpu registers for all cpus in the system.
+ */
+void
+nmi_eframes_save(void)
+{
+	cnodeid_t	cnode;
+
+	for(cnode = 0 ; cnode < numnodes; cnode++) 
+		nmi_node_eframe_save(cnode);
+}
+
+void
+cont_nmi_dump(void)
+{
+#ifndef REAL_NMI_SIGNAL
+	static atomic_t nmied_cpus = ATOMIC_INIT(0);
+
+	atomic_inc(&nmied_cpus);
+#endif
+	/* 
+	 * Use enter_panic_mode to allow only 1 cpu to proceed
+	 */
+	enter_panic_mode();
+
+#ifdef REAL_NMI_SIGNAL
+	/*
+	 * Wait up to 15 seconds for the other cpus to respond to the NMI.
+	 * If a cpu has not responded after 10 sec, send it 1 additional NMI.
+	 * This is for 2 reasons:
+	 *	- sometimes a MMSC fail to NMI all cpus.
+	 *	- on 512p SN0 system, the MMSC will only send NMIs to
+	 *	  half the cpus. Unfortunately, we dont know which cpus may be
+	 *	  NMIed - it depends on how the site chooses to configure.
+	 * 
+	 * Note: it has been measure that it takes the MMSC up to 2.3 secs to
+	 * send NMIs to all cpus on a 256p system.
+	 */
+	for (i=0; i < 1500; i++) {
+		for (node=0; node < numnodes; node++)
+			if (NODEPDA(node)->dump_count == 0)
+				break;
+		if (node == numnodes)
+			break;
+		if (i == 1000) {
+			for (node=0; node < numnodes; node++)
+				if (NODEPDA(node)->dump_count == 0) {
+					cpu = CNODE_TO_CPU_BASE(node);
+					for (n=0; n < CNODE_NUM_CPUS(node); cpu++, n++) {
+						CPUMASK_SETB(nmied_cpus, cpu);
+						SEND_NMI((cputonasid(cpu)), (cputoslice(cpu)));
+					}
+				}
+					
+		}
+		udelay(10000);
+	}
+#else
+	while (atomic_read(&nmied_cpus) != smp_num_cpus);
+#endif
+
+	/*
+	 * Save the nmi cpu registers for all cpu in the eframe format.
+	 */
+	nmi_eframes_save();
+	LOCAL_HUB_S(NI_PORT_RESET, NPR_PORTRESET | NPR_LOCALRESET);
+}
+