Fix reboot hangs that have happened with multiple processors

on Alpha 4100s.

Basically, if you're halting or you're rebooting, you should
tell all other processors to halt first. Define IPI_HALT- IPI_STOP
is not what we want for this purpose, which will call prom_halt(0)
on receipt.

The processor running the halt or reboot wil send an IPI_HALT to all
other processors, delay a bit, then continue to do what what it was
planning on doing (prom_halt({0|1})).

4 files changed, 26 insertions, 3 deletions

diff --git a/sys/alpha/alpha/machdep.c b/sys/alpha/alpha/machdep.c
index 856334f..b94b64a 100644
--- a/sys/alpha/alpha/machdep.c
+++ b/sys/alpha/alpha/machdep.c
@@ -239,8 +239,9 @@ static vm_offset_t pager_sva, pager_eva;
 static void
 alpha_srm_shutdown(void *junk, int howto)
 {
-	if (howto & RB_HALT)
-		alpha_pal_halt();
+	if (howto & RB_HALT) {
+		cpu_halt();
+	}
 }
 
 static void
@@ -1615,7 +1616,14 @@ cpu_boot(int howto)
 void
 cpu_halt(void)
 {
-	/*alpha_pal_halt(); */
+#ifdef	SMP
+	printf("sending IPI_HALT to other processors\n");
+	DELAY(1000000);
+	ipi_all_but_self(IPI_HALT);
+	DELAY(1000000);
+	printf("Halting Self\n");
+	DELAY(1000000);
+#endif
 	prom_halt(1);
 }
 
diff --git a/sys/alpha/alpha/mp_machdep.c b/sys/alpha/alpha/mp_machdep.c
index 414a1bc..74500b8 100644
--- a/sys/alpha/alpha/mp_machdep.c
+++ b/sys/alpha/alpha/mp_machdep.c
@@ -472,6 +472,9 @@ smp_handle_ipi(struct trapframe *frame)
 			atomic_clear_int(&started_cpus, cpumask);
 			atomic_clear_int(&stopped_cpus, cpumask);
 			break;
+		case IPI_HALT:
+			prom_halt(1);
+			/* NOTREACHED */
 		}
 	}
 
diff --git a/sys/alpha/alpha/vm_machdep.c b/sys/alpha/alpha/vm_machdep.c
index 195a934..87b0335 100644
--- a/sys/alpha/alpha/vm_machdep.c
+++ b/sys/alpha/alpha/vm_machdep.c
@@ -95,6 +95,9 @@
 #include <vm/vm_extern.h>
 
 #include <sys/user.h>
+#ifdef	SMP
+#include <machine/smp.h>
+#endif
 
 /*
  * quick version of vm_fault
@@ -388,6 +391,14 @@ vunmapbuf(bp)
 void
 cpu_reset()
 {
+#ifdef	SMP
+	printf("sending IPI_HALT to other processors\n");
+	DELAY(1000000);
+	ipi_all_but_self(IPI_HALT);
+	DELAY(1000000);
+	printf("Rebooting Self\n");
+	DELAY(1000000);
+#endif
 	prom_halt(0);
 }
 
diff --git a/sys/alpha/include/smp.h b/sys/alpha/include/smp.h
index 05af7f4..981647b 100644
--- a/sys/alpha/include/smp.h
+++ b/sys/alpha/include/smp.h
@@ -23,6 +23,7 @@
 #define	IPI_AST			0x0004
 #define	IPI_CHECKSTATE		0x0008
 #define	IPI_STOP		0x0010
+#define	IPI_HALT		0x1000
 
 #ifndef LOCORE