- Add a DDB command 'show intrcnt' to show the non-zero interrupt counts.

- Add a DDB function to dump the contents of an ithread and optionally
  details about each handler in that ithread.  This function can be used
  by MD code to implement DDB commands that display information about
  interrupt sources and their registered handlers.

2 files changed, 168 insertions, 0 deletions

diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c
index b605edf..a0c2bdc 100644
--- a/sys/kern/kern_intr.c
+++ b/sys/kern/kern_intr.c
@@ -27,6 +27,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_ddb.h"
+
 #include <sys/param.h>
 #include <sys/bus.h>
 #include <sys/conf.h>
@@ -49,6 +51,10 @@ __FBSDID("$FreeBSD$");
 #include <machine/cpu.h>
 #include <machine/md_var.h>
 #include <machine/stdarg.h>
+#ifdef DDB
+#include <ddb/ddb.h>
+#include <ddb/db_sym.h>
+#endif
 
 struct	int_entropy {
 	struct	proc *proc;
@@ -561,6 +567,143 @@ restart:
 	}
 }
 
+#ifdef DDB
+/*
+ * Dump details about an interrupt handler
+ */
+static void
+db_dump_intrhand(struct intrhand *ih)
+{
+	int comma;
+
+	db_printf("\t%-10s ", ih->ih_name);
+	switch (ih->ih_pri) {
+	case PI_REALTIME:
+		db_printf("CLK ");
+		break;
+	case PI_AV:
+		db_printf("AV  ");
+		break;
+	case PI_TTYHIGH:
+	case PI_TTYLOW:
+		db_printf("TTY ");
+		break;
+	case PI_TAPE:
+		db_printf("TAPE");
+		break;
+	case PI_NET:
+		db_printf("NET ");
+		break;
+	case PI_DISK:
+	case PI_DISKLOW:
+		db_printf("DISK");
+		break;
+	case PI_DULL:
+		db_printf("DULL");
+		break;
+	default:
+		if (ih->ih_pri >= PI_SOFT)
+			db_printf("SWI ");
+		else
+			db_printf("%4u", ih->ih_pri);
+		break;
+	}
+	db_printf(" ");
+	db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
+	db_printf("(%p)", ih->ih_argument);
+	if (ih->ih_need ||
+	    (ih->ih_flags & (IH_FAST | IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
+	    IH_MPSAFE)) != 0) {
+		db_printf(" {");
+		comma = 0;
+		if (ih->ih_flags & IH_FAST) {
+			db_printf("FAST");
+			comma = 1;
+		}
+		if (ih->ih_flags & IH_EXCLUSIVE) {
+			if (comma)
+				db_printf(", ");
+			db_printf("EXCL");
+			comma = 1;
+		}
+		if (ih->ih_flags & IH_ENTROPY) {
+			if (comma)
+				db_printf(", ");
+			db_printf("ENTROPY");
+			comma = 1;
+		}
+		if (ih->ih_flags & IH_DEAD) {
+			if (comma)
+				db_printf(", ");
+			db_printf("DEAD");
+			comma = 1;
+		}
+		if (ih->ih_flags & IH_MPSAFE) {
+			if (comma)
+				db_printf(", ");
+			db_printf("MPSAFE");
+			comma = 1;
+		}
+		if (ih->ih_need) {
+			if (comma)
+				db_printf(", ");
+			db_printf("NEED");
+		}
+		db_printf("}");
+	}
+	db_printf("\n");
+}
+
+/*
+ * Dump details about an ithread
+ */
+void
+db_dump_ithread(struct ithd *ithd, int handlers)
+{
+	struct proc *p;
+	struct intrhand *ih;
+	int comma;
+
+	if (ithd->it_td != NULL) {
+		p = ithd->it_td->td_proc;
+		db_printf("%s (pid %d)", p->p_comm, p->p_pid);
+	} else
+		db_printf("%s: (no thread)", ithd->it_name);
+	if ((ithd->it_flags & (IT_SOFT | IT_ENTROPY | IT_DEAD)) != 0 ||
+	    ithd->it_need) {
+		db_printf(" {");
+		comma = 0;
+		if (ithd->it_flags & IT_SOFT) {
+			db_printf("SOFT");
+			comma = 1;
+		}
+		if (ithd->it_flags & IT_ENTROPY) {
+			if (comma)
+				db_printf(", ");
+			db_printf("ENTROPY");
+			comma = 1;
+		}
+		if (ithd->it_flags & IT_DEAD) {
+			if (comma)
+				db_printf(", ");
+			db_printf("DEAD");
+			comma = 1;
+		}
+		if (ithd->it_need) {
+			if (comma)
+				db_printf(", ");
+			db_printf("NEED");
+		}
+		db_printf("}");
+	}
+	db_printf("\n");
+
+	if (handlers)
+		TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next)
+		    db_dump_intrhand(ih);
+}
+#endif /* DDB */
+
 /*
  * Start standard software interrupt threads
  */
@@ -609,3 +752,25 @@ sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
 
 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
     NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
+
+#ifdef DDB
+/*
+ * DDB command to dump the interrupt statistics.
+ */
+DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
+{
+	u_long *i;
+	char *cp;
+	int quit;
+
+	cp = intrnames;
+	db_setup_paging(db_simple_pager, &quit, DB_LINES_PER_PAGE);
+	for (i = intrcnt, quit = 0; i != eintrcnt && !quit; i++) {
+		if (*cp == '\0')
+			break;
+		if (*i != 0)
+			db_printf("%s\t%lu\n", cp, *i);
+		cp += strlen(cp) + 1;
+	}
+}
+#endif
diff --git a/sys/sys/interrupt.h b/sys/sys/interrupt.h
index 58a9dd0..cdf829d 100644
--- a/sys/sys/interrupt.h
+++ b/sys/sys/interrupt.h
@@ -111,6 +111,9 @@ extern char 	eintrnames[];	/* end of intrnames[] */
 extern u_long 	intrcnt[];	/* counts for for each device and stray */
 extern char 	intrnames[];	/* string table containing device names */
 
+#ifdef DDB
+void	db_dump_ithread(struct ithd *ithd, int handlers);
+#endif
 int	ithread_create(struct ithd **ithread, int vector, int flags,
 	    void (*disable)(int), void (*enable)(int), const char *fmt, ...)
 	    __printflike(6, 7);