Added a pctr pseudo-device for accessing the Pentium performance counters,

and a program pctrctl to set the counter functions.

1 files changed, 34 insertions, 0 deletions

diff --git a/sys/arch/i386/include/pctr.h b/sys/arch/i386/include/pctr.h
new file mode 100644
index 00000000000..641b3436ca5
--- /dev/null
+++ b/sys/arch/i386/include/pctr.h
@@ -0,0 +1,34 @@
+/*	$OpenBSD: pctr.h,v 1.1 1996/08/08 18:47:04 dm Exp $	*/
+
+/*
+ * Pentium performance counter driver for OpenBSD.
+ * Author: David Mazieres <dm@lcs.mit.edu>
+ */
+
+#ifndef _I386_PERFCNT_H_
+#define _I386_PERFCNT_H_
+
+typedef u_quad_t pctrval;
+
+#define PCTR_NUM 2
+
+struct pctrst {
+  u_short pctr_fn[PCTR_NUM];
+  pctrval pctr_tsc;
+  pctrval pctr_hwc[PCTR_NUM];
+  pctrval pctr_idl;
+};
+
+/* Bit values in fn fields and PIOCS ioctl's */
+#define PCTR_K 0x40    /* Monitor kernel-level events */
+#define PCTR_U 0x80    /* Monitor user-level events */
+#define PCTR_C 0x100   /* count cycles rather than events */
+
+/* ioctl to set which counter a device tracks. */
+#define PCIOCRD _IOR('c', 1, struct pctrst)   /* Read counter value */
+#define PCIOCS0 _IOW('c', 8, unsigned short)  /* Set counter 0 function */
+#define PCIOCS1 _IOW('c', 9, unsigned short)  /* Set counter 1 function */
+
+#define _PATH_PCTR "/dev/pctr"
+
+#endif /* ! _I386_PERFCNT_H_ */