Module Name: src
Committed By: jmcneill
Date: Wed Oct 7 16:03:10 UTC 2020
Modified Files:
src/sys/arch/aarch64/aarch64: cpu.c
Log Message:
Only touch PMC registers if Performance Monitor Extensions are present.
To generate a diff of this commit:
cvs rdiff -u -r1.54 -r1.55 src/sys/arch/aarch64/aarch64/cpu.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/aarch64/aarch64/cpu.c
diff -u src/sys/arch/aarch64/aarch64/cpu.c:1.54 src/sys/arch/aarch64/aarch64/cpu.c:1.55
--- src/sys/arch/aarch64/aarch64/cpu.c:1.54 Sat Jul 25 22:51:57 2020
+++ src/sys/arch/aarch64/aarch64/cpu.c Wed Oct 7 16:03:10 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: cpu.c,v 1.54 2020/07/25 22:51:57 riastradh Exp $ */
+/* $NetBSD: cpu.c,v 1.55 2020/10/07 16:03:10 jmcneill Exp $ */
/*
* Copyright (c) 2017 Ryo Shimizu <[email protected]>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: cpu.c,v 1.54 2020/07/25 22:51:57 riastradh Exp $");
+__KERNEL_RCSID(1, "$NetBSD: cpu.c,v 1.55 2020/10/07 16:03:10 jmcneill Exp $");
#include "locators.h"
#include "opt_arm_debug.h"
@@ -472,6 +472,13 @@ cpu_identify2(device_t self, struct cpu_
static void
cpu_init_counter(struct cpu_info *ci)
{
+ const uint64_t dfr0 = reg_id_aa64dfr0_el1_read();
+ const u_int pmuver = __SHIFTOUT(dfr0, ID_AA64DFR0_EL1_PMUVER);
+ if (pmuver == ID_AA64DFR0_EL1_PMUVER_NONE) {
+ /* Performance Monitors Extension not implemented. */
+ return;
+ }
+
reg_pmcr_el0_write(PMCR_E | PMCR_C);
reg_pmcntenset_el0_write(PMCNTEN_C);
