powerpc/64: Fix watchdog configuration regressions

This fixes a couple more bits of fallout from the new hard lockup watchdog
patch.

It restores the required hw_nmi_get_sample_period() function for the
perf watchdog, and removes some function declarations on 64e that are only
defined for 64s. This fixes the 64e build when the hardlockup detector is
enabled.

It restores the default behaviour of disabling the perf watchdog, and also
fixes disabling the 64s watchdog when running as a guest.

Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/nmi.h b/arch/powerpc/include/asm/nmi.h
index 6f8e79cd35d87f9eababcbbbba23c3d7f0f98f87..3760150a0ff0fb6964c709be983385bf48bdaecd 100644 (file)
--- a/arch/powerpc/include/asm/nmi.h
+++ b/arch/powerpc/include/asm/nmi.h
@@ -1,9 +1,8 @@
 #ifndef _ASM_NMI_H
 #define _ASM_NMI_H
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
+#ifdef CONFIG_PPC_WATCHDOG
 extern void arch_touch_nmi_watchdog(void);
-
 extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
                                           bool exclude_self);
 #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace

diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 1086ea37c83241a115378ae1de5971f6c004aaad..9ad37f827a975f1f2a7f165447f951c9e2aa8fa7 100644 (file)
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -25,7 +25,6 @@
 #include <linux/kvm_para.h>
 #include <linux/slab.h>
 #include <linux/of.h>
-#include <linux/nmi.h> /* hardlockup_detector_disable() */
 
 #include <asm/reg.h>
 #include <asm/sections.h>
@@ -719,12 +718,6 @@ static __init void kvm_free_tmp(void)
 
 static int __init kvm_guest_init(void)
 {
-       /*
-        * The hardlockup detector is likely to get false positives in
-        * KVM guests, so disable it by default.
-        */
-       hardlockup_detector_disable();
-
        if (!kvm_para_available())
                goto free_tmp;
 

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 7393bac3c7f42342043027298c44df3184fd36e4..b89c6aac48c9bc2d199b36e759d49c814e34c45c 100644 (file)
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -756,3 +756,31 @@ unsigned long memory_block_size_bytes(void)
 struct ppc_pci_io ppc_pci_io;
 EXPORT_SYMBOL(ppc_pci_io);
 #endif
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+u64 hw_nmi_get_sample_period(int watchdog_thresh)
+{
+       return ppc_proc_freq * watchdog_thresh;
+}
+#endif
+
+/*
+ * The perf based hardlockup detector breaks PMU event based branches, so
+ * disable it by default. Book3S has a soft-nmi hardlockup detector based
+ * on the decrementer interrupt, so it does not suffer from this problem.
+ *
+ * It is likely to get false positives in VM guests, so disable it there
+ * by default too.
+ */
+static int __init disable_hardlockup_detector(void)
+{
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+       hardlockup_detector_disable();
+#else
+       if (firmware_has_feature(FW_FEATURE_LPAR))
+               hardlockup_detector_disable();
+#endif
+
+       return 0;
+}
+early_initcall(disable_hardlockup_detector);