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authorDouglas Anderson <dianders@chromium.org>2023-05-19 10:18:37 -0700
committerAndrew Morton <akpm@linux-foundation.org>2023-06-09 17:44:21 -0700
commitd9b3629ade8ebffb0075e311409796a56bac8282 (patch)
treeef797384e21aa028322714d3992eb8d5d7795553 /kernel/watchdog.c
parentdf95d3085caa5b99a60eb033d7ad6c2ff2b43dbf (diff)
watchdog/hardlockup: have the perf hardlockup use __weak functions more cleanly
The fact that there watchdog_hardlockup_enable(), watchdog_hardlockup_disable(), and watchdog_hardlockup_probe() are declared __weak means that the configured hardlockup detector can define non-weak versions of those functions if it needs to. Instead of doing this, the perf hardlockup detector hooked itself into the default __weak implementation, which was a bit awkward. Clean this up. From comments, it looks as if the original design was done because the __weak function were expected to implemented by the architecture and not by the configured hardlockup detector. This got awkward when we tried to add the buddy lockup detector which was not arch-specific but wanted to hook into those same functions. This is not expected to have any functional impact. Link: https://lkml.kernel.org/r/20230519101840.v5.13.I847d9ec852449350997ba00401d2462a9cb4302b@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/watchdog.c')
-rw-r--r--kernel/watchdog.c30
1 files changed, 18 insertions, 12 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index c6790c7dc08d..e67125f64719 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -187,27 +187,33 @@ static inline void watchdog_hardlockup_kick(void) { }
#endif /* !CONFIG_HARDLOCKUP_DETECTOR_PERF */
/*
- * These functions can be overridden if an architecture implements its
- * own hardlockup detector.
+ * These functions can be overridden based on the configured hardlockdup detector.
*
* watchdog_hardlockup_enable/disable can be implemented to start and stop when
- * softlockup watchdog start and stop. The arch must select the
+ * softlockup watchdog start and stop. The detector must select the
* SOFTLOCKUP_DETECTOR Kconfig.
*/
-void __weak watchdog_hardlockup_enable(unsigned int cpu)
-{
- hardlockup_detector_perf_enable();
-}
+void __weak watchdog_hardlockup_enable(unsigned int cpu) { }
-void __weak watchdog_hardlockup_disable(unsigned int cpu)
-{
- hardlockup_detector_perf_disable();
-}
+void __weak watchdog_hardlockup_disable(unsigned int cpu) { }
/* Return 0, if a hardlockup watchdog is available. Error code otherwise */
int __weak __init watchdog_hardlockup_probe(void)
{
- return hardlockup_detector_perf_init();
+ /*
+ * If CONFIG_HAVE_NMI_WATCHDOG is defined then an architecture
+ * is assumed to have the hard watchdog available and we return 0.
+ */
+ if (IS_ENABLED(CONFIG_HAVE_NMI_WATCHDOG))
+ return 0;
+
+ /*
+ * Hardlockup detectors other than those using CONFIG_HAVE_NMI_WATCHDOG
+ * are required to implement a non-weak version of this probe function
+ * to tell whether they are available. If they don't override then
+ * we'll return -ENODEV.
+ */
+ return -ENODEV;
}
/**