Commit b2f21d1b7bc80150f2b7d1fecae5f64c9ead26fa
Committed by
Greg Kroah-Hartman
1 parent
793332a443
clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64
commit d6ad36913083d683aad4e02e53580c995f1a6ede upstream. Commit 0b46b8a718c6 (clocksource: arch_timer: Fix code to use physical timers when requested) introduces the use of physical counters in the ARM architected timer driver. However, he arm64 kernel uses CNTVCT in VDSO. When booting in EL2, the kernel switches to the physical timers to make things easier for KVM but it continues to use the virtual counter both in user and kernel. While in such scenario CNTVCT == CNTPCT (since CNTVOFF is initialised by the kernel to 0), we want to spot firmware bugs corrupting CNTVOFF early (which would affect CNTVCT). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 0b46b8a718c6 ("clocksource: arch_timer: Fix code to use physical timers when requested") Cc: Ian Campbell <ijc@hellion.org.uk> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
drivers/clocksource/arm_arch_timer.c
... | ... | @@ -462,7 +462,7 @@ |
462 | 462 | |
463 | 463 | /* Register the CP15 based counter if we have one */ |
464 | 464 | if (type & ARCH_CP15_TIMER) { |
465 | - if (arch_timer_use_virtual) | |
465 | + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) | |
466 | 466 | arch_timer_read_counter = arch_counter_get_cntvct; |
467 | 467 | else |
468 | 468 | arch_timer_read_counter = arch_counter_get_cntpct; |