kernel/linux.git/drivers/clocksource/arm_arch_timer.c, branch v4.14.286

arm64: arch_timer: Add workaround for ARM erratum 1188873

2022-04-02T10:41:08+00:00

commit 95b861a4a6d94f64d5242605569218160ebacdbe upstream. When running on Cortex-A76, a timer access from an AArch32 EL0 task may end up with a corrupted value or register. The workaround for this is to trap these accesses at EL1/EL2 and execute them there. This only affects versions r0p0, r1p0 and r2p0 of the CPU. Acked-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: James Morse Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI

2020-12-29T12:46:59+00:00

[ Upstream commit 8b7770b877d187bfdae1eaf587bd2b792479a31c ] ARM virtual counter supports event stream, it can only trigger an event when the trigger bit (the value of CNTKCTL_EL1.EVNTI) of CNTVCT_EL0 changes, so the actual period of event stream is 2^(cntkctl_evnti + 1). For example, when the trigger bit is 0, then virtual counter trigger an event for every two cycles. While we're at it, rework the way we compute the trigger bit position by making it more obvious that when bits [n:n-1] are both set (with n being the most significant bit), we pick bit (n + 1). Fixes: 037f637767a8 ("drivers: clocksource: add support for ARM architected timer event stream") Suggested-by: Marc Zyngier Signed-off-by: Keqian Zhu Acked-by: Marc Zyngier Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201204073126.6920-3-zhukeqian1@huawei.com Signed-off-by: Sasha Levin

clocksource/drivers/arm_arch_timer: Validate CNTFRQ after enabling frame

2017-12-10T12:40:41+00:00

[ Upstream commit 21492e1333a0d07af6968667f128e19088cf5ead ] The ACPI GTDT code validates the CNTFRQ field of each MMIO timer frame against the CNTFRQ system register of the current CPU, to ensure that they are equal, which is mandated by the architecture. However, reading the CNTFRQ field of a frame is not possible until the RFRQ bit in the frame's CNTACRn register is set, and doing so before that willl produce the following error: arch_timer: [Firmware Bug]: CNTFRQ mismatch: frame @ 0x00000000e0be0000: (0x00000000), CPU: (0x0ee6b280) arch_timer: Disabling MMIO timers due to CNTFRQ mismatch arch_timer: Failed to initialize memory-mapped timer. The reason is that the CNTFRQ field is RES0 if access is not enabled. So move the validation of CNTFRQ into the loop that iterates over the timers to find the best frame, but defer it until after we have selected the best frame, which should also have enabled the RFRQ bit. Signed-off-by: Ard Biesheuvel Signed-off-by: Mark Rutland Signed-off-by: Daniel Lezcano Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge branch 'linus' into locking/core, to pick up fixes

2017-08-25T09:04:51+00:00

Signed-off-by: Ingo Molnar

clocksource/drivers/arm_arch_timer: Fix mem frame loop initialization

2017-08-10T12:48:17+00:00

The loop to find the best memory frame in arch_timer_mem_acpi_init() initializes the loop counter with itself ('i = i'), which is suspicious in the first place and pointed out by clang. The loop condition is 'i < timer_count' and a prior for loop exits when 'i' reaches 'timer_count', therefore the second loop is never executed. Initialize the loop counter with 0 to iterate over all timers, which supposedly was the intention before the typo monster attacked. Fixes: c2743a36765d3 ("clocksource: arm_arch_timer: add GTDT support for memory-mapped timer") Signed-off-by: Matthias Kaehlcke Reported-by: Ard Biesheuvel Acked-by: Mark Rutland Signed-off-by: Daniel Lezcano

clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()

2017-08-10T10:29:00+00:00

Use the new static_branch_enable_cpuslocked() function to switch the workaround static key on the CPU hotplug path. Signed-off-by: Marc Zyngier Signed-off-by: Peter Zijlstra (Intel) Cc: Leo Yan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170801080257.5056-5-marc.zyngier@arm.com Signed-off-by: Ingo Molnar

Merge branch 'timers/urgent' into timers/core

2017-06-21T07:07:52+00:00

Pick up dependent changes.

clocksource/drivers: Rename CLOCKSOURCE_ACPI_DECLARE to TIMER_ACPI_DECLARE

2017-06-14T09:59:53+00:00

The macro name is now renamed to 'TIMER_ACPI_DECLARE' for consistency with the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change. Signed-off-by: Daniel Lezcano Reviewed-by: Linus Walleij

clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE

2017-06-14T09:58:45+00:00

The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the clocksource at early stage. However, this macro is also used to initialize the clockevent if any, or the clockevent only. It was originally suggested to declare another macro to initialize a clockevent, so in order to separate the two entities even they belong to the same IP. This was not accepted because of the impact on the DT where splitting a clocksource/clockevent definition does not make sense as it is a Linux concept not a hardware description. On the other side, the clocksource has not interrupt declared while the clockevent has, so it is easy from the driver to know if the description is for a clockevent or a clocksource, IOW it could be implemented at the driver level. So instead of dealing with a named clocksource macro, let's use a more generic one: TIMER_OF_DECLARE. The patch has not functional changes. Signed-off-by: Daniel Lezcano Acked-by: Heiko Stuebner Acked-by: Neil Armstrong Acked-by: Arnd Bergmann Acked-by: Matthias Brugger Reviewed-by: Linus Walleij

clocksource/drivers/arm_arch_timer: Fix read and iounmap of incorrect variable

2017-06-12T13:00:23+00:00

Fix boot warning 'Trying to vfree() nonexistent vm area' from arch_timer_mem_of_init(). Refactored code attempts to read and iounmap using address frame instead of address ioremap(frame->cntbase). Fixes: c389d701dfb70 ("clocksource: arm_arch_timer: split MMIO timer probing.") Signed-off-by: Frank Rowand Reviewed-by: Fu Wei Acked-by: Marc Zyngier Signed-off-by: Daniel Lezcano