linux/drivers/clocksource/arm_arch_timer.c, branch v4.1

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2015-04-24T15:23:45Z

Pull initial ACPI support for arm64 from Will Deacon: "This series introduces preliminary ACPI 5.1 support to the arm64 kernel using the "hardware reduced" profile. We don't support any peripherals yet, so it's fairly limited in scope: - MEMORY init (UEFI) - ACPI discovery (RSDP via UEFI) - CPU init (FADT) - GIC init (MADT) - SMP boot (MADT + PSCI) - ACPI Kconfig options (dependent on EXPERT) ACPI for arm64 has been in development for a while now and hardware has been available that can boot with either FDT or ACPI tables. This has been made possible by both changes to the ACPI spec to cater for ARM-based machines (known as "hardware-reduced" in ACPI parlance) but also a Linaro-driven effort to get this supported on top of the Linux kernel. This pull request is the result of that work. These changes allow us to initialise the CPUs, interrupt controller, and timers via ACPI tables, with memory information and cmdline coming from EFI. We don't support a hybrid ACPI/FDT scheme. Of course, there is still plenty of work to do (a serial console would be nice!) but I expect that to happen on a per-driver basis after this core series has been merged. Anyway, the diff stat here is fairly horrible, but splitting this up and merging it via all the different subsystems would have been extremely painful. Instead, we've got all the relevant Acks in place and I've not seen anything other than trivial (Kconfig) conflicts in -next (for completeness, I've included my resolution below). Nearly half of the insertions fall under Documentation/. So, we'll see how this goes. Right now, it all depends on EXPERT and I fully expect people to use FDT by default for the immediate future" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits) ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface() ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface ARM64: kernel: acpi: honour acpi=force command line parameter ARM64: kernel: acpi: refactor ACPI tables init and checks ARM64: kernel: psci: let ACPI probe PSCI version ARM64: kernel: psci: factor out probe function ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed ARM64 / ACPI: additions of ACPI documentation for arm64 Documentation: ACPI for ARM64 ARM64 / ACPI: Enable ARM64 in Kconfig XEN / ACPI: Make XEN ACPI depend on X86 ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 clocksource / arch_timer: Parse GTDT to initialize arch timer irqchip: Add GICv2 specific ACPI boot support ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi ACPI / processor: Make it possible to get CPU hardware ID via GICC ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID ARM64 / ACPI: Parse MADT for SMP initialization ...

clocksource/drivers/arm_arch_timer: Rename 'arch_timer_probed()' to 'arch_timer_needs_probing()' to reflect behaviour

2015-03-31T15:53:57Z

The arch_timer_probed() function returns whether the given time doesn't need to be probed. This can be the case when the timer has been probed already, but also when it has no corresponding enabled node in DT. Rename the function to arch_timer_needs_probing() and invert its return value to better reflect the function's purpose and behaviour. Signed-off-by: Laurent Pinchart Signed-off-by: Daniel Lezcano Acked-by: Sudeep Holla Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1427796746-373-1-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar

clocksource / arch_timer: Parse GTDT to initialize arch timer

2015-03-26T15:13:07Z

Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped). CC: Daniel Lezcano CC: Thomas Gleixner Originally-by: Amit Daniel Kachhap Tested-by: Suravee Suthikulpanit Tested-by: Yijing Wang Tested-by: Mark Langsdorf Tested-by: Jon Masters Tested-by: Timur Tabi Tested-by: Robert Richter Acked-by: Robert Richter Acked-by: Daniel Lezcano Reviewed-by: Grant Likely Signed-off-by: Hanjun Guo Signed-off-by: Will Deacon

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-01-07T03:29:20Z

arm_arch_timer: include clocksource.h directly

2015-01-06T18:18:50Z

This driver makes use of the clocksource code. Previously it had only included the proper header indirectly, but that chain was inadvertently broken by 74d23cc "time: move the timecounter/cyclecounter code into its own file." This patch fixes the issue by including clocksource.h directly. Signed-off-by: Richard Cochran Signed-off-by: David S. Miller

clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64

2014-12-16T21:26:44Z

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 Tested-by: Yingjoe Chen Cc: Daniel Lezcano Signed-off-by: Arnd Bergmann

Merge branch 'clocksource/physical-timers' into next/drivers

2014-12-05T07:32:16Z

* clocksource/physical-timers: clocksource: arch_timer: Allow the device tree to specify uninitialized timer registers clocksource: arch_timer: Fix code to use physical timers when requested

clocksource: arch_timer: Allow the device tree to specify uninitialized timer registers

2014-12-05T07:31:55Z

Some 32-bit (ARMv7) systems are architected like this: * The firmware doesn't know and doesn't care about hypervisor mode and we don't want to add the complexity of hypervisor there. * The firmware isn't involved in SMP bringup or resume. * The ARCH timer come up with an uninitialized offset (CNTVOFF) between the virtual and physical counters. Each core gets a different random offset. * The device boots in "Secure SVC" mode. * Nothing has touched the reset value of CNTHCTL.PL1PCEN or CNTHCTL.PL1PCTEN (both default to 1 at reset) On systems like the above, it doesn't make sense to use the virtual counter. There's nobody managing the offset and each time a core goes down and comes back up it will get reinitialized to some other random value. This adds an optional property which can inform the kernel of this situation, and firmware is free to remove the property if it is going to initialize the CNTVOFF registers when each CPU comes out of reset. Currently, the best course of action in this case is to use the physical timer, which is why it is important that CNTHCTL hasn't been changed from its reset value and it's a reasonable assumption given that the firmware has never entered HYP mode. Note that it's been said that on ARMv8 systems the firmware and kernel really can't be architected as described above. That means using the physical timer like this really only makes sense for ARMv7 systems. Signed-off-by: Doug Anderson Signed-off-by: Sonny Rao Reviewed-by: Mark Rutland Acked-by: Daniel Lezcano Acked-by: Catalin Marinas Signed-off-by: Olof Johansson

clocksource: arch_timer: Fix code to use physical timers when requested

2014-12-05T07:30:26Z

This is a bug fix for using physical arch timers when the arch_timer_use_virtual boolean is false. It restores the arch_counter_get_cntpct() function after removal in 0d651e4e "clocksource: arch_timer: use virtual counters" We need this on certain ARMv7 systems which are architected like this: * The firmware doesn't know and doesn't care about hypervisor mode and we don't want to add the complexity of hypervisor there. * The firmware isn't involved in SMP bringup or resume. * The ARCH timer come up with an uninitialized offset between the virtual and physical counters. Each core gets a different random offset. * The device boots in "Secure SVC" mode. * Nothing has touched the reset value of CNTHCTL.PL1PCEN or CNTHCTL.PL1PCTEN (both default to 1 at reset) One example of such as system is RK3288 where it is much simpler to use the physical counter since there's nobody managing the offset and each time a core goes down and comes back up it will get reinitialized to some other random value. Fixes: 0d651e4e65e9 ("clocksource: arch_timer: use virtual counters") Cc: stable@vger.kernel.org Signed-off-by: Sonny Rao Acked-by: Catalin Marinas Acked-by: Daniel Lezcano Signed-off-by: Olof Johansson

ARM/ARM64: arch-timer: fix arch_timer_probed logic

2014-10-26T19:50:00Z

Commit c387f07e6205 (clocksource: arm_arch_timer: Discard unavailable timers correctly) changed the way the driver makes sure both the memory and system-register timers have been probed before finalizing the probing. There is a interesting flaw in this logic that leads to this final step never to be executed. Things seems to work pretty well until something actually needs the data that is produced during this final stage. For example, KVM explodes on the first run of a guest when executed on a platform that has both memory and sysreg nodes (Juno, for example). Just fix the damned logic, and enjoy booting VMs again. Tested on a Juno system. Cc: Sudeep Holla Cc: Stephen Boyd Cc: Mark Rutland Cc: Daniel Lezcano Cc: Christoffer Dall Reported-by: Riku Voipio Acked-by: Mark Rutland Acked-by: Sudeep Holla Tested-by: Sudeep Holla Signed-off-by: Marc Zyngier Signed-off-by: Daniel Lezcano