linux/drivers/clocksource/arm_arch_timer.c, branch v3.11

clocksource+irqchip: delete __cpuinit usage from all related files

2013-07-14T23:36:57Z

The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/clocksource and drivers/irqchip uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: John Stultz Cc: Thomas Gleixner Acked-by: Thomas Gleixner Signed-off-by: Paul Gortmaker

clocksource: arch_timer: use virtual counters

2013-06-07T09:20:28Z

Switching between reading the virtual or physical counters is problematic, as some core code wants a view of time before we're fully set up. Using a function pointer and switching the source after the first read can make time appear to go backwards, and having a check in the read function is an unfortunate block on what we want to be a fast path. Instead, this patch makes us always use the virtual counters. If we're a guest, or don't have hyp mode, we'll use the virtual timers, and as such don't care about CNTVOFF as long as it doesn't change in such a way as to make time appear to travel backwards. As the guest will use the virtual timers, a (potential) KVM host must use the physical timers (which can wake up the host even if they fire while a guest is executing), and hence a host must have CNTVOFF set to zero so as to have a consistent view of time between the physical timers and virtual counters. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar Cc: Rob Herring

ARM: arch_timer: Silence debug preempt warnings

2013-04-27T00:17:29Z

Hot-plugging with CONFIG_DEBUG_PREEMPT=y on a device with arm architected timers causes a slew of "using smp_processor_id() in preemptible" warnings: BUG: using smp_processor_id() in preemptible [00000000] code: sh/111 caller is arch_timer_cpu_notify+0x14/0xc8 This happens because sometimes the cpu notifier, arch_timer_cpu_notify(), is called in preemptible context and other times in non-preemptible context but we use this_cpu_ptr() to retrieve the clockevent in all cases. We're only going to actually use the pointer in non-preemptible context though, so push the this_cpu_ptr() access down into the cases to force the checks to occur only in non-preemptible contexts. Cc: John Stultz Cc: Thomas Gleixner Cc: Mark Rutland Acked-by: Marc Zyngier Signed-off-by: Stephen Boyd Signed-off-by: Olof Johansson

ARM: convert arm/arm64 arch timer to use CLKSRC_OF init

2013-04-11T20:11:15Z

This converts arm and arm64 to use CLKSRC_OF DT based initialization for the arch timer. A new function arch_timer_arch_init is added to allow for arch specific setup. This has a side effect of enabling sched_clock on omap5 and exynos5. There should not be any reason not to use the arch timers for sched_clock. Signed-off-by: Rob Herring Cc: Russell King Cc: Kukjin Kim Cc: Tony Lindgren Cc: Simon Horman Cc: Magnus Damm Cc: Catalin Marinas Cc: Will Deacon Cc: John Stultz Cc: Thomas Gleixner Cc: linux-samsung-soc@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: linux-sh@vger.kernel.org Acked-by: Santosh Shilimkar

ARM: arch_timers: switch to physical timers if HYP mode is available

2013-01-31T15:52:00Z

If we're booted in HYP mode, it is possible that we'll run some kind of virtualized environment. In this case, it is a better to switch to the physical timers, and leave the virtual timers to guests. Signed-off-by: Marc Zyngier Signed-off-by: Mark Rutland Acked-by: Catalin Marinas

arm64: move from arm_generic to arm_arch_timer

2013-01-31T15:51:59Z

The arch_timer driver supports a superset of the functionality of the arm_generic driver, and is not tied to a particular arch. This patch moves arm64 to use the arch_timer driver, gaining additional functionality in doing so, and removes the (now unused) arm_generic driver. Timer-related hooks specific to arm64 are moved into arch/arm64/kernel/time.c. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar

arm: arch_timer: move core to drivers/clocksource

2013-01-31T15:51:49Z

The core functionality of the arch_timer driver is not directly tied to anything under arch/arm, and can be split out. This patch factors out the core of the arch_timer driver, so it can be shared with other architectures. A couple of functions are added so that architecture-specific code can interact with the driver without needing to touch its internals. The ARM_ARCH_TIMER config variable is moved out to drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with HAVE_ARM_ARCH_TIMER, which selects it. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier