linux.git/arch/arm/include/asm/arch_timer.h, branch v3.17

ARM: arch_timer: add support to configure and enable event stream

2013-09-26T08:47:26+00:00

This patch adds support for configuring the event stream frequency
and enabling it.

It also adds the hwcaps definitions to the user to detect this event
stream feature.

Cc: Russell King 
Cc: Lorenzo Pieralisi 
Acked-by: Catalin Marinas 
Acked-by: Will Deacon 
Acked-by: Olof Johansson 
Signed-off-by: Sudeep KarkadaNagesha

ARM/ARM64: arch_timer: add macros for bits in control register

2013-09-26T08:47:06+00:00

Add macros to describe the bitfields in the ARM architected timer
control register to make code easy to understand.

Reviewed-by: Lorenzo Pieralisi 
Reviewed-by: Will Deacon 
Acked-by: Catalin Marinas 
Acked-by: Olof Johansson 
Signed-off-by: Sudeep KarkadaNagesha

Merge branch 'timers/clockevents-next' of git://git.linaro.org/people/dlezcano/clockevents into timers/core

2013-08-21T12:59:23+00:00

* Support for memory mapped arch_timers
* Trivial fixes to the moxart timer code
* Documentation updates

Trivial conflicts in drivers/clocksource/arm_arch_timer.c. Fixed up
the newly added __cpuinit annotations as well.

Signed-off-by: Thomas Gleixner

clocksource: arch_timer: Push the read/write wrappers deeper

2013-07-31T23:13:37+00:00

We're going to introduce support to read and write the memory
mapped timer registers in the next patch, so push the cp15
read/write functions one level deeper. This simplifies the next
patch and makes it clearer what's going on.

Cc: Mark Rutland 
Cc: Marc Zyngier 
Signed-off-by: Stephen Boyd 
Signed-off-by: Daniel Lezcano 
Acked-by: Mark Rutland

clocksource: arch_timer: Make register accessors less error-prone

2013-07-31T23:13:35+00:00

Using an enum for the register we wish to access allows newer
compilers to determine if we've forgotten a case in our switch
statement. This allows us to remove the BUILD_BUG() instances in
the arm64 port, avoiding problems where optimizations may not
happen.

To try and force better code generation we're currently marking
the accessor functions as inline, but newer compilers can ignore
the inline keyword unless it's marked __always_inline. Luckily on
arm and arm64 inline is __always_inline, but let's make
everything __always_inline to be explicit.

Suggested-by: Thomas Gleixner 
Cc: Thomas Gleixner 
Cc: Mark Rutland 
Cc: Marc Zyngier 
Signed-off-by: Stephen Boyd 
Signed-off-by: Daniel Lezcano 
Acked-by: Mark Rutland

arm: delete cpuinit/CPUINIT usage from all ARM users

2013-07-14T23:36:52+00:00

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.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit  -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings.  In any case, they are temporary and harmless.

This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code.  It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Russell King 
Cc: Will Deacon 
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker

clocksource: arch_timer: use virtual counters

2013-06-07T09:20:28+00:00

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: convert arm/arm64 arch timer to use CLKSRC_OF init

2013-04-11T20:11:15+00:00

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_timer: move core to drivers/clocksource

2013-01-31T15:51:49+00:00

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

arm: arch_timer: add arch_counter_set_user_access

2013-01-31T15:51:39+00:00

Several bits in CNTKCTL reset to 0, including PL0VTEN. For architectures
using the generic timer which wish to have a fast gettimeofday vDSO
implementation, these bits must be set to 1 by the kernel. For
architectures without a vDSO, it's best to leave the bits set to 0 for
now to ensure that if and when support is added, it's implemented sanely
architecture wide.

As the bootloader might set PL0VTEN to a value that doesn't correspond
to that which the kernel prefers, we must explicitly set it to the
architecture port's preferred value.

This patch adds arch_counter_set_user_access, which sets the PL0 access
permissions to that required by the architecture. For arch/arm, this
currently means disabling all userspace access.

Signed-off-by: Mark Rutland 
Acked-by: Catalin Marinas