linux/arch/arc/kernel/time.c, branch v3.18

ARC: update some comments

2014-07-23T05:47:12Z

Signed-off-by: Vineet Gupta

ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)

2014-07-23T05:46:45Z

The current cpu-private IRQ registration is ugly as it requires need to expose arch_unmask_irq() outside of intc code. So switch to percpu IRQ APIs: -request_percpu_irq [boot core] -enable_percpu_irq [all cores] Encapsulated in helper arc_request_percpu_irq() Signed-off-by: Vineet Gupta

ARC: arc_local_timer_setup() need not pass own cpu id

2014-06-03T07:56:52Z

Signed-off-by: Vineet Gupta

ARC: [clockevent] simplify timer ISR

2014-03-26T09:01:30Z

* Remove one liner IRQ ACK accessor, it was coming in the way of readability. Signed-off-by: Vineet Gupta

ARC: [clockevent] can't be SoC specific

2014-03-26T09:01:29Z

So no point keeping it weak Signed-off-by: Vineet Gupta

ARC: [SMP] Disallow RTSC

2013-11-07T09:04:31Z

RTSC is strictly incore and must not be allowed in SMP configs Signed-off-by: Vineet Gupta

ARC: use weak instead of attribute__((weak))

2013-11-06T05:10:37Z

Signed-off-by: Vineet Gupta

arc: Replace __get_cpu_var uses

2013-11-06T05:10:37Z

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided and less registers are used when code is generated. At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too. The patchset includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, u); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(this_cpu_ptr(&x), y, sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to this_cpu_inc(y) Acked-by: Vineet Gupta Signed-off-by: Christoph Lameter

ARC: Use clockevents_config_and_register over clockevents_register_device

2013-09-27T10:58:48Z

clockevents_config_and_register is more clever and correct than doing it by hand; so use it. [vgupta: fixed build failure due to missing ; in patch] Signed-off-by: Uwe Kleine-König Signed-off-by: Vineet Gupta

arc: delete __cpuinit usage from all arc files

2013-06-27T09:07:58Z

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) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit 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 arch/arc uses of the __cpuinit macros from all C files. Currently arc does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Vineet Gupta Signed-off-by: Paul Gortmaker Signed-off-by: Vineet Gupta

linux/arch/arc/kernel/time.c, branch v3.18

ARC: update some comments

ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)

ARC: arc_local_timer_setup() need not pass own cpu id

ARC: [clockevent] simplify timer ISR

ARC: [clockevent] can't be SoC specific

ARC: [SMP] Disallow RTSC

ARC: use __weak instead of __attribute__((weak))

arc: Replace __get_cpu_var uses

ARC: Use clockevents_config_and_register over clockevents_register_device

arc: delete __cpuinit usage from all arc files

ARC: use weak instead of attribute__((weak))