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* ARC: clocksource: DT based probeVineet Gupta2016-05-091-53/+81
| | | | | | | | | | | | | | | | | | | | - Remove explicit clocksource setup and let it be done by OF framework by defining CLOCKSOURCE_OF_DECLARE() for various timers - This allows multiple clocksources to be potentially registered simultaneouly: previously we could only do one - as all of them had same arc_counter_setup() routine for registration - Setup routines also ensure that the underlying timer actually exists. - Remove some of the panic() calls if underlying timer is NOT detected as fallback clocksource might still be available 1. If GRFC doesn't exist, jiffies clocksource gets registered anyways 2. if RTC doesn't exist, TIMER1 can take over (as it is always present) Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: clockevent: DT based probeVineet Gupta2016-05-091-16/+43
| | | | | | | | | | | | | | | - timer frequency is derived from DT (no longer rely on top level DT "clock-frequency" probed early and exported by asm/clk.h) - TIMER0_IRQ need not be exported across arch code, confined to intc as it is property of same - Any failures in clockevent setup are considered pedantic and system panic()'s as there is no generic fallback (unlike clocksource where a jiffies based soft clocksource always exists) Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: clockevent: Prepare for DT based probeNoam Camus2016-05-091-0/+5
| | | | | | | | | | - call clocksource_probe() - This in turns needs of_clk_init() to be called earlier Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Noam Camus <noamc@ezchip.com> [vgupta: broken off from a bigger patch] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: clockevent: switch to cpu notifier for clockevent setupNoam Camus2016-05-091-21/+41
| | | | | | | | | | | | | | ARC Timers so far have been handled as "legacy" w/o explicit description in DT. This poses challenge for newer platforms wanting to use them. This series will eventually help move timers over to DT. This patch does a small change of using a CPU notifier to set clockevent on non-boot CPUs. So explicit setup is done only on boot CPU (which will later be done by DT) Signed-off-by: Noam Camus <noamc@ezchip.com> [vgupta: broken off from a bigger patch] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: opencode arc_request_percpu_irqVineet Gupta2016-05-091-3/+11
| | | | | | | | | | | | | | | - The idea is to remove the API usage since it has a subltle design flaw - relies on being called on cpu0 first. This is true for some early per cpu irqs such as TIMER/IPI, but not for late probed per cpu peripherals such a perf. And it's usage in perf has already bitten us once: see c6317bc7c5ab ("ARCv2: perf: Ensure perf intr gets enabled on all cores") where we ended up open coding it anyways - The seeming duplication will go away once we start using cpu notifier for timer setup Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Fix misspellings in comments.Adam Buchbinder2016-03-111-2/+2
| | | | | Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARCv2: clocksource: Rename GRTC -> GFRC ...Vineet Gupta2016-01-291-4/+4
| | | | | | ... it is now called Global Free Running Counter Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: remove @init_time, @init_irq platform callbacksVineet Gupta2015-10-281-3/+0
| | | | | | | | | | | These are not in use for ARC platforms. Moreover DT mechanims exist to probe them w/o explicit platform calls. - clocksource drivers can use CLOCKSOURCE_OF_DECLARE() - intc IRQCHIP_DECLARE() calls + cascading inside DT allows external intc to be probed automatically Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC/time: Migrate to new 'set-state' interfaceViresh Kumar2015-07-201-25/+15
| | | | | | | | | | | | | Migrate arc driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARCv2: SMP: clocksource: Enable Global Real Time counterVineet Gupta2015-06-221-0/+45
| | | | | | Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARCv2: clocksource: Introduce 64bit local RTC counterVineet Gupta2015-06-221-0/+50
| | | | | | Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: clocksource cleanupsVineet Gupta2015-06-191-10/+2
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: RIP broken 64bit RTSCVineet Gupta2015-06-191-48/+1
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: update some commentsVineet Gupta2014-07-231-3/+7
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)Vineet Gupta2014-07-231-15/+3
| | | | | | | | | | | | 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 <vgupta@synopsys.com>
* ARC: arc_local_timer_setup() need not pass own cpu idVineet Gupta2014-06-031-5/+6
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [clockevent] simplify timer ISRVineet Gupta2014-03-261-19/+15
| | | | | | * Remove one liner IRQ ACK accessor, it was coming in the way of readability. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [clockevent] can't be SoC specificVineet Gupta2014-03-261-2/+1
| | | | | | So no point keeping it weak Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [SMP] Disallow RTSCVineet Gupta2013-11-071-3/+4
| | | | | | RTSC is strictly incore and must not be allowed in SMP configs Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: use __weak instead of __attribute__((weak))Vineet Gupta2013-11-061-1/+1
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* arc: Replace __get_cpu_var usesChristoph Lameter2013-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __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 <vgupta@synopsys.com> Signed-off-by: Christoph Lameter <cl@linux.com>
* ARC: Use clockevents_config_and_register over clockevents_register_deviceUwe Kleine-König2013-09-271-5/+2
| | | | | | | | | | 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 <u.kleine-koenig@pengutronix.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* arc: delete __cpuinit usage from all arc filesPaul Gortmaker2013-06-271-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <vgupta@synopsys.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Disintegrate arcregs.hVineet Gupta2013-06-221-0/+11
| | | | | | | | | * Move the various sub-system defines/types into relevant files/functions (reduces compilation time) * move CPU specific stuff out of asm/tlb.h into asm/mmu.h Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Remove duplicate inclusion of header filesSachin Kamat2013-04-091-1/+0
| | | | | | | Some header files were included twice in the same file. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: 64bit RTSC timestamp hardware issueVineet Gupta2013-02-151-36/+2
| | | | | | | | | | | | | | | | | The 64bit RTSC is not reliable, causing spurious "jumps" in higher word, making Linux timekeeping go bonkers. So as of now just use the lower 32bit timestamp. A cleaner approach would have been removing RTSC support altogether as the 32bit RTSC is equivalent to old TIMER1 based solution, but some customers can use the 32bit RTSC in SMP syn fashion (vs. TIMER1 which being incore can't be done easily). A fallout of this is sched_clock()'s hardware assisted version needs to go away since it can't use 32bit wrapping counter - instead we use the generic "weak" jiffies based version. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: [Review] Multi-platform image #2: Board callback InfrastructureVineet Gupta2013-02-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The orig platform code orgnaization was singleton design pattern - only one platform (and board thereof) would build at a time. Thus any platform/board specific code (e.g. irq init, early init ...) expected by ARC common code was exported as well defined set of APIs, with only ONE instance building ever. Now with multiple-platform build requirement, that design of code no longer holds - multiple board specific calls need to build at the same time - so ARC common code can't use the API approach, it needs a callback based design where each board registers it's specific set of functions, and at runtime, depending on board detection, the callbacks are used from the registry. This commit adds all the infrastructure, where board specific callbacks are specified as a "maThine description". All the hooks are placed in right spots, no board callbacks registered yet (with MACHINE_STARt/END constructs) so the hooks will not run. Next commit will actually convert the platform to this infrastructure. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
* ARC: Timers/counters/delay managementVineet Gupta2013-02-111-0/+295
ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1. Both have exactly same capabilies. * programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT * for count 0 and LIMIT ~1, provides a free-running counter by auto-wrapping when limit is reached. * optionally interrupt when LIMIT is reached (oneshot event semantics) * rearming the interrupt provides periodic semantics * run at CPU clk ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for clocksource (free-running clock). Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence is more apt for clocksource when available. SMP poses a bit of challenge for global timekeeping clocksource / sched_clock() backend: -TIMER1 based local clocks are out-of-sync hence can't be used (thus we default to jiffies based cs as well as sched_clock() one/both of which platform can override with it's specific hardware assist) -RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue ensures that) and thus usable for both requirements. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Thomas Gleixner <tglx@linutronix.de>
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