From 5a9b5855c248d0298eac4d5490c7bc11c2f1983b Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 1 Jun 2013 23:39:38 -0700 Subject: ARM: sched_clock: Remove unused needs_suspend member The needs_suspend member is unused now that we always do the suspend/resume handling (see 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23)). Acked-by: Will Deacon Signed-off-by: Stephen Boyd Signed-off-by: John Stultz --- arch/arm/kernel/sched_clock.c | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index e8edcaa0e432..45efe86e8b08 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -24,7 +24,6 @@ struct clock_data { u32 mult; u32 shift; bool suspended; - bool needs_suspend; }; static void sched_clock_poll(unsigned long wrap_ticks); -- cgit v1.2.3 From ffbfb5e316f0db486798ccf1db36a577ffe79637 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 1 Jun 2013 23:39:39 -0700 Subject: ARM: sched_clock: Return suspended count earlier If we're suspended and sched_clock() is called we're going to read the hardware one more time and throw away that value and return back the cached value we saved during the suspend callback. This is wasteful. Let's short circuit all that and return the cached value as early as possible if we're suspended. Acked-by: Will Deacon Signed-off-by: Stephen Boyd Signed-off-by: John Stultz --- arch/arm/kernel/sched_clock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 45efe86e8b08..a781c59b93c0 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -55,9 +55,6 @@ static unsigned long long notrace cyc_to_sched_clock(u32 cyc, u32 mask) u64 epoch_ns; u32 epoch_cyc; - if (cd.suspended) - return cd.epoch_ns; - /* * Load the epoch_cyc and epoch_ns atomically. We do this by * ensuring that we always write epoch_cyc, epoch_ns and @@ -174,6 +171,9 @@ unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32; unsigned long long notrace sched_clock(void) { + if (cd.suspended) + return cd.epoch_ns; + return sched_clock_func(); } -- cgit v1.2.3 From 38ff87f77af0b5a93fc8581cff1d6e5692ab8970 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sat, 1 Jun 2013 23:39:40 -0700 Subject: sched_clock: Make ARM's sched_clock generic for all architectures Nothing about the sched_clock implementation in the ARM port is specific to the architecture. Generalize the code so that other architectures can use it by selecting GENERIC_SCHED_CLOCK. Signed-off-by: Stephen Boyd [jstultz: Merge minor collisions with other patches in my tree] Signed-off-by: John Stultz --- arch/arm/Kconfig | 1 + arch/arm/common/timer-sp.c | 2 +- arch/arm/include/asm/sched_clock.h | 16 --- arch/arm/kernel/Makefile | 2 +- arch/arm/kernel/arch_timer.c | 2 +- arch/arm/kernel/sched_clock.c | 216 ------------------------------ arch/arm/kernel/time.c | 4 +- arch/arm/mach-davinci/time.c | 2 +- arch/arm/mach-imx/time.c | 2 +- arch/arm/mach-integrator/integrator_ap.c | 2 +- arch/arm/mach-ixp4xx/common.c | 2 +- arch/arm/mach-mmp/time.c | 2 +- arch/arm/mach-msm/timer.c | 2 +- arch/arm/mach-omap1/time.c | 2 +- arch/arm/mach-omap2/timer.c | 2 +- arch/arm/mach-pxa/time.c | 2 +- arch/arm/mach-sa1100/time.c | 2 +- arch/arm/mach-u300/timer.c | 2 +- arch/arm/plat-iop/time.c | 2 +- arch/arm/plat-omap/counter_32k.c | 2 +- arch/arm/plat-orion/time.c | 2 +- arch/arm/plat-samsung/samsung-time.c | 2 +- arch/arm/plat-versatile/sched-clock.c | 2 +- drivers/clocksource/bcm2835_timer.c | 2 +- drivers/clocksource/clksrc-dbx500-prcmu.c | 3 +- drivers/clocksource/dw_apb_timer_of.c | 3 +- drivers/clocksource/mxs_timer.c | 2 +- drivers/clocksource/nomadik-mtu.c | 2 +- drivers/clocksource/samsung_pwm_timer.c | 2 +- drivers/clocksource/tegra20_timer.c | 2 +- drivers/clocksource/time-armada-370-xp.c | 2 +- drivers/clocksource/timer-marco.c | 2 +- drivers/clocksource/timer-prima2.c | 2 +- include/linux/sched_clock.h | 21 +++ init/Kconfig | 3 + init/main.c | 2 + kernel/time/Makefile | 1 + kernel/time/sched_clock.c | 215 +++++++++++++++++++++++++++++ 38 files changed, 273 insertions(+), 266 deletions(-) delete mode 100644 arch/arm/include/asm/sched_clock.h delete mode 100644 arch/arm/kernel/sched_clock.c create mode 100644 include/linux/sched_clock.h create mode 100644 kernel/time/sched_clock.c (limited to 'arch/arm/kernel') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 49d993cee512..53d3a356f61f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -14,6 +14,7 @@ config ARM select GENERIC_IRQ_PROBE select GENERIC_IRQ_SHOW select GENERIC_PCI_IOMAP + select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_IDLE_POLL_SETUP select GENERIC_STRNCPY_FROM_USER diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c index ddc740769601..023ee63827a2 100644 --- a/arch/arm/common/timer-sp.c +++ b/arch/arm/common/timer-sp.c @@ -28,8 +28,8 @@ #include #include #include +#include -#include #include #include diff --git a/arch/arm/include/asm/sched_clock.h b/arch/arm/include/asm/sched_clock.h deleted file mode 100644 index 3d520ddca61b..000000000000 --- a/arch/arm/include/asm/sched_clock.h +++ /dev/null @@ -1,16 +0,0 @@ -/* - * sched_clock.h: support for extending counters to full 64-bit ns counter - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#ifndef ASM_SCHED_CLOCK -#define ASM_SCHED_CLOCK - -extern void sched_clock_postinit(void); -extern void setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate); - -extern unsigned long long (*sched_clock_func)(void); - -#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5f3338eacad2..97cb0576d07c 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -16,7 +16,7 @@ CFLAGS_REMOVE_return_address.o = -pg # Object file lists. obj-y := elf.o entry-armv.o entry-common.o irq.o opcodes.o \ - process.o ptrace.o return_address.o sched_clock.o \ + process.o ptrace.o return_address.o \ setup.o signal.o stacktrace.o sys_arm.o time.o traps.o obj-$(CONFIG_ATAGS) += atags_parse.o diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 59dcdced6e30..221f07b11ccb 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -11,9 +11,9 @@ #include #include #include +#include #include -#include #include diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c deleted file mode 100644 index a781c59b93c0..000000000000 --- a/arch/arm/kernel/sched_clock.c +++ /dev/null @@ -1,216 +0,0 @@ -/* - * sched_clock.c: support for extending counters to full 64-bit ns counter - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -struct clock_data { - u64 epoch_ns; - u32 epoch_cyc; - u32 epoch_cyc_copy; - unsigned long rate; - u32 mult; - u32 shift; - bool suspended; -}; - -static void sched_clock_poll(unsigned long wrap_ticks); -static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0); -static int irqtime = -1; - -core_param(irqtime, irqtime, int, 0400); - -static struct clock_data cd = { - .mult = NSEC_PER_SEC / HZ, -}; - -static u32 __read_mostly sched_clock_mask = 0xffffffff; - -static u32 notrace jiffy_sched_clock_read(void) -{ - return (u32)(jiffies - INITIAL_JIFFIES); -} - -static u32 __read_mostly (*read_sched_clock)(void) = jiffy_sched_clock_read; - -static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift) -{ - return (cyc * mult) >> shift; -} - -static unsigned long long notrace cyc_to_sched_clock(u32 cyc, u32 mask) -{ - u64 epoch_ns; - u32 epoch_cyc; - - /* - * Load the epoch_cyc and epoch_ns atomically. We do this by - * ensuring that we always write epoch_cyc, epoch_ns and - * epoch_cyc_copy in strict order, and read them in strict order. - * If epoch_cyc and epoch_cyc_copy are not equal, then we're in - * the middle of an update, and we should repeat the load. - */ - do { - epoch_cyc = cd.epoch_cyc; - smp_rmb(); - epoch_ns = cd.epoch_ns; - smp_rmb(); - } while (epoch_cyc != cd.epoch_cyc_copy); - - return epoch_ns + cyc_to_ns((cyc - epoch_cyc) & mask, cd.mult, cd.shift); -} - -/* - * Atomically update the sched_clock epoch. - */ -static void notrace update_sched_clock(void) -{ - unsigned long flags; - u32 cyc; - u64 ns; - - cyc = read_sched_clock(); - ns = cd.epoch_ns + - cyc_to_ns((cyc - cd.epoch_cyc) & sched_clock_mask, - cd.mult, cd.shift); - /* - * Write epoch_cyc and epoch_ns in a way that the update is - * detectable in cyc_to_fixed_sched_clock(). - */ - raw_local_irq_save(flags); - cd.epoch_cyc_copy = cyc; - smp_wmb(); - cd.epoch_ns = ns; - smp_wmb(); - cd.epoch_cyc = cyc; - raw_local_irq_restore(flags); -} - -static void sched_clock_poll(unsigned long wrap_ticks) -{ - mod_timer(&sched_clock_timer, round_jiffies(jiffies + wrap_ticks)); - update_sched_clock(); -} - -void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) -{ - unsigned long r, w; - u64 res, wrap; - char r_unit; - - if (cd.rate > rate) - return; - - BUG_ON(bits > 32); - WARN_ON(!irqs_disabled()); - read_sched_clock = read; - sched_clock_mask = (1 << bits) - 1; - cd.rate = rate; - - /* calculate the mult/shift to convert counter ticks to ns. */ - clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0); - - r = rate; - if (r >= 4000000) { - r /= 1000000; - r_unit = 'M'; - } else if (r >= 1000) { - r /= 1000; - r_unit = 'k'; - } else - r_unit = ' '; - - /* calculate how many ns until we wrap */ - wrap = cyc_to_ns((1ULL << bits) - 1, cd.mult, cd.shift); - do_div(wrap, NSEC_PER_MSEC); - w = wrap; - - /* calculate the ns resolution of this counter */ - res = cyc_to_ns(1ULL, cd.mult, cd.shift); - pr_info("sched_clock: %u bits at %lu%cHz, resolution %lluns, wraps every %lums\n", - bits, r, r_unit, res, w); - - /* - * Start the timer to keep sched_clock() properly updated and - * sets the initial epoch. - */ - sched_clock_timer.data = msecs_to_jiffies(w - (w / 10)); - update_sched_clock(); - - /* - * Ensure that sched_clock() starts off at 0ns - */ - cd.epoch_ns = 0; - - /* Enable IRQ time accounting if we have a fast enough sched_clock */ - if (irqtime > 0 || (irqtime == -1 && rate >= 1000000)) - enable_sched_clock_irqtime(); - - pr_debug("Registered %pF as sched_clock source\n", read); -} - -static unsigned long long notrace sched_clock_32(void) -{ - u32 cyc = read_sched_clock(); - return cyc_to_sched_clock(cyc, sched_clock_mask); -} - -unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32; - -unsigned long long notrace sched_clock(void) -{ - if (cd.suspended) - return cd.epoch_ns; - - return sched_clock_func(); -} - -void __init sched_clock_postinit(void) -{ - /* - * If no sched_clock function has been provided at that point, - * make it the final one one. - */ - if (read_sched_clock == jiffy_sched_clock_read) - setup_sched_clock(jiffy_sched_clock_read, 32, HZ); - - sched_clock_poll(sched_clock_timer.data); -} - -static int sched_clock_suspend(void) -{ - sched_clock_poll(sched_clock_timer.data); - cd.suspended = true; - return 0; -} - -static void sched_clock_resume(void) -{ - cd.epoch_cyc = read_sched_clock(); - cd.epoch_cyc_copy = cd.epoch_cyc; - cd.suspended = false; -} - -static struct syscore_ops sched_clock_ops = { - .suspend = sched_clock_suspend, - .resume = sched_clock_resume, -}; - -static int __init sched_clock_syscore_init(void) -{ - register_syscore_ops(&sched_clock_ops); - return 0; -} -device_initcall(sched_clock_syscore_init); diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index abff4e9aaee0..98aee3258398 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -24,9 +24,9 @@ #include #include #include +#include #include -#include #include #include #include @@ -120,6 +120,4 @@ void __init time_init(void) machine_desc->init_time(); else clocksource_of_init(); - - sched_clock_postinit(); } diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c index bad361ec1666..7a55b5c95971 100644 --- a/arch/arm/mach-davinci/time.c +++ b/arch/arm/mach-davinci/time.c @@ -18,8 +18,8 @@ #include #include #include +#include -#include #include #include diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c index fea91313678b..cd46529e9eaa 100644 --- a/arch/arm/mach-imx/time.c +++ b/arch/arm/mach-imx/time.c @@ -26,8 +26,8 @@ #include #include #include +#include -#include #include #include "common.h" diff --git a/arch/arm/mach-integrator/integrator_ap.c b/arch/arm/mach-integrator/integrator_ap.c index b23c8e4f28e8..aa4346227c41 100644 --- a/arch/arm/mach-integrator/integrator_ap.c +++ b/arch/arm/mach-integrator/integrator_ap.c @@ -41,6 +41,7 @@ #include #include #include +#include #include