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author | Olof Johansson <olof@lixom.net> | 2013-04-17 10:10:01 -0700 |
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committer | Olof Johansson <olof@lixom.net> | 2013-04-17 10:10:01 -0700 |
commit | c3e0c873d0653e6e7628b5a8a9fcb3745444ca9e (patch) | |
tree | dd7448d5515c56604cd8e57f3d6399f5640d57a3 /arch/arm/kernel | |
parent | 228e3023eb0430b4b9ed0736f8f87c96a6cd9c7a (diff) | |
parent | 69a517b2471bcd1c5a175aad82647c1e2c24f08b (diff) | |
download | op-kernel-dev-c3e0c873d0653e6e7628b5a8a9fcb3745444ca9e.zip op-kernel-dev-c3e0c873d0653e6e7628b5a8a9fcb3745444ca9e.tar.gz |
Merge tag 'clksrc-cleanup-for-3.10-part2' of git://sources.calxeda.com/kernel/linux into late/clksrc
This is the 2nd part of ARM timer clean-ups for 3.10. This series has
the following changes:
- Add sched_clock selection logic to select the highest frequency clock
- Use full 64-bit arch timer counter for sched_clock
- Convert arch timer, sp804 and integrator-cp timers to CLKSRC_OF and
adapt all users to use clocksource_of_init
* tag 'clksrc-cleanup-for-3.10-part2' of git://sources.calxeda.com/kernel/linux:
devtree: add binding documentation for sp804
ARM: integrator-cp: convert use CLKSRC_OF for timer init
ARM: versatile: use OF init for sp804 timer
ARM: versatile: add versatile dtbs to dtbs target
ARM: vexpress: remove extra timer-sp control register clearing
ARM: dts: vexpress: disable CA9 core tile sp804 timer
ARM: vexpress: remove sp804 OF init
ARM: highbank: use OF init for sp804 timer
ARM: timer-sp: convert to use CLKSRC_OF init
OF: add empty of_device_is_available for !OF
ARM: convert arm/arm64 arch timer to use CLKSRC_OF init
ARM: make machine_desc->init_time default to clocksource_of_init
ARM: arch_timer: use full 64-bit counter for sched_clock
ARM: make sched_clock just call a function pointer
ARM: sched_clock: allow changing to higher frequency counter
Signed-off-by: Olof Johansson <olof@lixom.net>
This has a nasty set of conflicts with the exynos MCT code, which was
moved in a separate branch, and then fixed up when merged in, but still
conflicts a bit here. It should have been sorted out by this merge though.
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/arch_timer.c | 29 | ||||
-rw-r--r-- | arch/arm/kernel/sched_clock.c | 15 | ||||
-rw-r--r-- | arch/arm/kernel/time.c | 7 |
3 files changed, 32 insertions, 19 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index d957a51..59dcdce 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -22,9 +22,11 @@ static unsigned long arch_timer_read_counter_long(void) return arch_timer_read_counter(); } -static u32 arch_timer_read_counter_u32(void) +static u32 sched_clock_mult __read_mostly; + +static unsigned long long notrace arch_timer_sched_clock(void) { - return arch_timer_read_counter(); + return arch_timer_read_counter() * sched_clock_mult; } static struct delay_timer arch_delay_timer; @@ -37,25 +39,20 @@ static void __init arch_timer_delay_timer_register(void) register_current_timer_delay(&arch_delay_timer); } -int __init arch_timer_of_register(void) +int __init arch_timer_arch_init(void) { - int ret; + u32 arch_timer_rate = arch_timer_get_rate(); - ret = arch_timer_init(); - if (ret) - return ret; + if (arch_timer_rate == 0) + return -ENXIO; arch_timer_delay_timer_register(); - return 0; -} - -int __init arch_timer_sched_clock_init(void) -{ - if (arch_timer_get_rate() == 0) - return -ENXIO; + /* Cache the sched_clock multiplier to save a divide in the hot path. */ + sched_clock_mult = NSEC_PER_SEC / arch_timer_rate; + sched_clock_func = arch_timer_sched_clock; + pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n", + arch_timer_rate / 1000, sched_clock_mult); - setup_sched_clock(arch_timer_read_counter_u32, - 32, arch_timer_get_rate()); return 0; } diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index bd6f56b..8805848 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -20,6 +20,7 @@ struct clock_data { u64 epoch_ns; u32 epoch_cyc; u32 epoch_cyc_copy; + unsigned long rate; u32 mult; u32 shift; bool suspended; @@ -113,11 +114,14 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) u64 res, wrap; char r_unit; + if (cd.rate > rate) + return; + BUG_ON(bits > 32); WARN_ON(!irqs_disabled()); - WARN_ON(read_sched_clock != jiffy_sched_clock_read); 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); @@ -161,12 +165,19 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) pr_debug("Registered %pF as sched_clock source\n", read); } -unsigned long long notrace sched_clock(void) +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) +{ + return sched_clock_func(); +} + void __init sched_clock_postinit(void) { /* diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index 955d92d..abff4e9 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -22,6 +22,7 @@ #include <linux/errno.h> #include <linux/profile.h> #include <linux/timer.h> +#include <linux/clocksource.h> #include <linux/irq.h> #include <asm/thread_info.h> @@ -115,6 +116,10 @@ int __init register_persistent_clock(clock_access_fn read_boot, void __init time_init(void) { - machine_desc->init_time(); + if (machine_desc->init_time) + machine_desc->init_time(); + else + clocksource_of_init(); + sched_clock_postinit(); } |