path: root/arch/arm/kernel
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authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-07 11:22:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-07 11:22:14 -0700
commit1bf25e78af317e6d5d9b5594dfeb0036e0d589d6 (patch)
tree49dbd2d7bd6856b8ae1864c2dd0c0eb5e36d5398 /arch/arm/kernel
parent38f56f33ca381751f9b8910f67e7a805ec0b68cb (diff)
parent0592c2189ece16f3e0c5a56245634aba93d0c9dd (diff)
Merge tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC late cleanups from Arnd Bergmann: "These are cleanups and smaller changes that either depend on earlier feature branches or came in late during the development cycle. We normally try to get all cleanups early, so these are the exceptions: - A follow-up on the clocksource reworks, hopefully the last time we need to merge clocksource subsystem changes through arm-soc. A first set of patches was part of the original 3.10 arm-soc cleanup series because of interdependencies with timer drivers now moved out of arch/arm. - Migrating the SPEAr13xx platform away from using auxdata for DMA channel descriptions towards using information in device tree, based on the earlier SPEAr multiplatform series - A few follow-ups on the Atmel SAMA5 support and other changes for Atmel at91 based on the larger at91 reworks. - Moving the armada irqchip implementation to drivers/irqchip - Several OMAP cleanups following up on the larger series already merged in 3.10." * tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits) ARM: OMAP4: change the device names in usb_bind_phy ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a ARM: SPEAr: conditionalize SMP code ARM: arch_timer: Silence debug preempt warnings ARM: OMAP: remove unused variable serial: amba-pl011: fix !CONFIG_DMA_ENGINE case ata: arasan: remove the need for platform_data ARM: at91/sama5d34ek.dts: remove not needed compatibility string ARM: at91: dts: add MCI DMA support ARM: at91: dts: add i2c dma support ARM: at91: dts: set #dma-cells to the correct value ARM: at91: suspend both memory controllers on at91sam9263 irqchip: armada-370-xp: slightly cleanup irq controller driver irqchip: armada-370-xp: move IRQ handler to avoid forward declaration irqchip: move IRQ driver for Armada 370/XP ARM: mvebu: move L2 cache initialization in init_early() 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 ...
Diffstat (limited to 'arch/arm/kernel')
3 files changed, 32 insertions, 19 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index d957a51435d..59dcdced6e3 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)
-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;
- 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 59d2adb764a..e8edcaa0e43 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(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 955d92d265e..abff4e9aaee 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();