From 233bcb411cd32d15c4d04271fa06ca8f2dc24eb8 Mon Sep 17 00:00:00 2001 From: Elad Wexler Date: Thu, 12 Sep 2013 13:28:54 +0300 Subject: [PATCH 1/4] clocksource: Fix 'ret' data type of sysfs_override_clocksource() and sysfs_unbind_clocksource() sysfs_override_clocksource(): The expression 'if (ret >= 0)' is always true. This will cause clocksource_select() to always run. Thus modified ret to be of type ssize_t. sysfs_unbind_clocksource(): The expression 'if (ret < 0)' is always false. So in case sysfs_get_uname() failed, the expression won't take an effect. Thus modified ret to be of type ssize_t. Signed-off-by: Elad Wexler Signed-off-by: John Stultz --- kernel/time/clocksource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 64cf63ca09cc..c9317e14aae6 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -940,7 +940,7 @@ static ssize_t sysfs_override_clocksource(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - size_t ret; + ssize_t ret; mutex_lock(&clocksource_mutex); @@ -968,7 +968,7 @@ static ssize_t sysfs_unbind_clocksource(struct device *dev, { struct clocksource *cs; char name[CS_NAME_LEN]; - size_t ret; + ssize_t ret; ret = sysfs_get_uname(buf, name, count); if (ret < 0) From 07783397c6e3757de805bda5e1139a9e47aa7d74 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 17 Sep 2013 11:20:21 -0700 Subject: [PATCH 2/4] rtc: rtc-pl031: Set wakeup flag prior to registering rtcdev In some recent testing, I noticed the CLOCK_REALTIME_ALARM clockid wasn't functioning on my vexpress qemu environment. Looking into it I noticed the pl031 rtc driver doesn't set the wakeup flag on the device until after registering the device with the RTC subsystem. This causes the alarmtimer subsystem to not see the pl031 driver as a valid backing device, and that resuls in alarm clockids getting ENOTSUPP errors. Thus be sure to set the wakeup flag on the device prior to registering the rtcdev so the pl031 rtc driver can be used as the backing alarmtimer device. Cc: Linus Walleij Cc: Alessandro Zummo Cc: "Jon Medhurst (Tixy)" Cc: linux-arm-kernel@lists.infradead.org Acked-by: Linus Walleij Signed-off-by: John Stultz --- drivers/rtc/rtc-pl031.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c index 0f0609b1aa2c..e3b25712b659 100644 --- a/drivers/rtc/rtc-pl031.c +++ b/drivers/rtc/rtc-pl031.c @@ -371,6 +371,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id) } } + device_init_wakeup(&adev->dev, 1); ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, THIS_MODULE); if (IS_ERR(ldata->rtc)) { @@ -384,8 +385,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id) goto out_no_irq; } - device_init_wakeup(&adev->dev, 1); - return 0; out_no_irq: From 65cd4f6c99c1170bd0114dbd71b978012ea44d28 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 18 Jul 2013 16:21:18 -0700 Subject: [PATCH 3/4] arch_timer: Move to generic sched_clock framework Register with the generic sched_clock framework now that it supports 64 bits. This fixes two problems with the current sched_clock support for machines using the architected timers. First off, we don't subtract the start value from subsequent sched_clock calls so we can potentially start off with sched_clock returning gigantic numbers. Second, there is no support for suspend/resume handling so problems such as discussed in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23) can happen without this patch. Finally, it allows us to move the sched_clock setup into drivers clocksource out of the arch ports. Cc: Christopher Covington Cc: Catalin Marinas Acked-by: Will Deacon Signed-off-by: Stephen Boyd Signed-off-by: John Stultz --- arch/arm/kernel/arch_timer.c | 14 -------------- arch/arm64/Kconfig | 1 + arch/arm64/kernel/time.c | 10 ---------- drivers/clocksource/arm_arch_timer.c | 10 ++++++++++ 4 files changed, 11 insertions(+), 24 deletions(-) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 221f07b11ccb..1791f12c180b 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -11,7 +11,6 @@ #include #include #include -#include #include @@ -22,13 +21,6 @@ static unsigned long arch_timer_read_counter_long(void) return arch_timer_read_counter(); } -static u32 sched_clock_mult __read_mostly; - -static unsigned long long notrace arch_timer_sched_clock(void) -{ - return arch_timer_read_counter() * sched_clock_mult; -} - static struct delay_timer arch_delay_timer; static void __init arch_timer_delay_timer_register(void) @@ -48,11 +40,5 @@ int __init arch_timer_arch_init(void) arch_timer_delay_timer_register(); - /* 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); - return 0; } diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index c04454876bcb..35fd0eb57270 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -14,6 +14,7 @@ config ARM64 select GENERIC_IOMAP select GENERIC_IRQ_PROBE select GENERIC_IRQ_SHOW + select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL select HARDIRQS_SW_RESEND diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index 03dc3718eb13..29c39d5d77e3 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -61,13 +61,6 @@ unsigned long profile_pc(struct pt_regs *regs) EXPORT_SYMBOL(profile_pc); #endif -static u64 sched_clock_mult __read_mostly; - -unsigned long long notrace sched_clock(void) -{ - return arch_timer_read_counter() * sched_clock_mult; -} - void __init time_init(void) { u32 arch_timer_rate; @@ -78,9 +71,6 @@ void __init time_init(void) if (!arch_timer_rate) panic("Unable to initialise architected timer.\n"); - /* Cache the sched_clock multiplier to save a divide in the hot path. */ - sched_clock_mult = NSEC_PER_SEC / arch_timer_rate; - /* Calibrate the delay loop directly */ lpj_fine = arch_timer_rate / HZ; } diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index fbd9ccd5e114..5d527895c74d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -471,6 +472,15 @@ static int __init arch_timer_register(void) goto out; } + clocksource_register_hz(&clocksource_counter, arch_timer_rate); + cyclecounter.mult = clocksource_counter.mult; + cyclecounter.shift = clocksource_counter.shift; + timecounter_init(&timecounter, &cyclecounter, + arch_counter_get_cntvct()); + + /* 56 bits minimum, so we assume worst case rollover */ + sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate); + if (arch_timer_use_virtual) { ppi = arch_timer_ppi[VIRT_PPI]; err = request_percpu_irq(ppi, arch_timer_handler_virt, From b4042ceaabbd913bc5b397ddd1e396eeb312d72f Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 18 Jul 2013 16:21:19 -0700 Subject: [PATCH 4/4] sched_clock: Remove sched_clock_func() hook Nobody is using sched_clock_func() anymore now that sched_clock supports up to 64 bits. Remove the hook so that new code only uses sched_clock_register(). Signed-off-by: Stephen Boyd Signed-off-by: John Stultz --- include/linux/sched_clock.h | 2 -- kernel/time/sched_clock.c | 9 +-------- 2 files changed, 1 insertion(+), 10 deletions(-) diff --git a/include/linux/sched_clock.h b/include/linux/sched_clock.h index eca7abeb86fc..cddf0c2940b6 100644 --- a/include/linux/sched_clock.h +++ b/include/linux/sched_clock.h @@ -18,6 +18,4 @@ extern void setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate); extern void sched_clock_register(u64 (*read)(void), int bits, unsigned long rate); -extern unsigned long long (*sched_clock_func)(void); - #endif diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index f388baeaf2b6..68b799375981 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -63,7 +63,7 @@ static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift) return (cyc * mult) >> shift; } -static unsigned long long notrace sched_clock_32(void) +unsigned long long notrace sched_clock(void) { u64 epoch_ns; u64 epoch_cyc; @@ -170,13 +170,6 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) sched_clock_register(read_sched_clock_32_wrapper, bits, rate); } -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) { /*