ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime
sched_clock() is yet another blocker on the road to the single
image. This patch implements an idea by Russell King:
http://www.spinics.net/lists/linux-omap/msg49561.html
Instead of asking the platform to implement both sched_clock()
itself and the rollover callback, simply register a read()
function, and let the ARM code care about sched_clock() itself,
the conversion to ns and the rollover. sched_clock() uses
this read() function as an indirection to the platform code.
If the platform doesn't provide a read(), the code falls back
to the jiffy counter (just like the default sched_clock).
This allow some simplifications and possibly some footprint gain
when multiple platforms are compiled in. Among the drawbacks,
the removal of the *_fixed_sched_clock optimization which could
negatively impact some platforms (sa1100, tegra, versatile
and omap).
Tested on 11MPCore, OMAP4 and Tegra.
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Colin Cross <ccross@android.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: STEricsson <STEricsson_nomadik_linux@list.st.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/sched_clock.h b/arch/arm/include/asm/sched_clock.h
index c8e6ddf..e3f7572 100644
--- a/arch/arm/include/asm/sched_clock.h
+++ b/arch/arm/include/asm/sched_clock.h
@@ -8,113 +8,7 @@
#ifndef ASM_SCHED_CLOCK
#define ASM_SCHED_CLOCK
-#include <linux/kernel.h>
-#include <linux/types.h>
-
-struct clock_data {
- u64 epoch_ns;
- u32 epoch_cyc;
- u32 epoch_cyc_copy;
- u32 mult;
- u32 shift;
-};
-
-#define DEFINE_CLOCK_DATA(name) struct clock_data name
-
-static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
-{
- return (cyc * mult) >> shift;
-}
-
-/*
- * Atomically update the sched_clock epoch. Your update callback will
- * be called from a timer before the counter wraps - read the current
- * counter value, and call this function to safely move the epochs
- * forward. Only use this from the update callback.
- */
-static inline void update_sched_clock(struct clock_data *cd, u32 cyc, u32 mask)
-{
- unsigned long flags;
- u64 ns = cd->epoch_ns +
- cyc_to_ns((cyc - cd->epoch_cyc) & 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 = cyc;
- smp_wmb();
- cd->epoch_ns = ns;
- smp_wmb();
- cd->epoch_cyc_copy = cyc;
- raw_local_irq_restore(flags);
-}
-
-/*
- * If your clock rate is known at compile time, using this will allow
- * you to optimize the mult/shift loads away. This is paired with
- * init_fixed_sched_clock() to ensure that your mult/shift are correct.
- */
-static inline unsigned long long cyc_to_fixed_sched_clock(struct clock_data *cd,
- u32 cyc, u32 mask, u32 mult, u32 shift)
-{
- 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, mult, shift);
-}
-
-/*
- * Otherwise, you need to use this, which will obtain the mult/shift
- * from the clock_data structure. Use init_sched_clock() with this.
- */
-static inline unsigned long long cyc_to_sched_clock(struct clock_data *cd,
- u32 cyc, u32 mask)
-{
- return cyc_to_fixed_sched_clock(cd, cyc, mask, cd->mult, cd->shift);
-}
-
-/*
- * Initialize the clock data - calculate the appropriate multiplier
- * and shift. Also setup a timer to ensure that the epoch is refreshed
- * at the appropriate time interval, which will call your update
- * handler.
- */
-void init_sched_clock(struct clock_data *, void (*)(void),
- unsigned int, unsigned long);
-
-/*
- * Use this initialization function rather than init_sched_clock() if
- * you're using cyc_to_fixed_sched_clock, which will warn if your
- * constants are incorrect.
- */
-static inline void init_fixed_sched_clock(struct clock_data *cd,
- void (*update)(void), unsigned int bits, unsigned long rate,
- u32 mult, u32 shift)
-{
- init_sched_clock(cd, update, bits, rate);
- if (cd->mult != mult || cd->shift != shift) {
- pr_crit("sched_clock: wrong multiply/shift: %u>>%u vs calculated %u>>%u\n"
- "sched_clock: fix multiply/shift to avoid scheduler hiccups\n",
- mult, shift, cd->mult, cd->shift);
- }
-}
-
extern void sched_clock_postinit(void);
+extern void setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate);
#endif
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 9a46370..5416c7c 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -14,61 +14,153 @@
#include <asm/sched_clock.h>
+struct clock_data {
+ u64 epoch_ns;
+ u32 epoch_cyc;
+ u32 epoch_cyc_copy;
+ u32 mult;
+ u32 shift;
+};
+
static void sched_clock_poll(unsigned long wrap_ticks);
static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0);
-static void (*sched_clock_update_fn)(void);
+
+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 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
+{
+ return (cyc * mult) >> shift;
+}
+
+static unsigned long long 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 = cyc;
+ smp_wmb();
+ cd.epoch_ns = ns;
+ smp_wmb();
+ cd.epoch_cyc_copy = 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));
- sched_clock_update_fn();
+ update_sched_clock();
}
-void __init init_sched_clock(struct clock_data *cd, void (*update)(void),
- unsigned int clock_bits, unsigned long rate)
+void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
{
unsigned long r, w;
u64 res, wrap;
char r_unit;
- sched_clock_update_fn = update;
+ 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;
/* calculate the mult/shift to convert counter ticks to ns. */
- clocks_calc_mult_shift(&cd->mult, &cd->shift, rate, NSEC_PER_SEC, 0);
+ clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0);
r = rate;
if (r >= 4000000) {
r /= 1000000;
r_unit = 'M';
- } else {
+ } else if (r >= 1000) {
r /= 1000;
r_unit = 'k';
- }
+ } else
+ r_unit = ' ';
/* calculate how many ns until we wrap */
- wrap = cyc_to_ns((1ULL << clock_bits) - 1, cd->mult, cd->shift);
+ 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);
+ res = cyc_to_ns(1ULL, cd.mult, cd.shift);
pr_info("sched_clock: %u bits at %lu%cHz, resolution %lluns, wraps every %lums\n",
- clock_bits, r, r_unit, res, w);
+ 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();
+ update_sched_clock();
/*
* Ensure that sched_clock() starts off at 0ns
*/
- cd->epoch_ns = 0;
+ cd.epoch_ns = 0;
+
+ pr_debug("Registered %pF as sched_clock source\n", read);
+}
+
+unsigned long long notrace sched_clock(void)
+{
+ u32 cyc = read_sched_clock();
+ return cyc_to_sched_clock(cyc, sched_clock_mask);
}
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);
}
diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index b86a005..c1b12f9 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -17,7 +17,6 @@
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/serial.h>
-#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/platform_device.h>
#include <linux/serial_core.h>
@@ -403,18 +402,9 @@
/*
* sched_clock()
*/
-static DEFINE_CLOCK_DATA(cd);
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace ixp4xx_read_sched_clock(void)
{
- u32 cyc = *IXP4XX_OSTS;
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace ixp4xx_update_sched_clock(void)
-{
- u32 cyc = *IXP4XX_OSTS;
- update_sched_clock(&cd, cyc, (u32)~0);
+ return *IXP4XX_OSTS;
}
/*
@@ -430,7 +420,7 @@
EXPORT_SYMBOL(ixp4xx_timer_freq);
static void __init ixp4xx_clocksource_init(void)
{
- init_sched_clock(&cd, ixp4xx_update_sched_clock, 32, ixp4xx_timer_freq);
+ setup_sched_clock(ixp4xx_read_sched_clock, 32, ixp4xx_timer_freq);
clocksource_mmio_init(NULL, "OSTS", ixp4xx_timer_freq, 200, 32,
ixp4xx_clocksource_read);
diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
index 4e91ee6..71fc4ee 100644
--- a/arch/arm/mach-mmp/time.c
+++ b/arch/arm/mach-mmp/time.c
@@ -25,7 +25,6 @@
#include <linux/io.h>
#include <linux/irq.h>
-#include <linux/sched.h>
#include <asm/sched_clock.h>
#include <mach/addr-map.h>
@@ -42,8 +41,6 @@
#define MAX_DELTA (0xfffffffe)
#define MIN_DELTA (16)
-static DEFINE_CLOCK_DATA(cd);
-
/*
* FIXME: the timer needs some delay to stablize the counter capture
*/
@@ -59,16 +56,9 @@
return __raw_readl(TIMERS_VIRT_BASE + TMR_CVWR(1));
}
-unsigned long long notrace sched_clock(void)
+static u32 notrace mmp_read_sched_clock(void)
{
- u32 cyc = timer_read();
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace mmp_update_sched_clock(void)
-{
- u32 cyc = timer_read();
- update_sched_clock(&cd, cyc, (u32)~0);
+ return timer_read();
}
static irqreturn_t timer_interrupt(int irq, void *dev_id)
@@ -201,7 +191,7 @@
{
timer_config();
- init_sched_clock(&cd, mmp_update_sched_clock, 32, CLOCK_TICK_RATE);
+ setup_sched_clock(mmp_read_sched_clock, 32, CLOCK_TICK_RATE);
ckevt.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt.shift);
ckevt.max_delta_ns = clockevent_delta2ns(MAX_DELTA, &ckevt);
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index 485a21d..b8faffa 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -37,7 +37,6 @@
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
-#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/err.h>
@@ -190,30 +189,9 @@
* ---------------------------------------------------------------------------
*/
-static DEFINE_CLOCK_DATA(cd);
-
-static inline unsigned long long notrace _omap_mpu_sched_clock(void)
+static u32 notrace omap_mpu_read_sched_clock(void)
{
- u32 cyc = ~omap_mpu_timer_read(1);
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-#ifndef CONFIG_OMAP_32K_TIMER
-unsigned long long notrace sched_clock(void)
-{
- return _omap_mpu_sched_clock();
-}
-#else
-static unsigned long long notrace omap_mpu_sched_clock(void)
-{
- return _omap_mpu_sched_clock();
-}
-#endif
-
-static void notrace mpu_update_sched_clock(void)
-{
- u32 cyc = ~omap_mpu_timer_read(1);
- update_sched_clock(&cd, cyc, (u32)~0);
+ return ~omap_mpu_timer_read(1);
}
static void __init omap_init_clocksource(unsigned long rate)
@@ -223,7 +201,7 @@
"%s: can't register clocksource!\n";
omap_mpu_timer_start(1, ~0, 1);
- init_sched_clock(&cd, mpu_update_sched_clock, 32, rate);
+ setup_sched_clock(omap_mpu_read_sched_clock, 32, rate);
if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate,
300, 32, clocksource_mmio_readl_down))
@@ -254,30 +232,6 @@
}
#endif /* CONFIG_OMAP_MPU_TIMER */
-#if defined(CONFIG_OMAP_MPU_TIMER) && defined(CONFIG_OMAP_32K_TIMER)
-static unsigned long long (*preferred_sched_clock)(void);
-
-unsigned long long notrace sched_clock(void)
-{
- if (!preferred_sched_clock)
- return 0;
-
- return preferred_sched_clock();
-}
-
-static inline void preferred_sched_clock_init(bool use_32k_sched_clock)
-{
- if (use_32k_sched_clock)
- preferred_sched_clock = omap_32k_sched_clock;
- else
- preferred_sched_clock = omap_mpu_sched_clock;
-}
-#else
-static inline void preferred_sched_clock_init(bool use_32k_sched_clcok)
-{
-}
-#endif
-
static inline int omap_32k_timer_usable(void)
{
int res = false;
@@ -299,12 +253,8 @@
*/
static void __init omap1_timer_init(void)
{
- if (omap_32k_timer_usable()) {
- preferred_sched_clock_init(1);
- } else {
+ if (!omap_32k_timer_usable())
omap_mpu_timer_init();
- preferred_sched_clock_init(0);
- }
}
struct sys_timer omap1_timer = {
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 9edcd52..6eeff0e 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -254,7 +254,6 @@
/*
* clocksource
*/
-static DEFINE_CLOCK_DATA(cd);
static cycle_t clocksource_read_cycles(struct clocksource *cs)
{
return (cycle_t)__omap_dm_timer_read_counter(&clksrc, 1);
@@ -268,23 +267,12 @@
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-static void notrace dmtimer_update_sched_clock(void)
+static u32 notrace dmtimer_read_sched_clock(void)
{
- u32 cyc;
-
- cyc = __omap_dm_timer_read_counter(&clksrc, 1);
-
- update_sched_clock(&cd, cyc, (u32)~0);
-}
-
-unsigned long long notrace sched_clock(void)
-{
- u32 cyc = 0;
-
if (clksrc.reserved)
- cyc = __omap_dm_timer_read_counter(&clksrc, 1);
+ return __omap_dm_timer_read_counter(clksrc.io_base, 1);
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+ return 0;
}
/* Setup free-running counter for clocksource */
@@ -301,7 +289,7 @@
__omap_dm_timer_load_start(&clksrc,
OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
- init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate);
+ setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
pr_err("Could not register clocksource %s\n",
diff --git a/arch/arm/mach-picoxcell/time.c b/arch/arm/mach-picoxcell/time.c
index 90a554f..6c89cf8 100644
--- a/arch/arm/mach-picoxcell/time.c
+++ b/arch/arm/mach-picoxcell/time.c
@@ -11,7 +11,6 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
-#include <linux/sched.h>
#include <asm/mach/time.h>
#include <asm/sched_clock.h>
@@ -66,21 +65,11 @@
dw_apb_clocksource_register(cs);
}
-static DEFINE_CLOCK_DATA(cd);
static void __iomem *sched_io_base;
-unsigned long long notrace sched_clock(void)
+unsigned u32 notrace picoxcell_read_sched_clock(void)
{
- cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
-
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace picoxcell_update_sched_clock(void)
-{
- cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
-
- update_sched_clock(&cd, cyc, (u32)~0);
+ return __raw_readl(sched_io_base);
}
static const struct of_device_id picoxcell_rtc_ids[] __initconst = {
@@ -100,7 +89,7 @@
timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
of_node_put(sched_timer);
- init_sched_clock(&cd, picoxcell_update_sched_clock, 32, rate);
+ setup_sched_clock(picoxcell_read_sched_clock, 32, rate);
}
static const struct of_device_id picoxcell_timer_ids[] __initconst = {
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index de68470..b503049 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -16,7 +16,6 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/clockchips.h>
-#include <linux/sched.h>
#include <asm/div64.h>
#include <asm/mach/irq.h>
@@ -32,18 +31,10 @@
* long as there is always less than 582 seconds between successive
* calls to sched_clock() which should always be the case in practice.
*/
-static DEFINE_CLOCK_DATA(cd);
-unsigned long long notrace sched_clock(void)
+static u32 notrace pxa_read_sched_clock(void)
{
- u32 cyc = OSCR;
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace pxa_update_sched_clock(void)
-{
- u32 cyc = OSCR;
- update_sched_clock(&cd, cyc, (u32)~0);
+ return OSCR;
}
@@ -119,7 +110,7 @@
OIER = 0;
OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
- init_sched_clock(&cd, pxa_update_sched_clock, 32, clock_tick_rate);
+ setup_sched_clock(pxa_read_sched_clock, 32, clock_tick_rate);
clockevents_calc_mult_shift(&ckevt_pxa_osmr0, clock_tick_rate, 4);
ckevt_pxa_osmr0.max_delta_ns =
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index fa66024..1ee6d4c 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -12,7 +12,6 @@
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
-#include <linux/sched.h> /* just for sched_clock() - funny that */
#include <linux/timex.h>
#include <linux/clockchips.h>
@@ -20,29 +19,9 @@
#include <asm/sched_clock.h>
#include <mach/hardware.h>
-/*
- * This is the SA11x0 sched_clock implementation.
- */
-static DEFINE_CLOCK_DATA(cd);
-
-/*
- * Constants generated by clocks_calc_mult_shift(m, s, 3.6864MHz,
- * NSEC_PER_SEC, 60).
- * This gives a resolution of about 271ns and a wrap period of about 19min.
- */
-#define SC_MULT 2275555556u
-#define SC_SHIFT 23
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace sa100_read_sched_clock(void)
{
- u32 cyc = OSCR;
- return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT);
-}
-
-static void notrace sa1100_update_sched_clock(void)
-{
- u32 cyc = OSCR;
- update_sched_clock(&cd, cyc, (u32)~0);
+ return OSCR;
}
#define MIN_OSCR_DELTA 2
@@ -109,8 +88,7 @@
OIER = 0;
OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
- init_fixed_sched_clock(&cd, sa1100_update_sched_clock, 32,
- 3686400, SC_MULT, SC_SHIFT);
+ setup_sched_clock(sa1100_read_sched_clock, 32, 3686400);
clockevents_calc_mult_shift(&ckevt_sa1100_osmr0, 3686400, 4);
ckevt_sa1100_osmr0.max_delta_ns =
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
index e2272d2..732c724 100644
--- a/arch/arm/mach-tegra/timer.c
+++ b/arch/arm/mach-tegra/timer.c
@@ -19,7 +19,6 @@
#include <linux/init.h>
#include <linux/err.h>
-#include <linux/sched.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
@@ -106,25 +105,9 @@
.set_mode = tegra_timer_set_mode,
};
-static DEFINE_CLOCK_DATA(cd);
-
-/*
- * Constants generated by clocks_calc_mult_shift(m, s, 1MHz, NSEC_PER_SEC, 60).
- * This gives a resolution of about 1us and a wrap period of about 1h11min.
- */
-#define SC_MULT 4194304000u
-#define SC_SHIFT 22
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace tegra_read_sched_clock(void)
{
- u32 cyc = timer_readl(TIMERUS_CNTR_1US);
- return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT);
-}
-
-static void notrace tegra_update_sched_clock(void)
-{
- u32 cyc = timer_readl(TIMERUS_CNTR_1US);
- update_sched_clock(&cd, cyc, (u32)~0);
+ return timer_readl(TIMERUS_CNTR_1US);
}
/*
@@ -218,8 +201,7 @@
WARN(1, "Unknown clock rate");
}
- init_fixed_sched_clock(&cd, tegra_update_sched_clock, 32,
- 1000000, SC_MULT, SC_SHIFT);
+ setup_sched_clock(tegra_read_sched_clock, 32, 1000000);
if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
diff --git a/arch/arm/mach-u300/timer.c b/arch/arm/mach-u300/timer.c
index 5f51bde..bc1c789 100644
--- a/arch/arm/mach-u300/timer.c
+++ b/arch/arm/mach-u300/timer.c
@@ -9,7 +9,6 @@
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#include <linux/interrupt.h>
-#include <linux/sched.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/clockchips.h>
@@ -337,18 +336,10 @@
* this wraps around for now, since it is just a relative time
* stamp. (Inspired by OMAP implementation.)
*/
-static DEFINE_CLOCK_DATA(cd);
-unsigned long long notrace sched_clock(void)
+static u32 notrace u300_read_sched_clock(void)
{
- u32 cyc = readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace u300_update_sched_clock(void)
-{
- u32 cyc = readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);
- update_sched_clock(&cd, cyc, (u32)~0);
+ return readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);
}
@@ -366,7 +357,7 @@
clk_enable(clk);
rate = clk_get_rate(clk);
- init_sched_clock(&cd, u300_update_sched_clock, 32, rate);
+ setup_sched_clock(u300_read_sched_clock, 32, rate);
/*
* Disable the "OS" and "DD" timers - these are designed for Symbian!
diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c
index 568dd02..cbfbbe4 100644
--- a/arch/arm/plat-iop/time.c
+++ b/arch/arm/plat-iop/time.c
@@ -18,7 +18,6 @@
#include <linux/time.h>
#include <linux/init.h>
#include <linux/timex.h>
-#include <linux/sched.h>
#include <linux/io.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
@@ -52,21 +51,12 @@
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-static DEFINE_CLOCK_DATA(cd);
-
/*
* IOP sched_clock() implementation via its clocksource.
*/
-unsigned long long notrace sched_clock(void)
+static u32 notrace iop_read_sched_clock(void)
{
- u32 cyc = 0xffffffffu - read_tcr1();
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace iop_update_sched_clock(void)
-{
- u32 cyc = 0xffffffffu - read_tcr1();
- update_sched_clock(&cd, cyc, (u32)~0);
+ return 0xffffffffu - read_tcr1();
}
/*
@@ -152,7 +142,7 @@
{
u32 timer_ctl;
- init_sched_clock(&cd, iop_update_sched_clock, 32, tick_rate);
+ setup_sched_clock(iop_read_sched_clock, 32, tick_rate);
ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
iop_tick_rate = tick_rate;
diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index 4b0fe28..1c96cdb 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -108,18 +108,9 @@
static void __iomem *sched_clock_reg;
-static DEFINE_CLOCK_DATA(cd);
-unsigned long long notrace sched_clock(void)
+static u32 notrace mxc_read_sched_clock(void)
{
- cycle_t cyc = sched_clock_reg ? __raw_readl(sched_clock_reg) : 0;
-
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace mxc_update_sched_clock(void)
-{
- cycle_t cyc = sched_clock_reg ? __raw_readl(sched_clock_reg) : 0;
- update_sched_clock(&cd, cyc, (u32)~0);
+ return sched_clock_reg ? __raw_readl(sched_clock_reg) : 0;
}
static int __init mxc_clocksource_init(struct clk *timer_clk)
@@ -129,7 +120,7 @@
sched_clock_reg = reg;
- init_sched_clock(&cd, mxc_update_sched_clock, 32, c);
+ setup_sched_clock(mxc_read_sched_clock, 32, c);
return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32,
clocksource_mmio_readl_up);
}
diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c
index 30b6433..ad1b45b 100644
--- a/arch/arm/plat-nomadik/timer.c
+++ b/arch/arm/plat-nomadik/timer.c
@@ -17,7 +17,6 @@
#include <linux/clk.h>
#include <linux/jiffies.h>
#include <linux/err.h>
-#include <linux/sched.h>
#include <asm/mach/time.h>
#include <asm/sched_clock.h>
@@ -79,23 +78,12 @@
* local implementation which uses the clocksource to get some
* better resolution when scheduling the kernel.
*/
-static DEFINE_CLOCK_DATA(cd);
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace nomadik_read_sched_clock(void)
{
- u32 cyc;
-
if (unlikely(!mtu_base))
return 0;
- cyc = -readl(mtu_base + MTU_VAL(0));
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void notrace nomadik_update_sched_clock(void)
-{
- u32 cyc = -readl(mtu_base + MTU_VAL(0));
- update_sched_clock(&cd, cyc, (u32)~0);
+ return -readl(mtu_base + MTU_VAL(0));
}
#endif
@@ -231,9 +219,11 @@
rate, 200, 32, clocksource_mmio_readl_down))
pr_err("timer: failed to initialize clock source %s\n",
"mtu_0");
+
#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK
- init_sched_clock(&cd, nomadik_update_sched_clock, 32, rate);
+ setup_sched_clock(nomadik_read_sched_clock, 32, rate);
#endif
+
/* Timer 1 is used for events */
clockevents_calc_mult_shift(&nmdk_clkevt, rate, MTU_MIN_RANGE);
diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
index a6cbb71..5f0f229 100644
--- a/arch/arm/plat-omap/counter_32k.c
+++ b/arch/arm/plat-omap/counter_32k.c
@@ -17,7 +17,6 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
-#include <linux/sched.h>
#include <linux/clocksource.h>
#include <asm/sched_clock.h>
@@ -37,41 +36,9 @@
#define OMAP16XX_TIMER_32K_SYNCHRONIZED 0xfffbc410
-/*
- * Returns current time from boot in nsecs. It's OK for this to wrap
- * around for now, as it's just a relative time stamp.
- */
-static DEFINE_CLOCK_DATA(cd);
-
-/*
- * Constants generated by clocks_calc_mult_shift(m, s, 32768, NSEC_PER_SEC, 60).
- * This gives a resolution of about 30us and a wrap period of about 36hrs.
- */
-#define SC_MULT 4000000000u
-#define SC_SHIFT 17
-
-static inline unsigned long long notrace _omap_32k_sched_clock(void)
+static u32 notrace omap_32k_read_sched_clock(void)
{
- u32 cyc = timer_32k_base ? __raw_readl(timer_32k_base) : 0;
- return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT);
-}
-
-#if defined(CONFIG_OMAP_32K_TIMER) && !defined(CONFIG_OMAP_MPU_TIMER)
-unsigned long long notrace sched_clock(void)
-{
- return _omap_32k_sched_clock();
-}
-#else
-unsigned long long notrace omap_32k_sched_clock(void)
-{
- return _omap_32k_sched_clock();
-}
-#endif
-
-static void notrace omap_update_sched_clock(void)
-{
- u32 cyc = timer_32k_base ? __raw_readl(timer_32k_base) : 0;
- update_sched_clock(&cd, cyc, (u32)~0);
+ return timer_32k_base ? __raw_readl(timer_32k_base) : 0;
}
/**
@@ -147,8 +114,7 @@
clocksource_mmio_readl_up))
printk(err, "32k_counter");
- init_fixed_sched_clock(&cd, omap_update_sched_clock, 32,
- 32768, SC_MULT, SC_SHIFT);
+ setup_sched_clock(omap_32k_read_sched_clock, 32, 32768);
}
return 0;
}
diff --git a/arch/arm/plat-omap/include/plat/common.h b/arch/arm/plat-omap/include/plat/common.h
index 257f977..b4d7ec3 100644
--- a/arch/arm/plat-omap/include/plat/common.h
+++ b/arch/arm/plat-omap/include/plat/common.h
@@ -31,7 +31,6 @@
#include <plat/omap_hwmod.h>
extern int __init omap_init_clocksource_32k(void);
-extern unsigned long long notrace omap_32k_sched_clock(void);
extern void omap_reserve(void);
extern int omap_dss_reset(struct omap_hwmod *);
diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
index 69a6136..1ed8d13 100644
--- a/arch/arm/plat-orion/time.c
+++ b/arch/arm/plat-orion/time.c
@@ -12,7 +12,6 @@
*/
#include <linux/kernel.h>
-#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
@@ -60,24 +59,10 @@
* Orion's sched_clock implementation. It has a resolution of
* at least 7.5ns (133MHz TCLK).
*/
-static DEFINE_CLOCK_DATA(cd);
-unsigned long long notrace sched_clock(void)
+static u32 notrace orion_read_sched_clock(void)
{
- u32 cyc = ~readl(timer_base + TIMER0_VAL_OFF);
- return cyc_to_sched_clock(&cd, cyc, (u32)~0);
-}
-
-
-static void notrace orion_update_sched_clock(void)
-{
- u32 cyc = ~readl(timer_base + TIMER0_VAL_OFF);
- update_sched_clock(&cd, cyc, (u32)~0);
-}
-
-static void __init setup_sched_clock(unsigned long tclk)
-{
- init_sched_clock(&cd, orion_update_sched_clock, 32, tclk);
+ return ~readl(timer_base + TIMER0_VAL_OFF);
}
/*
@@ -217,7 +202,7 @@
/*
* Set scale and timer for sched_clock.
*/
- setup_sched_clock(tclk);
+ setup_sched_clock(orion_read_sched_clock, 32, tclk);
/*
* Setup free-running clocksource timer (interrupts
diff --git a/arch/arm/plat-s5p/s5p-time.c b/arch/arm/plat-s5p/s5p-time.c
index c833e7b..17c0a2c 100644
--- a/arch/arm/plat-s5p/s5p-time.c
+++ b/arch/arm/plat-s5p/s5p-time.c
@@ -10,7 +10,6 @@
* published by the Free Software Foundation.
*/
-#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/err.h>
@@ -321,26 +320,14 @@
* this wraps around for now, since it is just a relative time
* stamp. (Inspired by U300 implementation.)
*/
-static DEFINE_CLOCK_DATA(cd);
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace s5p_read_sched_clock(void)
{
void __iomem *reg = s5p_timer_reg();
if (!reg)
return 0;
- return cyc_to_sched_clock(&cd, ~__raw_readl(reg), (u32)~0);
-}
-
-static void notrace s5p_update_sched_clock(void)
-{
- void __iomem *reg = s5p_timer_reg();
-
- if (!reg)
- return;
-
- update_sched_clock(&cd, ~__raw_readl(reg), (u32)~0);
+ return ~__raw_readl(reg);
}
static void __init s5p_clocksource_init(void)
@@ -358,7 +345,7 @@
s5p_time_setup(timer_source.source_id, TCNT_MAX);
s5p_time_start(timer_source.source_id, PERIODIC);
- init_sched_clock(&cd, s5p_update_sched_clock, 32, clock_rate);
+ setup_sched_clock(s5p_read_sched_clock, 32, clock_rate);
if (clocksource_mmio_init(s5p_timer_reg(), "s5p_clocksource_timer",
clock_rate, 250, 32, clocksource_mmio_readl_down))
diff --git a/arch/arm/plat-versatile/sched-clock.c b/arch/arm/plat-versatile/sched-clock.c
index 3d6a4c2..b33b74c 100644
--- a/arch/arm/plat-versatile/sched-clock.c
+++ b/arch/arm/plat-versatile/sched-clock.c
@@ -18,41 +18,24 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/kernel.h>
#include <linux/io.h>
-#include <linux/sched.h>
#include <asm/sched_clock.h>
#include <plat/sched_clock.h>
-static DEFINE_CLOCK_DATA(cd);
static void __iomem *ctr;
-/*
- * Constants generated by clocks_calc_mult_shift(m, s, 24MHz, NSEC_PER_SEC, 60).
- * This gives a resolution of about 41ns and a wrap period of about 178s.
- */
-#define SC_MULT 2796202667u
-#define SC_SHIFT 26
-
-unsigned long long notrace sched_clock(void)
+static u32 notrace versatile_read_sched_clock(void)
{
- if (ctr) {
- u32 cyc = readl(ctr);
- return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0,
- SC_MULT, SC_SHIFT);
- } else
- return 0;
-}
+ if (ctr)
+ return readl(ctr);
-static void notrace versatile_update_sched_clock(void)
-{
- u32 cyc = readl(ctr);
- update_sched_clock(&cd, cyc, (u32)~0);
+ return 0;
}
void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
{
ctr = reg;
- init_fixed_sched_clock(&cd, versatile_update_sched_clock,
- 32, rate, SC_MULT, SC_SHIFT);
+ setup_sched_clock(versatile_read_sched_clock, 32, rate);
}