diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-05-16 12:14:21 +0100 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-05-17 19:16:41 +0100 |
commit | f32f4ce25745209f16a5a6cef7442144b596c68a (patch) | |
tree | 76083f10ee56c82177669bb100358ea2818f8f5a /arch/arm | |
parent | a8cbcd92bd4bf893085eddf7f58e63ea98503d94 (diff) | |
download | lwn-f32f4ce25745209f16a5a6cef7442144b596c68a.tar.gz lwn-f32f4ce25745209f16a5a6cef7442144b596c68a.zip |
[ARM] smp: allow re-use of realview localtimer TWD support
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r-- | arch/arm/Kconfig | 7 | ||||
-rw-r--r-- | arch/arm/include/asm/hardware/arm_twd.h | 21 | ||||
-rw-r--r-- | arch/arm/include/asm/localtimer.h | 12 | ||||
-rw-r--r-- | arch/arm/include/asm/smp_twd.h | 12 | ||||
-rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/kernel/smp_twd.c | 173 | ||||
-rw-r--r-- | arch/arm/mach-realview/Makefile | 3 | ||||
-rw-r--r-- | arch/arm/mach-realview/core.h | 3 | ||||
-rw-r--r-- | arch/arm/mach-realview/localtimer.c | 144 | ||||
-rw-r--r-- | arch/arm/mach-realview/realview_eb.c | 1 | ||||
-rw-r--r-- | arch/arm/mach-realview/realview_pb11mp.c | 1 |
11 files changed, 213 insertions, 165 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index f19a9519a723..93d63bf927d5 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -885,6 +885,12 @@ config HAVE_ARM_SCU help This option enables support for the ARM system coherency unit +config HAVE_ARM_TWD + bool + depends on SMP + help + This options enables support for the ARM timer and watchdog unit + choice prompt "Memory split" default VMSPLIT_3G @@ -925,6 +931,7 @@ config LOCAL_TIMERS bool "Use local timer interrupts" depends on SMP && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || REALVIEW_EB_A9MP) default y + select HAVE_ARM_TWD if ARCH_REALVIEW help Enable support for local timers on SMP platforms, rather then the legacy IPI broadcast method. Local timers allows the system diff --git a/arch/arm/include/asm/hardware/arm_twd.h b/arch/arm/include/asm/hardware/arm_twd.h deleted file mode 100644 index e521b70713c8..000000000000 --- a/arch/arm/include/asm/hardware/arm_twd.h +++ /dev/null @@ -1,21 +0,0 @@ -#ifndef __ASM_HARDWARE_TWD_H -#define __ASM_HARDWARE_TWD_H - -#define TWD_TIMER_LOAD 0x00 -#define TWD_TIMER_COUNTER 0x04 -#define TWD_TIMER_CONTROL 0x08 -#define TWD_TIMER_INTSTAT 0x0C - -#define TWD_WDOG_LOAD 0x20 -#define TWD_WDOG_COUNTER 0x24 -#define TWD_WDOG_CONTROL 0x28 -#define TWD_WDOG_INTSTAT 0x2C -#define TWD_WDOG_RESETSTAT 0x30 -#define TWD_WDOG_DISABLE 0x34 - -#define TWD_TIMER_CONTROL_ENABLE (1 << 0) -#define TWD_TIMER_CONTROL_ONESHOT (0 << 1) -#define TWD_TIMER_CONTROL_PERIODIC (1 << 1) -#define TWD_TIMER_CONTROL_IT_ENABLE (1 << 2) - -#endif diff --git a/arch/arm/include/asm/localtimer.h b/arch/arm/include/asm/localtimer.h index 3f8c9ebb646c..50c7e7cfd670 100644 --- a/arch/arm/include/asm/localtimer.h +++ b/arch/arm/include/asm/localtimer.h @@ -24,6 +24,16 @@ asmlinkage void do_local_timer(struct pt_regs *); #ifdef CONFIG_LOCAL_TIMERS + +#ifdef CONFIG_HAVE_ARM_TWD + +#include "smp_twd.h" + +#define local_timer_ack() twd_timer_ack() +#define local_timer_stop() twd_timer_stop() + +#else + /* * Platform provides this to acknowledge a local timer IRQ. * Returns true if the local timer IRQ is to be processed. @@ -35,6 +45,8 @@ int local_timer_ack(void); */ void local_timer_stop(void); +#endif + /* * Setup a local timer interrupt for a CPU. */ diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h new file mode 100644 index 000000000000..7be0978b2625 --- /dev/null +++ b/arch/arm/include/asm/smp_twd.h @@ -0,0 +1,12 @@ +#ifndef __ASMARM_SMP_TWD_H +#define __ASMARM_SMP_TWD_H + +struct clock_event_device; + +extern void __iomem *twd_base; + +void twd_timer_stop(void); +int twd_timer_ack(void); +void twd_timer_setup(struct clock_event_device *); + +#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 90ffbaf23b4e..ff89d0b3abc5 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o +obj-$(CONFIG_HAVE_ARM_TWD) += smp_twd.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c new file mode 100644 index 000000000000..aabd62d6bd19 --- /dev/null +++ b/arch/arm/kernel/smp_twd.c @@ -0,0 +1,173 @@ +/* + * linux/arch/arm/kernel/smp_twd.c + * + * Copyright (C) 2002 ARM Ltd. + * All Rights Reserved + * + * 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 <linux/init.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/smp.h> +#include <linux/jiffies.h> +#include <linux/clockchips.h> +#include <linux/irq.h> +#include <linux/io.h> + +#include <asm/smp_twd.h> +#include <asm/hardware/gic.h> + +#define TWD_TIMER_LOAD 0x00 +#define TWD_TIMER_COUNTER 0x04 +#define TWD_TIMER_CONTROL 0x08 +#define TWD_TIMER_INTSTAT 0x0C + +#define TWD_WDOG_LOAD 0x20 +#define TWD_WDOG_COUNTER 0x24 +#define TWD_WDOG_CONTROL 0x28 +#define TWD_WDOG_INTSTAT 0x2C +#define TWD_WDOG_RESETSTAT 0x30 +#define TWD_WDOG_DISABLE 0x34 + +#define TWD_TIMER_CONTROL_ENABLE (1 << 0) +#define TWD_TIMER_CONTROL_ONESHOT (0 << 1) +#define TWD_TIMER_CONTROL_PERIODIC (1 << 1) +#define TWD_TIMER_CONTROL_IT_ENABLE (1 << 2) + +/* set up by the platform code */ +void __iomem *twd_base; + +static unsigned long twd_timer_rate; + +static void twd_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + unsigned long ctrl; + + switch(mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* timer load already set up */ + ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE + | TWD_TIMER_CONTROL_PERIODIC; + break; + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT; + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + ctrl = 0; + } + + __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); +} + +static int twd_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL); + + __raw_writel(evt, twd_base + TWD_TIMER_COUNTER); + __raw_writel(ctrl | TWD_TIMER_CONTROL_ENABLE, twd_base + TWD_TIMER_CONTROL); + + return 0; +} + +/* + * local_timer_ack: checks for a local timer interrupt. + * + * If a local timer interrupt has occurred, acknowledge and return 1. + * Otherwise, return 0. + */ +int twd_timer_ack(void) +{ + if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) { + __raw_writel(1, twd_base + TWD_TIMER_INTSTAT); + return 1; + } + + return 0; +} + +static void __cpuinit twd_calibrate_rate(void) +{ + unsigned long load, count; + u64 waitjiffies; + + /* + * If this is the first time round, we need to work out how fast + * the timer ticks + */ + if (twd_timer_rate == 0) { + printk("Calibrating local timer... "); + + /* Wait for a tick to start */ + waitjiffies = get_jiffies_64() + 1; + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + /* OK, now the tick has started, let's get the timer going */ + waitjiffies += 5; + + /* enable, no interrupt or reload */ + __raw_writel(0x1, twd_base + TWD_TIMER_CONTROL); + + /* maximum value */ + __raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER); + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + count = __raw_readl(twd_base + TWD_TIMER_COUNTER); + + twd_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5); + + printk("%lu.%02luMHz.\n", twd_timer_rate / 1000000, + (twd_timer_rate / 100000) % 100); + } + + load = twd_timer_rate / HZ; + + __raw_writel(load, twd_base + TWD_TIMER_LOAD); +} + +/* + * Setup the local clock events for a CPU. + */ +void __cpuinit twd_timer_setup(struct clock_event_device *clk) +{ + unsigned long flags; + + twd_calibrate_rate(); + + clk->name = "local_timer"; + clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + clk->rating = 350; + clk->set_mode = twd_set_mode; + clk->set_next_event = twd_set_next_event; + clk->shift = 20; + clk->mult = div_sc(twd_timer_rate, NSEC_PER_SEC, clk->shift); + clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk); + clk->min_delta_ns = clockevent_delta2ns(0xf, clk); + + /* Make sure our local interrupt controller has this enabled */ + local_irq_save(flags); + get_irq_chip(clk->irq)->unmask(clk->irq); + local_irq_restore(flags); + + clockevents_register_device(clk); +} + +/* + * take a local timer down + */ +void __cpuexit twd_timer_stop(void) +{ + __raw_writel(0, twd_base + TWD_TIMER_CONTROL); +} diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile index 7bea8ffc4b59..e13d0947ad0b 100644 --- a/arch/arm/mach-realview/Makefile +++ b/arch/arm/mach-realview/Makefile @@ -7,5 +7,6 @@ obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o obj-$(CONFIG_MACH_REALVIEW_PB11MP) += realview_pb11mp.o obj-$(CONFIG_MACH_REALVIEW_PB1176) += realview_pb1176.o obj-$(CONFIG_MACH_REALVIEW_PBA8) += realview_pba8.o -obj-$(CONFIG_SMP) += platsmp.o headsmp.o localtimer.o +obj-$(CONFIG_SMP) += platsmp.o headsmp.o obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o +obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o diff --git a/arch/arm/mach-realview/core.h b/arch/arm/mach-realview/core.h index 21c08637683b..59a337ba4be7 100644 --- a/arch/arm/mach-realview/core.h +++ b/arch/arm/mach-realview/core.h @@ -51,9 +51,6 @@ extern struct mmc_platform_data realview_mmc0_plat_data; extern struct mmc_platform_data realview_mmc1_plat_data; extern struct clcd_board clcd_plat_data; extern void __iomem *gic_cpu_base_addr; -#ifdef CONFIG_LOCAL_TIMERS -extern void __iomem *twd_base; -#endif extern void __iomem *timer0_va_base; extern void __iomem *timer1_va_base; extern void __iomem *timer2_va_base; diff --git a/arch/arm/mach-realview/localtimer.c b/arch/arm/mach-realview/localtimer.c index cd98e7acd94d..60b4e111f459 100644 --- a/arch/arm/mach-realview/localtimer.c +++ b/arch/arm/mach-realview/localtimer.c @@ -9,154 +9,18 @@ * published by the Free Software Foundation. */ #include <linux/init.h> -#include <linux/kernel.h> -#include <linux/delay.h> #include <linux/smp.h> -#include <linux/jiffies.h> #include <linux/clockchips.h> -#include <linux/irq.h> -#include <linux/io.h> -#include <asm/hardware/arm_twd.h> -#include <asm/hardware/gic.h> -#include <mach/hardware.h> #include <asm/irq.h> - -#ifdef CONFIG_LOCAL_TIMERS - -/* set up by the platform code */ -void __iomem *twd_base; - -static unsigned long mpcore_timer_rate; - -static void local_timer_set_mode(enum clock_event_mode mode, - struct clock_event_device *evt) -{ - unsigned long ctrl; - - switch(mode) { - case CLOCK_EVT_MODE_PERIODIC: - /* timer load already set up */ - ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE - | TWD_TIMER_CONTROL_PERIODIC; - break; - case CLOCK_EVT_MODE_ONESHOT: - /* period set, and timer enabled in 'next_event' hook */ - ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT; - break; - case CLOCK_EVT_MODE_UNUSED: - case CLOCK_EVT_MODE_SHUTDOWN: - default: - ctrl = 0; - } - - __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); -} - -static int local_timer_set_next_event(unsigned long evt, - struct clock_event_device *unused) -{ - unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL); - - __raw_writel(evt, twd_base + TWD_TIMER_COUNTER); - __raw_writel(ctrl | TWD_TIMER_CONTROL_ENABLE, twd_base + TWD_TIMER_CONTROL); - - return 0; -} - -/* - * local_timer_ack: checks for a local timer interrupt. - * - * If a local timer interrupt has occurred, acknowledge and return 1. - * Otherwise, return 0. - */ -int local_timer_ack(void) -{ - if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) { - __raw_writel(1, twd_base + TWD_TIMER_INTSTAT); - return 1; - } - - return 0; -} - -static void __cpuinit twd_calibrate_rate(void) -{ - unsigned long load, count; - u64 waitjiffies; - - /* - * If this is the first time round, we need to work out how fast - * the timer ticks - */ - if (mpcore_timer_rate == 0) { - printk("Calibrating local timer... "); - - /* Wait for a tick to start */ - waitjiffies = get_jiffies_64() + 1; - - while (get_jiffies_64() < waitjiffies) - udelay(10); - - /* OK, now the tick has started, let's get the timer going */ - waitjiffies += 5; - - /* enable, no interrupt or reload */ - __raw_writel(0x1, twd_base + TWD_TIMER_CONTROL); - - /* maximum value */ - __raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER); - - while (get_jiffies_64() < waitjiffies) - udelay(10); - - count = __raw_readl(twd_base + TWD_TIMER_COUNTER); - - mpcore_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5); - - printk("%lu.%02luMHz.\n", mpcore_timer_rate / 1000000, - (mpcore_timer_rate / 100000) % 100); - } - - load = mpcore_timer_rate / HZ; - - __raw_writel(load, twd_base + TWD_TIMER_LOAD); -} +#include <asm/smp_twd.h> +#include <asm/localtimer.h> /* * Setup the local clock events for a CPU. */ void __cpuinit local_timer_setup(struct clock_event_device *evt) { - unsigned long flags; - - twd_calibrate_rate(); - - evt->name = "local_timer"; - evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; - evt->rating = 350; - evt->set_mode = local_timer_set_mode; - evt->set_next_event = local_timer_set_next_event; - evt->irq = IRQ_LOCALTIMER; - evt->shift = 20; - evt->mult = div_sc(mpcore_timer_rate, NSEC_PER_SEC, evt->shift); - evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt); - evt->min_delta_ns = clockevent_delta2ns(0xf, evt); - - /* Make sure our local interrupt controller has this enabled */ - local_irq_save(flags); - get_irq_chip(IRQ_LOCALTIMER)->unmask(IRQ_LOCALTIMER); - local_irq_restore(flags); - - clockevents_register_device(evt); + evt->irq = IRQ_LOCALTIMER; + twd_timer_setup(evt); } - -/* - * take a local timer down - */ -void __cpuexit local_timer_stop(void) -{ - __raw_writel(0, twd_base + TWD_TIMER_CONTROL); -} - -#endif /* CONFIG_LOCAL_TIMERS */ diff --git a/arch/arm/mach-realview/realview_eb.c b/arch/arm/mach-realview/realview_eb.c index c20fbef122b3..8dfa44e08a94 100644 --- a/arch/arm/mach-realview/realview_eb.c +++ b/arch/arm/mach-realview/realview_eb.c @@ -32,6 +32,7 @@ #include <asm/hardware/gic.h> #include <asm/hardware/icst307.h> #include <asm/hardware/cache-l2x0.h> +#include <asm/localtimer.h> #include <asm/mach/arch.h> #include <asm/mach/map.h> diff --git a/arch/arm/mach-realview/realview_pb11mp.c b/arch/arm/mach-realview/realview_pb11mp.c index ea1e60eca359..dc4b16943907 100644 --- a/arch/arm/mach-realview/realview_pb11mp.c +++ b/arch/arm/mach-realview/realview_pb11mp.c @@ -32,6 +32,7 @@ #include <asm/hardware/gic.h> #include <asm/hardware/icst307.h> #include <asm/hardware/cache-l2x0.h> +#include <asm/localtimer.h> #include <asm/mach/arch.h> #include <asm/mach/flash.h> |