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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2009-05-16 12:14:21 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-05-17 19:16:41 +0100
commitf32f4ce25745209f16a5a6cef7442144b596c68a (patch)
tree76083f10ee56c82177669bb100358ea2818f8f5a /arch/arm
parenta8cbcd92bd4bf893085eddf7f58e63ea98503d94 (diff)
downloadlwn-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/Kconfig7
-rw-r--r--arch/arm/include/asm/hardware/arm_twd.h21
-rw-r--r--arch/arm/include/asm/localtimer.h12
-rw-r--r--arch/arm/include/asm/smp_twd.h12
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/smp_twd.c173
-rw-r--r--arch/arm/mach-realview/Makefile3
-rw-r--r--arch/arm/mach-realview/core.h3
-rw-r--r--arch/arm/mach-realview/localtimer.c144
-rw-r--r--arch/arm/mach-realview/realview_eb.c1
-rw-r--r--arch/arm/mach-realview/realview_pb11mp.c1
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>