[PATCHv2 10/11] arm64: move from arm_generic to arm_arch_timer
Mark Rutland
mark.rutland at arm.com
Wed Dec 19 10:11:09 EST 2012
The arch_timer driver supports a superset of the functionality of the
arm_generic driver, and is not tied to a particular arch.
This patch moves arm64 to use the arch_timer driver, gaining additional
functionality in doing so, and removes the (now unused) arm_generic
driver. Timer-related hooks specific to arm64 are moved into
arch/arm64/kernel/time.c.
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
Acked-by: Marc Zyngier <marc.zyngier at arm.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/arch_timer.h | 133 +++++++++++++++++++
arch/arm64/include/asm/arm_generic.h | 100 ---------------
arch/arm64/kernel/time.c | 29 ++++-
drivers/clocksource/Kconfig | 5 -
drivers/clocksource/Makefile | 1 -
drivers/clocksource/arm_arch_timer.c | 1 +
drivers/clocksource/arm_generic.c | 232 ----------------------------------
include/clocksource/arm_generic.h | 21 ---
9 files changed, 162 insertions(+), 361 deletions(-)
create mode 100644 arch/arm64/include/asm/arch_timer.h
delete mode 100644 arch/arm64/include/asm/arm_generic.h
delete mode 100644 drivers/clocksource/arm_generic.c
delete mode 100644 include/clocksource/arm_generic.h
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f9ccff9..09b3036 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@ config ARM64
def_bool y
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+ select ARM_ARCH_TIMER
select COMMON_CLK
select GENERIC_CLOCKEVENTS
select GENERIC_HARDIRQS_NO_DEPRECATED
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
new file mode 100644
index 0000000..91e2a6a
--- /dev/null
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -0,0 +1,133 @@
+/*
+ * arch/arm64/include/asm/arch_timer.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier at arm.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_ARCH_TIMER_H
+#define __ASM_ARCH_TIMER_H
+
+#include <asm/barrier.h>
+
+#include <linux/init.h>
+#include <linux/types.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+static inline void arch_timer_reg_write(int access, int reg, u32 val)
+{
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("msr cntp_ctl_el0, %0" : : "r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("msr cntp_tval_el0, %0" : : "r" (val));
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("msr cntv_ctl_el0, %0" : : "r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("msr cntv_tval_el0, %0" : : "r" (val));
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else {
+ BUILD_BUG();
+ }
+
+ isb();
+}
+
+static inline u32 arch_timer_reg_read(int access, int reg)
+{
+ u32 val;
+
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("mrs %0, cntp_ctl_el0" : "=r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("mrs %0, cntv_ctl_el0" : "=r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("mrs %0, cntv_tval_el0" : "=r" (val));
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else {
+ BUILD_BUG();
+ }
+
+ return val;
+}
+
+static inline u32 arch_timer_get_cntfrq(void)
+{
+ u32 val;
+ asm volatile("mrs %0, cntfrq_el0" : "=r" (val));
+ return val;
+}
+
+static inline void __cpuinit arch_counter_set_user_access(void)
+{
+ u32 cntkctl;
+
+ /* Disable user access to the timers and the physical counter. */
+ asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl));
+ cntkctl &= ~((3 << 8) | (1 << 0));
+
+ /* Enable user access to the virtual counter and frequency. */
+ cntkctl |= (1 << 1);
+ asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl));
+}
+
+static inline u64 arch_counter_get_cntpct(void)
+{
+ u64 cval;
+
+ isb();
+ asm volatile("mrs %0, cntpct_el0" : "=r" (cval));
+
+ return cval;
+}
+
+static inline u64 arch_counter_get_cntvct(void)
+{
+ u64 cval;
+
+ isb();
+ asm volatile("mrs %0, cntvct_el0" : "=r" (cval));
+
+ return cval;
+}
+
+#endif
diff --git a/arch/arm64/include/asm/arm_generic.h b/arch/arm64/include/asm/arm_generic.h
deleted file mode 100644
index df2aeb8..0000000
--- a/arch/arm64/include/asm/arm_generic.h
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * arch/arm64/include/asm/arm_generic.h
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Marc Zyngier <marc.zyngier at arm.com>
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_ARM_GENERIC_H
-#define __ASM_ARM_GENERIC_H
-
-#include <linux/clocksource.h>
-
-#define ARCH_TIMER_CTRL_ENABLE (1 << 0)
-#define ARCH_TIMER_CTRL_IMASK (1 << 1)
-#define ARCH_TIMER_CTRL_ISTATUS (1 << 2)
-
-#define ARCH_TIMER_REG_CTRL 0
-#define ARCH_TIMER_REG_FREQ 1
-#define ARCH_TIMER_REG_TVAL 2
-
-static inline void arch_timer_reg_write(int reg, u32 val)
-{
- switch (reg) {
- case ARCH_TIMER_REG_CTRL:
- asm volatile("msr cntp_ctl_el0, %0" : : "r" (val));
- break;
- case ARCH_TIMER_REG_TVAL:
- asm volatile("msr cntp_tval_el0, %0" : : "r" (val));
- break;
- default:
- BUILD_BUG();
- }
-
- isb();
-}
-
-static inline u32 arch_timer_reg_read(int reg)
-{
- u32 val;
-
- switch (reg) {
- case ARCH_TIMER_REG_CTRL:
- asm volatile("mrs %0, cntp_ctl_el0" : "=r" (val));
- break;
- case ARCH_TIMER_REG_FREQ:
- asm volatile("mrs %0, cntfrq_el0" : "=r" (val));
- break;
- case ARCH_TIMER_REG_TVAL:
- asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));
- break;
- default:
- BUILD_BUG();
- }
-
- return val;
-}
-
-static inline void __cpuinit arch_counter_enable_user_access(void)
-{
- u32 cntkctl;
-
- /* Disable user access to the timers and the physical counter. */
- asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl));
- cntkctl &= ~((3 << 8) | (1 << 0));
-
- /* Enable user access to the virtual counter and frequency. */
- cntkctl |= (1 << 1);
- asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl));
-}
-
-static inline cycle_t arch_counter_get_cntpct(void)
-{
- cycle_t cval;
-
- asm volatile("mrs %0, cntpct_el0" : "=r" (cval));
-
- return cval;
-}
-
-static inline cycle_t arch_counter_get_cntvct(void)
-{
- cycle_t cval;
-
- asm volatile("mrs %0, cntvct_el0" : "=r" (cval));
-
- return cval;
-}
-
-#endif
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index 3b4b725..b0ef18d 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -31,8 +31,9 @@
#include <linux/syscore_ops.h>
#include <linux/timer.h>
#include <linux/irq.h>
+#include <linux/delay.h>
-#include <clocksource/arm_generic.h>
+#include <clocksource/arm_arch_timer.h>
#include <asm/thread_info.h>
#include <asm/stacktrace.h>
@@ -59,7 +60,31 @@ 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;
+}
+
+int read_current_timer(unsigned long *timer_value)
+{
+ *timer_value = arch_timer_read_counter();
+ return 0;
+}
+
void __init time_init(void)
{
- arm_generic_timer_init();
+ u32 arch_timer_rate;
+
+ if (arch_timer_init())
+ panic("Unable to initialise architected timer.\n");
+
+ arch_timer_rate = arch_timer_get_rate();
+
+ /* 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/Kconfig b/drivers/clocksource/Kconfig
index dbb085a..6479842 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -54,10 +54,5 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
help
Use the always on PRCMU Timer as sched_clock
-config CLKSRC_ARM_GENERIC
- def_bool y if ARM64
- help
- This option enables support for the ARM generic timer.
-
config ARM_ARCH_TIMER
bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 32f858c..e69511c 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -17,5 +17,4 @@ obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o
obj-$(CONFIG_SUNXI_TIMER) += sunxi_timer.o
-obj-$(CONFIG_CLKSRC_ARM_GENERIC) += arm_generic.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 823f2df..cfea474 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -332,6 +332,7 @@ out:
static const struct of_device_id arch_timer_of_match[] __initconst = {
{ .compatible = "arm,armv7-timer", },
+ { .compatible = "arm,armv8-timer", },
{},
};
diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c
deleted file mode 100644
index 8ae1a61..0000000
--- a/drivers/clocksource/arm_generic.c
+++ /dev/null
@@ -1,232 +0,0 @@
-/*
- * Generic timers support
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Marc Zyngier <marc.zyngier at arm.com>
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/smp.h>
-#include <linux/cpu.h>
-#include <linux/jiffies.h>
-#include <linux/interrupt.h>
-#include <linux/clockchips.h>
-#include <linux/of_irq.h>
-#include <linux/io.h>
-
-#include <clocksource/arm_generic.h>
-
-#include <asm/arm_generic.h>
-
-static u32 arch_timer_rate;
-static u64 sched_clock_mult __read_mostly;
-static DEFINE_PER_CPU(struct clock_event_device, arch_timer_evt);
-static int arch_timer_ppi;
-
-static irqreturn_t arch_timer_handle_irq(int irq, void *dev_id)
-{
- struct clock_event_device *evt = dev_id;
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- if (ctrl & ARCH_TIMER_CTRL_ISTATUS) {
- ctrl |= ARCH_TIMER_CTRL_IMASK;
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
- evt->event_handler(evt);
- return IRQ_HANDLED;
- }
-
- return IRQ_NONE;
-}
-
-static void arch_timer_stop(void)
-{
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-}
-
-static void arch_timer_set_mode(enum clock_event_mode mode,
- struct clock_event_device *clk)
-{
- switch (mode) {
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_SHUTDOWN:
- arch_timer_stop();
- break;
- default:
- break;
- }
-}
-
-static int arch_timer_set_next_event(unsigned long evt,
- struct clock_event_device *unused)
-{
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- ctrl |= ARCH_TIMER_CTRL_ENABLE;
- ctrl &= ~ARCH_TIMER_CTRL_IMASK;
-
- arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-
- return 0;
-}
-
-static void __cpuinit arch_timer_setup(struct clock_event_device *clk)
-{
- /* Let's make sure the timer is off before doing anything else */
- arch_timer_stop();
-
- clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
- clk->name = "arch_sys_timer";
- clk->rating = 400;
- clk->set_mode = arch_timer_set_mode;
- clk->set_next_event = arch_timer_set_next_event;
- clk->irq = arch_timer_ppi;
- clk->cpumask = cpumask_of(smp_processor_id());
-
- clockevents_config_and_register(clk, arch_timer_rate,
- 0xf, 0x7fffffff);
-
- enable_percpu_irq(clk->irq, 0);
-
- /* Ensure the virtual counter is visible to userspace for the vDSO. */
- arch_counter_enable_user_access();
-}
-
-static void __init arch_timer_calibrate(void)
-{
- if (arch_timer_rate == 0) {
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0);
- arch_timer_rate = arch_timer_reg_read(ARCH_TIMER_REG_FREQ);
-
- /* Check the timer frequency. */
- if (arch_timer_rate == 0)
- panic("Architected timer frequency is set to zero.\n"
- "You must set this in your .dts file\n");
- }
-
- /* Cache the sched_clock multiplier to save a divide in the hot path. */
-
- sched_clock_mult = DIV_ROUND_CLOSEST(NSEC_PER_SEC, arch_timer_rate);
-
- pr_info("Architected local timer running at %u.%02uMHz.\n",
- arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
-}
-
-static cycle_t arch_counter_read(struct clocksource *cs)
-{
- return arch_counter_get_cntpct();
-}
-
-static struct clocksource clocksource_counter = {
- .name = "arch_sys_counter",
- .rating = 400,
- .read = arch_counter_read,
- .mask = CLOCKSOURCE_MASK(56),
- .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
-};
-
-int read_current_timer(unsigned long *timer_value)
-{
- *timer_value = arch_counter_get_cntpct();
- return 0;
-}
-
-unsigned long long notrace sched_clock(void)
-{
- return arch_counter_get_cntvct() * sched_clock_mult;
-}
-
-static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
- struct clock_event_device *clk = per_cpu_ptr(&arch_timer_evt, cpu);
-
- switch(action) {
- case CPU_STARTING:
- case CPU_STARTING_FROZEN:
- arch_timer_setup(clk);
- break;
-
- case CPU_DYING:
- case CPU_DYING_FROZEN:
- pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
- clk->irq, cpu);
- disable_percpu_irq(clk->irq);
- arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata arch_timer_cpu_nb = {
- .notifier_call = arch_timer_cpu_notify,
-};
-
-static const struct of_device_id arch_timer_of_match[] __initconst = {
- { .compatible = "arm,armv8-timer" },
- {},
-};
-
-int __init arm_generic_timer_init(void)
-{
- struct device_node *np;
- int err;
- u32 freq;
-
- np = of_find_matching_node(NULL, arch_timer_of_match);
- if (!np) {
- pr_err("arch_timer: can't find DT node\n");
- return -ENODEV;
- }
-
- /* Try to determine the frequency from the device tree or CNTFRQ */
- if (!of_property_read_u32(np, "clock-frequency", &freq))
- arch_timer_rate = freq;
- arch_timer_calibrate();
-
- arch_timer_ppi = irq_of_parse_and_map(np, 0);
- pr_info("arch_timer: found %s irq %d\n", np->name, arch_timer_ppi);
-
- err = request_percpu_irq(arch_timer_ppi, arch_timer_handle_irq,
- np->name, &arch_timer_evt);
- if (err) {
- pr_err("arch_timer: can't register interrupt %d (%d)\n",
- arch_timer_ppi, err);
- return err;
- }
-
- clocksource_register_hz(&clocksource_counter, arch_timer_rate);
-
- /* Calibrate the delay loop directly */
- lpj_fine = DIV_ROUND_CLOSEST(arch_timer_rate, HZ);
-
- /* Immediately configure the timer on the boot CPU */
- arch_timer_setup(this_cpu_ptr(&arch_timer_evt));
-
- register_cpu_notifier(&arch_timer_cpu_nb);
-
- return 0;
-}
diff --git a/include/clocksource/arm_generic.h b/include/clocksource/arm_generic.h
deleted file mode 100644
index 5b41b0d..0000000
--- a/include/clocksource/arm_generic.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __CLKSOURCE_ARM_GENERIC_H
-#define __CLKSOURCE_ARM_GENERIC_H
-
-extern int arm_generic_timer_init(void);
-
-#endif
--
1.7.0.4
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