arm64: move from arm_generic to arm_arch_timer
Mark Rutland [Tue, 20 Nov 2012 10:06:00 +0000 (10:06 +0000)]
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@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm64/Kconfig
arch/arm64/include/asm/arch_timer.h [new file with mode: 0644]
arch/arm64/include/asm/arm_generic.h [deleted file]
arch/arm64/kernel/time.c
drivers/clocksource/Kconfig
drivers/clocksource/Makefile
drivers/clocksource/arm_arch_timer.c
drivers/clocksource/arm_generic.c [deleted file]
include/clocksource/arm_generic.h [deleted file]

index f8f362a..2b6cef6 100644 (file)
@@ -3,6 +3,7 @@ config ARM64
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
        select ARM_AMBA
+       select ARM_ARCH_TIMER
        select CLONE_BACKWARDS
        select COMMON_CLK
        select GENERIC_CLOCKEVENTS
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
new file mode 100644 (file)
index 0000000..91e2a6a
--- /dev/null
@@ -0,0 +1,133 @@
+/*
+ * arch/arm64/include/asm/arch_timer.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@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 (file)
index 6ece2f1..0000000
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * arch/arm64/include/asm/arm_generic.h
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Marc Zyngier <marc.zyngier@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;
-
-       isb();
-       asm volatile("mrs %0, cntpct_el0" : "=r" (cval));
-
-       return cval;
-}
-
-static inline cycle_t arch_counter_get_cntvct(void)
-{
-       cycle_t cval;
-
-       isb();
-       asm volatile("mrs %0, cntvct_el0" : "=r" (cval));
-
-       return cval;
-}
-
-#endif
index 3b4b725..b0ef18d 100644 (file)
@@ -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;
 }
index dbb085a..6479842 100644 (file)
@@ -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
index 32f858c..e69511c 100644 (file)
@@ -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
index 3e4739d..ec30a73 100644 (file)
@@ -338,6 +338,7 @@ 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 (file)
index 8ae1a61..0000000
+++ /dev/null
@@ -1,232 +0,0 @@
-/*
- * Generic timers support
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Marc Zyngier <marc.zyngier@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 (file)
index 5b41b0d..0000000
+++ /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