ARM: smp_twd: Divorce smp_twd from local timer API

Separate the smp_twd timers from the local timer API. This will
allow us to remove ARM local timer support in the near future and
gets us closer to moving this driver to drivers/clocksource.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

11 files changed, 56 insertions, 34 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 53d3a356f61f..374a1d8900ec 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -638,7 +638,7 @@ config ARCH_SHMOBILE
         select CLKDEV_LOOKUP
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_CLK
         select HAVE_MACH_CLKDEV
         select HAVE_SMP
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 90525d9d290b..aac1495b44de 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/clk.h>
+#include <linux/cpu.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -24,7 +25,6 @@
 
 #include <asm/smp_plat.h>
 #include <asm/smp_twd.h>
-#include <asm/localtimer.h>
 
 /* set up by the platform code */
 static void __iomem *twd_base;
@@ -33,7 +33,7 @@ static struct clk *twd_clk;
 static unsigned long twd_timer_rate;
 static DEFINE_PER_CPU(bool, percpu_setup_called);
 
-static struct clock_event_device __percpu **twd_evt;
+static struct clock_event_device __percpu *twd_evt;
 static int twd_ppi;
 
 static void twd_set_mode(enum clock_event_mode mode,
@@ -90,8 +90,10 @@ static int twd_timer_ack(void)
         return 0;
 }
 
-static void twd_timer_stop(struct clock_event_device *clk)
+static void twd_timer_stop(void)
 {
+        struct clock_event_device *clk = __this_cpu_ptr(twd_evt);
+
         twd_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
         disable_percpu_irq(clk->irq);
 }
@@ -106,7 +108,7 @@ static void twd_update_frequency(void *new_rate)
 {
         twd_timer_rate = *((unsigned long *) new_rate);
 
-        clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate);
+        clockevents_update_freq(__this_cpu_ptr(twd_evt), twd_timer_rate);
 }
 
 static int twd_rate_change(struct notifier_block *nb,
@@ -132,7 +134,7 @@ static struct notifier_block twd_clk_nb = {
 
 static int twd_clk_init(void)
 {
-        if (twd_evt && *__this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
+        if (twd_evt && __this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
                 return clk_notifier_register(twd_clk, &twd_clk_nb);
 
         return 0;
@@ -151,7 +153,7 @@ static void twd_update_frequency(void *data)
 {
         twd_timer_rate = clk_get_rate(twd_clk);
 
-        clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate);
+        clockevents_update_freq(__this_cpu_ptr(twd_evt), twd_timer_rate);
 }
 
 static int twd_cpufreq_transition(struct notifier_block *nb,
@@ -177,7 +179,7 @@ static struct notifier_block twd_cpufreq_nb = {
 
 static int twd_cpufreq_init(void)
 {
-        if (twd_evt && *__this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
+        if (twd_evt && __this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk))
                 return cpufreq_register_notifier(&twd_cpufreq_nb,
                         CPUFREQ_TRANSITION_NOTIFIER);
 
@@ -228,7 +230,7 @@ static void __cpuinit twd_calibrate_rate(void)
 
 static irqreturn_t twd_handler(int irq, void *dev_id)
 {
-        struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
+        struct clock_event_device *evt = dev_id;
 
         if (twd_timer_ack()) {
                 evt->event_handler(evt);
@@ -265,9 +267,9 @@ static void twd_get_clock(struct device_node *np)
 /*
  * Setup the local clock events for a CPU.
  */
-static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
+static void __cpuinit twd_timer_setup(void)
 {
-        struct clock_event_device **this_cpu_clk;
+        struct clock_event_device *clk = __this_cpu_ptr(twd_evt);
         int cpu = smp_processor_id();
 
         /*
@@ -276,9 +278,9 @@ static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
          */
         if (per_cpu(percpu_setup_called, cpu)) {
                 __raw_writel(0, twd_base + TWD_TIMER_CONTROL);
-                clockevents_register_device(*__this_cpu_ptr(twd_evt));
+                clockevents_register_device(clk);
                 enable_percpu_irq(clk->irq, 0);
-                return 0;
+                return;
         }
         per_cpu(percpu_setup_called, cpu) = true;
 
@@ -297,27 +299,37 @@ static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
         clk->set_mode = twd_set_mode;
         clk->set_next_event = twd_set_next_event;
         clk->irq = twd_ppi;
-
-        this_cpu_clk = __this_cpu_ptr(twd_evt);
-        *this_cpu_clk = clk;
+        clk->cpumask = cpumask_of(cpu);
 
         clockevents_config_and_register(clk, twd_timer_rate,
                                         0xf, 0xffffffff);
         enable_percpu_irq(clk->irq, 0);
+}
 
-        return 0;
+static int __cpuinit twd_timer_cpu_notify(struct notifier_block *self,
+                                           unsigned long action, void *hcpu)
+{
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_STARTING:
+                twd_timer_setup();
+                break;
+        case CPU_DYING:
+                twd_timer_stop();
+                break;
+        }
+
+        return NOTIFY_OK;
 }
 
-static struct local_timer_ops twd_lt_ops __cpuinitdata = {
-        .setup  = twd_timer_setup,
-        .stop   = twd_timer_stop,
+static struct notifier_block twd_timer_cpu_nb __cpuinitdata = {
+        .notifier_call = twd_timer_cpu_notify,
 };
 
 static int __init twd_local_timer_common_register(struct device_node *np)
 {
         int err;
 
-        twd_evt = alloc_percpu(struct clock_event_device *);
+        twd_evt = alloc_percpu(struct clock_event_device);
         if (!twd_evt) {
                 err = -ENOMEM;
                 goto out_free;
@@ -329,12 +341,22 @@ static int __init twd_local_timer_common_register(struct device_node *np)
                 goto out_free;
         }
 
-        err = local_timer_register(&twd_lt_ops);
+        err = register_cpu_notifier(&twd_timer_cpu_nb);
         if (err)
                 goto out_irq;
 
         twd_get_clock(np);
 
+        /*
+         * Immediately configure the timer on the boot CPU, unless we need
+         * jiffies to be incrementing to calibrate the rate in which case
+         * setup the timer in late_time_init.
+         */
+        if (twd_timer_rate)
+                twd_timer_setup();
+        else
+                late_time_init = twd_timer_setup;
+
         return 0;
 
 out_irq:
diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig
index cd9fcb1cd7ab..6acbdabf6222 100644
--- a/arch/arm/mach-highbank/Kconfig
+++ b/arch/arm/mach-highbank/Kconfig
@@ -12,7 +12,7 @@ config ARCH_HIGHBANK
         select CPU_V7
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select MAILBOX
         select PL320_MBOX
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index ba44328464f3..c8adc79028b8 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -798,7 +798,7 @@ config SOC_IMX6Q
         select COMMON_CLK
         select CPU_V7
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_CAN_FLEXCAN if CAN
         select HAVE_IMX_ANATOP
         select HAVE_IMX_GPC
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index f49cd51e162a..edb950a1af05 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -90,7 +90,7 @@ config ARCH_OMAP4
         select CACHE_L2X0
         select CPU_V7
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select LOCAL_TIMERS if SMP
         select OMAP_INTERCONNECT
diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index d210c0f9c2c4..9db2029aa632 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -13,7 +13,7 @@ config REALVIEW_EB_A9MP
         depends on MACH_REALVIEW_EB
         select CPU_V7
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
         help
@@ -26,7 +26,7 @@ config REALVIEW_EB_ARM11MP
         select ARCH_HAS_BARRIERS if SMP
         select CPU_V6K
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
         help
@@ -48,7 +48,7 @@ config MACH_REALVIEW_PB11MP
         select ARM_GIC
         select CPU_V6K
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_PATA_PLATFORM
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
@@ -92,7 +92,7 @@ config MACH_REALVIEW_PBX
         select ARCH_SPARSEMEM_ENABLE if CPU_V7 && !REALVIEW_HIGH_PHYS_OFFSET
         select ARM_GIC
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_PATA_PLATFORM
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
diff --git a/arch/arm/mach-spear/Kconfig b/arch/arm/mach-spear/Kconfig
index 442917eedff3..df0d59afeb40 100644
--- a/arch/arm/mach-spear/Kconfig
+++ b/arch/arm/mach-spear/Kconfig
@@ -23,7 +23,7 @@ config ARCH_SPEAR13XX
         select CPU_V7
         select GPIO_SPEAR_SPICS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
         select PINCTRL
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 84d72fc36dfe..1f3ea1f6cedf 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -8,7 +8,7 @@ config ARCH_TEGRA
         select COMMON_CLK
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_CLK
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
index 6a4387e39df8..0614ee2b0523 100644
--- a/arch/arm/mach-ux500/Kconfig
+++ b/arch/arm/mach-ux500/Kconfig
@@ -8,7 +8,7 @@ config ARCH_U8500
         select CPU_V7
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_SMP
         select MIGHT_HAVE_CACHE_L2X0
         help
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 5907e10c37fd..5bfdd73dea19 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -10,7 +10,7 @@ config ARCH_VEXPRESS
         select CPU_V7
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select HAVE_CLK
         select HAVE_PATA_PLATFORM
         select HAVE_SMP
diff --git a/arch/arm/mach-zynq/Kconfig b/arch/arm/mach-zynq/Kconfig
index c1d61f281e68..04f8a4a6e755 100644
--- a/arch/arm/mach-zynq/Kconfig
+++ b/arch/arm/mach-zynq/Kconfig
@@ -6,7 +6,7 @@ config ARCH_ZYNQ
         select CPU_V7
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
-        select HAVE_ARM_TWD if LOCAL_TIMERS
+        select HAVE_ARM_TWD if SMP
         select ICST
         select MIGHT_HAVE_CACHE_L2X0
         select USE_OF