5 files changed, 316 insertions, 125 deletions

diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 62e75475e57e..d40229d9a1c9 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -2,11 +2,12 @@
 #define __ASMARM_ARCH_TIMER_H
 
 #include <asm/errno.h>
+#include <linux/clocksource.h>
 
 #ifdef CONFIG_ARM_ARCH_TIMER
-#define ARCH_HAS_READ_CURRENT_TIMER
 int arch_timer_of_register(void);
 int arch_timer_sched_clock_init(void);
+struct timecounter *arch_timer_get_timecounter(void);
 #else
 static inline int arch_timer_of_register(void)
 {
@@ -17,6 +18,11 @@ static inline int arch_timer_sched_clock_init(void)
 {
         return -ENXIO;
 }
+
+static inline struct timecounter *arch_timer_get_timecounter(void)
+{
+        return NULL;
+}
 #endif
 
 #endif
diff --git a/arch/arm/include/asm/delay.h b/arch/arm/include/asm/delay.h
index dc6145120de3..ab98fdd083bd 100644
--- a/arch/arm/include/asm/delay.h
+++ b/arch/arm/include/asm/delay.h
@@ -15,6 +15,11 @@
 
 #ifndef __ASSEMBLY__
 
+struct delay_timer {
+        unsigned long (*read_current_timer)(void);
+        unsigned long freq;
+};
+
 extern struct arm_delay_ops {
         void (*delay)(unsigned long);
         void (*const_udelay)(unsigned long);
@@ -56,6 +61,10 @@ extern void __loop_delay(unsigned long loops);
 extern void __loop_udelay(unsigned long usecs);
 extern void __loop_const_udelay(unsigned long);
 
+/* Delay-loop timer registration. */
+#define ARCH_HAS_READ_CURRENT_TIMER
+extern void register_current_timer_delay(const struct delay_timer *timer);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* defined(_ARM_DELAY_H) */
diff --git a/arch/arm/include/asm/timex.h b/arch/arm/include/asm/timex.h
index 5e711722ebf4..9acc135dad94 100644
--- a/arch/arm/include/asm/timex.h
+++ b/arch/arm/include/asm/timex.h
@@ -12,13 +12,9 @@
 #ifndef _ASMARM_TIMEX_H
 #define _ASMARM_TIMEX_H
 
-#include <asm/arch_timer.h>
 #include <mach/timex.h>
 
-#ifdef ARCH_HAS_READ_CURRENT_TIMER
+typedef unsigned long cycles_t;
 #define get_cycles()    ({ cycles_t c; read_current_timer(&c) ? 0 : c; })
-#endif
-
-#include <asm-generic/timex.h>
 
 #endif
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index cf258807160d..c8ef20747ee7 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -21,18 +21,28 @@
 #include <linux/io.h>
 
 #include <asm/cputype.h>
+#include <asm/delay.h>
 #include <asm/localtimer.h>
 #include <asm/arch_timer.h>
 #include <asm/system_info.h>
 #include <asm/sched_clock.h>
 
 static unsigned long arch_timer_rate;
-static int arch_timer_ppi;
-static int arch_timer_ppi2;
+
+enum ppi_nr {
+        PHYS_SECURE_PPI,
+        PHYS_NONSECURE_PPI,
+        VIRT_PPI,
+        HYP_PPI,
+        MAX_TIMER_PPI
+};
+
+static int arch_timer_ppi[MAX_TIMER_PPI];
 
 static struct clock_event_device __percpu **arch_timer_evt;
+static struct delay_timer arch_delay_timer;
 
-extern void init_current_timer_delay(unsigned long freq);
+static bool arch_timer_use_virtual = true;
 
 /*
  * Architected system timer support.
@@ -46,50 +56,104 @@ extern void init_current_timer_delay(unsigned long freq);
 #define ARCH_TIMER_REG_FREQ             1
 #define ARCH_TIMER_REG_TVAL             2
 
-static void arch_timer_reg_write(int reg, u32 val)
+#define ARCH_TIMER_PHYS_ACCESS          0
+#define ARCH_TIMER_VIRT_ACCESS          1
+
+/*
+ * These register accessors are marked inline so the compiler can
+ * nicely work out which register we want, and chuck away the rest of
+ * the code. At least it does so with a recent GCC (4.6.3).
+ */
+static inline void arch_timer_reg_write(const int access, const int reg, u32 val)
 {
-        switch (reg) {
-        case ARCH_TIMER_REG_CTRL:
-                asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
-                break;
-        case ARCH_TIMER_REG_TVAL:
-                asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
-                break;
+        if (access == ARCH_TIMER_PHYS_ACCESS) {
+                switch (reg) {
+                case ARCH_TIMER_REG_CTRL:
+                        asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
+                        break;
+                case ARCH_TIMER_REG_TVAL:
+                        asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
+                        break;
+                }
+        }
+
+        if (access == ARCH_TIMER_VIRT_ACCESS) {
+                switch (reg) {
+                case ARCH_TIMER_REG_CTRL:
+                        asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
+                        break;
+                case ARCH_TIMER_REG_TVAL:
+                        asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
+                        break;
+                }
         }
 
         isb();
 }
 
-static u32 arch_timer_reg_read(int reg)
+static inline u32 arch_timer_reg_read(const int access, const int reg)
 {
-        u32 val;
+        u32 val = 0;
+
+        if (access == ARCH_TIMER_PHYS_ACCESS) {
+                switch (reg) {
+                case ARCH_TIMER_REG_CTRL:
+                        asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
+                        break;
+                case ARCH_TIMER_REG_TVAL:
+                        asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
+                        break;
+                case ARCH_TIMER_REG_FREQ:
+                        asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
+                        break;
+                }
+        }
 
-        switch (reg) {
-        case ARCH_TIMER_REG_CTRL:
-                asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
-                break;
-        case ARCH_TIMER_REG_FREQ:
-                asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
-                break;
-        case ARCH_TIMER_REG_TVAL:
-                asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
-                break;
-        default:
-                BUG();
+        if (access == ARCH_TIMER_VIRT_ACCESS) {
+                switch (reg) {
+                case ARCH_TIMER_REG_CTRL:
+                        asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
+                        break;
+                case ARCH_TIMER_REG_TVAL:
+                        asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
+                        break;
+                }
         }
 
         return val;
 }
 
-static irqreturn_t arch_timer_handler(int irq, void *dev_id)
+static inline cycle_t arch_timer_counter_read(const int access)
 {
-        struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
-        unsigned long ctrl;
+        cycle_t cval = 0;
+
+        if (access == ARCH_TIMER_PHYS_ACCESS)
+                asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval));
+
+        if (access == ARCH_TIMER_VIRT_ACCESS)
+                asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
+
+        return cval;
+}
+
+static inline cycle_t arch_counter_get_cntpct(void)
+{
+        return arch_timer_counter_read(ARCH_TIMER_PHYS_ACCESS);
+}
 
-        ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
+static inline cycle_t arch_counter_get_cntvct(void)
+{
+        return arch_timer_counter_read(ARCH_TIMER_VIRT_ACCESS);
+}
+
+static irqreturn_t inline timer_handler(const int access,
+                                        struct clock_event_device *evt)
+{
+        unsigned long ctrl;
+        ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
         if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
                 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
-                arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
+                arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
                 evt->event_handler(evt);
                 return IRQ_HANDLED;
         }
@@ -97,63 +161,100 @@ static irqreturn_t arch_timer_handler(int irq, void *dev_id)
         return IRQ_NONE;
 }
 
-static void arch_timer_disable(void)
+static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
 {
-        unsigned long ctrl;
+        struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
 
-        ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
-        ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
-        arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
+        return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
 }
 
-static void arch_timer_set_mode(enum clock_event_mode mode,
-                                struct clock_event_device *clk)
+static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
 {
+        struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
+
+        return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
+}
+
+static inline void timer_set_mode(const int access, int mode)
+{
+        unsigned long ctrl;
         switch (mode) {
         case CLOCK_EVT_MODE_UNUSED:
         case CLOCK_EVT_MODE_SHUTDOWN:
-                arch_timer_disable();
+                ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
+                ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
+                arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
                 break;
         default:
                 break;
         }
 }
 
-static int arch_timer_set_next_event(unsigned long evt,
-                                     struct clock_event_device *unused)
+static void arch_timer_set_mode_virt(enum clock_event_mode mode,
+                                     struct clock_event_device *clk)
 {
-        unsigned long ctrl;
+        timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
+}
 
-        ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
+static void arch_timer_set_mode_phys(enum clock_event_mode mode,
+                                     struct clock_event_device *clk)
+{
+        timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
+}
+
+static inline void set_next_event(const int access, unsigned long evt)
+{
+        unsigned long ctrl;
+        ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
         ctrl |= ARCH_TIMER_CTRL_ENABLE;
         ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
+        arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
+        arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
+}
 
-        arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
-        arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
+static int arch_timer_set_next_event_virt(unsigned long evt,
+                                          struct clock_event_device *unused)
+{
+        set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
+        return 0;
+}
 
+static int arch_timer_set_next_event_phys(unsigned long evt,
+                                          struct clock_event_device *unused)
+{
+        set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
         return 0;
 }
 
 static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
 {
-        /* Be safe... */
-        arch_timer_disable();
-
         clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
         clk->name = "arch_sys_timer";
         clk->rating = 450;
-        clk->set_mode = arch_timer_set_mode;
-        clk->set_next_event = arch_timer_set_next_event;
-        clk->irq = arch_timer_ppi;
+        if (arch_timer_use_virtual) {
+                clk->irq = arch_timer_ppi[VIRT_PPI];
+                clk->set_mode = arch_timer_set_mode_virt;
+                clk->set_next_event = arch_timer_set_next_event_virt;
+        } else {
+                clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
+                clk->set_mode = arch_timer_set_mode_phys;
+                clk->set_next_event = arch_timer_set_next_event_phys;
+        }
+
+        clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
 
         clockevents_config_and_register(clk, arch_timer_rate,
                                         0xf, 0x7fffffff);
 
         *__this_cpu_ptr(arch_timer_evt) = clk;
 
-        enable_percpu_irq(clk->irq, 0);
-        if (arch_timer_ppi2)
-                enable_percpu_irq(arch_timer_ppi2, 0);
+        if (arch_timer_use_virtual)
+                enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
+        else {
+                enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
+                if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+                        enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
+        }
 
         return 0;
 }
@@ -173,8 +274,8 @@ static int arch_timer_available(void)
                 return -ENXIO;
 
         if (arch_timer_rate == 0) {
-                arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0);
-                freq = arch_timer_reg_read(ARCH_TIMER_REG_FREQ);
+                freq = arch_timer_reg_read(ARCH_TIMER_PHYS_ACCESS,
+                                           ARCH_TIMER_REG_FREQ);
 
                 /* Check the timer frequency. */
                 if (freq == 0) {
@@ -185,52 +286,57 @@ static int arch_timer_available(void)
                 arch_timer_rate = freq;
         }
 
-        pr_info_once("Architected local timer running at %lu.%02luMHz.\n",
-                     arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
+        pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
+                     arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100,
+                     arch_timer_use_virtual ? "virt" : "phys");
         return 0;
 }
 
-static inline cycle_t arch_counter_get_cntpct(void)
+static u32 notrace arch_counter_get_cntpct32(void)
 {
-        u32 cvall, cvalh;
-
-        asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (cvall), "=r" (cvalh));
+        cycle_t cnt = arch_counter_get_cntpct();
 
-        return ((cycle_t) cvalh << 32) | cvall;
-}
-
-static inline cycle_t arch_counter_get_cntvct(void)
-{
-        u32 cvall, cvalh;
-
-        asm volatile("mrrc p15, 1, %0, %1, c14" : "=r" (cvall), "=r" (cvalh));
-
-        return ((cycle_t) cvalh << 32) | cvall;
+        /*
+         * The sched_clock infrastructure only knows about counters
+         * with at most 32bits. Forget about the upper 24 bits for the
+         * time being...
+         */
+        return (u32)cnt;
 }
 
 static u32 notrace arch_counter_get_cntvct32(void)
 {
-        cycle_t cntvct = arch_counter_get_cntvct();
+        cycle_t cnt = arch_counter_get_cntvct();
 
         /*
          * The sched_clock infrastructure only knows about counters
          * with at most 32bits. Forget about the upper 24 bits for the
          * time being...
          */
-        return (u32)(cntvct & (u32)~0);
+        return (u32)cnt;
 }
 
 static cycle_t arch_counter_read(struct clocksource *cs)
 {
+        /*
+         * Always use the physical counter for the clocksource.
+         * CNTHCTL.PL1PCTEN must be set to 1.
+         */
         return arch_counter_get_cntpct();
 }
 
-int read_current_timer(unsigned long *timer_val)
+static unsigned long arch_timer_read_current_timer(void)
 {
-        if (!arch_timer_rate)
-                return -ENXIO;
-        *timer_val = arch_counter_get_cntpct();
-        return 0;
+        return arch_counter_get_cntpct();
+}
+
+static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
+{
+        /*
+         * Always use the physical counter for the clocksource.
+         * CNTHCTL.PL1PCTEN must be set to 1.
+         */
+        return arch_counter_get_cntpct();
 }
 
 static struct clocksource clocksource_counter = {
@@ -241,14 +347,32 @@ static struct clocksource clocksource_counter = {
         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+static struct cyclecounter cyclecounter = {
+        .read   = arch_counter_read_cc,
+        .mask   = CLOCKSOURCE_MASK(56),
+};
+
+static struct timecounter timecounter;
+
+struct timecounter *arch_timer_get_timecounter(void)
+{
+        return &timecounter;
+}
+
 static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
 {
         pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
                  clk->irq, smp_processor_id());
-        disable_percpu_irq(clk->irq);
-        if (arch_timer_ppi2)
-                disable_percpu_irq(arch_timer_ppi2);
-        arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
+
+        if (arch_timer_use_virtual)
+                disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
+        else {
+                disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
+                if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+                        disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
+        }
+
+        clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
 }
 
 static struct local_timer_ops arch_timer_ops __cpuinitdata = {
@@ -261,36 +385,48 @@ static struct clock_event_device arch_timer_global_evt;
 static int __init arch_timer_register(void)
 {
         int err;
+        int ppi;
 
         err = arch_timer_available();
         if (err)
-                return err;
+                goto out;
 
         arch_timer_evt = alloc_percpu(struct clock_event_device *);
-        if (!arch_timer_evt)
-                return -ENOMEM;
+        if (!arch_timer_evt) {
+                err = -ENOMEM;
+                goto out;
+        }
 
         clocksource_register_hz(&clocksource_counter, arch_timer_rate);
+        cyclecounter.mult = clocksource_counter.mult;
+        cyclecounter.shift = clocksource_counter.shift;
+        timecounter_init(&timecounter, &cyclecounter,
+                         arch_counter_get_cntpct());
+
+        if (arch_timer_use_virtual) {
+                ppi = arch_timer_ppi[VIRT_PPI];
+                err = request_percpu_irq(ppi, arch_timer_handler_virt,
+                                         "arch_timer", arch_timer_evt);
+        } else {
+                ppi = arch_timer_ppi[PHYS_SECURE_PPI];
+                err = request_percpu_irq(ppi, arch_timer_handler_phys,
+                                         "arch_timer", arch_timer_evt);
+                if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
+                        ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
+                        err = request_percpu_irq(ppi, arch_timer_handler_phys,
+                                                 "arch_timer", arch_timer_evt);
+                        if (err)
+                                free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
+                                                arch_timer_evt);
+                }
+        }
 
-        err = request_percpu_irq(arch_timer_ppi, arch_timer_handler,
-                                 "arch_timer", arch_timer_evt);
         if (err) {
                 pr_err("arch_timer: can't register interrupt %d (%d)\n",
-                       arch_timer_ppi, err);
+                       ppi, err);
                 goto out_free;
         }
 
-        if (arch_timer_ppi2) {
-                err = request_percpu_irq(arch_timer_ppi2, arch_timer_handler,
-                                         "arch_timer", arch_timer_evt);
-                if (err) {
-                        pr_err("arch_timer: can't register interrupt %d (%d)\n",
-                               arch_timer_ppi2, err);
-                        arch_timer_ppi2 = 0;
-                        goto out_free_irq;
-                }
-        }
-
         err = local_timer_register(&arch_timer_ops);
         if (err) {
                 /*
@@ -302,21 +438,29 @@ static int __init arch_timer_register(void)
                 arch_timer_global_evt.cpumask = cpumask_of(0);
                 err = arch_timer_setup(&arch_timer_global_evt);
         }
-
         if (err)
                 goto out_free_irq;
 
-        init_current_timer_delay(arch_timer_rate);
+        /* Use the architected timer for the delay loop. */
+        arch_delay_timer.read_current_timer = &arch_timer_read_current_timer;
+        arch_delay_timer.freq = arch_timer_rate;
+        register_current_timer_delay(&arch_delay_timer);
         return 0;
 
 out_free_irq:
-        free_percpu_irq(arch_timer_ppi, arch_timer_evt);
-        if (arch_timer_ppi2)
-                free_percpu_irq(arch_timer_ppi2, arch_timer_evt);
+        if (arch_timer_use_virtual)
+                free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
+        else {
+                free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
+                                arch_timer_evt);
+                if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+                        free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
+                                        arch_timer_evt);
+        }
 
 out_free:
         free_percpu(arch_timer_evt);
-
+out:
         return err;
 }
 
@@ -329,6 +473,7 @@ int __init arch_timer_of_register(void)
 {
         struct device_node *np;
         u32 freq;
+        int i;
 
         np = of_find_matching_node(NULL, arch_timer_of_match);
         if (!np) {
@@ -340,22 +485,40 @@ int __init arch_timer_of_register(void)
         if (!of_property_read_u32(np, "clock-frequency", &freq))
                 arch_timer_rate = freq;
 
-        arch_timer_ppi = irq_of_parse_and_map(np, 0);
-        arch_timer_ppi2 = irq_of_parse_and_map(np, 1);
-        pr_info("arch_timer: found %s irqs %d %d\n",
-                np->name, arch_timer_ppi, arch_timer_ppi2);
+        for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
+                arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+
+        /*
+         * If no interrupt provided for virtual timer, we'll have to
+         * stick to the physical timer. It'd better be accessible...
+         */
+        if (!arch_timer_ppi[VIRT_PPI]) {
+                arch_timer_use_virtual = false;
+
+                if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
+                    !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
+                        pr_warn("arch_timer: No interrupt available, giving up\n");
+                        return -EINVAL;
+                }
+        }
 
         return arch_timer_register();
 }
 
 int __init arch_timer_sched_clock_init(void)
 {
+        u32 (*cnt32)(void);
         int err;
 
         err = arch_timer_available();
         if (err)
                 return err;
 
-        setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate);
+        if (arch_timer_use_virtual)
+                cnt32 = arch_counter_get_cntvct32;
+        else
+                cnt32 = arch_counter_get_cntpct32;
+
+        setup_sched_clock(cnt32, 32, arch_timer_rate);
         return 0;
 }
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c
index 395d5fbb8fa2..9d0a30032d7f 100644
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -34,7 +34,18 @@ struct arm_delay_ops arm_delay_ops = {
         .udelay         = __loop_udelay,
 };
 
-#ifdef ARCH_HAS_READ_CURRENT_TIMER
+static const struct delay_timer *delay_timer;
+static bool delay_calibrated;
+
+int read_current_timer(unsigned long *timer_val)
+{
+        if (!delay_timer)
+                return -ENXIO;
+
+        *timer_val = delay_timer->read_current_timer();
+        return 0;
+}
+
 static void __timer_delay(unsigned long cycles)
 {
         cycles_t start = get_cycles();
@@ -55,18 +66,24 @@ static void __timer_udelay(unsigned long usecs)
         __timer_const_udelay(usecs * UDELAY_MULT);
 }
 
-void __init init_current_timer_delay(unsigned long freq)
+void __init register_current_timer_delay(const struct delay_timer *timer)
 {
-        pr_info("Switching to timer-based delay loop\n");
-        lpj_fine                        = freq / HZ;
-        loops_per_jiffy                 = lpj_fine;
-        arm_delay_ops.delay             = __timer_delay;
-        arm_delay_ops.const_udelay      = __timer_const_udelay;
-        arm_delay_ops.udelay            = __timer_udelay;
+        if (!delay_calibrated) {
+                pr_info("Switching to timer-based delay loop\n");
+                delay_timer                     = timer;
+                lpj_fine                        = timer->freq / HZ;
+                loops_per_jiffy                 = lpj_fine;
+                arm_delay_ops.delay             = __timer_delay;
+                arm_delay_ops.const_udelay      = __timer_const_udelay;
+                arm_delay_ops.udelay            = __timer_udelay;
+                delay_calibrated                = true;
+        } else {
+                pr_info("Ignoring duplicate/late registration of read_current_timer delay\n");
+        }
 }
 
 unsigned long __cpuinit calibrate_delay_is_known(void)
 {
+        delay_calibrated = true;
         return lpj_fine;
 }
-#endif