From f48b5f12799dbabba4a9c799a9bef0775b2f977d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 7 Sep 2012 18:09:57 +0100 Subject: ARM: 7523/1: arch_timers: enable the use of the virtual timer At the moment, the arch_timer driver only uses the physical timer, which can cause problem if PL2 hasn't enabled PL1 access in CNTHCTL, which is likely in a virtualized environment. Instead, the virtual timer is always available. This patch enables the use of the virtual timer, unless no interrupt is provided in the DT for it, in which case it falls back to the physical timer. Signed-off-by: Marc Zyngier Signed-off-by: Russell King --- arch/arm/kernel/arch_timer.c | 343 ++++++++++++++++++++++++++++++------------- 1 file changed, 241 insertions(+), 102 deletions(-) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index cf258807160d..c4e20b69197a 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -27,13 +27,23 @@ #include 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; 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; +} - ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL); +static inline cycle_t arch_counter_get_cntpct(void) +{ + return arch_timer_counter_read(ARCH_TIMER_PHYS_ACCESS); +} + +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); +} + +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); +} - ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL); +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) { @@ -185,43 +286,42 @@ 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(); } @@ -245,10 +345,16 @@ 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 +367,44 @@ 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); - err = request_percpu_irq(arch_timer_ppi, arch_timer_handler, - "arch_timer", arch_timer_evt); + 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); + } + } + 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) { /* @@ -310,13 +424,19 @@ static int __init arch_timer_register(void) 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 +449,7 @@ 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 +461,40 @@ 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; } -- cgit v1.2.1 From a1b2dde70419ae947fd7c9c8fcad7da005dc600e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 7 Sep 2012 18:09:58 +0100 Subject: ARM: 7522/1: arch_timers: register a time/cycle counter Some subsystems (KVM for example) need access to a cycle counter. In the KVM case, this is used to measure the time delta between host and guest in order to accurately generate timer events for the guest. Signed-off-by: Marc Zyngier Signed-off-by: Russell King --- arch/arm/include/asm/arch_timer.h | 7 +++++++ arch/arm/kernel/arch_timer.c | 25 +++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 62e75475e57e..ad9b155c8262 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -2,11 +2,13 @@ #define __ASMARM_ARCH_TIMER_H #include +#include #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 +19,11 @@ 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/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index c4e20b69197a..c04c2a6da470 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -333,6 +333,15 @@ int read_current_timer(unsigned long *timer_val) return 0; } +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 = { .name = "arch_sys_counter", .rating = 400, @@ -341,6 +350,18 @@ 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", @@ -380,6 +401,10 @@ static int __init arch_timer_register(void) } 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]; -- cgit v1.2.1 From 56942fec06efa0e17df0f4c3b438332c923b9014 Mon Sep 17 00:00:00 2001 From: Jonathan Austin Date: Fri, 21 Sep 2012 18:51:44 +0100 Subject: ARM: 7538/1: delay: add registration mechanism for delay timer sources The current timer-based delay loop relies on the architected timer to initiate the switch away from the polling-based implementation. This is unfortunate for platforms without the architected timers but with a suitable delay source (that is, constant frequency, always powered-up and ticking as long as the CPUs are online). This patch introduces a registration mechanism for the delay timer (which provides an unconditional read_current_timer implementation) and updates the architected timer code to use the new interface. Reviewed-by: Stephen Boyd Signed-off-by: Jonathan Austin Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/arch_timer.h | 1 - arch/arm/include/asm/delay.h | 9 +++++++++ arch/arm/include/asm/timex.h | 6 ------ arch/arm/kernel/arch_timer.c | 17 ++++++++--------- arch/arm/lib/delay.c | 34 ++++++++++++++++++++++++++-------- 5 files changed, 43 insertions(+), 24 deletions(-) diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index ad9b155c8262..d40229d9a1c9 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -5,7 +5,6 @@ #include #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); 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 ce119442277c..9acc135dad94 100644 --- a/arch/arm/include/asm/timex.h +++ b/arch/arm/include/asm/timex.h @@ -12,15 +12,9 @@ #ifndef _ASMARM_TIMEX_H #define _ASMARM_TIMEX_H -#include #include typedef unsigned long cycles_t; - -#ifdef ARCH_HAS_READ_CURRENT_TIMER #define get_cycles() ({ cycles_t c; read_current_timer(&c) ? 0 : c; }) -#else -#define get_cycles() (0) -#endif #endif diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index c04c2a6da470..c8ef20747ee7 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -21,6 +21,7 @@ #include #include +#include #include #include #include @@ -39,8 +40,7 @@ enum ppi_nr { static int arch_timer_ppi[MAX_TIMER_PPI]; static struct clock_event_device __percpu **arch_timer_evt; - -extern void init_current_timer_delay(unsigned long freq); +static struct delay_timer arch_delay_timer; static bool arch_timer_use_virtual = true; @@ -325,12 +325,9 @@ static cycle_t arch_counter_read(struct clocksource *cs) 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) @@ -441,11 +438,13 @@ 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: diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c index d6dacc69254e..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(); @@ -55,17 +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; - 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 -- cgit v1.2.1