diff options
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/arch_timer.c | 350 | ||||
| -rw-r--r-- | arch/arm/kernel/bios32.c | 37 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 3 |
4 files changed, 380 insertions, 11 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 7b787d642af..22b0f1e255f 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -34,6 +34,7 @@ obj-$(CONFIG_ARM_CPU_SUSPEND) += sleep.o suspend.o obj-$(CONFIG_SMP) += smp.o smp_tlb.o obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o obj-$(CONFIG_HAVE_ARM_TWD) += smp_twd.o +obj-$(CONFIG_ARM_ARCH_TIMER) += arch_timer.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c new file mode 100644 index 00000000000..dd58035621f --- /dev/null +++ b/arch/arm/kernel/arch_timer.c @@ -0,0 +1,350 @@ +/* + * linux/arch/arm/kernel/arch_timer.c + * + * Copyright (C) 2011 ARM Ltd. + * All Rights Reserved + * + * 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. + */ +#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/clockchips.h> +#include <linux/interrupt.h> +#include <linux/of_irq.h> +#include <linux/io.h> + +#include <asm/cputype.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; + +static struct clock_event_device __percpu **arch_timer_evt; + +/* + * Architected system timer support. + */ + +#define ARCH_TIMER_CTRL_ENABLE (1 << 0) +#define ARCH_TIMER_CTRL_IT_MASK (1 << 1) +#define ARCH_TIMER_CTRL_IT_STAT (1 << 2) + +#define ARCH_TIMER_REG_CTRL 0 +#define ARCH_TIMER_REG_FREQ 1 +#define ARCH_TIMER_REG_TVAL 2 + +static void arch_timer_reg_write(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; + } + + isb(); +} + +static u32 arch_timer_reg_read(int reg) +{ + u32 val; + + 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(); + } + + return val; +} + +static irqreturn_t arch_timer_handler(int irq, void *dev_id) +{ + struct clock_event_device *evt = *(struct clock_event_device **)dev_id; + unsigned long ctrl; + + ctrl = arch_timer_reg_read(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); + evt->event_handler(evt); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static void arch_timer_disable(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_disable(); + 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_IT_MASK; + + arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt); + arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl); + + return 0; +} + +static int __cpuinit arch_timer_setup(struct clock_event_device *clk) +{ + /* Be safe... */ + arch_timer_disable(); + + clk->features = CLOCK_EVT_FEAT_ONESHOT; + 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; + + 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); + + return 0; +} + +/* Is the optional system timer available? */ +static int local_timer_is_architected(void) +{ + return (cpu_architecture() >= CPU_ARCH_ARMv7) && + ((read_cpuid_ext(CPUID_EXT_PFR1) >> 16) & 0xf) == 1; +} + +static int arch_timer_available(void) +{ + unsigned long freq; + + if (!local_timer_is_architected()) + 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); + + /* Check the timer frequency. */ + if (freq == 0) { + pr_warn("Architected timer frequency not available\n"); + return -EINVAL; + } + + arch_timer_rate = freq; + } + + pr_info_once("Architected local timer running at %lu.%02luMHz.\n", + arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100); + return 0; +} + +static inline cycle_t arch_counter_get_cntpct(void) +{ + u32 cvall, cvalh; + + asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (cvall), "=r" (cvalh)); + + 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; +} + +static u32 notrace arch_counter_get_cntvct32(void) +{ + cycle_t cntvct = 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); +} + +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, +}; + +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); +} + +static struct local_timer_ops arch_timer_ops __cpuinitdata = { + .setup = arch_timer_setup, + .stop = arch_timer_stop, +}; + +static struct clock_event_device arch_timer_global_evt; + +static int __init arch_timer_register(void) +{ + int err; + + err = arch_timer_available(); + if (err) + return err; + + arch_timer_evt = alloc_percpu(struct clock_event_device *); + if (!arch_timer_evt) + return -ENOMEM; + + clocksource_register_hz(&clocksource_counter, arch_timer_rate); + + 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); + 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) { + /* + * We couldn't register as a local timer (could be + * because we're on a UP platform, or because some + * other local timer is already present...). Try as a + * global timer instead. + */ + arch_timer_global_evt.cpumask = cpumask_of(0); + err = arch_timer_setup(&arch_timer_global_evt); + } + + if (err) + goto out_free_irq; + + 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); + +out_free: + free_percpu(arch_timer_evt); + + return err; +} + +static const struct of_device_id arch_timer_of_match[] __initconst = { + { .compatible = "arm,armv7-timer", }, + {}, +}; + +int __init arch_timer_of_register(void) +{ + struct device_node *np; + 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_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); + + return arch_timer_register(); +} + +int __init arch_timer_sched_clock_init(void) +{ + int err; + + err = arch_timer_available(); + if (err) + return err; + + setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate); + return 0; +} diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index ede5f7741c4..25552508c3f 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -374,16 +374,29 @@ EXPORT_SYMBOL(pcibios_fixup_bus); #endif /* - * Swizzle the device pin each time we cross a bridge. - * This might update pin and returns the slot number. + * Swizzle the device pin each time we cross a bridge. If a platform does + * not provide a swizzle function, we perform the standard PCI swizzling. + * + * The default swizzling walks up the bus tree one level at a time, applying + * the standard swizzle function at each step, stopping when it finds the PCI + * root bus. This will return the slot number of the bridge device on the + * root bus and the interrupt pin on that device which should correspond + * with the downstream device interrupt. + * + * Platforms may override this, in which case the slot and pin returned + * depend entirely on the platform code. However, please note that the + * PCI standard swizzle is implemented on plug-in cards and Cardbus based + * PCI extenders, so it can not be ignored. */ static u8 __devinit pcibios_swizzle(struct pci_dev *dev, u8 *pin) { struct pci_sys_data *sys = dev->sysdata; - int slot = 0, oldpin = *pin; + int slot, oldpin = *pin; if (sys->swizzle) slot = sys->swizzle(dev, pin); + else + slot = pci_common_swizzle(dev, pin); if (debug_pci) printk("PCI: %s swizzling pin %d => pin %d slot %d\n", @@ -410,7 +423,7 @@ static int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return irq; } -static void __init pcibios_init_hw(struct hw_pci *hw) +static void __init pcibios_init_hw(struct hw_pci *hw, struct list_head *head) { struct pci_sys_data *sys = NULL; int ret; @@ -424,7 +437,6 @@ static void __init pcibios_init_hw(struct hw_pci *hw) #ifdef CONFIG_PCI_DOMAINS sys->domain = hw->domain; #endif - sys->hw = hw; sys->busnr = busnr; sys->swizzle = hw->swizzle; sys->map_irq = hw->map_irq; @@ -440,14 +452,18 @@ static void __init pcibios_init_hw(struct hw_pci *hw) &iomem_resource, sys->mem_offset); } - sys->bus = hw->scan(nr, sys); + if (hw->scan) + sys->bus = hw->scan(nr, sys); + else + sys->bus = pci_scan_root_bus(NULL, sys->busnr, + hw->ops, sys, &sys->resources); if (!sys->bus) panic("PCI: unable to scan bus!"); busnr = sys->bus->subordinate + 1; - list_add(&sys->node, &hw->buses); + list_add(&sys->node, head); } else { kfree(sys); if (ret < 0) @@ -459,19 +475,18 @@ static void __init pcibios_init_hw(struct hw_pci *hw) void __init pci_common_init(struct hw_pci *hw) { struct pci_sys_data *sys; - - INIT_LIST_HEAD(&hw->buses); + LIST_HEAD(head); pci_add_flags(PCI_REASSIGN_ALL_RSRC); if (hw->preinit) hw->preinit(); - pcibios_init_hw(hw); + pcibios_init_hw(hw, &head); if (hw->postinit) hw->postinit(); pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq); - list_for_each_entry(sys, &hw->buses, node) { + list_for_each_entry(sys, &head, node) { struct pci_bus *bus = sys->bus; if (!pci_has_flag(PCI_PROBE_ONLY)) { diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 8f464465977..cf58558ef4b 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -454,6 +454,9 @@ static struct local_timer_ops *lt_ops; #ifdef CONFIG_LOCAL_TIMERS int local_timer_register(struct local_timer_ops *ops) { + if (!is_smp() || !setup_max_cpus) + return -ENXIO; + if (lt_ops) return -EBUSY; |