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OpenCloudOS-Kernel/drivers/clocksource/arm_arch_timer.c

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/*
* linux/drivers/clocksource/arm_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.
*/
#define pr_fmt(fmt) "arm_arch_timer: " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/sched/clock.h>
#include <linux/sched_clock.h>
#include <linux/acpi.h>
#include <asm/arch_timer.h>
#include <asm/virt.h>
#include <clocksource/arm_arch_timer.h>
#define CNTTIDR 0x08
#define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
#define CNTACR(n) (0x40 + ((n) * 4))
#define CNTACR_RPCT BIT(0)
#define CNTACR_RVCT BIT(1)
#define CNTACR_RFRQ BIT(2)
#define CNTACR_RVOFF BIT(3)
#define CNTACR_RWVT BIT(4)
#define CNTACR_RWPT BIT(5)
#define CNTVCT_LO 0x08
#define CNTVCT_HI 0x0c
#define CNTFRQ 0x10
#define CNTP_TVAL 0x28
#define CNTP_CTL 0x2c
#define CNTV_TVAL 0x38
#define CNTV_CTL 0x3c
#define ARCH_CP15_TIMER BIT(0)
#define ARCH_MEM_TIMER BIT(1)
static unsigned arch_timers_present __initdata;
static void __iomem *arch_counter_base;
struct arch_timer {
void __iomem *base;
struct clock_event_device evt;
};
#define to_arch_timer(e) container_of(e, struct arch_timer, evt)
static u32 arch_timer_rate;
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 enum ppi_nr arch_timer_uses_ppi = VIRT_PPI;
static bool arch_timer_c3stop;
static bool arch_timer_mem_use_virtual;
static bool arch_counter_suspend_stop;
static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
static int __init early_evtstrm_cfg(char *buf)
{
return strtobool(buf, &evtstrm_enable);
}
early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
/*
* Architected system timer support.
*/
#ifdef CONFIG_FSL_ERRATUM_A008585
/*
* The number of retries is an arbitrary value well beyond the highest number
* of iterations the loop has been observed to take.
*/
#define __fsl_a008585_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 200; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely(_old != _new) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
static u32 notrace fsl_a008585_read_cntp_tval_el0(void)
{
return __fsl_a008585_read_reg(cntp_tval_el0);
}
static u32 notrace fsl_a008585_read_cntv_tval_el0(void)
{
return __fsl_a008585_read_reg(cntv_tval_el0);
}
static u64 notrace fsl_a008585_read_cntvct_el0(void)
{
return __fsl_a008585_read_reg(cntvct_el0);
}
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
/*
* Verify whether the value of the second read is larger than the first by
* less than 32 is the only way to confirm the value is correct, so clear the
* lower 5 bits to check whether the difference is greater than 32 or not.
* Theoretically the erratum should not occur more than twice in succession
* when reading the system counter, but it is possible that some interrupts
* may lead to more than twice read errors, triggering the warning, so setting
* the number of retries far beyond the number of iterations the loop has been
* observed to take.
*/
#define __hisi_161010101_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 50; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely((_new - _old) >> 5) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
static u32 notrace hisi_161010101_read_cntp_tval_el0(void)
{
return __hisi_161010101_read_reg(cntp_tval_el0);
}
static u32 notrace hisi_161010101_read_cntv_tval_el0(void)
{
return __hisi_161010101_read_reg(cntv_tval_el0);
}
static u64 notrace hisi_161010101_read_cntvct_el0(void)
{
return __hisi_161010101_read_reg(cntvct_el0);
}
#endif
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround = NULL;
EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled);
EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
static const struct arch_timer_erratum_workaround ool_workarounds[] = {
#ifdef CONFIG_FSL_ERRATUM_A008585
{
.id = "fsl,erratum-a008585",
.read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0,
.read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0,
.read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
},
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
{
.id = "hisilicon,erratum-161010101",
.read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
.read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
},
#endif
};
#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static __always_inline
void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
struct clock_event_device *clk)
{
if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
struct arch_timer *timer = to_arch_timer(clk);
switch (reg) {
case ARCH_TIMER_REG_CTRL:
writel_relaxed(val, timer->base + CNTP_CTL);
break;
case ARCH_TIMER_REG_TVAL:
writel_relaxed(val, timer->base + CNTP_TVAL);
break;
}
} else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
struct arch_timer *timer = to_arch_timer(clk);
switch (reg) {
case ARCH_TIMER_REG_CTRL:
writel_relaxed(val, timer->base + CNTV_CTL);
break;
case ARCH_TIMER_REG_TVAL:
writel_relaxed(val, timer->base + CNTV_TVAL);
break;
}
} else {
arch_timer_reg_write_cp15(access, reg, val);
}
}
static __always_inline
u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
struct clock_event_device *clk)
{
u32 val;
if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
struct arch_timer *timer = to_arch_timer(clk);
switch (reg) {
case ARCH_TIMER_REG_CTRL:
val = readl_relaxed(timer->base + CNTP_CTL);
break;
case ARCH_TIMER_REG_TVAL:
val = readl_relaxed(timer->base + CNTP_TVAL);
break;
}
} else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
struct arch_timer *timer = to_arch_timer(clk);
switch (reg) {
case ARCH_TIMER_REG_CTRL:
val = readl_relaxed(timer->base + CNTV_CTL);
break;
case ARCH_TIMER_REG_TVAL:
val = readl_relaxed(timer->base + CNTV_TVAL);
break;
}
} else {
val = arch_timer_reg_read_cp15(access, reg);
}
return val;
}
static __always_inline irqreturn_t timer_handler(const int access,
struct clock_event_device *evt)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
ctrl |= ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
evt->event_handler(evt);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
}
static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
}
static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
}
static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
}
static __always_inline int timer_shutdown(const int access,
struct clock_event_device *clk)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
return 0;
}
static int arch_timer_shutdown_virt(struct clock_event_device *clk)
{
return timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
}
static int arch_timer_shutdown_phys(struct clock_event_device *clk)
{
return timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
}
static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk)
{
return timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk);
}
static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk)
{
return timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk);
}
static __always_inline void set_next_event(const int access, unsigned long evt,
struct clock_event_device *clk)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
ctrl |= ARCH_TIMER_CTRL_ENABLE;
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk);
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
static __always_inline void erratum_set_next_event_generic(const int access,
unsigned long evt, struct clock_event_device *clk)
{
unsigned long ctrl;
u64 cval = evt + arch_counter_get_cntvct();
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
ctrl |= ARCH_TIMER_CTRL_ENABLE;
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
if (access == ARCH_TIMER_PHYS_ACCESS)
write_sysreg(cval, cntp_cval_el0);
else if (access == ARCH_TIMER_VIRT_ACCESS)
write_sysreg(cval, cntv_cval_el0);
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
static int erratum_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
{
erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
return 0;
}
static int erratum_set_next_event_phys(unsigned long evt,
struct clock_event_device *clk)
{
erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
return 0;
}
#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static int arch_timer_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
{
set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
return 0;
}
static int arch_timer_set_next_event_phys(unsigned long evt,
struct clock_event_device *clk)
{
set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
return 0;
}
static int arch_timer_set_next_event_virt_mem(unsigned long evt,
struct clock_event_device *clk)
{
set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
return 0;
}
static int arch_timer_set_next_event_phys_mem(unsigned long evt,
struct clock_event_device *clk)
{
set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
return 0;
}
static void erratum_workaround_set_sne(struct clock_event_device *clk)
{
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
if (!static_branch_unlikely(&arch_timer_read_ool_enabled))
return;
if (arch_timer_uses_ppi == VIRT_PPI)
clk->set_next_event = erratum_set_next_event_virt;
else
clk->set_next_event = erratum_set_next_event_phys;
#endif
}
static void __arch_timer_setup(unsigned type,
struct clock_event_device *clk)
{
clk->features = CLOCK_EVT_FEAT_ONESHOT;
if (type == ARCH_CP15_TIMER) {
if (arch_timer_c3stop)
clk->features |= CLOCK_EVT_FEAT_C3STOP;
clk->name = "arch_sys_timer";
clk->rating = 450;
clk->cpumask = cpumask_of(smp_processor_id());
clk->irq = arch_timer_ppi[arch_timer_uses_ppi];
switch (arch_timer_uses_ppi) {
case VIRT_PPI:
clk->set_state_shutdown = arch_timer_shutdown_virt;
clk->set_state_oneshot_stopped = arch_timer_shutdown_virt;
clk->set_next_event = arch_timer_set_next_event_virt;
break;
case PHYS_SECURE_PPI:
case PHYS_NONSECURE_PPI:
case HYP_PPI:
clk->set_state_shutdown = arch_timer_shutdown_phys;
clk->set_state_oneshot_stopped = arch_timer_shutdown_phys;
clk->set_next_event = arch_timer_set_next_event_phys;
break;
default:
BUG();
}
erratum_workaround_set_sne(clk);
} else {
clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
clk->name = "arch_mem_timer";
clk->rating = 400;
clk->cpumask = cpu_all_mask;
if (arch_timer_mem_use_virtual) {
clk->set_state_shutdown = arch_timer_shutdown_virt_mem;
clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem;
clk->set_next_event =
arch_timer_set_next_event_virt_mem;
} else {
clk->set_state_shutdown = arch_timer_shutdown_phys_mem;
clk->set_state_oneshot_stopped = arch_timer_shutdown_phys_mem;
clk->set_next_event =
arch_timer_set_next_event_phys_mem;
}
}
clk->set_state_shutdown(clk);
clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
}
static void arch_timer_evtstrm_enable(int divider)
{
u32 cntkctl = arch_timer_get_cntkctl();
cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
/* Set the divider and enable virtual event stream */
cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
| ARCH_TIMER_VIRT_EVT_EN;
arch_timer_set_cntkctl(cntkctl);
elf_hwcap |= HWCAP_EVTSTRM;
#ifdef CONFIG_COMPAT
compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
#endif
}
static void arch_timer_configure_evtstream(void)
{
int evt_stream_div, pos;
/* Find the closest power of two to the divisor */
evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
pos = fls(evt_stream_div);
if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
pos--;
/* enable event stream */
arch_timer_evtstrm_enable(min(pos, 15));
}
static void arch_counter_set_user_access(void)
{
u32 cntkctl = arch_timer_get_cntkctl();
/* Disable user access to the timers and the physical counter */
/* Also disable virtual event stream */
cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
| ARCH_TIMER_USR_VT_ACCESS_EN
| ARCH_TIMER_VIRT_EVT_EN
| ARCH_TIMER_USR_PCT_ACCESS_EN);
/* Enable user access to the virtual counter */
cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
arch_timer_set_cntkctl(cntkctl);
}
static bool arch_timer_has_nonsecure_ppi(void)
{
return (arch_timer_uses_ppi == PHYS_SECURE_PPI &&
arch_timer_ppi[PHYS_NONSECURE_PPI]);
}
static u32 check_ppi_trigger(int irq)
{
u32 flags = irq_get_trigger_type(irq);
if (flags != IRQF_TRIGGER_HIGH && flags != IRQF_TRIGGER_LOW) {
pr_warn("WARNING: Invalid trigger for IRQ%d, assuming level low\n", irq);
pr_warn("WARNING: Please fix your firmware\n");
flags = IRQF_TRIGGER_LOW;
}
return flags;
}
static int arch_timer_starting_cpu(unsigned int cpu)
{
struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
u32 flags;
__arch_timer_setup(ARCH_CP15_TIMER, clk);
flags = check_ppi_trigger(arch_timer_ppi[arch_timer_uses_ppi]);
enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], flags);
if (arch_timer_has_nonsecure_ppi()) {
flags = check_ppi_trigger(arch_timer_ppi[PHYS_NONSECURE_PPI]);
enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], flags);
}
arch_counter_set_user_access();
if (evtstrm_enable)
arch_timer_configure_evtstream();
return 0;
}
static void
arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
{
/* Who has more than one independent system counter? */
if (arch_timer_rate)
return;
/*
* Try to determine the frequency from the device tree or CNTFRQ,
* if ACPI is enabled, get the frequency from CNTFRQ ONLY.
*/
if (!acpi_disabled ||
of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
if (cntbase)
arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
else
arch_timer_rate = arch_timer_get_cntfrq();
}
/* Check the timer frequency. */
if (arch_timer_rate == 0)
pr_warn("Architected timer frequency not available\n");
}
static void arch_timer_banner(unsigned type)
{
pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
type & ARCH_CP15_TIMER ? "cp15" : "",
type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? " and " : "",
type & ARCH_MEM_TIMER ? "mmio" : "",
(unsigned long)arch_timer_rate / 1000000,
(unsigned long)(arch_timer_rate / 10000) % 100,
type & ARCH_CP15_TIMER ?
(arch_timer_uses_ppi == VIRT_PPI) ? "virt" : "phys" :
"",
type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? "/" : "",
type & ARCH_MEM_TIMER ?
arch_timer_mem_use_virtual ? "virt" : "phys" :
"");
}
u32 arch_timer_get_rate(void)
{
return arch_timer_rate;
}
static u64 arch_counter_get_cntvct_mem(void)
{
u32 vct_lo, vct_hi, tmp_hi;
do {
vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
} while (vct_hi != tmp_hi);
return ((u64) vct_hi << 32) | vct_lo;
}
/*
* Default to cp15 based access because arm64 uses this function for
* sched_clock() before DT is probed and the cp15 method is guaranteed
* to exist on arm64. arm doesn't use this before DT is probed so even
* if we don't have the cp15 accessors we won't have a problem.
*/
u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct;
static u64 arch_counter_read(struct clocksource *cs)
{
return arch_timer_read_counter();
}
static u64 arch_counter_read_cc(const struct cyclecounter *cc)
{
return arch_timer_read_counter();
}
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 struct cyclecounter cyclecounter __ro_after_init = {
.read = arch_counter_read_cc,
.mask = CLOCKSOURCE_MASK(56),
};
static struct arch_timer_kvm_info arch_timer_kvm_info;
struct arch_timer_kvm_info *arch_timer_get_kvm_info(void)
{
return &arch_timer_kvm_info;
}
static void __init arch_counter_register(unsigned type)
{
u64 start_count;
/* Register the CP15 based counter if we have one */
if (type & ARCH_CP15_TIMER) {
if (IS_ENABLED(CONFIG_ARM64) || arch_timer_uses_ppi == VIRT_PPI)
arch_timer_read_counter = arch_counter_get_cntvct;
else
arch_timer_read_counter = arch_counter_get_cntpct;
clocksource_counter.archdata.vdso_direct = true;
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
/*
* Don't use the vdso fastpath if errata require using
* the out-of-line counter accessor.
*/
if (static_branch_unlikely(&arch_timer_read_ool_enabled))
clocksource_counter.archdata.vdso_direct = false;
#endif
} else {
arch_timer_read_counter = arch_counter_get_cntvct_mem;
}
if (!arch_counter_suspend_stop)
clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
start_count = arch_timer_read_counter();
clocksource_register_hz(&clocksource_counter, arch_timer_rate);
cyclecounter.mult = clocksource_counter.mult;
cyclecounter.shift = clocksource_counter.shift;
timecounter_init(&arch_timer_kvm_info.timecounter,
&cyclecounter, start_count);
/* 56 bits minimum, so we assume worst case rollover */
sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
}
static void 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(arch_timer_ppi[arch_timer_uses_ppi]);
if (arch_timer_has_nonsecure_ppi())
disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
clk->set_state_shutdown(clk);
}
static int arch_timer_dying_cpu(unsigned int cpu)
{
struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
arch_timer_stop(clk);
return 0;
}
#ifdef CONFIG_CPU_PM
static unsigned int saved_cntkctl;
static int arch_timer_cpu_pm_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
if (action == CPU_PM_ENTER)
saved_cntkctl = arch_timer_get_cntkctl();
else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
arch_timer_set_cntkctl(saved_cntkctl);
return NOTIFY_OK;
}
static struct notifier_block arch_timer_cpu_pm_notifier = {
.notifier_call = arch_timer_cpu_pm_notify,
};
static int __init arch_timer_cpu_pm_init(void)
{
return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
}
static void __init arch_timer_cpu_pm_deinit(void)
{
WARN_ON(cpu_pm_unregister_notifier(&arch_timer_cpu_pm_notifier));
}
#else
static int __init arch_timer_cpu_pm_init(void)
{
return 0;
}
static void __init arch_timer_cpu_pm_deinit(void)
{
}
#endif
static int __init arch_timer_register(void)
{
int err;
int ppi;
arch_timer_evt = alloc_percpu(struct clock_event_device);
if (!arch_timer_evt) {
err = -ENOMEM;
goto out;
}
ppi = arch_timer_ppi[arch_timer_uses_ppi];
switch (arch_timer_uses_ppi) {
case VIRT_PPI:
err = request_percpu_irq(ppi, arch_timer_handler_virt,
"arch_timer", arch_timer_evt);
break;
case PHYS_SECURE_PPI:
case PHYS_NONSECURE_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);
}
break;
case HYP_PPI:
err = request_percpu_irq(ppi, arch_timer_handler_phys,
"arch_timer", arch_timer_evt);
break;
default:
BUG();
}
if (err) {
pr_err("arch_timer: can't register interrupt %d (%d)\n",
ppi, err);
goto out_free;
}
err = arch_timer_cpu_pm_init();
if (err)
goto out_unreg_notify;
/* Register and immediately configure the timer on the boot CPU */
err = cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_STARTING,
"clockevents/arm/arch_timer:starting",
arch_timer_starting_cpu, arch_timer_dying_cpu);
if (err)
goto out_unreg_cpupm;
return 0;
out_unreg_cpupm:
arch_timer_cpu_pm_deinit();
out_unreg_notify:
free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt);
if (arch_timer_has_nonsecure_ppi())
free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
arch_timer_evt);
out_free:
free_percpu(arch_timer_evt);
out:
return err;
}
static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
{
int ret;
irq_handler_t func;
struct arch_timer *t;
t = kzalloc(sizeof(*t), GFP_KERNEL);
if (!t)
return -ENOMEM;
t->base = base;
t->evt.irq = irq;
__arch_timer_setup(ARCH_MEM_TIMER, &t->evt);
if (arch_timer_mem_use_virtual)
func = arch_timer_handler_virt_mem;
else
func = arch_timer_handler_phys_mem;
ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
if (ret) {
pr_err("arch_timer: Failed to request mem timer irq\n");
kfree(t);
}
return ret;
}
static const struct of_device_id arch_timer_of_match[] __initconst = {
{ .compatible = "arm,armv7-timer", },
{ .compatible = "arm,armv8-timer", },
{},
};
static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
{ .compatible = "arm,armv7-timer-mem", },
{},
};
static bool __init
arch_timer_needs_probing(int type, const struct of_device_id *matches)
{
struct device_node *dn;
bool needs_probing = false;
dn = of_find_matching_node(NULL, matches);
if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
needs_probing = true;
of_node_put(dn);
return needs_probing;
}
static int __init arch_timer_common_init(void)
{
unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
/* Wait until both nodes are probed if we have two timers */
if ((arch_timers_present & mask) != mask) {
if (arch_timer_needs_probing(ARCH_MEM_TIMER, arch_timer_mem_of_match))
return 0;
if (arch_timer_needs_probing(ARCH_CP15_TIMER, arch_timer_of_match))
return 0;
}
arch_timer_banner(arch_timers_present);
arch_counter_register(arch_timers_present);
return arch_timer_arch_init();
}
static int __init arch_timer_init(void)
{
int ret;
/*
* If HYP mode is available, we know that the physical timer
* has been configured to be accessible from PL1. Use it, so
* that a guest can use the virtual timer instead.
*
* If no interrupt provided for virtual timer, we'll have to
* stick to the physical timer. It'd better be accessible...
*
* On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
* accesses to CNTP_*_EL1 registers are silently redirected to
* their CNTHP_*_EL2 counterparts, and use a different PPI
* number.
*/
if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
bool has_ppi;
if (is_kernel_in_hyp_mode()) {
arch_timer_uses_ppi = HYP_PPI;
has_ppi = !!arch_timer_ppi[HYP_PPI];
} else {
arch_timer_uses_ppi = PHYS_SECURE_PPI;
has_ppi = (!!arch_timer_ppi[PHYS_SECURE_PPI] ||
!!arch_timer_ppi[PHYS_NONSECURE_PPI]);
}
if (!has_ppi) {
pr_warn("arch_timer: No interrupt available, giving up\n");
return -EINVAL;
}
}
ret = arch_timer_register();
if (ret)
return ret;
ret = arch_timer_common_init();
if (ret)
return ret;
arch_timer_kvm_info.virtual_irq = arch_timer_ppi[VIRT_PPI];
return 0;
}
static int __init arch_timer_of_init(struct device_node *np)
{
int i;
if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: multiple nodes in dt, skipping\n");
return 0;
}
arch_timers_present |= ARCH_CP15_TIMER;
for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
arch_timer_detect_rate(NULL, np);
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
if (of_property_read_bool(np, ool_workarounds[i].id)) {
timer_unstable_counter_workaround = &ool_workarounds[i];
static_branch_enable(&arch_timer_read_ool_enabled);
pr_info("arch_timer: Enabling workaround for %s\n",
timer_unstable_counter_workaround->id);
break;
}
}
#endif
/*
* If we cannot rely on firmware initializing the timer registers then
* we should use the physical timers instead.
*/
if (IS_ENABLED(CONFIG_ARM) &&
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
arch_timer_uses_ppi = PHYS_SECURE_PPI;
/* On some systems, the counter stops ticking when in suspend. */
arch_counter_suspend_stop = of_property_read_bool(np,
"arm,no-tick-in-suspend");
return arch_timer_init();
}
CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
static int __init arch_timer_mem_init(struct device_node *np)
{
struct device_node *frame, *best_frame = NULL;
void __iomem *cntctlbase, *base;
unsigned int irq, ret = -EINVAL;
u32 cnttidr;
arch_timers_present |= ARCH_MEM_TIMER;
cntctlbase = of_iomap(np, 0);
if (!cntctlbase) {
pr_err("arch_timer: Can't find CNTCTLBase\n");
return -ENXIO;
}
cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
/*
* Try to find a virtual capable frame. Otherwise fall back to a
* physical capable frame.
*/
for_each_available_child_of_node(np, frame) {
int n;
u32 cntacr;
if (of_property_read_u32(frame, "frame-number", &n)) {
pr_err("arch_timer: Missing frame-number\n");
of_node_put(frame);
goto out;
}
/* Try enabling everything, and see what sticks */
cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
writel_relaxed(cntacr, cntctlbase + CNTACR(n));
cntacr = readl_relaxed(cntctlbase + CNTACR(n));
if ((cnttidr & CNTTIDR_VIRT(n)) &&
!(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
of_node_put(best_frame);
best_frame = frame;
arch_timer_mem_use_virtual = true;
break;
}
if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
continue;
of_node_put(best_frame);
best_frame = of_node_get(frame);
}
ret= -ENXIO;
base = arch_counter_base = of_io_request_and_map(best_frame, 0,
"arch_mem_timer");
if (IS_ERR(base)) {
pr_err("arch_timer: Can't map frame's registers\n");
goto out;
}
if (arch_timer_mem_use_virtual)
irq = irq_of_parse_and_map(best_frame, 1);
else
irq = irq_of_parse_and_map(best_frame, 0);
ret = -EINVAL;
if (!irq) {
pr_err("arch_timer: Frame missing %s irq",
arch_timer_mem_use_virtual ? "virt" : "phys");
goto out;
}
arch_timer_detect_rate(base, np);
ret = arch_timer_mem_register(base, irq);
if (ret)
goto out;
return arch_timer_common_init();
out:
iounmap(cntctlbase);
of_node_put(best_frame);
return ret;
}
CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
arch_timer_mem_init);
#ifdef CONFIG_ACPI
static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
{
int trigger, polarity;
if (!interrupt)
return 0;
trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
: ACPI_LEVEL_SENSITIVE;
polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
: ACPI_ACTIVE_HIGH;
return acpi_register_gsi(NULL, interrupt, trigger, polarity);
}
/* Initialize per-processor generic timer */
static int __init arch_timer_acpi_init(struct acpi_table_header *table)
{
struct acpi_table_gtdt *gtdt;
if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: already initialized, skipping\n");
return -EINVAL;
}
gtdt = container_of(table, struct acpi_table_gtdt, header);
arch_timers_present |= ARCH_CP15_TIMER;
arch_timer_ppi[PHYS_SECURE_PPI] =
map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
gtdt->secure_el1_flags);
arch_timer_ppi[PHYS_NONSECURE_PPI] =
map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
gtdt->non_secure_el1_flags);
arch_timer_ppi[VIRT_PPI] =
map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
gtdt->virtual_timer_flags);
arch_timer_ppi[HYP_PPI] =
map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
gtdt->non_secure_el2_flags);
/* Get the frequency from CNTFRQ */
arch_timer_detect_rate(NULL, NULL);
/* Always-on capability */
arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
arch_timer_init();
return 0;
}
CLOCKSOURCE_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
#endif
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