#define CNTACR_RWVT BIT(4)
#define CNTACR_RWPT BIT(5)
-#define CNTVCT_LO 0x08
-#define CNTVCT_HI 0x0c
+#define CNTVCT_LO 0x00
+#define CNTPCT_LO 0x08
#define CNTFRQ 0x10
-#define CNTP_TVAL 0x28
+#define CNTP_CVAL_LO 0x20
#define CNTP_CTL 0x2c
-#define CNTV_TVAL 0x38
+#define CNTV_CVAL_LO 0x30
#define CNTV_CTL 0x3c
-static unsigned arch_timers_present __initdata;
+/*
+ * The minimum amount of time a generic counter is guaranteed to not roll over
+ * (40 years)
+ */
+#define MIN_ROLLOVER_SECS (40ULL * 365 * 24 * 3600)
-static void __iomem *arch_counter_base __ro_after_init;
+static unsigned arch_timers_present __initdata;
struct arch_timer {
void __iomem *base;
struct clock_event_device evt;
};
+static struct arch_timer *arch_timer_mem __ro_after_init;
+
#define to_arch_timer(e) container_of(e, struct arch_timer, evt)
static u32 arch_timer_rate __ro_after_init;
early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
/*
+ * Makes an educated guess at a valid counter width based on the Generic Timer
+ * specification. Of note:
+ * 1) the system counter is at least 56 bits wide
+ * 2) a roll-over time of not less than 40 years
+ *
+ * See 'ARM DDI 0487G.a D11.1.2 ("The system counter")' for more details.
+ */
+static int arch_counter_get_width(void)
+{
+ u64 min_cycles = MIN_ROLLOVER_SECS * arch_timer_rate;
+
+ /* guarantee the returned width is within the valid range */
+ return clamp_val(ilog2(min_cycles - 1) + 1, 56, 64);
+}
+
+/*
* Architected system timer support.
*/
static __always_inline
-void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
+void arch_timer_reg_write(int access, enum arch_timer_reg reg, u64 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);
+ writel_relaxed((u32)val, timer->base + CNTP_CTL);
break;
- case ARCH_TIMER_REG_TVAL:
- writel_relaxed(val, timer->base + CNTP_TVAL);
+ case ARCH_TIMER_REG_CVAL:
+ /*
+ * Not guaranteed to be atomic, so the timer
+ * must be disabled at this point.
+ */
+ writeq_relaxed(val, timer->base + CNTP_CVAL_LO);
break;
+ default:
+ BUILD_BUG();
}
} 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);
+ writel_relaxed((u32)val, timer->base + CNTV_CTL);
break;
- case ARCH_TIMER_REG_TVAL:
- writel_relaxed(val, timer->base + CNTV_TVAL);
+ case ARCH_TIMER_REG_CVAL:
+ /* Same restriction as above */
+ writeq_relaxed(val, timer->base + CNTV_CVAL_LO);
break;
+ default:
+ BUILD_BUG();
}
} else {
arch_timer_reg_write_cp15(access, reg, val);
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;
+ default:
+ BUILD_BUG();
}
} else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
struct arch_timer *timer = to_arch_timer(clk);
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;
+ default:
+ BUILD_BUG();
}
} else {
val = arch_timer_reg_read_cp15(access, reg);
.id = CSID_ARM_ARCH_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),
};
struct ate_acpi_oem_info {
_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_cntpct_el0(void)
{
return __fsl_a008585_read_reg(cntpct_el0);
_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_cntpct_el0(void)
{
return __hisi_161010101_read_reg(cntpct_el0);
{
return __sun50i_a64_read_reg(cntvct_el0);
}
-
-static u32 notrace sun50i_a64_read_cntp_tval_el0(void)
-{
- return read_sysreg(cntp_cval_el0) - sun50i_a64_read_cntpct_el0();
-}
-
-static u32 notrace sun50i_a64_read_cntv_tval_el0(void)
-{
- return read_sysreg(cntv_cval_el0) - sun50i_a64_read_cntvct_el0();
-}
#endif
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0);
-static void erratum_set_next_event_tval_generic(const int access, unsigned long evt,
+static void erratum_set_next_event_generic(const int access, unsigned long evt,
struct clock_event_device *clk)
{
unsigned long ctrl;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
-static __maybe_unused int erratum_set_next_event_tval_virt(unsigned long evt,
+static __maybe_unused int erratum_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
{
- erratum_set_next_event_tval_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
+ erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
return 0;
}
-static __maybe_unused int erratum_set_next_event_tval_phys(unsigned long evt,
+static __maybe_unused int erratum_set_next_event_phys(unsigned long evt,
struct clock_event_device *clk)
{
- erratum_set_next_event_tval_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
+ erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
return 0;
}
.match_type = ate_match_dt,
.id = "fsl,erratum-a008585",
.desc = "Freescale erratum a005858",
- .read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0,
- .read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0,
.read_cntpct_el0 = fsl_a008585_read_cntpct_el0,
.read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
- .set_next_event_phys = erratum_set_next_event_tval_phys,
- .set_next_event_virt = erratum_set_next_event_tval_virt,
+ .set_next_event_phys = erratum_set_next_event_phys,
+ .set_next_event_virt = erratum_set_next_event_virt,
},
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
.match_type = ate_match_dt,
.id = "hisilicon,erratum-161010101",
.desc = "HiSilicon erratum 161010101",
- .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
- .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
.read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
- .set_next_event_phys = erratum_set_next_event_tval_phys,
- .set_next_event_virt = erratum_set_next_event_tval_virt,
+ .set_next_event_phys = erratum_set_next_event_phys,
+ .set_next_event_virt = erratum_set_next_event_virt,
},
{
.match_type = ate_match_acpi_oem_info,
.id = hisi_161010101_oem_info,
.desc = "HiSilicon erratum 161010101",
- .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
- .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
.read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
- .set_next_event_phys = erratum_set_next_event_tval_phys,
- .set_next_event_virt = erratum_set_next_event_tval_virt,
+ .set_next_event_phys = erratum_set_next_event_phys,
+ .set_next_event_virt = erratum_set_next_event_virt,
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_858921
.match_type = ate_match_dt,
.id = "allwinner,erratum-unknown1",
.desc = "Allwinner erratum UNKNOWN1",
- .read_cntp_tval_el0 = sun50i_a64_read_cntp_tval_el0,
- .read_cntv_tval_el0 = sun50i_a64_read_cntv_tval_el0,
.read_cntpct_el0 = sun50i_a64_read_cntpct_el0,
.read_cntvct_el0 = sun50i_a64_read_cntvct_el0,
- .set_next_event_phys = erratum_set_next_event_tval_phys,
- .set_next_event_virt = erratum_set_next_event_tval_virt,
+ .set_next_event_phys = erratum_set_next_event_phys,
+ .set_next_event_virt = erratum_set_next_event_virt,
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_1418040
struct clock_event_device *clk)
{
unsigned long ctrl;
+ u64 cnt;
+
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);
+
+ if (access == ARCH_TIMER_PHYS_ACCESS)
+ cnt = __arch_counter_get_cntpct();
+ else
+ cnt = __arch_counter_get_cntvct();
+
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
return 0;
}
+static u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo)
+{
+ u32 cnt_lo, cnt_hi, tmp_hi;
+
+ do {
+ cnt_hi = readl_relaxed(t->base + offset_lo + 4);
+ cnt_lo = readl_relaxed(t->base + offset_lo);
+ tmp_hi = readl_relaxed(t->base + offset_lo + 4);
+ } while (cnt_hi != tmp_hi);
+
+ return ((u64) cnt_hi << 32) | cnt_lo;
+}
+
+static __always_inline void set_next_event_mem(const int access, unsigned long evt,
+ struct clock_event_device *clk)
+{
+ struct arch_timer *timer = to_arch_timer(clk);
+ unsigned long ctrl;
+ u64 cnt;
+
+ 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_MEM_VIRT_ACCESS)
+ cnt = arch_counter_get_cnt_mem(timer, CNTVCT_LO);
+ else
+ cnt = arch_counter_get_cnt_mem(timer, CNTPCT_LO);
+
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
+}
+
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);
+ set_next_event_mem(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);
+ set_next_event_mem(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
return 0;
}
+static u64 __arch_timer_check_delta(void)
+{
+#ifdef CONFIG_ARM64
+ const struct midr_range broken_cval_midrs[] = {
+ /*
+ * XGene-1 implements CVAL in terms of TVAL, meaning
+ * that the maximum timer range is 32bit. Shame on them.
+ */
+ MIDR_ALL_VERSIONS(MIDR_CPU_MODEL(ARM_CPU_IMP_APM,
+ APM_CPU_PART_POTENZA)),
+ {},
+ };
+
+ if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
+ pr_warn_once("Broken CNTx_CVAL_EL1, limiting width to 32bits");
+ return CLOCKSOURCE_MASK(32);
+ }
+#endif
+ return CLOCKSOURCE_MASK(arch_counter_get_width());
+}
+
static void __arch_timer_setup(unsigned type,
struct clock_event_device *clk)
{
+ u64 max_delta;
+
clk->features = CLOCK_EVT_FEAT_ONESHOT;
if (type == ARCH_TIMER_TYPE_CP15) {
}
clk->set_next_event = sne;
+ max_delta = __arch_timer_check_delta();
} else {
clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
clk->name = "arch_mem_timer";
clk->set_next_event =
arch_timer_set_next_event_phys_mem;
}
+
+ max_delta = CLOCKSOURCE_MASK(56);
}
clk->set_state_shutdown(clk);
- clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
+ clockevents_config_and_register(clk, arch_timer_rate, 0xf, max_delta);
}
static void arch_timer_evtstrm_enable(int divider)
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;
+ return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO);
}
static struct arch_timer_kvm_info arch_timer_kvm_info;
static void __init arch_counter_register(unsigned type)
{
u64 start_count;
+ int width;
/* Register the CP15 based counter if we have one */
if (type & ARCH_TIMER_TYPE_CP15) {
arch_timer_read_counter = arch_counter_get_cntvct_mem;
}
+ width = arch_counter_get_width();
+ clocksource_counter.mask = CLOCKSOURCE_MASK(width);
+ cyclecounter.mask = CLOCKSOURCE_MASK(width);
+
if (!arch_counter_suspend_stop)
clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
start_count = arch_timer_read_counter();
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);
+ sched_clock_register(arch_timer_read_counter, width, arch_timer_rate);
}
static void arch_timer_stop(struct clock_event_device *clk)
{
int ret;
irq_handler_t func;
- struct arch_timer *t;
- t = kzalloc(sizeof(*t), GFP_KERNEL);
- if (!t)
+ arch_timer_mem = kzalloc(sizeof(*arch_timer_mem), GFP_KERNEL);
+ if (!arch_timer_mem)
return -ENOMEM;
- t->base = base;
- t->evt.irq = irq;
- __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &t->evt);
+ arch_timer_mem->base = base;
+ arch_timer_mem->evt.irq = irq;
+ __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &arch_timer_mem->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);
+ ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &arch_timer_mem->evt);
if (ret) {
pr_err("Failed to request mem timer irq\n");
- kfree(t);
+ kfree(arch_timer_mem);
+ arch_timer_mem = NULL;
}
return ret;
return ret;
}
- arch_counter_base = base;
arch_timers_present |= ARCH_TIMER_TYPE_MEM;
return 0;