Messages in this thread Patch in this message | | | From | Rodolfo Giometti <> | Date | Tue, 19 Aug 2008 23:50:11 +0200 | Subject | [PATCH 09/10] PPS: low level IRQ timestamps recording. |
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Add low level IRQ timestamps recording for x86 (32 and 64 bits) platforms and enable UART clients in order to use it.
This improves PPS precision. :)
Signed-off-by: Rodolfo Giometti <giometti@linux.it> --- arch/x86/kernel/irq_32.c | 18 ++++++++++++++++++ arch/x86/kernel/irq_64.c | 22 ++++++++++++++++++++-- drivers/pps/Kconfig | 12 ++++++++++++ drivers/pps/clients/pps-ldisc.c | 18 ++++++++++++++++++ include/linux/pps.h | 1 + 5 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 1cf8c1f..3013d0d 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -15,6 +15,7 @@ #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/delay.h> +#include <linux/pps.h> #include <asm/apic.h> #include <asm/uaccess.h> @@ -25,6 +26,11 @@ EXPORT_PER_CPU_SYMBOL(irq_stat); DEFINE_PER_CPU(struct pt_regs *, irq_regs); EXPORT_PER_CPU_SYMBOL(irq_regs); +#ifdef CONFIG_PPS_IRQ_EVENTS +struct pps_ktime pps_irq_ts[NR_IRQS]; +EXPORT_SYMBOL(pps_irq_ts); +#endif + /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves. @@ -225,6 +231,12 @@ unsigned int do_IRQ(struct pt_regs *regs) /* high bit used in ret_from_ code */ int overflow, irq = ~regs->orig_ax; struct irq_desc *desc = irq_desc + irq; +#ifdef CONFIG_PPS_IRQ_EVENTS + struct timespec __ts; + + /* Get IRQ timestamps as soon as possible for the PPS layer */ + getnstimeofday(&__ts); +#endif if (unlikely((unsigned)irq >= NR_IRQS)) { printk(KERN_EMERG "%s: cannot handle IRQ %d\n", @@ -232,6 +244,12 @@ unsigned int do_IRQ(struct pt_regs *regs) BUG(); } +#ifdef CONFIG_PPS_IRQ_EVENTS + /* Then, after sanity check, store the IRQ timestamp */ + pps_irq_ts[irq].sec = __ts.tv_sec; + pps_irq_ts[irq].nsec = __ts.tv_nsec; +#endif + old_regs = set_irq_regs(regs); irq_enter(); diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 1f78b23..1ea77a7 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -17,9 +17,15 @@ #include <asm/io_apic.h> #include <asm/idle.h> #include <asm/smp.h> +#include <linux/pps.h> atomic_t irq_err_count; +#ifdef CONFIG_PPS_IRQ_EVENTS +struct pps_ktime pps_irq_ts[NR_IRQS]; +EXPORT_SYMBOL(pps_irq_ts); +#endif + /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves. @@ -188,6 +194,12 @@ u64 arch_irq_stat(void) asmlinkage unsigned int do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); +#ifdef CONFIG_PPS_IRQ_EVENTS + struct timespec __ts; + + /* Get IRQ timestamps as soon as possible for the PPS layer */ + getnstimeofday(&__ts); +#endif /* high bit used in ret_from_ code */ unsigned vector = ~regs->orig_ax; @@ -201,9 +213,15 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) stack_overflow_check(regs); #endif - if (likely(irq < NR_IRQS)) + if (likely(irq < NR_IRQS)) { +#ifdef CONFIG_PPS_IRQ_EVENTS + /* Then, after sanity check, store the IRQ timestamp */ + pps_irq_ts[irq].sec = __ts.tv_sec; + pps_irq_ts[irq].nsec = __ts.tv_nsec; +#endif + generic_handle_irq(irq); - else { + } else { if (!disable_apic) ack_APIC_irq(); diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig index 1afe4e0..7c0b094 100644 --- a/drivers/pps/Kconfig +++ b/drivers/pps/Kconfig @@ -22,6 +22,18 @@ config PPS To compile this driver as a module, choose M here: the module will be called pps_core.ko. +config PPS_IRQ_EVENTS + bool "Use low level IRQ timestamps" + depends on PPS && (X86_32 || X86_64) + default yes + help + Say Y here if you wish using low level IRQ timestamps to register + PPS events. + + This should improve PPS resolution but it delays echo functions + call. Note also that this function is not implemented on all + platforms and PPS clients! + config PPS_DEBUG bool "PPS debugging messages" depends on PPS diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index f1efa26..20d2c2e 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -26,6 +26,22 @@ #define PPS_TTY_MAGIC 0x0001 +#ifdef CONFIG_PPS_IRQ_EVENTS + +static void pps_tty_dcd_change(struct uart_port *port, unsigned int status, + struct timespec *ts) +{ + int id = (int) port->info->port.tty->disc_data; + + pps_event(id, &pps_irq_ts[port->irq], + status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, port); + + pr_debug("[IRQev] PPS %s at %lu on source #%d\n", + status ? "assert" : "clear", jiffies, id); +} + +#else + static void pps_tty_dcd_change(struct uart_port *port, unsigned int status, struct timespec *ts) { @@ -53,6 +69,8 @@ static void pps_tty_dcd_change(struct uart_port *port, unsigned int status, status ? "assert" : "clear", jiffies, id); } +#endif /* CONFIG_PPS_IRQ_EVENTS */ + static int pps_tty_open(struct tty_struct *tty) { struct pps_source_info info; diff --git a/include/linux/pps.h b/include/linux/pps.h index 53e171c..bb9a2e6 100644 --- a/include/linux/pps.h +++ b/include/linux/pps.h @@ -181,6 +181,7 @@ struct pps_device { extern spinlock_t pps_idr_lock; extern struct idr pps_idr; +extern struct pps_ktime pps_irq_ts[]; extern struct device_attribute pps_attrs[]; -- 1.5.4.3
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