Messages in this thread Patch in this message | | | From | Rodolfo Giometti <> | Date | Mon, 24 Nov 2008 17:00:51 +0100 | Subject | [PATCH 9/9] 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 | 16 ++++++++++++++++ arch/x86/kernel/irq_64.c | 21 +++++++++++++++++++-- drivers/pps/Kconfig | 12 ++++++++++++ include/linux/pps.h | 1 + include/linux/serial_core.h | 7 ++++++- 5 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index a513826..7fce1e2 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 timespec pps_irq_ts[NR_IRQS]; +EXPORT_SYMBOL(pps_irq_ts); +#endif + #ifdef CONFIG_DEBUG_STACKOVERFLOW /* Debugging check for stack overflow: is there less than 1KB free? */ static int check_stack_overflow(void) @@ -204,7 +210,12 @@ unsigned int do_IRQ(struct pt_regs *regs) unsigned vector = ~regs->orig_ax; struct irq_desc *desc; unsigned irq; +#ifdef CONFIG_PPS_IRQ_EVENTS + struct timespec ts; + /* Get IRQ timestamps as soon as possible for the PPS layer */ + getnstimeofday(&ts); +#endif old_regs = set_irq_regs(regs); irq_enter(); @@ -219,6 +230,11 @@ 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] = ts; +#endif + if (!execute_on_irq_stack(overflow, desc, irq)) { if (unlikely(overflow)) print_stack_overflow(); diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 60eb84e..a1457a0 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -17,6 +17,12 @@ #include <asm/io_apic.h> #include <asm/idle.h> #include <asm/smp.h> +#include <linux/pps.h> + +#ifdef CONFIG_PPS_IRQ_EVENTS +struct timespec pps_irq_ts[NR_IRQS]; +EXPORT_SYMBOL(pps_irq_ts); +#endif #ifdef CONFIG_DEBUG_STACKOVERFLOW /* @@ -51,6 +57,12 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); struct irq_desc *desc; +#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; @@ -65,9 +77,14 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) #endif desc = irq_to_desc(irq); - if (likely(desc)) + if (likely(desc)) { +#ifdef CONFIG_PPS_IRQ_EVENTS + /* Then, after sanity check, store the IRQ timestamp */ + pps_irq_ts[irq] = ts; +#endif + generic_handle_irq_desc(irq, desc); - 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/include/linux/pps.h b/include/linux/pps.h index b5c3cf9..191190e 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 timespec pps_irq_ts[]; extern struct device_attribute pps_attrs[]; diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index be8e653..d168c04 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -165,6 +165,7 @@ #include <linux/tty.h> #include <linux/mutex.h> #include <linux/sysrq.h> +#include <linux/pps.h> struct uart_port; struct uart_info; @@ -492,7 +493,11 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status) struct timespec ts; if (ld && ld->ops->dcd_change) +#ifdef CONFIG_PPS_IRQ_EVENTS + ts = pps_irq_ts[port->irq]; +#else getnstimeofday(&ts); +#endif port->icount.dcd++; #ifdef CONFIG_HARD_PPS @@ -508,7 +513,7 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status) } if (ld && ld->ops->dcd_change) - ld->ops->dcd_change(port, status, &ts); + ld->ops->dcd_change(info->port.tty, status, &ts); if (ld) tty_ldisc_deref(ld); } -- 1.5.4.3
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