[PATCH] x86_64: Allow to run main time keeping from the local APIC interrupt (73dea47f) · Commits · 戴 / test

Documentation/x86_64/boot-options.txt

+7 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,13 @@ APICs
		no_timer_check Don't check the IO-APIC timer. This can work around
		problems with incorrect timer initialization on some boards.

		apicmaintimer Run time keeping from the local APIC timer instead
		of using the PIT/HPET interrupt for this. This is useful
		when the PIT/HPET interrupts are unreliable.

		noapicmaintimer Don't do time keeping using the APIC timer.
		Useful when this option was auto selected, but doesn't work.

		Early Console

		syntax: earlyprintk=vga

arch/x86_64/kernel/apic.c

+32 −2

Original line number	Diff line number	Diff line
		@@ -35,8 +35,11 @@
		#include <asm/mach_apic.h>
		#include <asm/nmi.h>
		#include <asm/idle.h>
		#include <asm/proto.h>
		#include <asm/timex.h>

		int apic_verbosity;
		int apic_runs_main_timer;

		int disable_apic_timer __initdata;

		@@ -702,9 +705,17 @@ static void setup_APIC_timer(unsigned int clocks)
		c2 \|= inb_p(0x40) << 8;
		} while (c2 - c1 < 300);
		}

		__setup_APIC_LVTT(clocks);

		/* Turn off PIT interrupt if we use APIC timer as main timer.
		Only works with the PM timer right now
		TBD fix it for HPET too. */
		if (vxtime.mode == VXTIME_PMTMR &&
		smp_processor_id() == boot_cpu_id &&
		apic_runs_main_timer == 1 &&
		!cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
		stop_timer_interrupt();
		apic_runs_main_timer++;
		}
		local_irq_restore(flags);
		}

		@@ -872,6 +883,8 @@ void smp_local_timer_interrupt(struct pt_regs *regs)
		#ifdef CONFIG_SMP
		update_process_times(user_mode(regs));
		#endif
		if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
		main_timer_handler(regs);
		/*
		* We take the 'long' return path, and there every subsystem
		* grabs the appropriate locks (kernel lock/ irq lock).
		@@ -1081,10 +1094,27 @@ static __init int setup_nolapic(char *str)

		static __init int setup_noapictimer(char *str)
		{
		if (str[0] != ' ' && str[0] != 0)
		return -1;
		disable_apic_timer = 1;
		return 0;
		}

		static __init int setup_apicmaintimer(char *str)
		{
		apic_runs_main_timer = 1;
		nohpet = 1;
		return 0;
		}
		__setup("apicmaintimer", setup_apicmaintimer);

		static __init int setup_noapicmaintimer(char *str)
		{
		apic_runs_main_timer = -1;
		return 0;
		}
		__setup("noapicmaintimer", setup_noapicmaintimer);

		/* dummy parsing: see setup.c */

		__setup("disableapic", setup_disableapic);

arch/x86_64/kernel/time.c

+38 −7

Original line number	Diff line number	Diff line
		@@ -51,7 +51,7 @@ extern int using_apic_timer;
		DEFINE_SPINLOCK(rtc_lock);
		DEFINE_SPINLOCK(i8253_lock);

		static int nohpet __initdata = 0;
		int nohpet __initdata = 0;
		static int notsc __initdata = 0;

		#undef HPET_HACK_ENABLE_DANGEROUS
		@@ -345,7 +345,7 @@ static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
		#endif
		}

		static irqreturn_t timer_interrupt(int irq, void dev_id, struct pt_regs regs)
		void main_timer_handler(struct pt_regs *regs)
		{
		static unsigned long rtc_update = 0;
		unsigned long tsc;
		@@ -458,12 +458,17 @@ static irqreturn_t timer_interrupt(int irq, void dev_id, struct pt_regs regs)
		}

		write_sequnlock(&xtime_lock);
		}

		static irqreturn_t timer_interrupt(int irq, void dev_id, struct pt_regs regs)
		{
		if (apic_runs_main_timer > 1)
		return IRQ_HANDLED;
		main_timer_handler(regs);
		#ifdef CONFIG_X86_LOCAL_APIC
		if (using_apic_timer)
		smp_send_timer_broadcast_ipi();
		#endif

		return IRQ_HANDLED;
		}

		@@ -843,17 +848,43 @@ static int hpet_reenable(void)
		return hpet_timer_stop_set_go(hpet_tick);
		}

		void __init pit_init(void)
		#define PIT_MODE 0x43
		#define PIT_CH0 0x40

		static void __init __pit_init(int val, u8 mode)
		{
		unsigned long flags;

		spin_lock_irqsave(&i8253_lock, flags);
		outb_p(0x34, 0x43); /* binary, mode 2, LSB/MSB, ch 0 */
		outb_p(LATCH & 0xff, 0x40); /* LSB */
		outb_p(LATCH >> 8, 0x40); /* MSB */
		outb_p(mode, PIT_MODE);
		outb_p(val & 0xff, PIT_CH0); /* LSB */
		outb_p(val >> 8, PIT_CH0); /* MSB */
		spin_unlock_irqrestore(&i8253_lock, flags);
		}

		void __init pit_init(void)
		{
		__pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */
		}

		void __init pit_stop_interrupt(void)
		{
		__pit_init(0, 0x30); /* mode 0 */
		}

		void __init stop_timer_interrupt(void)
		{
		char *name;
		if (vxtime.hpet_address) {
		name = "HPET";
		hpet_timer_stop_set_go(0);
		} else {
		name = "PIT";
		pit_stop_interrupt();
		}
		printk(KERN_INFO "timer: %s interrupt stopped.\n", name);
		}

		int __init time_setup(char *str)
		{
		report_lost_ticks = 1;

include/asm-x86_64/apic.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#define APIC_DEBUG 2

		extern int apic_verbosity;
		extern int apic_runs_main_timer;

		/*
		* Define the default level of output to be very little

include/asm-x86_64/proto.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,8 @@ extern u32 pmtmr_ioport;
		#endif
		extern unsigned long long monotonic_base;
		extern int sysctl_vsyscall;
		extern int nohpet;
		extern unsigned long vxtime_hz;

		extern void do_softirq_thunk(void);

		@@ -69,6 +71,9 @@ extern void free_bootmem_generic(unsigned long phys, unsigned len);

		extern void load_gs_index(unsigned gs);

		extern void stop_timer_interrupt(void);
		extern void main_timer_handler(struct pt_regs *regs);

		extern unsigned long end_pfn_map;

		extern void show_trace(unsigned long * rsp);

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