From 7460ed2844ffad7141e30271c0c3da8336e66014 Mon Sep 17 00:00:00 2001 From: john stultz Date: Fri, 16 Feb 2007 01:28:21 -0800 Subject: [PATCH] [PATCH] time: x86_64: re-enable vsyscall support for x86_64 Cleanup and re-enable vsyscall gettimeofday using the generic clocksource infrastructure. [akpm@osdl.org: cleanup] Signed-off-by: John Stultz Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andi Kleen Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/Kconfig | 4 + arch/x86_64/kernel/hpet.c | 6 ++ arch/x86_64/kernel/time.c | 6 -- arch/x86_64/kernel/tsc.c | 7 ++ arch/x86_64/kernel/vmlinux.lds.S | 28 +++---- arch/x86_64/kernel/vsyscall.c | 123 ++++++++++++++++++------------- include/asm-x86_64/proto.h | 2 - include/asm-x86_64/timex.h | 1 - include/asm-x86_64/vsyscall.h | 29 ++------ 9 files changed, 106 insertions(+), 100 deletions(-) diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig index 286b4606fb1e..56eb14c98475 100644 --- a/arch/x86_64/Kconfig +++ b/arch/x86_64/Kconfig @@ -28,6 +28,10 @@ config GENERIC_TIME bool default y +config GENERIC_TIME_VSYSCALL + bool + default y + config ZONE_DMA32 bool default y diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c index c23738899ae9..65a0edd71a17 100644 --- a/arch/x86_64/kernel/hpet.c +++ b/arch/x86_64/kernel/hpet.c @@ -458,6 +458,11 @@ static cycle_t read_hpet(void) return (cycle_t)readl(hpet_ptr); } +static cycle_t __vsyscall_fn vread_hpet(void) +{ + return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0); +} + struct clocksource clocksource_hpet = { .name = "hpet", .rating = 250, @@ -466,6 +471,7 @@ struct clocksource clocksource_hpet = { .mult = 0, /* set below */ .shift = HPET_SHIFT, .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .vread = vread_hpet, }; static int __init init_hpet_clocksource(void) diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index d84208e3c618..a87c51705620 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -53,13 +53,7 @@ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL(rtc_lock); DEFINE_SPINLOCK(i8253_lock); -unsigned long vxtime_hz = PIT_TICK_RATE; - -struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */ - volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; -struct timespec __xtime __section_xtime; -struct timezone __sys_tz __section_sys_tz; unsigned long profile_pc(struct pt_regs *regs) { diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c index 8c92f2fe7e2e..895831865019 100644 --- a/arch/x86_64/kernel/tsc.c +++ b/arch/x86_64/kernel/tsc.c @@ -180,6 +180,12 @@ static cycle_t read_tsc(void) return ret; } +static cycle_t __vsyscall_fn vread_tsc(void) +{ + cycle_t ret = (cycle_t)get_cycles_sync(); + return ret; +} + static struct clocksource clocksource_tsc = { .name = "tsc", .rating = 300, @@ -188,6 +194,7 @@ static struct clocksource clocksource_tsc = { .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, + .vread = vread_tsc, }; void mark_tsc_unstable(void) diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S index c360c4225244..b73212c0a550 100644 --- a/arch/x86_64/kernel/vmlinux.lds.S +++ b/arch/x86_64/kernel/vmlinux.lds.S @@ -88,31 +88,25 @@ SECTIONS __vsyscall_0 = VSYSCALL_VIRT_ADDR; . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); - .xtime_lock : AT(VLOAD(.xtime_lock)) { *(.xtime_lock) } - xtime_lock = VVIRT(.xtime_lock); - - .vxtime : AT(VLOAD(.vxtime)) { *(.vxtime) } - vxtime = VVIRT(.vxtime); + .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) } + . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); + .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data)) + { *(.vsyscall_gtod_data) } + vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data); .vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) { *(.vgetcpu_mode) } vgetcpu_mode = VVIRT(.vgetcpu_mode); - .sys_tz : AT(VLOAD(.sys_tz)) { *(.sys_tz) } - sys_tz = VVIRT(.sys_tz); - - .sysctl_vsyscall : AT(VLOAD(.sysctl_vsyscall)) { *(.sysctl_vsyscall) } - sysctl_vsyscall = VVIRT(.sysctl_vsyscall); - - .xtime : AT(VLOAD(.xtime)) { *(.xtime) } - xtime = VVIRT(.xtime); - . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) } jiffies = VVIRT(.jiffies); - .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { *(.vsyscall_1) } - .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { *(.vsyscall_2) } - .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) { *(.vsyscall_3) } + .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) + { *(.vsyscall_1) } + .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) + { *(.vsyscall_2) } + .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) + { *(.vsyscall_3) } . = VSYSCALL_VIRT_ADDR + 4096; diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c index 313dc6ad780b..180ff919eaf9 100644 --- a/arch/x86_64/kernel/vsyscall.c +++ b/arch/x86_64/kernel/vsyscall.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -34,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -44,56 +46,41 @@ #define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr))) #define __syscall_clobber "r11","rcx","memory" -int __sysctl_vsyscall __section_sysctl_vsyscall = 1; -seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED; +struct vsyscall_gtod_data_t { + seqlock_t lock; + int sysctl_enabled; + struct timeval wall_time_tv; + struct timezone sys_tz; + cycle_t offset_base; + struct clocksource clock; +}; int __vgetcpu_mode __section_vgetcpu_mode; -#include - -static __always_inline void timeval_normalize(struct timeval * tv) +struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data = { - time_t __sec; + .lock = SEQLOCK_UNLOCKED, + .sysctl_enabled = 1, +}; - __sec = tv->tv_usec / 1000000; - if (__sec) { - tv->tv_usec %= 1000000; - tv->tv_sec += __sec; - } +void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) +{ + unsigned long flags; + + write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags); + /* copy vsyscall data */ + vsyscall_gtod_data.clock = *clock; + vsyscall_gtod_data.wall_time_tv.tv_sec = wall_time->tv_sec; + vsyscall_gtod_data.wall_time_tv.tv_usec = wall_time->tv_nsec/1000; + vsyscall_gtod_data.sys_tz = sys_tz; + write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } -static __always_inline void do_vgettimeofday(struct timeval * tv) -{ - long sequence, t; - unsigned long sec, usec; - - do { - sequence = read_seqbegin(&__xtime_lock); - - sec = __xtime.tv_sec; - usec = __xtime.tv_nsec / 1000; - - if (__vxtime.mode != VXTIME_HPET) { - t = get_cycles_sync(); - if (t < __vxtime.last_tsc) - t = __vxtime.last_tsc; - usec += ((t - __vxtime.last_tsc) * - __vxtime.tsc_quot) >> 32; - /* See comment in x86_64 do_gettimeofday. */ - } else { - usec += ((readl((void __iomem *) - fix_to_virt(VSYSCALL_HPET) + 0xf0) - - __vxtime.last) * __vxtime.quot) >> 32; - } - } while (read_seqretry(&__xtime_lock, sequence)); - - tv->tv_sec = sec + usec / 1000000; - tv->tv_usec = usec % 1000000; -} - -/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */ +/* RED-PEN may want to readd seq locking, but then the variable should be + * write-once. + */ static __always_inline void do_get_tz(struct timezone * tz) { - *tz = __sys_tz; + *tz = __vsyscall_gtod_data.sys_tz; } static __always_inline int gettimeofday(struct timeval *tv, struct timezone *tz) @@ -101,7 +88,8 @@ static __always_inline int gettimeofday(struct timeval *tv, struct timezone *tz) int ret; asm volatile("vsysc2: syscall" : "=a" (ret) - : "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber ); + : "0" (__NR_gettimeofday),"D" (tv),"S" (tz) + : __syscall_clobber ); return ret; } @@ -114,10 +102,44 @@ static __always_inline long time_syscall(long *t) return secs; } +static __always_inline void do_vgettimeofday(struct timeval * tv) +{ + cycle_t now, base, mask, cycle_delta; + unsigned long seq, mult, shift, nsec_delta; + cycle_t (*vread)(void); + do { + seq = read_seqbegin(&__vsyscall_gtod_data.lock); + + vread = __vsyscall_gtod_data.clock.vread; + if (unlikely(!__vsyscall_gtod_data.sysctl_enabled || !vread)) { + gettimeofday(tv,0); + return; + } + now = vread(); + base = __vsyscall_gtod_data.clock.cycle_last; + mask = __vsyscall_gtod_data.clock.mask; + mult = __vsyscall_gtod_data.clock.mult; + shift = __vsyscall_gtod_data.clock.shift; + + *tv = __vsyscall_gtod_data.wall_time_tv; + + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq)); + + /* calculate interval: */ + cycle_delta = (now - base) & mask; + /* convert to nsecs: */ + nsec_delta = (cycle_delta * mult) >> shift; + + /* convert to usecs and add to timespec: */ + tv->tv_usec += nsec_delta / NSEC_PER_USEC; + while (tv->tv_usec > USEC_PER_SEC) { + tv->tv_sec += 1; + tv->tv_usec -= USEC_PER_SEC; + } +} + int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) { - if (!__sysctl_vsyscall) - return gettimeofday(tv,tz); if (tv) do_vgettimeofday(tv); if (tz) @@ -129,11 +151,11 @@ int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) * unlikely */ time_t __vsyscall(1) vtime(time_t *t) { - if (!__sysctl_vsyscall) + if (unlikely(!__vsyscall_gtod_data.sysctl_enabled)) return time_syscall(t); else if (t) - *t = __xtime.tv_sec; - return __xtime.tv_sec; + *t = __vsyscall_gtod_data.wall_time_tv.tv_sec; + return __vsyscall_gtod_data.wall_time_tv.tv_sec; } /* Fast way to get current CPU and node. @@ -210,7 +232,7 @@ static int vsyscall_sysctl_change(ctl_table *ctl, int write, struct file * filp, ret = -ENOMEM; goto out; } - if (!sysctl_vsyscall) { + if (!vsyscall_gtod_data.sysctl_enabled) { writew(SYSCALL, map1); writew(SYSCALL, map2); } else { @@ -232,7 +254,8 @@ static int vsyscall_sysctl_nostrat(ctl_table *t, int __user *name, int nlen, static ctl_table kernel_table2[] = { { .ctl_name = 99, .procname = "vsyscall64", - .data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644, + .data = &vsyscall_gtod_data.sysctl_enabled, .maxlen = sizeof(int), + .mode = 0644, .strategy = vsyscall_sysctl_nostrat, .proc_handler = vsyscall_sysctl_change }, {} diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h index f590ae088f0d..f54f3abf93ce 100644 --- a/include/asm-x86_64/proto.h +++ b/include/asm-x86_64/proto.h @@ -45,9 +45,7 @@ extern u32 pmtmr_ioport; #else #define pmtmr_ioport 0 #endif -extern int sysctl_vsyscall; extern int nohpet; -extern unsigned long vxtime_hz; extern void early_printk(const char *fmt, ...) __attribute__((format(printf,1,2))); diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h index beb6d9014a63..8c6808a3fba4 100644 --- a/include/asm-x86_64/timex.h +++ b/include/asm-x86_64/timex.h @@ -27,7 +27,6 @@ extern int read_current_timer(unsigned long *timer_value); #define NS_SCALE 10 /* 2^10, carefully chosen */ #define US_SCALE 32 /* 2^32, arbitralrily chosen */ -extern struct vxtime_data vxtime; extern void mark_tsc_unstable(void); extern void set_cyc2ns_scale(unsigned long khz); #endif diff --git a/include/asm-x86_64/vsyscall.h b/include/asm-x86_64/vsyscall.h index 0c7847165eae..82b4afe65c91 100644 --- a/include/asm-x86_64/vsyscall.h +++ b/include/asm-x86_64/vsyscall.h @@ -16,46 +16,27 @@ enum vsyscall_num { #ifdef __KERNEL__ #include -#define __section_vxtime __attribute__ ((unused, __section__ (".vxtime"), aligned(16))) #define __section_vgetcpu_mode __attribute__ ((unused, __section__ (".vgetcpu_mode"), aligned(16))) #define __section_jiffies __attribute__ ((unused, __section__ (".jiffies"), aligned(16))) -#define __section_sys_tz __attribute__ ((unused, __section__ (".sys_tz"), aligned(16))) -#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16))) -#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16))) -#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16))) -#define VXTIME_TSC 1 -#define VXTIME_HPET 2 -#define VXTIME_PMTMR 3 +/* Definitions for CONFIG_GENERIC_TIME definitions */ +#define __section_vsyscall_gtod_data __attribute__ \ + ((unused, __section__ (".vsyscall_gtod_data"),aligned(16))) +#define __vsyscall_fn __attribute__ ((unused,__section__(".vsyscall_fn"))) #define VGETCPU_RDTSCP 1 #define VGETCPU_LSL 2 -struct vxtime_data { - long hpet_address; /* HPET base address */ - int last; - unsigned long last_tsc; - long quot; - long tsc_quot; - int mode; -}; - #define hpet_readl(a) readl((const void __iomem *)fix_to_virt(FIX_HPET_BASE) + a) #define hpet_writel(d,a) writel(d, (void __iomem *)fix_to_virt(FIX_HPET_BASE) + a) -/* vsyscall space (readonly) */ -extern struct vxtime_data __vxtime; extern int __vgetcpu_mode; -extern struct timespec __xtime; extern volatile unsigned long __jiffies; -extern struct timezone __sys_tz; -extern seqlock_t __xtime_lock; /* kernel space (writeable) */ -extern struct vxtime_data vxtime; extern int vgetcpu_mode; extern struct timezone sys_tz; -extern int sysctl_vsyscall; +extern struct vsyscall_gtod_data_t vsyscall_gtod_data; #endif /* __KERNEL__ */