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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
[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 <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@muc.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
1489939f0a
commit
7460ed2844
9 changed files with 106 additions and 100 deletions
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@ -28,6 +28,10 @@ config GENERIC_TIME
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bool
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default y
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config GENERIC_TIME_VSYSCALL
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bool
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default y
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config ZONE_DMA32
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bool
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default y
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@ -458,6 +458,11 @@ static cycle_t read_hpet(void)
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return (cycle_t)readl(hpet_ptr);
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}
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static cycle_t __vsyscall_fn vread_hpet(void)
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{
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return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
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}
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struct clocksource clocksource_hpet = {
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.name = "hpet",
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.rating = 250,
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@ -466,6 +471,7 @@ struct clocksource clocksource_hpet = {
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.mult = 0, /* set below */
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.shift = HPET_SHIFT,
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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.vread = vread_hpet,
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};
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static int __init init_hpet_clocksource(void)
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@ -53,13 +53,7 @@ DEFINE_SPINLOCK(rtc_lock);
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EXPORT_SYMBOL(rtc_lock);
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DEFINE_SPINLOCK(i8253_lock);
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unsigned long vxtime_hz = PIT_TICK_RATE;
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struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */
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volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
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struct timespec __xtime __section_xtime;
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struct timezone __sys_tz __section_sys_tz;
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unsigned long profile_pc(struct pt_regs *regs)
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{
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@ -180,6 +180,12 @@ static cycle_t read_tsc(void)
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return ret;
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}
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static cycle_t __vsyscall_fn vread_tsc(void)
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{
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cycle_t ret = (cycle_t)get_cycles_sync();
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return ret;
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}
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static struct clocksource clocksource_tsc = {
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.name = "tsc",
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.rating = 300,
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@ -188,6 +194,7 @@ static struct clocksource clocksource_tsc = {
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.shift = 22,
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.flags = CLOCK_SOURCE_IS_CONTINUOUS |
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CLOCK_SOURCE_MUST_VERIFY,
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.vread = vread_tsc,
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};
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void mark_tsc_unstable(void)
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@ -88,31 +88,25 @@ SECTIONS
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__vsyscall_0 = VSYSCALL_VIRT_ADDR;
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. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
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.xtime_lock : AT(VLOAD(.xtime_lock)) { *(.xtime_lock) }
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xtime_lock = VVIRT(.xtime_lock);
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.vxtime : AT(VLOAD(.vxtime)) { *(.vxtime) }
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vxtime = VVIRT(.vxtime);
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.vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) }
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. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
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.vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data))
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{ *(.vsyscall_gtod_data) }
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vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
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.vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) { *(.vgetcpu_mode) }
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vgetcpu_mode = VVIRT(.vgetcpu_mode);
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.sys_tz : AT(VLOAD(.sys_tz)) { *(.sys_tz) }
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sys_tz = VVIRT(.sys_tz);
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.sysctl_vsyscall : AT(VLOAD(.sysctl_vsyscall)) { *(.sysctl_vsyscall) }
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sysctl_vsyscall = VVIRT(.sysctl_vsyscall);
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.xtime : AT(VLOAD(.xtime)) { *(.xtime) }
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xtime = VVIRT(.xtime);
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. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
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.jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
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jiffies = VVIRT(.jiffies);
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.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { *(.vsyscall_1) }
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.vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { *(.vsyscall_2) }
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.vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) { *(.vsyscall_3) }
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.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1))
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{ *(.vsyscall_1) }
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.vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2))
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{ *(.vsyscall_2) }
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.vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3))
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{ *(.vsyscall_3) }
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. = VSYSCALL_VIRT_ADDR + 4096;
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@ -26,6 +26,7 @@
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#include <linux/seqlock.h>
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#include <linux/jiffies.h>
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#include <linux/sysctl.h>
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#include <linux/clocksource.h>
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#include <linux/getcpu.h>
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#include <linux/cpu.h>
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#include <linux/smp.h>
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@ -34,6 +35,7 @@
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#include <asm/vsyscall.h>
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#include <asm/pgtable.h>
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#include <asm/page.h>
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#include <asm/unistd.h>
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#include <asm/fixmap.h>
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#include <asm/errno.h>
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#include <asm/io.h>
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@ -44,56 +46,41 @@
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#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
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#define __syscall_clobber "r11","rcx","memory"
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int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
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seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
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struct vsyscall_gtod_data_t {
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seqlock_t lock;
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int sysctl_enabled;
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struct timeval wall_time_tv;
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struct timezone sys_tz;
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cycle_t offset_base;
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struct clocksource clock;
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};
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int __vgetcpu_mode __section_vgetcpu_mode;
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#include <asm/unistd.h>
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static __always_inline void timeval_normalize(struct timeval * tv)
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struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data =
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{
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time_t __sec;
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.lock = SEQLOCK_UNLOCKED,
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.sysctl_enabled = 1,
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};
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__sec = tv->tv_usec / 1000000;
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if (__sec) {
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tv->tv_usec %= 1000000;
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tv->tv_sec += __sec;
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}
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void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
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{
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unsigned long flags;
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write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
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/* copy vsyscall data */
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vsyscall_gtod_data.clock = *clock;
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vsyscall_gtod_data.wall_time_tv.tv_sec = wall_time->tv_sec;
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vsyscall_gtod_data.wall_time_tv.tv_usec = wall_time->tv_nsec/1000;
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vsyscall_gtod_data.sys_tz = sys_tz;
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write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
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}
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static __always_inline void do_vgettimeofday(struct timeval * tv)
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{
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long sequence, t;
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unsigned long sec, usec;
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do {
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sequence = read_seqbegin(&__xtime_lock);
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sec = __xtime.tv_sec;
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usec = __xtime.tv_nsec / 1000;
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if (__vxtime.mode != VXTIME_HPET) {
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t = get_cycles_sync();
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if (t < __vxtime.last_tsc)
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t = __vxtime.last_tsc;
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usec += ((t - __vxtime.last_tsc) *
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__vxtime.tsc_quot) >> 32;
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/* See comment in x86_64 do_gettimeofday. */
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} else {
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usec += ((readl((void __iomem *)
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fix_to_virt(VSYSCALL_HPET) + 0xf0) -
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__vxtime.last) * __vxtime.quot) >> 32;
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}
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} while (read_seqretry(&__xtime_lock, sequence));
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tv->tv_sec = sec + usec / 1000000;
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tv->tv_usec = usec % 1000000;
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}
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/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
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/* RED-PEN may want to readd seq locking, but then the variable should be
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* write-once.
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*/
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static __always_inline void do_get_tz(struct timezone * tz)
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{
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*tz = __sys_tz;
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*tz = __vsyscall_gtod_data.sys_tz;
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}
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static __always_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
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int ret;
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asm volatile("vsysc2: syscall"
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: "=a" (ret)
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: "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber );
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: "0" (__NR_gettimeofday),"D" (tv),"S" (tz)
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: __syscall_clobber );
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return ret;
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}
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return secs;
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}
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static __always_inline void do_vgettimeofday(struct timeval * tv)
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{
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cycle_t now, base, mask, cycle_delta;
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unsigned long seq, mult, shift, nsec_delta;
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cycle_t (*vread)(void);
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do {
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seq = read_seqbegin(&__vsyscall_gtod_data.lock);
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vread = __vsyscall_gtod_data.clock.vread;
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if (unlikely(!__vsyscall_gtod_data.sysctl_enabled || !vread)) {
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gettimeofday(tv,0);
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return;
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}
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now = vread();
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base = __vsyscall_gtod_data.clock.cycle_last;
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mask = __vsyscall_gtod_data.clock.mask;
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mult = __vsyscall_gtod_data.clock.mult;
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shift = __vsyscall_gtod_data.clock.shift;
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*tv = __vsyscall_gtod_data.wall_time_tv;
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} while (read_seqretry(&__vsyscall_gtod_data.lock, seq));
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/* calculate interval: */
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cycle_delta = (now - base) & mask;
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/* convert to nsecs: */
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nsec_delta = (cycle_delta * mult) >> shift;
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/* convert to usecs and add to timespec: */
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tv->tv_usec += nsec_delta / NSEC_PER_USEC;
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while (tv->tv_usec > USEC_PER_SEC) {
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tv->tv_sec += 1;
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tv->tv_usec -= USEC_PER_SEC;
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}
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}
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int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz)
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{
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if (!__sysctl_vsyscall)
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return gettimeofday(tv,tz);
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if (tv)
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do_vgettimeofday(tv);
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if (tz)
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* unlikely */
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time_t __vsyscall(1) vtime(time_t *t)
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{
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if (!__sysctl_vsyscall)
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if (unlikely(!__vsyscall_gtod_data.sysctl_enabled))
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return time_syscall(t);
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else if (t)
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*t = __xtime.tv_sec;
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return __xtime.tv_sec;
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*t = __vsyscall_gtod_data.wall_time_tv.tv_sec;
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return __vsyscall_gtod_data.wall_time_tv.tv_sec;
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}
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/* Fast way to get current CPU and node.
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ret = -ENOMEM;
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goto out;
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}
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if (!sysctl_vsyscall) {
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if (!vsyscall_gtod_data.sysctl_enabled) {
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writew(SYSCALL, map1);
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writew(SYSCALL, map2);
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} else {
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static ctl_table kernel_table2[] = {
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{ .ctl_name = 99, .procname = "vsyscall64",
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.data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644,
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.data = &vsyscall_gtod_data.sysctl_enabled, .maxlen = sizeof(int),
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.mode = 0644,
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.strategy = vsyscall_sysctl_nostrat,
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.proc_handler = vsyscall_sysctl_change },
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{}
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@ -45,9 +45,7 @@ extern u32 pmtmr_ioport;
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#else
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#define pmtmr_ioport 0
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#endif
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extern int sysctl_vsyscall;
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extern int nohpet;
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extern unsigned long vxtime_hz;
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extern void early_printk(const char *fmt, ...) __attribute__((format(printf,1,2)));
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@ -27,7 +27,6 @@ extern int read_current_timer(unsigned long *timer_value);
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#define NS_SCALE 10 /* 2^10, carefully chosen */
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#define US_SCALE 32 /* 2^32, arbitralrily chosen */
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extern struct vxtime_data vxtime;
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extern void mark_tsc_unstable(void);
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extern void set_cyc2ns_scale(unsigned long khz);
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#endif
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@ -16,46 +16,27 @@ enum vsyscall_num {
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#ifdef __KERNEL__
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#include <linux/seqlock.h>
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#define __section_vxtime __attribute__ ((unused, __section__ (".vxtime"), aligned(16)))
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#define __section_vgetcpu_mode __attribute__ ((unused, __section__ (".vgetcpu_mode"), aligned(16)))
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#define __section_jiffies __attribute__ ((unused, __section__ (".jiffies"), aligned(16)))
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#define __section_sys_tz __attribute__ ((unused, __section__ (".sys_tz"), aligned(16)))
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#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16)))
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#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16)))
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#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))
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#define VXTIME_TSC 1
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#define VXTIME_HPET 2
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#define VXTIME_PMTMR 3
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/* Definitions for CONFIG_GENERIC_TIME definitions */
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#define __section_vsyscall_gtod_data __attribute__ \
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((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
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#define __vsyscall_fn __attribute__ ((unused,__section__(".vsyscall_fn")))
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#define VGETCPU_RDTSCP 1
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#define VGETCPU_LSL 2
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struct vxtime_data {
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long hpet_address; /* HPET base address */
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int last;
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unsigned long last_tsc;
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long quot;
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long tsc_quot;
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int mode;
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};
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#define hpet_readl(a) readl((const void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
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#define hpet_writel(d,a) writel(d, (void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
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/* vsyscall space (readonly) */
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extern struct vxtime_data __vxtime;
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extern int __vgetcpu_mode;
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extern struct timespec __xtime;
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extern volatile unsigned long __jiffies;
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extern struct timezone __sys_tz;
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extern seqlock_t __xtime_lock;
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/* kernel space (writeable) */
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extern struct vxtime_data vxtime;
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extern int vgetcpu_mode;
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extern struct timezone sys_tz;
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extern int sysctl_vsyscall;
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extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
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#endif /* __KERNEL__ */
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