diff options
| -rw-r--r-- | arch/x86/include/asm/clocksource.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/tsc.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/vgtod.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/vsyscall.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/Makefile | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/alternative.c | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/hpet.c | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/tsc.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/vread_tsc_64.c | 36 | ||||
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 53 |
12 files changed, 57 insertions, 79 deletions
diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h index a5df33f..3882c65 100644 --- a/arch/x86/include/asm/clocksource.h +++ b/arch/x86/include/asm/clocksource.h @@ -7,8 +7,12 @@ #define __ARCH_HAS_CLOCKSOURCE_DATA +#define VCLOCK_NONE 0 /* No vDSO clock available. */ +#define VCLOCK_TSC 1 /* vDSO should use vread_tsc. */ +#define VCLOCK_HPET 2 /* vDSO should use vread_hpet. */ + struct arch_clocksource_data { - cycle_t (*vread)(void); + int vclock_mode; }; #endif /* CONFIG_X86_64 */ diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index 9db5583..83e2efd 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -51,10 +51,6 @@ extern int unsynchronized_tsc(void); extern int check_tsc_unstable(void); extern unsigned long native_calibrate_tsc(void); -#ifdef CONFIG_X86_64 -extern cycles_t vread_tsc(void); -#endif - /* * Boot-time check whether the TSCs are synchronized across * all CPUs/cores: diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index aa5add8..815285b 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -13,7 +13,7 @@ struct vsyscall_gtod_data { struct timezone sys_tz; struct { /* extract of a clocksource struct */ - cycle_t (*vread)(void); + int vclock_mode; cycle_t cycle_last; cycle_t mask; u32 mult; diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h index d555973..6010707 100644 --- a/arch/x86/include/asm/vsyscall.h +++ b/arch/x86/include/asm/vsyscall.h @@ -16,10 +16,6 @@ enum vsyscall_num { #ifdef __KERNEL__ #include <linux/seqlock.h> -/* Definitions for CONFIG_GENERIC_TIME definitions */ -#define __vsyscall_fn \ - __attribute__ ((unused, __section__(".vsyscall_fn"))) notrace - #define VGETCPU_RDTSCP 1 #define VGETCPU_LSL 2 diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index cc0469a..2deef3d 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -24,17 +24,12 @@ endif nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_vsyscall_64.o := $(PROFILING) -g0 $(nostackp) CFLAGS_hpet.o := $(nostackp) -CFLAGS_vread_tsc_64.o := $(nostackp) CFLAGS_paravirt.o := $(nostackp) GCOV_PROFILE_vsyscall_64.o := n GCOV_PROFILE_hpet.o := n GCOV_PROFILE_tsc.o := n -GCOV_PROFILE_vread_tsc_64.o := n GCOV_PROFILE_paravirt.o := n -# vread_tsc_64 is hot and should be fully optimized: -CFLAGS_REMOVE_vread_tsc_64.o = -pg -fno-optimize-sibling-calls - obj-y := process_$(BITS).o signal.o entry_$(BITS).o obj-y += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o obj-y += time.o ioport.o ldt.o dumpstack.o @@ -43,7 +38,7 @@ obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o -obj-$(CONFIG_X86_64) += syscall_64.o vsyscall_64.o vread_tsc_64.o +obj-$(CONFIG_X86_64) += syscall_64.o vsyscall_64.o obj-$(CONFIG_X86_64) += vsyscall_emu_64.o obj-y += bootflag.o e820.o obj-y += pci-dma.o quirks.o topology.o kdebugfs.o diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ddb207b..c638228 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -14,7 +14,6 @@ #include <asm/pgtable.h> #include <asm/mce.h> #include <asm/nmi.h> -#include <asm/vsyscall.h> #include <asm/cacheflush.h> #include <asm/tlbflush.h> #include <asm/io.h> @@ -250,7 +249,6 @@ static void __init_or_module add_nops(void *insns, unsigned int len) extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; extern s32 __smp_locks[], __smp_locks_end[]; -extern char __vsyscall_0; void *text_poke_early(void *addr, const void *opcode, size_t len); /* Replace instructions with better alternatives for this CPU type. @@ -294,12 +292,6 @@ void __init_or_module apply_alternatives(struct alt_instr *start, add_nops(insnbuf + a->replacementlen, a->instrlen - a->replacementlen); -#ifdef CONFIG_X86_64 - /* vsyscall code is not mapped yet. resolve it manually. */ - if (instr >= (u8 *)VSYSCALL_START && instr < (u8*)VSYSCALL_END) { - instr = __va(instr - (u8*)VSYSCALL_START + (u8*)__pa_symbol(&__vsyscall_0)); - } -#endif text_poke_early(instr, insnbuf, a->instrlen); } } diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 0e07257bb..d10cc00 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -738,13 +738,6 @@ static cycle_t read_hpet(struct clocksource *cs) return (cycle_t)hpet_readl(HPET_COUNTER); } -#ifdef CONFIG_X86_64 -static cycle_t __vsyscall_fn vread_hpet(void) -{ - return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0); -} -#endif - static struct clocksource clocksource_hpet = { .name = "hpet", .rating = 250, @@ -753,7 +746,7 @@ static struct clocksource clocksource_hpet = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, .resume = hpet_resume_counter, #ifdef CONFIG_X86_64 - .archdata = { .vread = vread_hpet }, + .archdata = { .vclock_mode = VCLOCK_HPET }, #endif }; diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index e7a74b8..56c633a 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -777,7 +777,7 @@ static struct clocksource clocksource_tsc = { .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, #ifdef CONFIG_X86_64 - .archdata = { .vread = vread_tsc }, + .archdata = { .vclock_mode = VCLOCK_TSC }, #endif }; diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 8017471..4aa9c54 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -169,9 +169,6 @@ SECTIONS .vsyscall : AT(VLOAD(.vsyscall)) { *(.vsyscall_0) - . = ALIGN(L1_CACHE_BYTES); - *(.vsyscall_fn) - . = 1024; *(.vsyscall_1) diff --git a/arch/x86/kernel/vread_tsc_64.c b/arch/x86/kernel/vread_tsc_64.c deleted file mode 100644 index a81aa9e..0000000 --- a/arch/x86/kernel/vread_tsc_64.c +++ /dev/null @@ -1,36 +0,0 @@ -/* This code runs in userspace. */ - -#define DISABLE_BRANCH_PROFILING -#include <asm/vgtod.h> - -notrace cycle_t __vsyscall_fn vread_tsc(void) -{ - cycle_t ret; - u64 last; - - /* - * Empirically, a fence (of type that depends on the CPU) - * before rdtsc is enough to ensure that rdtsc is ordered - * with respect to loads. The various CPU manuals are unclear - * as to whether rdtsc can be reordered with later loads, - * but no one has ever seen it happen. - */ - rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); - - last = VVAR(vsyscall_gtod_data).clock.cycle_last; - - if (likely(ret >= last)) - return ret; - - /* - * GCC likes to generate cmov here, but this branch is extremely - * predictable (it's just a funciton of time and the likely is - * very likely) and there's a data dependence, so force GCC - * to generate a branch instead. I don't barrier() because - * we don't actually need a barrier, and if this function - * ever gets inlined it will generate worse code. - */ - asm volatile (""); - return last; -} diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 12d488f..dda7dff 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -74,7 +74,7 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags); /* copy vsyscall data */ - vsyscall_gtod_data.clock.vread = clock->archdata.vread; + vsyscall_gtod_data.clock.vclock_mode = clock->archdata.vclock_mode; vsyscall_gtod_data.clock.cycle_last = clock->cycle_last; vsyscall_gtod_data.clock.mask = clock->mask; vsyscall_gtod_data.clock.mult = mult; diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index cf54813..8792d6e 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -17,6 +17,7 @@ #include <linux/time.h> #include <linux/string.h> #include <asm/vsyscall.h> +#include <asm/fixmap.h> #include <asm/vgtod.h> #include <asm/timex.h> #include <asm/hpet.h> @@ -25,6 +26,43 @@ #define gtod (&VVAR(vsyscall_gtod_data)) +notrace static cycle_t vread_tsc(void) +{ + cycle_t ret; + u64 last; + + /* + * Empirically, a fence (of type that depends on the CPU) + * before rdtsc is enough to ensure that rdtsc is ordered + * with respect to loads. The various CPU manuals are unclear + * as to whether rdtsc can be reordered with later loads, + * but no one has ever seen it happen. + */ + rdtsc_barrier(); + ret = (cycle_t)vget_cycles(); + + last = VVAR(vsyscall_gtod_data).clock.cycle_last; + + if (likely(ret >= last)) + return ret; + + /* + * GCC likes to generate cmov here, but this branch is extremely + * predictable (it's just a funciton of time and the likely is + * very likely) and there's a data dependence, so force GCC + * to generate a branch instead. I don't barrier() because + * we don't actually need a barrier, and if this function + * ever gets inlined it will generate worse code. + */ + asm volatile (""); + return last; +} + +static notrace cycle_t vread_hpet(void) +{ + return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0); +} + notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { long ret; @@ -36,9 +74,12 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) notrace static inline long vgetns(void) { long v; - cycles_t (*vread)(void); - vread = gtod->clock.vread; - v = (vread() - gtod->clock.cycle_last) & gtod->clock.mask; + cycles_t cycles; + if (gtod->clock.vclock_mode == VCLOCK_TSC) + cycles = vread_tsc(); + else + cycles = vread_hpet(); + v = (cycles - gtod->clock.cycle_last) & gtod->clock.mask; return (v * gtod->clock.mult) >> gtod->clock.shift; } @@ -118,11 +159,11 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) { switch (clock) { case CLOCK_REALTIME: - if (likely(gtod->clock.vread)) + if (likely(gtod->clock.vclock_mode != VCLOCK_NONE)) return do_realtime(ts); break; case CLOCK_MONOTONIC: - if (likely(gtod->clock.vread)) + if (likely(gtod->clock.vclock_mode != VCLOCK_NONE)) return do_monotonic(ts); break; case CLOCK_REALTIME_COARSE: @@ -139,7 +180,7 @@ int clock_gettime(clockid_t, struct timespec *) notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) { long ret; - if (likely(gtod->clock.vread)) { + if (likely(gtod->clock.vclock_mode != VCLOCK_NONE)) { if (likely(tv != NULL)) { BUILD_BUG_ON(offsetof(struct timeval, tv_usec) != offsetof(struct timespec, tv_nsec) || |
