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7c03156f34
This patch add the VDSO time support for the IA32 Emulation Layer. Due the nature of the kernel headers and the LP64 compiler where the size of a long and a pointer differs against a 32 bit compiler, there is some type hacking necessary for optimal performance. The vsyscall_gtod_data struture must be a rearranged to serve 32- and 64-bit code access at the same time: - The seqcount_t was replaced by an unsigned, this makes the vsyscall_gtod_data intedepend of kernel configuration and internal functions. - All kernel internal structures are replaced by fix size elements which works for 32- and 64-bit access - The inner struct clock was removed to pack the whole struct. The "unsigned seq" would be handled by functions derivated from seqcount_t. Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-11-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/*
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* Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
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* Copyright 2003 Andi Kleen, SuSE Labs.
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*
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* Modified for x86 32 bit architecture by
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* Stefani Seibold <stefani@seibold.net>
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* sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
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*
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* Thanks to hpa@transmeta.com for some useful hint.
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* Special thanks to Ingo Molnar for his early experience with
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* a different vsyscall implementation for Linux/IA32 and for the name.
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*
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*/
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#include <linux/timekeeper_internal.h>
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#include <asm/vgtod.h>
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#include <asm/vvar.h>
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DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);
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void update_vsyscall_tz(void)
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{
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vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest;
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vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime;
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}
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void update_vsyscall(struct timekeeper *tk)
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{
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struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data;
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gtod_write_begin(vdata);
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/* copy vsyscall data */
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vdata->vclock_mode = tk->clock->archdata.vclock_mode;
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vdata->cycle_last = tk->clock->cycle_last;
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vdata->mask = tk->clock->mask;
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vdata->mult = tk->mult;
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vdata->shift = tk->shift;
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vdata->wall_time_sec = tk->xtime_sec;
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vdata->wall_time_snsec = tk->xtime_nsec;
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vdata->monotonic_time_sec = tk->xtime_sec
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+ tk->wall_to_monotonic.tv_sec;
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vdata->monotonic_time_snsec = tk->xtime_nsec
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+ (tk->wall_to_monotonic.tv_nsec
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<< tk->shift);
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while (vdata->monotonic_time_snsec >=
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(((u64)NSEC_PER_SEC) << tk->shift)) {
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vdata->monotonic_time_snsec -=
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((u64)NSEC_PER_SEC) << tk->shift;
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vdata->monotonic_time_sec++;
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}
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vdata->wall_time_coarse_sec = tk->xtime_sec;
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vdata->wall_time_coarse_nsec = (long)(tk->xtime_nsec >> tk->shift);
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vdata->monotonic_time_coarse_sec =
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vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
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vdata->monotonic_time_coarse_nsec =
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vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
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while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
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vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
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vdata->monotonic_time_coarse_sec++;
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}
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gtod_write_end(vdata);
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}
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