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![Vincenzo Frascino](/assets/img/avatar_default.png)
The x86 vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday [ tglx: Massaged changelog and cleaned up the function signature formatting ] Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Cc: Shijith Thotton <sthotton@marvell.com> Cc: Andre Przywara <andre.przywara@arm.com> Link: https://lkml.kernel.org/r/20190621095252.32307-23-vincenzo.frascino@arm.com
106 lines
2.6 KiB
C
106 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_PVCLOCK_H
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#define _ASM_X86_PVCLOCK_H
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#include <asm/clocksource.h>
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#include <asm/pvclock-abi.h>
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/* some helper functions for xen and kvm pv clock sources */
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u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
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u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
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void pvclock_set_flags(u8 flags);
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unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
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void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
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struct pvclock_vcpu_time_info *vcpu,
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struct timespec64 *ts);
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void pvclock_resume(void);
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void pvclock_touch_watchdogs(void);
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static __always_inline
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unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
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{
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unsigned version = src->version & ~1;
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/* Make sure that the version is read before the data. */
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virt_rmb();
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return version;
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}
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static __always_inline
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bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
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unsigned version)
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{
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/* Make sure that the version is re-read after the data. */
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virt_rmb();
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return unlikely(version != src->version);
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}
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/*
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* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
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* yielding a 64-bit result.
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*/
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static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
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{
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u64 product;
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#ifdef __i386__
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u32 tmp1, tmp2;
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#else
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ulong tmp;
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#endif
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if (shift < 0)
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delta >>= -shift;
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else
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delta <<= shift;
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#ifdef __i386__
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__asm__ (
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"mul %5 ; "
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"mov %4,%%eax ; "
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"mov %%edx,%4 ; "
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"mul %5 ; "
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"xor %5,%5 ; "
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"add %4,%%eax ; "
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"adc %5,%%edx ; "
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: "=A" (product), "=r" (tmp1), "=r" (tmp2)
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: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
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#elif defined(__x86_64__)
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__asm__ (
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"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
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: [lo]"=a"(product),
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[hi]"=d"(tmp)
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: "0"(delta),
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[mul_frac]"rm"((u64)mul_frac));
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#else
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#error implement me!
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#endif
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return product;
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}
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static __always_inline
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u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
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{
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u64 delta = tsc - src->tsc_timestamp;
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u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
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src->tsc_shift);
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return src->system_time + offset;
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}
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struct pvclock_vsyscall_time_info {
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struct pvclock_vcpu_time_info pvti;
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} __attribute__((__aligned__(SMP_CACHE_BYTES)));
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#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
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#ifdef CONFIG_PARAVIRT_CLOCK
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void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
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struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
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#else
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static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
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{
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return NULL;
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}
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#endif
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#endif /* _ASM_X86_PVCLOCK_H */
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