4c5a116ada
MIPS already uses and S390 will need the vdso data pointer in __arch_get_hw_counter(). This works nicely as long as the architecture does not support time namespaces in the VDSO. With time namespaces enabled the regular accessor to the vdso data pointer __arch_get_vdso_data() will return the namespace specific VDSO data page for tasks which are part of a non-root time namespace. This would cause the architectures which need the vdso data pointer in __arch_get_hw_counter() to access the wrong vdso data page. Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in from the call sites in the core code. For architectures which do not need the data pointer in their counter accessor function the compiler will just optimize it out. Fix up all existing architecture implementations and make MIPS utilize the pointer instead of invoking the accessor function. No functional change and no change in the resulting object code (except MIPS). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de
148 lines
3.2 KiB
C
148 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2018 ARM Limited
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*/
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#ifndef __ASM_VDSO_GETTIMEOFDAY_H
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#define __ASM_VDSO_GETTIMEOFDAY_H
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#ifndef __ASSEMBLY__
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#include <asm/barrier.h>
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#include <asm/errno.h>
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#include <asm/unistd.h>
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#include <asm/vdso/cp15.h>
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#include <uapi/linux/time.h>
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#define VDSO_HAS_CLOCK_GETRES 1
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extern struct vdso_data *__get_datapage(void);
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static __always_inline int gettimeofday_fallback(
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struct __kernel_old_timeval *_tv,
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struct timezone *_tz)
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{
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register struct timezone *tz asm("r1") = _tz;
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register struct __kernel_old_timeval *tv asm("r0") = _tv;
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register long ret asm ("r0");
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register long nr asm("r7") = __NR_gettimeofday;
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asm volatile(
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" swi #0\n"
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: "=r" (ret)
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: "r" (tv), "r" (tz), "r" (nr)
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: "memory");
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return ret;
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}
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static __always_inline long clock_gettime_fallback(
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clockid_t _clkid,
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struct __kernel_timespec *_ts)
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{
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register struct __kernel_timespec *ts asm("r1") = _ts;
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register clockid_t clkid asm("r0") = _clkid;
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register long ret asm ("r0");
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register long nr asm("r7") = __NR_clock_gettime64;
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asm volatile(
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" swi #0\n"
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: "=r" (ret)
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: "r" (clkid), "r" (ts), "r" (nr)
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: "memory");
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return ret;
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}
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static __always_inline long clock_gettime32_fallback(
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clockid_t _clkid,
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struct old_timespec32 *_ts)
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{
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register struct old_timespec32 *ts asm("r1") = _ts;
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register clockid_t clkid asm("r0") = _clkid;
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register long ret asm ("r0");
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register long nr asm("r7") = __NR_clock_gettime;
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asm volatile(
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" swi #0\n"
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: "=r" (ret)
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: "r" (clkid), "r" (ts), "r" (nr)
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: "memory");
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return ret;
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}
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static __always_inline int clock_getres_fallback(
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clockid_t _clkid,
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struct __kernel_timespec *_ts)
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{
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register struct __kernel_timespec *ts asm("r1") = _ts;
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register clockid_t clkid asm("r0") = _clkid;
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register long ret asm ("r0");
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register long nr asm("r7") = __NR_clock_getres_time64;
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asm volatile(
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" swi #0\n"
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: "=r" (ret)
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: "r" (clkid), "r" (ts), "r" (nr)
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: "memory");
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return ret;
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}
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static __always_inline int clock_getres32_fallback(
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clockid_t _clkid,
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struct old_timespec32 *_ts)
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{
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register struct old_timespec32 *ts asm("r1") = _ts;
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register clockid_t clkid asm("r0") = _clkid;
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register long ret asm ("r0");
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register long nr asm("r7") = __NR_clock_getres;
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asm volatile(
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" swi #0\n"
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: "=r" (ret)
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: "r" (clkid), "r" (ts), "r" (nr)
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: "memory");
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return ret;
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}
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static inline bool arm_vdso_hres_capable(void)
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{
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return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
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}
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#define __arch_vdso_hres_capable arm_vdso_hres_capable
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static __always_inline u64 __arch_get_hw_counter(int clock_mode,
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const struct vdso_data *vd)
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{
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#ifdef CONFIG_ARM_ARCH_TIMER
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u64 cycle_now;
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/*
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* Core checks for mode already, so this raced against a concurrent
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* update. Return something. Core will do another round and then
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* see the mode change and fallback to the syscall.
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*/
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if (clock_mode == VDSO_CLOCKMODE_NONE)
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return 0;
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isb();
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cycle_now = read_sysreg(CNTVCT);
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return cycle_now;
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#else
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/* Make GCC happy. This is compiled out anyway */
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return 0;
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#endif
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}
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static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
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{
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return __get_datapage();
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}
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#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
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