mips: Add support for generic vDSO (24640f23) · Commits · 戴 / test

arch/mips/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@ config MIPS
		select GENERIC_CLOCKEVENTS
		select GENERIC_CMOS_UPDATE
		select GENERIC_CPU_AUTOPROBE
		select GENERIC_GETTIMEOFDAY
		select GENERIC_IOMAP
		select GENERIC_IRQ_PROBE
		select GENERIC_IRQ_SHOW
		@@ -74,6 +75,7 @@ config MIPS
		select HAVE_STACKPROTECTOR
		select HAVE_SYSCALL_TRACEPOINTS
		select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT \|\| !SMP
		select HAVE_GENERIC_VDSO
		select IRQ_FORCED_THREADING
		select ISA if EISA
		select MODULES_USE_ELF_RELA if MODULES && 64BIT

arch/mips/include/asm/vdso.h

+2 −76

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		#define __ASM_VDSO_H

		#include <linux/mm_types.h>
		#include <vdso/datapage.h>

		#include <asm/barrier.h>

		@@ -49,84 +50,9 @@ extern struct mips_vdso_image vdso_image_o32;
		extern struct mips_vdso_image vdso_image_n32;
		#endif

		/**
		* union mips_vdso_data - Data provided by the kernel for the VDSO.
		* @xtime_sec: Current real time (seconds part).
		* @xtime_nsec: Current real time (nanoseconds part, shifted).
		* @wall_to_mono_sec: Wall-to-monotonic offset (seconds part).
		* @wall_to_mono_nsec: Wall-to-monotonic offset (nanoseconds part).
		* @seq_count: Counter to synchronise updates (odd = updating).
		* @cs_shift: Clocksource shift value.
		* @clock_mode: Clocksource to use for time functions.
		* @cs_mult: Clocksource multiplier value.
		* @cs_cycle_last: Clock cycle value at last update.
		* @cs_mask: Clocksource mask value.
		* @tz_minuteswest: Minutes west of Greenwich (from timezone).
		* @tz_dsttime: Type of DST correction (from timezone).
		*
		* This structure contains data needed by functions within the VDSO. It is
		* populated by the kernel and mapped read-only into user memory. The time
		* fields are mirrors of internal data from the timekeeping infrastructure.
		*
		* Note: Care should be taken when modifying as the layout must remain the same
		* for both 64- and 32-bit (for 32-bit userland on 64-bit kernel).
		*/
		union mips_vdso_data {
		struct {
		u64 xtime_sec;
		u64 xtime_nsec;
		u64 wall_to_mono_sec;
		u64 wall_to_mono_nsec;
		u32 seq_count;
		u32 cs_shift;
		u8 clock_mode;
		u32 cs_mult;
		u64 cs_cycle_last;
		u64 cs_mask;
		s32 tz_minuteswest;
		s32 tz_dsttime;
		};

		struct vdso_data data[CS_BASES];
		u8 page[PAGE_SIZE];
		};

		static inline u32 vdso_data_read_begin(const union mips_vdso_data *data)
		{
		u32 seq;

		while (true) {
		seq = READ_ONCE(data->seq_count);
		if (likely(!(seq & 1))) {
		/* Paired with smp_wmb() in vdso_data_write_(). /
		smp_rmb();
		return seq;
		}

		cpu_relax();
		}
		}

		static inline bool vdso_data_read_retry(const union mips_vdso_data *data,
		u32 start_seq)
		{
		/* Paired with smp_wmb() in vdso_data_write_(). /
		smp_rmb();
		return unlikely(data->seq_count != start_seq);
		}

		static inline void vdso_data_write_begin(union mips_vdso_data *data)
		{
		++data->seq_count;

		/* Ensure sequence update is written before other data page values. */
		smp_wmb();
		}

		static inline void vdso_data_write_end(union mips_vdso_data *data)
		{
		/* Ensure data values are written before updating sequence again. */
		smp_wmb();
		++data->seq_count;
		}

		#endif /* __ASM_VDSO_H */

arch/mips/include/asm/vdso/gettimeofday.h

0 → 100644

+151 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2018 ARM Limited
		* Copyright (C) 2015 Imagination Technologies
		* Author: Alex Smith <alex.smith@imgtec.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of the GNU General Public License as published by the
		* Free Software Foundation; either version 2 of the License, or (at your
		* option) any later version.
		*/
		#ifndef __ASM_VDSO_GETTIMEOFDAY_H
		#define __ASM_VDSO_GETTIMEOFDAY_H

		#ifndef __ASSEMBLY__

		#include <linux/compiler.h>
		#include <linux/time.h>

		#include <asm/vdso/vdso.h>
		#include <asm/clocksource.h>
		#include <asm/io.h>
		#include <asm/unistd.h>
		#include <asm/vdso.h>

		#ifdef CONFIG_MIPS_CLOCK_VSYSCALL

		static __always_inline long gettimeofday_fallback(
		struct __kernel_old_timeval *_tv,
		struct timezone *_tz)
		{
		register struct timezone *tz asm("a1") = _tz;
		register struct __kernel_old_timeval *tv asm("a0") = _tv;
		register long ret asm("v0");
		register long nr asm("v0") = __NR_gettimeofday;
		register long error asm("a3");

		asm volatile(
		" syscall\n"
		: "=r" (ret), "=r" (error)
		: "r" (tv), "r" (tz), "r" (nr)
		: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
		"$14", "$15", "$24", "$25", "hi", "lo", "memory");

		return error ? -ret : ret;
		}

		#else

		static __always_inline long gettimeofday_fallback(
		struct __kernel_old_timeval *_tv,
		struct timezone *_tz)
		{
		return -1;
		}

		#endif

		static __always_inline long clock_gettime_fallback(
		clockid_t _clkid,
		struct __kernel_timespec *_ts)
		{
		register struct __kernel_timespec *ts asm("a1") = _ts;
		register clockid_t clkid asm("a0") = _clkid;
		register long ret asm("v0");
		#if _MIPS_SIM == _MIPS_SIM_ABI64
		register long nr asm("v0") = __NR_clock_gettime;
		#else
		register long nr asm("v0") = __NR_clock_gettime64;
		#endif
		register long error asm("a3");

		asm volatile(
		" syscall\n"
		: "=r" (ret), "=r" (error)
		: "r" (clkid), "r" (ts), "r" (nr)
		: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
		"$14", "$15", "$24", "$25", "hi", "lo", "memory");

		return error ? -ret : ret;
		}

		#ifdef CONFIG_CSRC_R4K

		static __always_inline u64 read_r4k_count(void)
		{
		unsigned int count;

		__asm__ __volatile__(
		" .set push\n"
		" .set mips32r2\n"
		" rdhwr %0, $2\n"
		" .set pop\n"
		: "=r" (count));

		return count;
		}

		#endif

		#ifdef CONFIG_CLKSRC_MIPS_GIC

		static __always_inline u64 read_gic_count(const struct vdso_data *data)
		{
		void __iomem *gic = get_gic(data);
		u32 hi, hi2, lo;

		do {
		hi = __raw_readl(gic + sizeof(lo));
		lo = __raw_readl(gic);
		hi2 = __raw_readl(gic + sizeof(lo));
		} while (hi2 != hi);

		return (((u64)hi) << 32) + lo;
		}

		#endif

		static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
		{
		#ifdef CONFIG_CLKSRC_MIPS_GIC
		const struct vdso_data *data = get_vdso_data();
		#endif
		u64 cycle_now;

		switch (clock_mode) {
		#ifdef CONFIG_CSRC_R4K
		case VDSO_CLOCK_R4K:
		cycle_now = read_r4k_count();
		break;
		#endif
		#ifdef CONFIG_CLKSRC_MIPS_GIC
		case VDSO_CLOCK_GIC:
		cycle_now = read_gic_count(data);
		break;
		#endif
		default:
		cycle_now = 0;
		break;
		}

		return cycle_now;
		}

		static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
		{
		return get_vdso_data();
		}

		#endif /* !__ASSEMBLY__ */

		#endif /* __ASM_VDSO_GETTIMEOFDAY_H */

arch/mips/vdso/vdso.h→arch/mips/include/asm/vdso/vdso.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -68,14 +68,14 @@ static inline unsigned long get_vdso_base(void)
		return addr;
		}

		static inline const union mips_vdso_data *get_vdso_data(void)
		static inline const struct vdso_data *get_vdso_data(void)
		{
		return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE);
		return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE);
		}

		#ifdef CONFIG_CLKSRC_MIPS_GIC

		static inline void __iomem get_gic(const union mips_vdso_data data)
		static inline void __iomem get_gic(const struct vdso_data data)
		{
		return (void __iomem *)data - PAGE_SIZE;
		}

arch/mips/include/asm/vdso/vsyscall.h

0 → 100644

+43 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0 */
		#ifndef __ASM_VDSO_VSYSCALL_H
		#define __ASM_VDSO_VSYSCALL_H

		#ifndef __ASSEMBLY__

		#include <linux/timekeeper_internal.h>
		#include <vdso/datapage.h>

		extern struct vdso_data *vdso_data;

		/*
		* Update the vDSO data page to keep in sync with kernel timekeeping.
		*/
		static __always_inline
		struct vdso_data *__mips_get_k_vdso_data(void)
		{
		return vdso_data;
		}
		#define __arch_get_k_vdso_data __mips_get_k_vdso_data

		static __always_inline
		int __mips_get_clock_mode(struct timekeeper *tk)
		{
		u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;

		return clock_mode;
		}
		#define __arch_get_clock_mode __mips_get_clock_mode

		static __always_inline
		int __mips_use_vsyscall(struct vdso_data *vdata)
		{
		return (vdata[CS_HRES_COARSE].clock_mode != VDSO_CLOCK_NONE);
		}
		#define __arch_use_vsyscall __mips_use_vsyscall

		/* The asm-generic header needs to be included after the definitions above */
		#include <asm-generic/vdso/vsyscall.h>

		#endif /* !__ASSEMBLY__ */

		#endif /* __ASM_VDSO_VSYSCALL_H */

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