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Commit e2f04577 authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Alistair Delva
Browse files

BACKPORT: arm: vdso: Enable arm to use common headers 



Enable arm to use only the common headers in the implementation
of the vDSO library.

Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lkml.kernel.org/r/20200320145351.32292-25-vincenzo.frascino@arm.com


(cherry picked from commit 78c8516141014cf6322ac899c3832f66612504bb)
Signed-off-by: default avatarMark Salyzyn <salyzyn@google.com>
Bug: 154668398
Change-Id: I6a1aa15a3973253d9a158886785b07b343b4b014
parent 292257f3

arch/arm/include/asm/cp15.h

+1 −19
Original line number Diff line number Diff line
@@ -50,25 +50,7 @@ 


#ifdef CONFIG_CPU_CP15



#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	\

	"mrc", "mcr", __stringify(p15, Op1, %0, CRn, CRm, Op2), u32

#define __ACCESS_CP15_64(Op1, CRm)		\

	"mrrc", "mcrr", __stringify(p15, Op1, %Q0, %R0, CRm), u64



#define __read_sysreg(r, w, c, t) ({				\

	t __val;						\

	asm volatile(r " " c : "=r" (__val));			\

	__val;							\

})

#define read_sysreg(...)		__read_sysreg(__VA_ARGS__)



#define __write_sysreg(v, r, w, c, t)	asm volatile(w " " c : : "r" ((t)(v)))

#define write_sysreg(v, ...)		__write_sysreg(v, __VA_ARGS__)



#define BPIALL				__ACCESS_CP15(c7, 0, c5, 6)

#define ICIALLU				__ACCESS_CP15(c7, 0, c5, 0)



#define CNTVCT				__ACCESS_CP15_64(1, c14)

#include <asm/vdso/cp15.h>



extern unsigned long cr_alignment;	/* defined in entry-armv.S */

arch/arm/include/asm/processor.h

+1 −10
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <asm/ptrace.h>

#include <asm/types.h>

#include <asm/unified.h>

#include <asm/vdso/processor.h>



#ifdef __KERNEL__

#define STACK_TOP	((current->personality & ADDR_LIMIT_32BIT) ? \
@@ -94,16 +95,6 @@ extern void release_thread(struct task_struct *); 


unsigned long get_wchan(struct task_struct *p);



#if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)

#define cpu_relax()						\

	do {							\

		smp_mb();					\

		__asm__ __volatile__("nop; nop; nop; nop; nop; nop; nop; nop; nop; nop;");	\

	} while (0)

#else

#define cpu_relax()			barrier()

#endif



#define task_pt_regs(p) \

	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)

arch/arm/include/asm/vdso/cp15.h

0 → 100644
+38 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Copyright (C) 2020 ARM Ltd.

 */

#ifndef __ASM_VDSO_CP15_H

#define __ASM_VDSO_CP15_H



#ifndef __ASSEMBLY__



#ifdef CONFIG_CPU_CP15



#include <linux/stringify.h>



#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	\

	"mrc", "mcr", __stringify(p15, Op1, %0, CRn, CRm, Op2), u32

#define __ACCESS_CP15_64(Op1, CRm)		\

	"mrrc", "mcrr", __stringify(p15, Op1, %Q0, %R0, CRm), u64



#define __read_sysreg(r, w, c, t) ({				\

	t __val;						\

	asm volatile(r " " c : "=r" (__val));			\

	__val;							\

})

#define read_sysreg(...)		__read_sysreg(__VA_ARGS__)



#define __write_sysreg(v, r, w, c, t)	asm volatile(w " " c : : "r" ((t)(v)))

#define write_sysreg(v, ...)		__write_sysreg(v, __VA_ARGS__)



#define BPIALL				__ACCESS_CP15(c7, 0, c5, 6)

#define ICIALLU				__ACCESS_CP15(c7, 0, c5, 0)



#define CNTVCT				__ACCESS_CP15_64(1, c14)



#endif /* CONFIG_CPU_CP15 */



#endif /* __ASSEMBLY__ */



#endif /* __ASM_VDSO_CP15_H */

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

0 → 100644
+145 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Copyright (C) 2018 ARM Limited

 */

#ifndef __ASM_VDSO_GETTIMEOFDAY_H

#define __ASM_VDSO_GETTIMEOFDAY_H



#ifndef __ASSEMBLY__



#include <asm/errno.h>

#include <asm/unistd.h>

#include <asm/vdso/cp15.h>

#include <uapi/linux/time.h>



#define VDSO_HAS_CLOCK_GETRES		1



extern struct vdso_data *__get_datapage(void);



static __always_inline int gettimeofday_fallback(

				struct __kernel_old_timeval *_tv,

				struct timezone *_tz)

{

	register struct timezone *tz asm("r1") = _tz;

	register struct __kernel_old_timeval *tv asm("r0") = _tv;

	register long ret asm ("r0");

	register long nr asm("r7") = __NR_gettimeofday;



	asm volatile(

	"	swi #0\n"

	: "=r" (ret)

	: "r" (tv), "r" (tz), "r" (nr)

	: "memory");



	return ret;

}



static __always_inline long clock_gettime_fallback(

					clockid_t _clkid,

					struct __kernel_timespec *_ts)

{

	register struct __kernel_timespec *ts asm("r1") = _ts;

	register clockid_t clkid asm("r0") = _clkid;

	register long ret asm ("r0");

	register long nr asm("r7") = __NR_clock_gettime64;



	asm volatile(

	"	swi #0\n"

	: "=r" (ret)

	: "r" (clkid), "r" (ts), "r" (nr)

	: "memory");



	return ret;

}



static __always_inline long clock_gettime32_fallback(

					clockid_t _clkid,

					struct old_timespec32 *_ts)

{

	register struct old_timespec32 *ts asm("r1") = _ts;

	register clockid_t clkid asm("r0") = _clkid;

	register long ret asm ("r0");

	register long nr asm("r7") = __NR_clock_gettime;



	asm volatile(

	"	swi #0\n"

	: "=r" (ret)

	: "r" (clkid), "r" (ts), "r" (nr)

	: "memory");



	return ret;

}



static __always_inline int clock_getres_fallback(

					clockid_t _clkid,

					struct __kernel_timespec *_ts)

{

	register struct __kernel_timespec *ts asm("r1") = _ts;

	register clockid_t clkid asm("r0") = _clkid;

	register long ret asm ("r0");

	register long nr asm("r7") = __NR_clock_getres_time64;



	asm volatile(

	"       swi #0\n"

	: "=r" (ret)

	: "r" (clkid), "r" (ts), "r" (nr)

	: "memory");



	return ret;

}



static __always_inline int clock_getres32_fallback(

					clockid_t _clkid,

					struct old_timespec32 *_ts)

{

	register struct old_timespec32 *ts asm("r1") = _ts;

	register clockid_t clkid asm("r0") = _clkid;

	register long ret asm ("r0");

	register long nr asm("r7") = __NR_clock_getres;



	asm volatile(

	"       swi #0\n"

	: "=r" (ret)

	: "r" (clkid), "r" (ts), "r" (nr)

	: "memory");



	return ret;

}



static inline bool arm_vdso_hres_capable(void)

{

	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);

}

#define __arch_vdso_hres_capable arm_vdso_hres_capable



static __always_inline u64 __arch_get_hw_counter(int clock_mode)

{

#ifdef CONFIG_ARM_ARCH_TIMER

	u64 cycle_now;



	/*

	 * Core checks for mode already, so this raced against a concurrent

	 * update. Return something. Core will do another round and then

	 * see the mode change and fallback to the syscall.

	 */

	if (clock_mode == VDSO_CLOCKMODE_NONE)

		return 0;



	isb();

	cycle_now = read_sysreg(CNTVCT);



	return cycle_now;

#else

	/* Make GCC happy. This is compiled out anyway */

	return 0;

#endif

}



static __always_inline const struct vdso_data *__arch_get_vdso_data(void)

{

	return __get_datapage();

}



#endif /* !__ASSEMBLY__ */



#endif /* __ASM_VDSO_GETTIMEOFDAY_H */

arch/arm/include/asm/vdso/processor.h

0 → 100644
+22 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Copyright (C) 2020 ARM Ltd.

 */

#ifndef __ASM_VDSO_PROCESSOR_H

#define __ASM_VDSO_PROCESSOR_H



#ifndef __ASSEMBLY__



#if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)

#define cpu_relax()						\

	do {							\

		smp_mb();					\

		__asm__ __volatile__("nop; nop; nop; nop; nop; nop; nop; nop; nop; nop;");	\

	} while (0)

#else

#define cpu_relax()			barrier()

#endif



#endif /* __ASSEMBLY__ */



#endif /* __ASM_VDSO_PROCESSOR_H */