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sparc64: vdso: Introduce vdso/processor.h

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The generic vDSO library expects a vdso/processor.h with an definition of
cpu_relax().

Split out cpu_relax() into this dedicated header.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>
Link: https://patch.msgid.link/20260304-vdso-sparc64-generic-2-v6-9-d8eb3b0e1410@linutronix.de
This commit is contained in:
Thomas Weißschuh 2026-03-04 08:49:06 +01:00 committed by Thomas Gleixner
parent d60c682bce
commit e13e3059dc
4 changed files with 44 additions and 27 deletions
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3
arch/sparc/include/asm/processor.h
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@ -1,6 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ___ASM_SPARC_PROCESSOR_H
#define ___ASM_SPARC_PROCESSOR_H
#include <asm/vdso/processor.h>
#if defined(__sparc__) && defined(__arch64__)
#include <asm/processor_64.h>
#else

2
arch/sparc/include/asm/processor_32.h
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@ -91,8 +91,6 @@ unsigned long __get_wchan(struct task_struct *);
extern struct task_struct *last_task_used_math;
int do_mathemu(struct pt_regs *regs, struct task_struct *fpt);
#define cpu_relax() barrier()
extern void (*sparc_idle)(void);
#endif

25
arch/sparc/include/asm/processor_64.h
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@ -182,31 +182,6 @@ unsigned long __get_wchan(struct task_struct *task);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->u_regs[UREG_FP])
/* Please see the commentary in asm/backoff.h for a description of
* what these instructions are doing and how they have been chosen.
* To make a long story short, we are trying to yield the current cpu
* strand during busy loops.
*/
#ifdef BUILD_VDSO
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
::: "memory")
#else /* ! BUILD_VDSO */
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
".section .pause_3insn_patch,\"ax\"\n\t"\
".word 99b\n\t" \
"wr %%g0, 128, %%asr27\n\t" \
"nop\n\t" \
"nop\n\t" \
".previous" \
::: "memory")
#endif
/* Prefetch support. This is tuned for UltraSPARC-III and later.
* UltraSPARC-I will treat these as nops, and UltraSPARC-II has
* a shallower prefetch queue than later chips.

41
arch/sparc/include/asm/vdso/processor.h Normal file
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@ -0,0 +1,41 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_SPARC_VDSO_PROCESSOR_H
#define _ASM_SPARC_VDSO_PROCESSOR_H
#include <linux/compiler.h>
#if defined(__arch64__)
/* Please see the commentary in asm/backoff.h for a description of
* what these instructions are doing and how they have been chosen.
* To make a long story short, we are trying to yield the current cpu
* strand during busy loops.
*/
#ifdef BUILD_VDSO
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
::: "memory")
#else /* ! BUILD_VDSO */
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
".section .pause_3insn_patch,\"ax\"\n\t"\
".word 99b\n\t" \
"wr %%g0, 128, %%asr27\n\t" \
"nop\n\t" \
"nop\n\t" \
".previous" \
::: "memory")
#endif /* BUILD_VDSO */
#else /* ! __arch64__ */
#define cpu_relax() barrier()
#endif /* __arch64__ */
#endif /* _ASM_SPARC_VDSO_PROCESSOR_H */