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f6dc8c5b8e
During the recent discussion of taking 'volatile' off of the spinlock, I noticed that while most arches #define cpu_relax() such that it implies barrier(), some arches define cpu_relax() to be empty. This patch changes the definition of cpu_relax() for frv, h8300, m68knommu, sh, sh64, v850 and xtensa from an empty while(0) to the compiler barrier(). Signed-off-by: Chase Venters <chase.venters@clientec.com> Acked-by: Arjan van de Ven <arjan@Linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
136 lines
3.5 KiB
C
136 lines
3.5 KiB
C
/*
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* include/asm-h8300/processor.h
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*
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* Copyright (C) 2002 Yoshinori Sato
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*
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* Based on: linux/asm-m68nommu/processor.h
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*
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* Copyright (C) 1995 Hamish Macdonald
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*/
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#ifndef __ASM_H8300_PROCESSOR_H
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#define __ASM_H8300_PROCESSOR_H
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/*
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* Default implementation of macro that returns current
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* instruction pointer ("program counter").
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*/
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#define current_text_addr() ({ __label__ _l; _l: &&_l;})
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#include <linux/compiler.h>
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#include <asm/segment.h>
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#include <asm/fpu.h>
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#include <asm/ptrace.h>
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#include <asm/current.h>
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static inline unsigned long rdusp(void) {
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extern unsigned int sw_usp;
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return(sw_usp);
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}
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static inline void wrusp(unsigned long usp) {
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extern unsigned int sw_usp;
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sw_usp = usp;
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}
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/*
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* User space process size: 3.75GB. This is hardcoded into a few places,
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* so don't change it unless you know what you are doing.
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*/
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#define TASK_SIZE (0xFFFFFFFFUL)
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/*
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* This decides where the kernel will search for a free chunk of vm
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* space during mmap's. We won't be using it
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*/
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#define TASK_UNMAPPED_BASE 0
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struct thread_struct {
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unsigned long ksp; /* kernel stack pointer */
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unsigned long usp; /* user stack pointer */
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unsigned long ccr; /* saved status register */
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unsigned long esp0; /* points to SR of stack frame */
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struct {
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unsigned short *addr;
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unsigned short inst;
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} breakinfo;
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};
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#define INIT_THREAD { \
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.ksp = sizeof(init_stack) + (unsigned long)init_stack, \
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.usp = 0, \
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.ccr = PS_S, \
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.esp0 = 0, \
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.breakinfo = { \
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.addr = (unsigned short *)-1, \
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.inst = 0 \
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} \
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}
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/*
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* Do necessary setup to start up a newly executed thread.
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*
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* pass the data segment into user programs if it exists,
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* it can't hurt anything as far as I can tell
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*/
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#if defined(__H8300H__)
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#define start_thread(_regs, _pc, _usp) \
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do { \
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set_fs(USER_DS); /* reads from user space */ \
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(_regs)->pc = (_pc); \
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(_regs)->ccr &= 0x00; /* clear kernel flag */ \
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(_regs)->er5 = current->mm->start_data; /* GOT base */ \
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wrusp((unsigned long)(_usp) - sizeof(unsigned long)*3); \
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} while(0)
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#endif
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#if defined(__H8300S__)
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#define start_thread(_regs, _pc, _usp) \
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do { \
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set_fs(USER_DS); /* reads from user space */ \
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(_regs)->pc = (_pc); \
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(_regs)->ccr = 0x00; /* clear kernel flag */ \
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(_regs)->exr = 0x78; /* enable all interrupts */ \
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(_regs)->er5 = current->mm->start_data; /* GOT base */ \
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/* 14 = space for retaddr(4), vector(4), er0(4) and ext(2) on stack */ \
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wrusp(((unsigned long)(_usp)) - 14); \
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} while(0)
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#endif
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/* Forward declaration, a strange C thing */
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struct task_struct;
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/* Free all resources held by a thread. */
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static inline void release_thread(struct task_struct *dead_task)
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{
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}
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extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
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#define prepare_to_copy(tsk) do { } while (0)
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/*
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* Free current thread data structures etc..
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*/
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static inline void exit_thread(void)
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{
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}
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/*
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* Return saved PC of a blocked thread.
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*/
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unsigned long thread_saved_pc(struct task_struct *tsk);
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unsigned long get_wchan(struct task_struct *p);
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#define KSTK_EIP(tsk) \
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({ \
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unsigned long eip = 0; \
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if ((tsk)->thread.esp0 > PAGE_SIZE && \
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MAP_NR((tsk)->thread.esp0) < max_mapnr) \
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eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
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eip; })
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#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
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#define cpu_relax() barrier()
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#endif
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