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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>
121 lines
3.2 KiB
C
121 lines
3.2 KiB
C
/*
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* include/asm-v850/processor.h
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*
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* Copyright (C) 2001,02,03 NEC Electronics Corporation
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* Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*
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* Written by Miles Bader <miles@gnu.org>
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*/
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#ifndef __V850_PROCESSOR_H__
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#define __V850_PROCESSOR_H__
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#ifndef __ASSEMBLY__ /* <linux/thread_info.h> is not asm-safe. */
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#include <linux/thread_info.h>
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#endif
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#include <linux/compiler.h>
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#include <asm/ptrace.h>
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#include <asm/entry.h>
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/* Some code expects `segment' stuff to be defined here. */
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#include <asm/segment.h>
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/*
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* The only places this is used seem to be horrible bletcherous kludges,
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* so we just define it to be as large as possible.
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*/
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#define TASK_SIZE (0xFFFFFFFF)
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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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#ifndef __ASSEMBLY__
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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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/* If you change this, you must change the associated assembly-languages
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constants defined below, THREAD_*. */
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struct thread_struct {
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/* kernel stack pointer (must be first field in structure) */
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unsigned long ksp;
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};
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#define INIT_THREAD { sizeof init_stack + (unsigned long)init_stack }
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/* Do necessary setup to start up a newly executed thread. */
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static inline void start_thread (struct pt_regs *regs,
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unsigned long pc, unsigned long usp)
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{
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regs->pc = pc;
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regs->gpr[GPR_SP] = usp;
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regs->kernel_mode = 0;
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}
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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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/* Prepare to copy thread state - unlazy all lazy status */
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#define prepare_to_copy(tsk) do { } while (0)
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extern int kernel_thread (int (*fn)(void *), void * arg, unsigned long flags);
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/* Free current thread data structures etc. */
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static inline void exit_thread (void)
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{
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}
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/* Return the registers saved during context-switch by the currently
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not-running thread T. Note that this only includes some registers!
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See entry.S for details. */
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#define thread_saved_regs(t) \
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((struct pt_regs*)((t)->thread.ksp + STATE_SAVE_PT_OFFSET))
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/* Return saved (kernel) PC of a blocked thread. Actually, we return the
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LP register, because the thread is actually blocked in switch_thread,
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and we're interested in the PC it will _return_ to. */
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#define thread_saved_pc(t) (thread_saved_regs(t)->gpr[GPR_LP])
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unsigned long get_wchan (struct task_struct *p);
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/* Return some info about the user process TASK. */
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#define task_tos(task) ((unsigned long)task_stack_page(task) + THREAD_SIZE)
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#define task_pt_regs(task) ((struct pt_regs *)task_tos (task) - 1)
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#define task_sp(task) (task_pt_regs (task)->gpr[GPR_SP])
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#define task_pc(task) (task_pt_regs (task)->pc)
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/* Grotty old names for some. */
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#define KSTK_EIP(task) task_pc (task)
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#define KSTK_ESP(task) task_sp (task)
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#define cpu_relax() barrier()
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#else /* __ASSEMBLY__ */
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#define THREAD_KSP 0
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#endif /* !__ASSEMBLY__ */
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#endif /* __V850_PROCESSOR_H__ */
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