forked from Minki/linux
96419b7c4d
arm26 currently has a 256 kB THREAD_SIZE (sic). Looking at the comment in the code, this seems to be based on a misunderstanding. The comment says: this needs attention (see kernel/fork.c which gets a nice div by zero if this is lower than 8*32768 kernel/fork.c does: max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE) Therefore, a division by 0 is impossible for all reasonable cases with THREAD_SIZE >= PAGE_SIZE. Since the minimum PAGE_SIZE Linux uses on the arm26 architecture is 16k, PAGE_SIZE should be sufficient for THREAD_SIZE. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Ian Molton <spyro@f2s.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
141 lines
3.7 KiB
C
141 lines
3.7 KiB
C
/*
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* linux/include/asm-arm26/thread_info.h
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*
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* Copyright (C) 2002 Russell King.
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* Copyright (C) 2003 Ian Molton.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __ASM_ARM_THREAD_INFO_H
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#define __ASM_ARM_THREAD_INFO_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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struct task_struct;
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struct exec_domain;
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#include <linux/compiler.h>
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#include <asm/fpstate.h>
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#include <asm/ptrace.h>
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#include <asm/types.h>
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typedef unsigned long mm_segment_t;
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struct cpu_context_save {
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__u32 r4;
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__u32 r5;
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__u32 r6;
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__u32 r7;
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__u32 r8;
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__u32 r9;
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__u32 sl;
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__u32 fp;
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__u32 sp;
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__u32 pc;
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};
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/*
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* low level task data that entry.S needs immediate access to.
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* We assume cpu_context follows immedately after cpu_domain.
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*/
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struct thread_info {
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unsigned long flags; /* low level flags */
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int preempt_count; /* 0 => preemptable, <0 => bug */
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mm_segment_t addr_limit; /* address limit */
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struct task_struct *task; /* main task structure */
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struct exec_domain *exec_domain; /* execution domain */
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__u32 cpu; /* cpu */
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struct cpu_context_save cpu_context; /* cpu context */
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struct restart_block restart_block;
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union fp_state fpstate;
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};
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task &tsk, \
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.exec_domain &default_exec_domain, \
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.flags 0, \
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.preempt_count 0, \
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.addr_limit KERNEL_DS, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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/*
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* how to get the thread information struct from C
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*/
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static inline struct thread_info *current_thread_info(void) __attribute_const__;
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static inline struct thread_info *current_thread_info(void)
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{
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register unsigned long sp asm ("sp");
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return (struct thread_info *)(sp & ~0x1fff);
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}
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#define THREAD_SIZE PAGE_SIZE
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#define task_pt_regs(task) ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE - 8) - 1)
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extern struct thread_info *alloc_thread_info(struct task_struct *task);
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extern void free_thread_info(struct thread_info *);
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#define thread_saved_pc(tsk) \
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((unsigned long)(pc_pointer(task_thread_info(tsk)->cpu_context.pc)))
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#define thread_saved_fp(tsk) \
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((unsigned long)(task_thread_info(tsk)->cpu_context.fp))
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#else /* !__ASSEMBLY__ */
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#define TI_FLAGS 0
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#define TI_PREEMPT 4
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#define TI_ADDR_LIMIT 8
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#define TI_TASK 12
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#define TI_EXEC_DOMAIN 16
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#define TI_CPU 20
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#define TI_CPU_SAVE 24
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#define TI_RESTART_BLOCK 28
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#define TI_FPSTATE 68
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#endif
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#define PREEMPT_ACTIVE 0x04000000
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/*
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* thread information flags:
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* TIF_SYSCALL_TRACE - syscall trace active
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* TIF_NOTIFY_RESUME - resumption notification requested
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* TIF_SIGPENDING - signal pending
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* TIF_NEED_RESCHED - rescheduling necessary
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* TIF_USEDFPU - FPU was used by this task this quantum (SMP)
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* TIF_POLLING_NRFLAG - true if poll_idle() is polling TIF_NEED_RESCHED
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*/
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#define TIF_NOTIFY_RESUME 0
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#define TIF_SIGPENDING 1
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#define TIF_NEED_RESCHED 2
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#define TIF_SYSCALL_TRACE 8
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#define TIF_USED_FPU 16
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#define TIF_POLLING_NRFLAG 17
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#define TIF_MEMDIE 18
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#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
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#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
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#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
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#define _TIF_USED_FPU (1 << TIF_USED_FPU)
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#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
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/*
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* Change these and you break ASM code in entry-common.S
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*/
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#define _TIF_WORK_MASK 0x000000ff
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#endif /* __KERNEL__ */
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#endif /* __ASM_ARM_THREAD_INFO_H */
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