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/*
* include/asm-cris/processor.h
*
* Copyright (C) 2000, 2001 Axis Communications AB
*
* Authors: Bjorn Wesen Initial version
*
*/
#ifndef __ASM_CRIS_PROCESSOR_H
#define __ASM_CRIS_PROCESSOR_H
#include <linux/config.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/ptrace.h>
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({void *pc; __asm__ ("move.d $pc,%0" : "=rm" (pc)); pc; })
/* CRIS has no problems with write protection */
#define wp_works_ok 1
/*
* User space process size. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#ifdef CONFIG_CRIS_LOW_MAP
#define TASK_SIZE (0x50000000UL) /* 1.25 GB */
#else
#define TASK_SIZE (0xB0000000UL) /* 2.75 GB */
#endif
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
/* THREAD_SIZE is the size of the task_struct/kernel_stack combo.
* normally, the stack is found by doing something like p + THREAD_SIZE
* in CRIS, a page is 8192 bytes, which seems like a sane size
*/
#define THREAD_SIZE PAGE_SIZE
#define KERNEL_STACK_SIZE PAGE_SIZE
/* CRIS thread_struct. this really has nothing to do with the processor itself, since
* CRIS does not do any hardware task-switching, but it's here for legacy reasons.
* The thread_struct here is used when task-switching using _resume defined in entry.S.
* The offsets here are hardcoded into _resume - if you change this struct, you need to
* change them as well!!!
*/
struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
unsigned long dccr; /* saved flag register */
};
/*
* At user->kernel entry, the pt_regs struct is stacked on the top of the kernel-stack.
* This macro allows us to find those regs for a task.
* Notice that subsequent pt_regs stackings, like recursive interrupts occuring while
* we're in the kernel, won't affect this - only the first user->kernel transition
* registers are reached by this.
*/
#define user_regs(task) (((struct pt_regs *)((unsigned long)(task) + THREAD_SIZE)) - 1)
/*
* Dito but for the currently running task
*/
#define current_regs() user_regs(current)
#define INIT_THREAD { \
0, 0, 0x20 } /* ccr = int enable, nothing else */
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
/* give the thread a program location
* set user-mode (The 'U' flag (User mode flag) is CCR/DCCR bit 8)
* switch user-stackpointer
*/
#define start_thread(regs, ip, usp) do { \
set_fs(USER_DS); \
regs->irp = ip; \
regs->dccr |= 1 << U_DCCR_BITNR; \
wrusp(usp); \
} while(0)
unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) \
({ \
unsigned long eip = 0; \
unsigned long regs = (unsigned long)user_regs(tsk); \
if (regs > PAGE_SIZE && \
VALID_PAGE(virt_to_page(regs))) \
eip = ((struct pt_regs *)regs)->irp; \
eip; })
#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
#define copy_segments(tsk, mm) do { } while (0)
#define release_segments(mm) do { } while (0)
#define forget_segments() do { } while (0)
/*
* Free current thread data structures etc..
*/
static inline void exit_thread(void)
{
/* Nothing needs to be done. */
}
/* Free all resources held by a thread. */
static inline void release_thread(struct task_struct *dead_task)
{
/* Nothing needs to be done. */
}
/*
* Return saved PC of a blocked thread.
*/
extern inline unsigned long thread_saved_pc(struct thread_struct *t)
{
return (unsigned long)user_regs(t)->irp;
}
#define alloc_task_struct() ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
#define free_task_struct(p) free_pages((unsigned long) (p), 1)
#define get_task_struct(tsk) atomic_inc(&virt_to_page(tsk)->count)
#define init_task (init_task_union.task)
#define init_stack (init_task_union.stack)
#define cpu_relax() do { } while (0)
#endif /* __ASM_CRIS_PROCESSOR_H */
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