segment.h

arm平台上的uclinux系统全部源代码

/*
 * linux/include/asm-arm/proc-armv/segment.h
 *
 * Copyright (C) 1996 Russell King
 */

#ifndef __ASM_PROC_SEGMENT_H
#define __ASM_PROC_SEGMENT_H

static __inline__ void __put_user(unsigned long x, void * y, int size)
{
	switch (size) {
	case 1:
	__asm__(
       "teq	%2, #0\n"
       "strnebt	%0, [%1]\n"
       "streqb	%0, [%1]\n"
	: : "r" (x), "r" (y), "r" (current->tss.fs)
	: "lr", "cc");
	break;
	case 2:
	{ register unsigned long tmp1 = x; void *tmp2 = y;
	__asm__ __volatile__(
       "teq	%4, #0\n"
       "strnebt	%0, [%1], #1\n"
       "streqb	%0, [%1], #1\n"
       "mov	%0, %0, lsr #8\n"
       "strnebt	%0, [%1]\n"
       "streqb	%0, [%1]\n"
	: "=&r" (tmp1), "=&r" (tmp2)
	: "0" (tmp1), "1" (tmp2), "r" (current->tss.fs)
	: "lr", "cc");
	}
	break;
	case 4:
	__asm__(
       "teq	%2, #0\n"
       "strnet	%0, [%1]\n"
       "streq	%0, [%1]\n"
	: : "r" (x), "r" (y), "r" (current->tss.fs)
	: "lr", "cc");
	break;
	default:
	bad_user_access_length ();
	}
}

static __inline__ unsigned long __get_user(const void *y, int size)
{
	unsigned long result;

	switch (size) {
	case 1:
	__asm__(
       "teq	%2, #0\n"
       "ldrnebt	%0, [%1]\n"
       "ldreqb	%0, [%1]\n"
	: "=r" (result)
	: "r" (y), "r" (current->tss.fs)
	: "lr", "cc");
	return result;
	case 2:
	__asm__(
       "teq	%2, #0\n"
       "ldrnet	%0, [%1]\n"
       "ldreq	%0, [%1]\n"
       "mov	%0, %0, lsl #16\n"
       "mov	%0, %0, lsr #16\n"
	: "=&r" (result)
	: "r" (y), "r" (current->tss.fs)
	: "lr", "cc");
	return result;
	case 4:
	__asm__(
       "teq	%2, #0\n"
       "ldrnet	%0, [%1]\n"
       "ldreq	%0, [%1]\n"
	: "=r" (result)
	: "r" (y), "r" (current->tss.fs)
	: "lr", "cc");
	return result;
	default:
	return bad_user_access_length ();
	}
}		

#endif /* __ASM_PROC_SEGMENT_H */