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/*
* linux/include/asm-arm/proc-armv/system.h
*
* Copyright (C) 1996 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_PROC_SYSTEM_H
#define __ASM_PROC_SYSTEM_H
#include <linux/config.h>
#define set_cr(x) \
__asm__ __volatile__( \
"mcr p15, 0, %0, c1, c0 @ set CR" \
: : "r" (x))
#define CR_M (1 << 0) /* MMU enable */
#define CR_A (1 << 1) /* Alignment abort enable */
#define CR_C (1 << 2) /* Dcache enable */
#define CR_W (1 << 3) /* Write buffer enable */
#define CR_P (1 << 4) /* 32-bit exception handler */
#define CR_D (1 << 5) /* 32-bit data address range */
#define CR_L (1 << 6) /* Implementation defined */
#define CD_B (1 << 7) /* Big endian */
#define CR_S (1 << 8) /* System MMU protection */
#define CD_R (1 << 9) /* ROM MMU protection */
#define CR_F (1 << 10) /* Implementation defined */
#define CR_Z (1 << 11) /* Implementation defined */
#define CR_I (1 << 12) /* Icache enable */
#define CR_V (1 << 13) /* Vectors relocated to 0xffff0000 */
#define CR_RR (1 << 14) /* Round Robin cache replacement */
extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
extern unsigned long cr_alignment; /* defined in entry-armv.S */
#ifdef __ARM_ARCH_4__
#define vectors_base() ((cr_alignment & CR_V) ? 0xffff0000 : 0)
#else
#define vectors_base() (0)
#endif
/*
* A couple of speedups for the ARM
*/
/*
* Save the current interrupt enable state & disable IRQs
*/
#define __save_flags_cli(x) \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ save_flags_cli\n" \
" orr %1, %0, #128\n" \
" msr cpsr_c, %1" \
: "=r" (x), "=r" (temp) \
: \
: "memory"); \
})
/*
* Enable IRQs
*/
#define __sti() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ sti\n" \
" bic %0, %0, #128\n" \
" msr cpsr_c, %0" \
: "=r" (temp) \
: \
: "memory"); \
})
/*
* Disable IRQs
*/
#define __cli() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ cli\n" \
" orr %0, %0, #128\n" \
" msr cpsr_c, %0" \
: "=r" (temp) \
: \
: "memory"); \
})
/*
* Enable FIQs
*/
#define __stf() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ stf\n" \
" bic %0, %0, #64\n" \
" msr cpsr_c, %0" \
: "=r" (temp) \
: \
: "memory"); \
})
/*
* Disable FIQs
*/
#define __clf() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ clf\n" \
" orr %0, %0, #64\n" \
" msr cpsr_c, %0" \
: "=r" (temp) \
: \
: "memory"); \
})
/*
* save current IRQ & FIQ state
*/
#define __save_flags(x) \
__asm__ __volatile__( \
"mrs %0, cpsr @ save_flags\n" \
: "=r" (x) \
: \
: "memory")
/*
* restore saved IRQ & FIQ state
*/
#define __restore_flags(x) \
__asm__ __volatile__( \
"msr cpsr_c, %0 @ restore_flags\n" \
: \
: "r" (x) \
: "memory")
#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
/*
* On the StrongARM, "swp" is terminally broken since it bypasses the
* cache totally. This means that the cache becomes inconsistent, and,
* since we use normal loads/stores as well, this is really bad.
* Typically, this causes oopsen in filp_close, but could have other,
* more disasterous effects. There are two work-arounds:
* 1. Disable interrupts and emulate the atomic swap
* 2. Clean the cache, perform atomic swap, flush the cache
*
* We choose (1) since its the "easiest" to achieve here and is not
* dependent on the processor type.
*/
#define swp_is_buggy
#endif
static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
{
extern void __bad_xchg(volatile void *, int);
unsigned long ret;
#ifdef swp_is_buggy
unsigned long flags;
#endif
switch (size) {
#ifdef swp_is_buggy
case 1:
__save_flags_cli(flags);
ret = *(volatile unsigned char *)ptr;
*(volatile unsigned char *)ptr = x;
__restore_flags(flags);
break;
case 4:
__save_flags_cli(flags);
ret = *(volatile unsigned long *)ptr;
*(volatile unsigned long *)ptr = x;
__restore_flags(flags);
break;
#else
case 1: __asm__ __volatile__ ("swpb %0, %1, [%2]"
: "=r" (ret)
: "r" (x), "r" (ptr)
: "memory");
break;
case 4: __asm__ __volatile__ ("swp %0, %1, [%2]"
: "=r" (ret)
: "r" (x), "r" (ptr)
: "memory");
break;
#endif
default: __bad_xchg(ptr, size);
}
return ret;
}
#endif
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