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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
/*
* Save the current interrupt enable state & disable IRQs
*/
#ifdef CONFIG_ARM64
/*
* Save the current interrupt enable state
* and disable IRQs/FIQs
*/
#define local_irq_save(flags) \
({ \
asm volatile( \
"mrs %0, daif\n" \
"msr daifset, #3" \
: "=r" (flags) \
: \
: "memory"); \
})
/*
* restore saved IRQ & FIQ state
*/
#define local_irq_restore(flags) \
({ \
asm volatile( \
"msr daif, %0" \
: \
: "r" (flags) \
: "memory"); \
})
/*
* Enable IRQs/FIQs
*/
#define local_irq_enable() \
({ \
asm volatile( \
"msr daifclr, #3" \
: \
: \
: "memory"); \
})
/*
* Disable IRQs/FIQs
*/
#define local_irq_disable() \
({ \
asm volatile( \
"msr daifset, #3" \
: \
: \
: "memory"); \
})
#else /* CONFIG_ARM64 */
#define local_irq_save(x) \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ local_irq_save\n" \
" orr %1, %0, #128\n" \
" msr cpsr_c, %1" \
: "=r" (x), "=r" (temp) \
: \
: "memory"); \
})
/*
* Enable IRQs
*/
#define local_irq_enable() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ local_irq_enable\n" \
" bic %0, %0, #128\n" \
" msr cpsr_c, %0" \
: "=r" (temp) \
: \
: "memory"); \
})
/*
* Disable IRQs
*/
#define local_irq_disable() \
({ \
unsigned long temp; \
__asm__ __volatile__( \
"mrs %0, cpsr @ local_irq_disable\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 the current interrupt enable state.
*/
#define local_save_flags(x) \
({ \
__asm__ __volatile__( \
"mrs %0, cpsr @ local_save_flags\n" \
: "=r" (x) \
: \
: "memory"); \
})
/*
* restore saved IRQ & FIQ state
*/
#define local_irq_restore(x) \
__asm__ __volatile__( \
"msr cpsr_c, %0 @ local_irq_restore\n" \
: \
: "r" (x) \
: "memory")
#endif /* CONFIG_ARM64 */
#if defined(CONFIG_ARM64)
/*
* 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:
local_irq_save(flags);
ret = *(volatile unsigned char *)ptr;
*(volatile unsigned char *)ptr = x;
local_irq_restore(flags);
break;
case 4:
local_irq_save(flags);
ret = *(volatile unsigned long *)ptr;
*(volatile unsigned long *)ptr = x;
local_irq_restore(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), ret = 0;
}
return ret;
}
#endif
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