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/*

 * linux/include/asm-arm/semaphore.h

 */

#ifndef __ASM_PROC_SEMAPHORE_H

#define __ASM_PROC_SEMAPHORE_H

/*

 * This is ugly, but we want the default case to fall through.

 * "__down" is the actual routine that waits...

 */

extern inline void down(struct semaphore * sem)

{

        __asm__ __volatile__ ("

        @ atomic down operation

        mrs     r0, cpsr

        orr     r1, r0, #128            @ disable IRQs

        bic     r0, r0, #0x80000000     @ clear N

        msr     cpsr, r1

        ldr     r1, [%0]

        subs    r1, r1, #1

        str     r1, [%0]

        orrmi   r0, r0, #0x80000000     @ set N

        msr     cpsr, r0

        movmi   r0, %0

        blmi    " SYMBOL_NAME_STR(__down)

                : : "r" (sem) : "r0", "r1", "r2", "r3", "ip", "lr", "cc");

}

/*

 * This is ugly, but we want the default case to fall through.

 * "__down_interruptible" is the actual routine that waits...

 */

extern inline int down_interruptible (struct semaphore * sem)

{

        int result;

        __asm__ __volatile__ ("

        @ atomic down operation

        mrs     r0, cpsr

        orr     r1, r0, #128            @ disable IRQs

        bic     r0, r0, #0x80000000     @ clear N

        msr     cpsr, r1

        ldr     r1, [%1]

        subs    r1, r1, #1

        str     r1, [%1]

        orrmi   r0, r0, #0x80000000     @ set N

        msr     cpsr, r0

        movmi   r0, %1

        movpl   r0, #0

        blmi    " SYMBOL_NAME_STR(__down_interruptible) "

        mov     %0, r0"

                : "=r" (result)

                : "r" (sem)

                : "r0", "r1", "r2", "r3", "ip", "lr", "cc");

        return result;

}

/*

 * Note! This is subtle. We jump to wake people up only if

 * the semaphore was negative (== somebody was waiting on it).

 * The default case (no contention) will result in NO

 * jumps for both down() and up().

 */

extern inline void up(struct semaphore * sem)

{

        __asm__ __volatile__ ("

        @ atomic up operation

        mrs     r0, cpsr

        orr     r1, r0, #128            @ disable IRQs

        bic     r0, r0, #0x80000000     @ clear N

        msr     cpsr, r1

        ldr     r1, [%0]

        adds    r1, r1, #1

        str     r1, [%0]

        orrls   r0, r0, #0x80000000     @ set N

        msr     cpsr, r0

        movmi   r0, %0

        blmi    " SYMBOL_NAME_STR(__up)

                : : "r" (sem) : "r0", "r1", "r2", "r3", "ip", "lr", "cc");

}

#endif