Commit 348738af authored by Sam Ravnborg's avatar Sam Ravnborg Committed by David S. Miller
Browse files

sparc32: drop unused atomic24 support 



atomic24 support was used to semaphores in the past - but is no longer used.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 371de6e4

arch/sparc/include/asm/atomic_32.h

+0 −100
Original line number Diff line number Diff line
@@ -52,106 +52,6 @@ extern void atomic_set(atomic_t *, int); 
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)

#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)





/* This is the old 24-bit implementation.  It's still used internally

 * by some sparc-specific code, notably the semaphore implementation.

 */

typedef struct { volatile int counter; } atomic24_t;



#ifndef CONFIG_SMP



#define ATOMIC24_INIT(i)  { (i) }

#define atomic24_read(v)          ((v)->counter)

#define atomic24_set(v, i)        (((v)->counter) = i)



#else

/* We do the bulk of the actual work out of line in two common

 * routines in assembler, see arch/sparc/lib/atomic.S for the

 * "fun" details.

 *

 * For SMP the trick is you embed the spin lock byte within

 * the word, use the low byte so signedness is easily retained

 * via a quick arithmetic shift.  It looks like this:

 *

 *	----------------------------------------

 *	| signed 24-bit counter value |  lock  |  atomic_t

 *	----------------------------------------

 *	 31                          8 7      0

 */



#define ATOMIC24_INIT(i)	{ ((i) << 8) }



static inline int atomic24_read(const atomic24_t *v)

{

	int ret = v->counter;



	while(ret & 0xff)

		ret = v->counter;



	return ret >> 8;

}



#define atomic24_set(v, i)	(((v)->counter) = ((i) << 8))

#endif



static inline int __atomic24_add(int i, atomic24_t *v)

{

	register volatile int *ptr asm("g1");

	register int increment asm("g2");

	register int tmp1 asm("g3");

	register int tmp2 asm("g4");

	register int tmp3 asm("g7");



	ptr = &v->counter;

	increment = i;



	__asm__ __volatile__(

	"mov	%%o7, %%g4\n\t"

	"call	___atomic24_add\n\t"

	" add	%%o7, 8, %%o7\n"

	: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)

	: "0" (increment), "r" (ptr)

	: "memory", "cc");



	return increment;

}



static inline int __atomic24_sub(int i, atomic24_t *v)

{

	register volatile int *ptr asm("g1");

	register int increment asm("g2");

	register int tmp1 asm("g3");

	register int tmp2 asm("g4");

	register int tmp3 asm("g7");



	ptr = &v->counter;

	increment = i;



	__asm__ __volatile__(

	"mov	%%o7, %%g4\n\t"

	"call	___atomic24_sub\n\t"

	" add	%%o7, 8, %%o7\n"

	: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)

	: "0" (increment), "r" (ptr)

	: "memory", "cc");



	return increment;

}



#define atomic24_add(i, v) ((void)__atomic24_add((i), (v)))

#define atomic24_sub(i, v) ((void)__atomic24_sub((i), (v)))



#define atomic24_dec_return(v) __atomic24_sub(1, (v))

#define atomic24_inc_return(v) __atomic24_add(1, (v))



#define atomic24_sub_and_test(i, v) (__atomic24_sub((i), (v)) == 0)

#define atomic24_dec_and_test(v) (__atomic24_sub(1, (v)) == 0)



#define atomic24_inc(v) ((void)__atomic24_add(1, (v)))

#define atomic24_dec(v) ((void)__atomic24_sub(1, (v)))



#define atomic24_add_negative(i, v) (__atomic24_add((i), (v)) < 0)



/* Atomic operations are already serializing */

#define smp_mb__before_atomic_dec()	barrier()

#define smp_mb__after_atomic_dec()	barrier()

arch/sparc/lib/atomic_32.S

+0 −55
Original line number Diff line number Diff line
@@ -40,60 +40,5 @@ ___xchg32_sun4md: 
	 mov	%g4, %o7

#endif



	/* Read asm-sparc/atomic.h carefully to understand how this works for SMP.

	 * Really, some things here for SMP are overly clever, go read the header.

	 */

	.globl	___atomic24_add

___atomic24_add:

	rd	%psr, %g3		! Keep the code small, old way was stupid

	nop; nop; nop;			! Let the bits set

	or	%g3, PSR_PIL, %g7	! Disable interrupts

	wr	%g7, 0x0, %psr		! Set %psr

	nop; nop; nop;			! Let the bits set

#ifdef CONFIG_SMP

1:	ldstub	[%g1 + 3], %g7		! Spin on the byte lock for SMP.

	orcc	%g7, 0x0, %g0		! Did we get it?

	bne	1b			! Nope...

	 ld	[%g1], %g7		! Load locked atomic24_t

	sra	%g7, 8, %g7		! Get signed 24-bit integer

	add	%g7, %g2, %g2		! Add in argument

	sll	%g2, 8, %g7		! Transpose back to atomic24_t

	st	%g7, [%g1]		! Clever: This releases the lock as well.

#else

	ld	[%g1], %g7		! Load locked atomic24_t

	add	%g7, %g2, %g2		! Add in argument

	st	%g2, [%g1]		! Store it back

#endif

	wr	%g3, 0x0, %psr		! Restore original PSR_PIL

	nop; nop; nop;			! Let the bits set

	jmpl	%o7, %g0		! NOTE: not + 8, see callers in atomic.h

	 mov	%g4, %o7		! Restore %o7



	.globl	___atomic24_sub

___atomic24_sub:

	rd	%psr, %g3		! Keep the code small, old way was stupid

	nop; nop; nop;			! Let the bits set

	or	%g3, PSR_PIL, %g7	! Disable interrupts

	wr	%g7, 0x0, %psr		! Set %psr

	nop; nop; nop;			! Let the bits set

#ifdef CONFIG_SMP

1:	ldstub	[%g1 + 3], %g7		! Spin on the byte lock for SMP.

	orcc	%g7, 0x0, %g0		! Did we get it?

	bne	1b			! Nope...

	 ld	[%g1], %g7		! Load locked atomic24_t

	sra	%g7, 8, %g7		! Get signed 24-bit integer

	sub	%g7, %g2, %g2		! Subtract argument

	sll	%g2, 8, %g7		! Transpose back to atomic24_t

	st	%g7, [%g1]		! Clever: This releases the lock as well

#else

	ld	[%g1], %g7		! Load locked atomic24_t

	sub	%g7, %g2, %g2		! Subtract argument

	st	%g2, [%g1]		! Store it back

#endif

	wr	%g3, 0x0, %psr		! Restore original PSR_PIL

	nop; nop; nop;			! Let the bits set

	jmpl	%o7, %g0		! NOTE: not + 8, see callers in atomic.h

	 mov	%g4, %o7		! Restore %o7



	.globl  __atomic_end

__atomic_end:

arch/sparc/lib/ksyms.c

+0 −6
Original line number Diff line number Diff line
@@ -62,8 +62,6 @@ extern void ___rw_read_enter(void); 
extern void ___rw_read_try(void);

extern void ___rw_read_exit(void);

extern void ___rw_write_enter(void);

extern void ___atomic24_add(void);

extern void ___atomic24_sub(void);



/* Alias functions whose names begin with "." and export the aliases.

 * The module references will be fixed up by module_frob_arch_sections.
@@ -97,10 +95,6 @@ EXPORT_SYMBOL(___rw_read_exit); 
EXPORT_SYMBOL(___rw_write_enter);

#endif



/* Atomic operations. */

EXPORT_SYMBOL(___atomic24_add);

EXPORT_SYMBOL(___atomic24_sub);



EXPORT_SYMBOL(__ashrdi3);

EXPORT_SYMBOL(__ashldi3);

EXPORT_SYMBOL(__lshrdi3);