atomic24 support was used to semaphores in the past - but is no longer used.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
#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()
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:
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.
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);
projects / mv-sheeva.git / commitdiff