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Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-…
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…linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Terminally fix local_{dec,sub}_if_positive
  [MIPS] Type proof reimplementation of cmpxchg.
  [MIPS] pg-r4k.c: Fix a typo in an R4600 v2 erratum workaround
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Linus Torvalds committed Oct 3, 2007
2 parents 66b1f1a + 9ea0f04 commit c7659e2
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Showing 4 changed files with 110 additions and 329 deletions.
2 changes: 1 addition & 1 deletion arch/mips/mm/pg-r4k.c
Original file line number Diff line number Diff line change
Expand Up @@ -209,7 +209,7 @@ static inline void build_cdex_p(void)
}

if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
build_insn_word(0x3c01a000); /* lui $at, 0xa000 */
build_insn_word(0x8c200000); /* lw $zero, ($at) */

mi.c_format.opcode = cache_op;
mi.c_format.rs = 4; /* $a0 */
Expand Down
107 changes: 107 additions & 0 deletions include/asm-mips/cmpxchg.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,107 @@
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003, 06, 07 by Ralf Baechle ([email protected])
*/
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H

#include <linux/irqflags.h>

#define __HAVE_ARCH_CMPXCHG 1

#define __cmpxchg_asm(ld, st, m, old, new) \
({ \
__typeof(*(m)) __ret; \
\
if (cpu_has_llsc && R10000_LLSC_WAR) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
" .set mips3 \n" \
"1: " ld " %0, %2 # __cmpxchg_asm \n" \
" bne %0, %z3, 2f \n" \
" .set mips0 \n" \
" move $1, %z4 \n" \
" .set mips3 \n" \
" " st " $1, %1 \n" \
" beqzl $1, 1b \n" \
"2: \n" \
" .set pop \n" \
: "=&r" (__ret), "=R" (*m) \
: "R" (*m), "Jr" (old), "Jr" (new) \
: "memory"); \
} else if (cpu_has_llsc) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
" .set mips3 \n" \
"1: " ld " %0, %2 # __cmpxchg_asm \n" \
" bne %0, %z3, 2f \n" \
" .set mips0 \n" \
" move $1, %z4 \n" \
" .set mips3 \n" \
" " st " $1, %1 \n" \
" beqz $1, 3f \n" \
"2: \n" \
" .subsection 2 \n" \
"3: b 1b \n" \
" .previous \n" \
" .set pop \n" \
: "=&r" (__ret), "=R" (*m) \
: "R" (*m), "Jr" (old), "Jr" (new) \
: "memory"); \
} else { \
unsigned long __flags; \
\
raw_local_irq_save(__flags); \
__ret = *m; \
if (__ret == old) \
*m = new; \
raw_local_irq_restore(__flags); \
} \
\
__ret; \
})

/*
* This function doesn't exist, so you'll get a linker error
* if something tries to do an invalid cmpxchg().
*/
extern void __cmpxchg_called_with_bad_pointer(void);

#define __cmpxchg(ptr,old,new,barrier) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __res = 0; \
\
barrier; \
\
switch (sizeof(*(__ptr))) { \
case 4: \
__res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \
break; \
case 8: \
if (sizeof(long) == 8) { \
__res = __cmpxchg_asm("lld", "scd", __ptr, \
__old, __new); \
break; \
} \
default: \
__cmpxchg_called_with_bad_pointer(); \
break; \
} \
\
barrier; \
\
__res; \
})

#define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_llsc_mb())
#define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new,)

#endif /* __ASM_CMPXCHG_H */
69 changes: 1 addition & 68 deletions include/asm-mips/local.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
#include <linux/percpu.h>
#include <linux/bitops.h>
#include <asm/atomic.h>
#include <asm/cmpxchg.h>
#include <asm/war.h>

typedef struct
Expand Down Expand Up @@ -114,68 +115,6 @@ static __inline__ long local_sub_return(long i, local_t * l)
return result;
}

/*
* local_sub_if_positive - conditionally subtract integer from atomic variable
* @i: integer value to subtract
* @l: pointer of type local_t
*
* Atomically test @l and subtract @i if @l is greater or equal than @i.
* The function returns the old value of @l minus @i.
*/
static __inline__ long local_sub_if_positive(long i, local_t * l)
{
unsigned long result;

if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
__SC "%0, %2 \n"
" .set noreorder \n"
" beqzl %0, 1b \n"
" dsubu %0, %1, %3 \n"
" .set reorder \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
__SC "%0, %2 \n"
" .set noreorder \n"
" beqz %0, 1b \n"
" dsubu %0, %1, %3 \n"
" .set reorder \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else {
unsigned long flags;

local_irq_save(flags);
result = l->a.counter;
result -= i;
if (result >= 0)
l->a.counter = result;
local_irq_restore(flags);
}

return result;
}

#define local_cmpxchg(l, o, n) \
((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
#define local_xchg(l, n) (xchg_local(&((l)->a.counter),(n)))
Expand Down Expand Up @@ -233,12 +172,6 @@ static __inline__ long local_sub_if_positive(long i, local_t * l)
*/
#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)

/*
* local_dec_if_positive - decrement by 1 if old value positive
* @l: pointer of type local_t
*/
#define local_dec_if_positive(l) local_sub_if_positive(1, l)

/*
* local_add_negative - add and test if negative
* @l: pointer of type local_t
Expand Down
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