* Ingo Molnar <mingo@xxxxxxx> wrote:
>
> * Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Thu, 19 Jun 2008, Ingo Molnar wrote:
> > >
> > > Below is the commit, it needed a small amount of massaging to apply the
> > > void * -> unsigned long * change in the x86/bitops topic.
> >
> > Well, that's your bug right there.
> >
> > The macros very much depended on the pointers being "void *", due to
> > the pointer arithmetic (which is a gcc extension that we use
> > extensively - "void *" arithmetic works as if it was a byte
> > pointer).
>
> duh, yeah - of course. Will retry with that fixed :)
yep, the patch below got it all going and it passed 5 hours of testing
already. Thanks,
Ingo
------------------->
commit 7dbceaf9bb68919651901b101f44edd5391ee489
Author: Ingo Molnar <mingo@xxxxxxx>
Date: Fri Jun 20 07:28:24 2008 +0200
x86, bitops: make constant-bit set/clear_bit ops faster, adapt, clean up
fix integration bug introduced by "x86: bitops take an unsigned long *"
which turned "(void *) + x" into "(long *) + x".
small cleanups to make it more apparent which value get propagated where.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
diff --git a/include/asm-x86/bitops.h b/include/asm-x86/bitops.h
index ab7635a..6c50548 100644
--- a/include/asm-x86/bitops.h
+++ b/include/asm-x86/bitops.h
@@ -28,16 +28,15 @@
#define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
#endif
-#define ADDR BITOP_ADDR(addr)
+#define ADDR BITOP_ADDR(addr)
/*
* We do the locked ops that don't return the old value as
* a mask operation on a byte.
*/
-#define IS_IMMEDIATE(nr) \
- (__builtin_constant_p(nr))
-#define CONST_MASK_ADDR BITOP_ADDR(addr + (nr>>3))
-#define CONST_MASK (1 << (nr & 7))
+#define IS_IMMEDIATE(nr) (__builtin_constant_p(nr))
+#define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3))
+#define CONST_MASK(nr) (1 << ((nr) & 7))
/**
* set_bit - Atomically set a bit in memory
@@ -56,13 +55,17 @@
*/
static inline void set_bit(unsigned int nr, volatile unsigned long *addr)
{
- if (IS_IMMEDIATE(nr))
- asm volatile(LOCK_PREFIX "orb %1,%0" : CONST_MASK_ADDR : "i" (CONST_MASK) : "memory");
- else
- asm volatile(LOCK_PREFIX "bts %1,%0" : ADDR : "Ir" (nr) : "memory");
+ if (IS_IMMEDIATE(nr)) {
+ asm volatile(LOCK_PREFIX "orb %1,%0"
+ : CONST_MASK_ADDR(nr, addr)
+ : "i" (CONST_MASK(nr))
+ : "memory");
+ } else {
+ asm volatile(LOCK_PREFIX "bts %1,%0"
+ : BITOP_ADDR(addr) : "Ir" (nr) : "memory");
+ }
}
-
/**
* __set_bit - Set a bit in memory
* @nr: the bit to set
@@ -89,10 +92,15 @@ static inline void __set_bit(int nr, volatile unsigned long *addr)
*/
static inline void clear_bit(int nr, volatile unsigned long *addr)
{
- if (IS_IMMEDIATE(nr))
- asm volatile(LOCK_PREFIX "andb %1,%0" : CONST_MASK_ADDR : "i" (~CONST_MASK));
- else
- asm volatile(LOCK_PREFIX "btr %1,%0" : ADDR : "Ir" (nr));
+ if (IS_IMMEDIATE(nr)) {
+ asm volatile(LOCK_PREFIX "andb %1,%0"
+ : CONST_MASK_ADDR(nr, addr)
+ : "i" (~CONST_MASK(nr)));
+ } else {
+ asm volatile(LOCK_PREFIX "btr %1,%0"
+ : BITOP_ADDR(addr)
+ : "Ir" (nr));
+ }
}
/*
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