x86: revert commit 709f744 ("x86: bitops asm constraint fixes")
709f744 causes my computer to freeze during the start up of X and my
login manger (GDM). It gets to the point where it has shown the default
X mouse cursor logo (a big X / cross) and does not respond to anything
from that point on.
This worked fine before 709f744, and it works fine with 709f744
reverted on top of Linus' current tree (f74d505). The revert had
conflicts, as far as I can tell due to white space changes. The diff I
ended up with is below.
It is 100% reproducible.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/bitops.h b/include/asm-x86/bitops.h
index b81a4d4..ee4b3ea 100644
--- a/include/asm-x86/bitops.h
+++ b/include/asm-x86/bitops.h
@@ -23,13 +23,10 @@
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
/* Technically wrong, but this avoids compilation errors on some gcc
versions. */
-#define ADDR "=m" (*(volatile long *)addr)
-#define BIT_ADDR "=m" (((volatile int *)addr)[nr >> 5])
+#define ADDR "=m" (*(volatile long *) addr)
#else
#define ADDR "+m" (*(volatile long *) addr)
-#define BIT_ADDR "+m" (((volatile int *)addr)[nr >> 5])
#endif
-#define BASE_ADDR "m" (*(volatile int *)addr)
/**
* set_bit - Atomically set a bit in memory
@@ -77,7 +74,7 @@
*/
static inline void clear_bit(int nr, volatile void *addr)
{
- asm volatile(LOCK_PREFIX "btr %1,%2" : BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ asm volatile(LOCK_PREFIX "btr %1,%0" : ADDR : "Ir" (nr));
}
/*
@@ -96,7 +93,7 @@
static inline void __clear_bit(int nr, volatile void *addr)
{
- asm volatile("btr %1,%2" : BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
}
/*
@@ -131,7 +128,7 @@
*/
static inline void __change_bit(int nr, volatile void *addr)
{
- asm volatile("btc %1,%2" : BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
}
/**
@@ -145,7 +142,7 @@
*/
static inline void change_bit(int nr, volatile void *addr)
{
- asm volatile(LOCK_PREFIX "btc %1,%2" : BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr));
}
/**
@@ -191,9 +188,10 @@
{
int oldbit;
- asm volatile("bts %2,%3\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ asm("bts %2,%1\n\t"
+ "sbb %0,%0"
+ : "=r" (oldbit), ADDR
+ : "Ir" (nr));
return oldbit;
}
@@ -229,9 +227,10 @@
{
int oldbit;
- asm volatile("btr %2,%3\n\t"
+ asm volatile("btr %2,%1\n\t"
"sbb %0,%0"
- : "=r" (oldbit), BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ : "=r" (oldbit), ADDR
+ : "Ir" (nr));
return oldbit;
}
@@ -240,9 +239,10 @@
{
int oldbit;
- asm volatile("btc %2,%3\n\t"
+ asm volatile("btc %2,%1\n\t"
"sbb %0,%0"
- : "=r" (oldbit), BIT_ADDR : "Ir" (nr), BASE_ADDR);
+ : "=r" (oldbit), ADDR
+ : "Ir" (nr) : "memory");
return oldbit;
}
@@ -276,11 +276,10 @@
{
int oldbit;
- asm volatile("bt %2,%3\n\t"
+ asm volatile("bt %2,%1\n\t"
"sbb %0,%0"
: "=r" (oldbit)
- : "m" (((volatile const int *)addr)[nr >> 5]),
- "Ir" (nr), BASE_ADDR);
+ : "m" (*(unsigned long *)addr), "Ir" (nr));
return oldbit;
}
@@ -397,8 +396,6 @@
}
#endif /* __KERNEL__ */
-#undef BASE_ADDR
-#undef BIT_ADDR
#undef ADDR
static inline void set_bit_string(unsigned long *bitmap,