sh: GUSA atomic rollback support.

This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Stuart Menefy
2007-11-30 16:12:36 +09:00
committed by Paul Mundt
parent 53ff09422e
commit 1efe4ce3ca
13 changed files with 590 additions and 180 deletions

View File

@@ -11,97 +11,18 @@
/* For __swab32 */
#include <asm/byteorder.h>
static inline void set_bit(int nr, volatile void * addr)
{
int mask;
volatile unsigned int *a = addr;
unsigned long flags;
#ifdef CONFIG_GUSA_RB
#include <asm/bitops-grb.h>
#else
#include <asm/bitops-irq.h>
#endif
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
*a |= mask;
local_irq_restore(flags);
}
/*
* clear_bit() doesn't provide any barrier for the compiler.
*/
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
static inline void clear_bit(int nr, volatile void * addr)
{
int mask;
volatile unsigned int *a = addr;
unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
*a &= ~mask;
local_irq_restore(flags);
}
static inline void change_bit(int nr, volatile void * addr)
{
int mask;
volatile unsigned int *a = addr;
unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
*a ^= mask;
local_irq_restore(flags);
}
static inline int test_and_set_bit(int nr, volatile void * addr)
{
int mask, retval;
volatile unsigned int *a = addr;
unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
retval = (mask & *a) != 0;
*a |= mask;
local_irq_restore(flags);
return retval;
}
static inline int test_and_clear_bit(int nr, volatile void * addr)
{
int mask, retval;
volatile unsigned int *a = addr;
unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
retval = (mask & *a) != 0;
*a &= ~mask;
local_irq_restore(flags);
return retval;
}
static inline int test_and_change_bit(int nr, volatile void * addr)
{
int mask, retval;
volatile unsigned int *a = addr;
unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
local_irq_save(flags);
retval = (mask & *a) != 0;
*a ^= mask;
local_irq_restore(flags);
return retval;
}
#include <asm-generic/bitops/non-atomic.h>