mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 21:24:00 +08:00
1efe4ce3ca
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>
41 lines
796 B
C
41 lines
796 B
C
#ifndef __ASM_SH_CMPXCHG_IRQ_H
|
|
#define __ASM_SH_CMPXCHG_IRQ_H
|
|
|
|
static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
|
|
{
|
|
unsigned long flags, retval;
|
|
|
|
local_irq_save(flags);
|
|
retval = *m;
|
|
*m = val;
|
|
local_irq_restore(flags);
|
|
return retval;
|
|
}
|
|
|
|
static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
|
|
{
|
|
unsigned long flags, retval;
|
|
|
|
local_irq_save(flags);
|
|
retval = *m;
|
|
*m = val & 0xff;
|
|
local_irq_restore(flags);
|
|
return retval;
|
|
}
|
|
|
|
static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
|
|
unsigned long new)
|
|
{
|
|
__u32 retval;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
retval = *m;
|
|
if (retval == old)
|
|
*m = new;
|
|
local_irq_restore(flags); /* implies memory barrier */
|
|
return retval;
|
|
}
|
|
|
|
#endif /* __ASM_SH_CMPXCHG_IRQ_H */
|