mirror of
https://github.com/torvalds/linux.git
synced 2024-11-14 08:02:07 +00:00
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>
71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
#ifndef __ASM_SH_CMPXCHG_GRB_H
|
|
#define __ASM_SH_CMPXCHG_GRB_H
|
|
|
|
static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
|
|
{
|
|
unsigned long retval;
|
|
|
|
__asm__ __volatile__ (
|
|
" .align 2 \n\t"
|
|
" mova 1f, r0 \n\t" /* r0 = end point */
|
|
" nop \n\t"
|
|
" mov r15, r1 \n\t" /* r1 = saved sp */
|
|
" mov #-4, r15 \n\t" /* LOGIN */
|
|
" mov.l @%1, %0 \n\t" /* load old value */
|
|
" mov.l %2, @%1 \n\t" /* store new value */
|
|
"1: mov r1, r15 \n\t" /* LOGOUT */
|
|
: "=&r" (retval),
|
|
"+r" (m)
|
|
: "r" (val)
|
|
: "memory", "r0", "r1");
|
|
|
|
return retval;
|
|
}
|
|
|
|
static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
|
|
{
|
|
unsigned long retval;
|
|
|
|
__asm__ __volatile__ (
|
|
" .align 2 \n\t"
|
|
" mova 1f, r0 \n\t" /* r0 = end point */
|
|
" mov r15, r1 \n\t" /* r1 = saved sp */
|
|
" mov #-6, r15 \n\t" /* LOGIN */
|
|
" mov.b @%1, %0 \n\t" /* load old value */
|
|
" extu.b %0, %0 \n\t" /* extend as unsigned */
|
|
" mov.b %2, @%1 \n\t" /* store new value */
|
|
"1: mov r1, r15 \n\t" /* LOGOUT */
|
|
: "=&r" (retval),
|
|
"+r" (m)
|
|
: "r" (val)
|
|
: "memory" , "r0", "r1");
|
|
|
|
return retval;
|
|
}
|
|
|
|
static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
|
|
unsigned long new)
|
|
{
|
|
unsigned long retval;
|
|
|
|
__asm__ __volatile__ (
|
|
" .align 2 \n\t"
|
|
" mova 1f, r0 \n\t" /* r0 = end point */
|
|
" nop \n\t"
|
|
" mov r15, r1 \n\t" /* r1 = saved sp */
|
|
" mov #-8, r15 \n\t" /* LOGIN */
|
|
" mov.l @%1, %0 \n\t" /* load old value */
|
|
" cmp/eq %0, %2 \n\t"
|
|
" bf 1f \n\t" /* if not equal */
|
|
" mov.l %2, @%1 \n\t" /* store new value */
|
|
"1: mov r1, r15 \n\t" /* LOGOUT */
|
|
: "=&r" (retval),
|
|
"+r" (m)
|
|
: "r" (new)
|
|
: "memory" , "r0", "r1", "t");
|
|
|
|
return retval;
|
|
}
|
|
|
|
#endif /* __ASM_SH_CMPXCHG_GRB_H */
|