diff options
| author | Stuart Menefy <stuart.menefy@st.com> | 2007-11-30 07:12:36 (GMT) |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2008-01-28 04:18:58 (GMT) |
| commit | 1efe4ce3ca126da77e450d5a83f7201949d76f62 (patch) | |
| tree | fbae9902aa4103a9e86d06f841d580f24682e7b3 /include/asm-sh/cmpxchg-grb.h | |
| parent | 53ff09422e5e7a6d6198b767c8f494e43ec8e3ae (diff) | |
| download | linux-fsl-qoriq-1efe4ce3ca126da77e450d5a83f7201949d76f62.tar.xz | |
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>
Diffstat (limited to 'include/asm-sh/cmpxchg-grb.h')
| -rw-r--r-- | include/asm-sh/cmpxchg-grb.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/asm-sh/cmpxchg-grb.h b/include/asm-sh/cmpxchg-grb.h new file mode 100644 index 0000000..e2681ab --- /dev/null +++ b/include/asm-sh/cmpxchg-grb.h @@ -0,0 +1,70 @@ +#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 */ |