kernel-ark/arch/sh/include/asm/atomic-llsc.h
Paul Mundt 8c0b8139c8 sh: consolidate atomic_cmpxchg()/atomic_add_unless() definitions.
The LL/SC and IRQ versions were using generic stubs while the GRB version
was just reimplementing what it already had for the standard cmpxchg()
code. As we have optimized cmpxchg() implementations that are decoupled
from the atomic code, simply falling back on the generic wrapper does the
right thing. With this in place the GRB case is unaffected while the
LL/SC case gets to use its optimized cmpxchg().

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-08 17:02:17 +09:00

108 lines
2.1 KiB
C

#ifndef __ASM_SH_ATOMIC_LLSC_H
#define __ASM_SH_ATOMIC_LLSC_H
/*
* To get proper branch prediction for the main line, we must branch
* forward to code at the end of this object's .text section, then
* branch back to restart the operation.
*/
static inline void atomic_add(int i, atomic_t *v)
{
unsigned long tmp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_add \n"
" add %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
: "=&z" (tmp)
: "r" (i), "r" (&v->counter)
: "t");
}
static inline void atomic_sub(int i, atomic_t *v)
{
unsigned long tmp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_sub \n"
" sub %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
: "=&z" (tmp)
: "r" (i), "r" (&v->counter)
: "t");
}
/*
* SH-4A note:
*
* We basically get atomic_xxx_return() for free compared with
* atomic_xxx(). movli.l/movco.l require r0 due to the instruction
* encoding, so the retval is automatically set without having to
* do any special work.
*/
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long temp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_add_return \n"
" add %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
" synco \n"
: "=&z" (temp)
: "r" (i), "r" (&v->counter)
: "t");
return temp;
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long temp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_sub_return \n"
" sub %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
" synco \n"
: "=&z" (temp)
: "r" (i), "r" (&v->counter)
: "t");
return temp;
}
static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
unsigned long tmp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_clear_mask \n"
" and %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
: "=&z" (tmp)
: "r" (~mask), "r" (&v->counter)
: "t");
}
static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
{
unsigned long tmp;
__asm__ __volatile__ (
"1: movli.l @%2, %0 ! atomic_set_mask \n"
" or %1, %0 \n"
" movco.l %0, @%2 \n"
" bf 1b \n"
: "=&z" (tmp)
: "r" (mask), "r" (&v->counter)
: "t");
}
#endif /* __ASM_SH_ATOMIC_LLSC_H */