linux/arch/arm64/include/asm/atomic_lse.h
Will Deacon 0bc671d3f4 arm64: cmpxchg: avoid "cc" clobber in ll/sc routines
We can perform the cmpxchg comparison using eor and cbnz which avoids
the "cc" clobber for the ll/sc case and consequently for the LSE case
where we may have to fall-back on the ll/sc code at runtime.

Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 15:28:52 +01:00

435 lines
10 KiB
C

/*
* Based on arch/arm/include/asm/atomic.h
*
* Copyright (C) 1996 Russell King.
* Copyright (C) 2002 Deep Blue Solutions Ltd.
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_ATOMIC_LSE_H
#define __ASM_ATOMIC_LSE_H
#ifndef __ARM64_IN_ATOMIC_IMPL
#error "please don't include this file directly"
#endif
#define __LL_SC_ATOMIC(op) __LL_SC_CALL(atomic_##op)
static inline void atomic_andnot(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(andnot),
" stclr %w[i], %[v]\n")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic_or(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(or),
" stset %w[i], %[v]\n")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic_xor(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(xor),
" steor %w[i], %[v]\n")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic_add(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(add),
" stadd %w[i], %[v]\n")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline int atomic_add_return(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC(add_return),
/* LSE atomics */
" ldaddal %w[i], w30, %[v]\n"
" add %w[i], %w[i], w30")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30", "memory");
return w0;
}
static inline void atomic_and(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC(and),
/* LSE atomics */
" mvn %w[i], %w[i]\n"
" stclr %w[i], %[v]")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic_sub(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC(sub),
/* LSE atomics */
" neg %w[i], %w[i]\n"
" stadd %w[i], %[v]")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC(sub_return)
" nop",
/* LSE atomics */
" neg %w[i], %w[i]\n"
" ldaddal %w[i], w30, %[v]\n"
" add %w[i], %w[i], w30")
: [i] "+r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30", "memory");
return w0;
}
static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
{
register unsigned long x0 asm ("x0") = (unsigned long)ptr;
register int w1 asm ("w1") = old;
register int w2 asm ("w2") = new;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC(cmpxchg)
" nop",
/* LSE atomics */
" mov w30, %w[old]\n"
" casal w30, %w[new], %[v]\n"
" mov %w[ret], w30")
: [ret] "+r" (x0), [v] "+Q" (ptr->counter)
: [old] "r" (w1), [new] "r" (w2)
: "x30", "memory");
return x0;
}
#undef __LL_SC_ATOMIC
#define __LL_SC_ATOMIC64(op) __LL_SC_CALL(atomic64_##op)
static inline void atomic64_andnot(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(andnot),
" stclr %[i], %[v]\n")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic64_or(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(or),
" stset %[i], %[v]\n")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic64_xor(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(xor),
" steor %[i], %[v]\n")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic64_add(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(add),
" stadd %[i], %[v]\n")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline long atomic64_add_return(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(add_return),
/* LSE atomics */
" ldaddal %[i], x30, %[v]\n"
" add %[i], %[i], x30")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30", "memory");
return x0;
}
static inline void atomic64_and(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(and),
/* LSE atomics */
" mvn %[i], %[i]\n"
" stclr %[i], %[v]")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline void atomic64_sub(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(sub),
/* LSE atomics */
" neg %[i], %[i]\n"
" stadd %[i], %[v]")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30");
}
static inline long atomic64_sub_return(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(sub_return)
" nop",
/* LSE atomics */
" neg %[i], %[i]\n"
" ldaddal %[i], x30, %[v]\n"
" add %[i], %[i], x30")
: [i] "+r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: "x30", "memory");
return x0;
}
static inline long atomic64_cmpxchg(atomic64_t *ptr, long old, long new)
{
register unsigned long x0 asm ("x0") = (unsigned long)ptr;
register long x1 asm ("x1") = old;
register long x2 asm ("x2") = new;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(cmpxchg)
" nop",
/* LSE atomics */
" mov x30, %[old]\n"
" casal x30, %[new], %[v]\n"
" mov %[ret], x30")
: [ret] "+r" (x0), [v] "+Q" (ptr->counter)
: [old] "r" (x1), [new] "r" (x2)
: "x30", "memory");
return x0;
}
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
register long x0 asm ("x0") = (long)v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" nop\n"
__LL_SC_ATOMIC64(dec_if_positive)
" nop\n"
" nop\n"
" nop\n"
" nop\n"
" nop",
/* LSE atomics */
"1: ldr x30, %[v]\n"
" subs %[ret], x30, #1\n"
" b.mi 2f\n"
" casal x30, %[ret], %[v]\n"
" sub x30, x30, #1\n"
" sub x30, x30, %[ret]\n"
" cbnz x30, 1b\n"
"2:")
: [ret] "+&r" (x0), [v] "+Q" (v->counter)
:
: "x30", "cc", "memory");
return x0;
}
#undef __LL_SC_ATOMIC64
#define __LL_SC_CMPXCHG(op) __LL_SC_CALL(__cmpxchg_case_##op)
#define __CMPXCHG_CASE(w, sz, name, mb, cl...) \
static inline unsigned long __cmpxchg_case_##name(volatile void *ptr, \
unsigned long old, \
unsigned long new) \
{ \
register unsigned long x0 asm ("x0") = (unsigned long)ptr; \
register unsigned long x1 asm ("x1") = old; \
register unsigned long x2 asm ("x2") = new; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
"nop\n" \
__LL_SC_CMPXCHG(name) \
"nop", \
/* LSE atomics */ \
" mov " #w "30, %" #w "[old]\n" \
" cas" #mb #sz "\t" #w "30, %" #w "[new], %[v]\n" \
" mov %" #w "[ret], " #w "30") \
: [ret] "+r" (x0), [v] "+Q" (*(unsigned long *)ptr) \
: [old] "r" (x1), [new] "r" (x2) \
: "x30" , ##cl); \
\
return x0; \
}
__CMPXCHG_CASE(w, b, 1, )
__CMPXCHG_CASE(w, h, 2, )
__CMPXCHG_CASE(w, , 4, )
__CMPXCHG_CASE(x, , 8, )
__CMPXCHG_CASE(w, b, mb_1, al, "memory")
__CMPXCHG_CASE(w, h, mb_2, al, "memory")
__CMPXCHG_CASE(w, , mb_4, al, "memory")
__CMPXCHG_CASE(x, , mb_8, al, "memory")
#undef __LL_SC_CMPXCHG
#undef __CMPXCHG_CASE
#define __LL_SC_CMPXCHG_DBL(op) __LL_SC_CALL(__cmpxchg_double##op)
#define __CMPXCHG_DBL(name, mb, cl...) \
static inline int __cmpxchg_double##name(unsigned long old1, \
unsigned long old2, \
unsigned long new1, \
unsigned long new2, \
volatile void *ptr) \
{ \
unsigned long oldval1 = old1; \
unsigned long oldval2 = old2; \
register unsigned long x0 asm ("x0") = old1; \
register unsigned long x1 asm ("x1") = old2; \
register unsigned long x2 asm ("x2") = new1; \
register unsigned long x3 asm ("x3") = new2; \
register unsigned long x4 asm ("x4") = (unsigned long)ptr; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
" nop\n" \
" nop\n" \
" nop\n" \
__LL_SC_CMPXCHG_DBL(name), \
/* LSE atomics */ \
" casp" #mb "\t%[old1], %[old2], %[new1], %[new2], %[v]\n"\
" eor %[old1], %[old1], %[oldval1]\n" \
" eor %[old2], %[old2], %[oldval2]\n" \
" orr %[old1], %[old1], %[old2]") \
: [old1] "+r" (x0), [old2] "+r" (x1), \
[v] "+Q" (*(unsigned long *)ptr) \
: [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \
[oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \
: "x30" , ##cl); \
\
return x0; \
}
__CMPXCHG_DBL( , )
__CMPXCHG_DBL(_mb, al, "memory")
#undef __LL_SC_CMPXCHG_DBL
#undef __CMPXCHG_DBL
#endif /* __ASM_ATOMIC_LSE_H */