csky: Atomic operations

This patch adds atomic, cmpxchg, spinlock files.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
This commit is contained in:
Guo Ren 2018-09-05 14:25:16 +08:00
parent e38a5272ba
commit a0ae62806f
5 changed files with 665 additions and 0 deletions

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_CSKY_ATOMIC_H
#define __ASM_CSKY_ATOMIC_H
#include <linux/version.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#ifdef CONFIG_CPU_HAS_LDSTEX
#define __atomic_add_unless __atomic_add_unless
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
unsigned long tmp, ret;
smp_mb();
asm volatile (
"1: ldex.w %0, (%3) \n"
" mov %1, %0 \n"
" cmpne %0, %4 \n"
" bf 2f \n"
" add %0, %2 \n"
" stex.w %0, (%3) \n"
" bez %0, 1b \n"
"2: \n"
: "=&r" (tmp), "=&r" (ret)
: "r" (a), "r"(&v->counter), "r"(u)
: "memory");
if (ret != u)
smp_mb();
return ret;
}
#define ATOMIC_OP(op, c_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
unsigned long tmp; \
\
asm volatile ( \
"1: ldex.w %0, (%2) \n" \
" " #op " %0, %1 \n" \
" stex.w %0, (%2) \n" \
" bez %0, 1b \n" \
: "=&r" (tmp) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
}
#define ATOMIC_OP_RETURN(op, c_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned long tmp, ret; \
\
smp_mb(); \
asm volatile ( \
"1: ldex.w %0, (%3) \n" \
" " #op " %0, %2 \n" \
" mov %1, %0 \n" \
" stex.w %0, (%3) \n" \
" bez %0, 1b \n" \
: "=&r" (tmp), "=&r" (ret) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
smp_mb(); \
\
return ret; \
}
#define ATOMIC_FETCH_OP(op, c_op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
unsigned long tmp, ret; \
\
smp_mb(); \
asm volatile ( \
"1: ldex.w %0, (%3) \n" \
" mov %1, %0 \n" \
" " #op " %0, %2 \n" \
" stex.w %0, (%3) \n" \
" bez %0, 1b \n" \
: "=&r" (tmp), "=&r" (ret) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
smp_mb(); \
\
return ret; \
}
#else /* CONFIG_CPU_HAS_LDSTEX */
#include <linux/irqflags.h>
#define __atomic_add_unless __atomic_add_unless
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
unsigned long tmp, ret, flags;
raw_local_irq_save(flags);
asm volatile (
" ldw %0, (%3) \n"
" mov %1, %0 \n"
" cmpne %0, %4 \n"
" bf 2f \n"
" add %0, %2 \n"
" stw %0, (%3) \n"
"2: \n"
: "=&r" (tmp), "=&r" (ret)
: "r" (a), "r"(&v->counter), "r"(u)
: "memory");
raw_local_irq_restore(flags);
return ret;
}
#define ATOMIC_OP(op, c_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
unsigned long tmp, flags; \
\
raw_local_irq_save(flags); \
\
asm volatile ( \
" ldw %0, (%2) \n" \
" " #op " %0, %1 \n" \
" stw %0, (%2) \n" \
: "=&r" (tmp) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
\
raw_local_irq_restore(flags); \
}
#define ATOMIC_OP_RETURN(op, c_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned long tmp, ret, flags; \
\
raw_local_irq_save(flags); \
\
asm volatile ( \
" ldw %0, (%3) \n" \
" " #op " %0, %2 \n" \
" stw %0, (%3) \n" \
" mov %1, %0 \n" \
: "=&r" (tmp), "=&r" (ret) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
\
raw_local_irq_restore(flags); \
\
return ret; \
}
#define ATOMIC_FETCH_OP(op, c_op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
unsigned long tmp, ret, flags; \
\
raw_local_irq_save(flags); \
\
asm volatile ( \
" ldw %0, (%3) \n" \
" mov %1, %0 \n" \
" " #op " %0, %2 \n" \
" stw %0, (%3) \n" \
: "=&r" (tmp), "=&r" (ret) \
: "r" (i), "r"(&v->counter) \
: "memory"); \
\
raw_local_irq_restore(flags); \
\
return ret; \
}
#endif /* CONFIG_CPU_HAS_LDSTEX */
#define atomic_add_return atomic_add_return
ATOMIC_OP_RETURN(add, +)
#define atomic_sub_return atomic_sub_return
ATOMIC_OP_RETURN(sub, -)
#define atomic_fetch_add atomic_fetch_add
ATOMIC_FETCH_OP(add, +)
#define atomic_fetch_sub atomic_fetch_sub
ATOMIC_FETCH_OP(sub, -)
#define atomic_fetch_and atomic_fetch_and
ATOMIC_FETCH_OP(and, &)
#define atomic_fetch_or atomic_fetch_or
ATOMIC_FETCH_OP(or, |)
#define atomic_fetch_xor atomic_fetch_xor
ATOMIC_FETCH_OP(xor, ^)
#define atomic_and atomic_and
ATOMIC_OP(and, &)
#define atomic_or atomic_or
ATOMIC_OP(or, |)
#define atomic_xor atomic_xor
ATOMIC_OP(xor, ^)
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#include <asm-generic/atomic.h>
#endif /* __ASM_CSKY_ATOMIC_H */

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_CSKY_CMPXCHG_H
#define __ASM_CSKY_CMPXCHG_H
#ifdef CONFIG_CPU_HAS_LDSTEX
#include <asm/barrier.h>
extern void __bad_xchg(void);
#define __xchg(new, ptr, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
unsigned long tmp; \
switch (size) { \
case 4: \
smp_mb(); \
asm volatile ( \
"1: ldex.w %0, (%3) \n" \
" mov %1, %2 \n" \
" stex.w %1, (%3) \n" \
" bez %1, 1b \n" \
: "=&r" (__ret), "=&r" (tmp) \
: "r" (__new), "r"(__ptr) \
:); \
smp_mb(); \
break; \
default: \
__bad_xchg(); \
} \
__ret; \
})
#define xchg(ptr, x) (__xchg((x), (ptr), sizeof(*(ptr))))
#define __cmpxchg(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(new) __tmp; \
__typeof__(old) __old = (old); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
smp_mb(); \
asm volatile ( \
"1: ldex.w %0, (%3) \n" \
" cmpne %0, %4 \n" \
" bt 2f \n" \
" mov %1, %2 \n" \
" stex.w %1, (%3) \n" \
" bez %1, 1b \n" \
"2: \n" \
: "=&r" (__ret), "=&r" (__tmp) \
: "r" (__new), "r"(__ptr), "r"(__old) \
:); \
smp_mb(); \
break; \
default: \
__bad_xchg(); \
} \
__ret; \
})
#define cmpxchg(ptr, o, n) \
(__cmpxchg((ptr), (o), (n), sizeof(*(ptr))))
#else
#include <asm-generic/cmpxchg.h>
#endif
#endif /* __ASM_CSKY_CMPXCHG_H */

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_CSKY_SPINLOCK_H
#define __ASM_CSKY_SPINLOCK_H
#include <linux/spinlock_types.h>
#include <asm/barrier.h>
#ifdef CONFIG_QUEUED_RWLOCKS
/*
* Ticket-based spin-locking.
*/
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
arch_spinlock_t lockval;
u32 ticket_next = 1 << TICKET_NEXT;
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%2) \n"
" mov %1, %0 \n"
" add %0, %3 \n"
" stex.w %0, (%2) \n"
" bez %0, 1b \n"
: "=&r" (tmp), "=&r" (lockval)
: "r"(p), "r"(ticket_next)
: "cc");
while (lockval.tickets.next != lockval.tickets.owner)
lockval.tickets.owner = READ_ONCE(lock->tickets.owner);
smp_mb();
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
u32 tmp, contended, res;
u32 ticket_next = 1 << TICKET_NEXT;
u32 *p = &lock->lock;
do {
asm volatile (
" ldex.w %0, (%3) \n"
" movi %2, 1 \n"
" rotli %1, %0, 16 \n"
" cmpne %1, %0 \n"
" bt 1f \n"
" movi %2, 0 \n"
" add %0, %0, %4 \n"
" stex.w %0, (%3) \n"
"1: \n"
: "=&r" (res), "=&r" (tmp), "=&r" (contended)
: "r"(p), "r"(ticket_next)
: "cc");
} while (!res);
if (!contended)
smp_mb();
return !contended;
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
smp_mb();
WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1);
}
static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
return lock.tickets.owner == lock.tickets.next;
}
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
return !arch_spin_value_unlocked(READ_ONCE(*lock));
}
static inline int arch_spin_is_contended(arch_spinlock_t *lock)
{
struct __raw_tickets tickets = READ_ONCE(lock->tickets);
return (tickets.next - tickets.owner) > 1;
}
#define arch_spin_is_contended arch_spin_is_contended
#include <asm/qrwlock.h>
/* See include/linux/spinlock.h */
#define smp_mb__after_spinlock() smp_mb()
#else /* CONFIG_QUEUED_RWLOCKS */
/*
* Test-and-set spin-locking.
*/
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" bnez %0, 1b \n"
" movi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
smp_mb();
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
smp_mb();
WRITE_ONCE(lock->lock, 0);
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" bnez %0, 2f \n"
" movi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
" movi %0, 0 \n"
"2: \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
if (!tmp)
smp_mb();
return !tmp;
}
#define arch_spin_is_locked(x) (READ_ONCE((x)->lock) != 0)
/*
* read lock/unlock/trylock
*/
static inline void arch_read_lock(arch_rwlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" blz %0, 1b \n"
" addi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
smp_mb();
}
static inline void arch_read_unlock(arch_rwlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
smp_mb();
asm volatile (
"1: ldex.w %0, (%1) \n"
" subi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
}
static inline int arch_read_trylock(arch_rwlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" blz %0, 2f \n"
" addi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
" movi %0, 0 \n"
"2: \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
if (!tmp)
smp_mb();
return !tmp;
}
/*
* write lock/unlock/trylock
*/
static inline void arch_write_lock(arch_rwlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" bnez %0, 1b \n"
" subi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
smp_mb();
}
static inline void arch_write_unlock(arch_rwlock_t *lock)
{
smp_mb();
WRITE_ONCE(lock->lock, 0);
}
static inline int arch_write_trylock(arch_rwlock_t *lock)
{
u32 *p = &lock->lock;
u32 tmp;
asm volatile (
"1: ldex.w %0, (%1) \n"
" bnez %0, 2f \n"
" subi %0, 1 \n"
" stex.w %0, (%1) \n"
" bez %0, 1b \n"
" movi %0, 0 \n"
"2: \n"
: "=&r" (tmp)
: "r"(p)
: "cc");
if (!tmp)
smp_mb();
return !tmp;
}
#endif /* CONFIG_QUEUED_RWLOCKS */
#endif /* __ASM_CSKY_SPINLOCK_H */

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_CSKY_SPINLOCK_TYPES_H
#define __ASM_CSKY_SPINLOCK_TYPES_H
#ifndef __LINUX_SPINLOCK_TYPES_H
# error "please don't include this file directly"
#endif
#define TICKET_NEXT 16
typedef struct {
union {
u32 lock;
struct __raw_tickets {
/* little endian */
u16 owner;
u16 next;
} tickets;
};
} arch_spinlock_t;
#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } }
#ifdef CONFIG_QUEUED_RWLOCKS
#include <asm-generic/qrwlock_types.h>
#else /* CONFIG_NR_CPUS > 2 */
typedef struct {
u32 lock;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { 0 }
#endif /* CONFIG_QUEUED_RWLOCKS */
#endif /* __ASM_CSKY_SPINLOCK_TYPES_H */

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arch/csky/kernel/atomic.S Normal file
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/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/linkage.h>
#include <abi/entry.h>
.text
/*
* int csky_cmpxchg(int oldval, int newval, int *ptr)
*
* If *ptr != oldval && return 1,
* else *ptr = newval return 0.
*/
#ifdef CONFIG_CPU_HAS_LDSTEX
ENTRY(csky_cmpxchg)
USPTOKSP
mfcr a3, epc
INCTRAP a3
subi sp, 8
stw a3, (sp, 0)
mfcr a3, epsr
stw a3, (sp, 4)
psrset ee
1:
ldex a3, (a2)
cmpne a0, a3
bt16 2f
mov a3, a1
stex a3, (a2)
bez a3, 1b
2:
sync.is
mvc a0
ldw a3, (sp, 0)
mtcr a3, epc
ldw a3, (sp, 4)
mtcr a3, epsr
addi sp, 8
KSPTOUSP
rte
END(csky_cmpxchg)
#else
ENTRY(csky_cmpxchg)
USPTOKSP
mfcr a3, epc
INCTRAP a3
subi sp, 8
stw a3, (sp, 0)
mfcr a3, epsr
stw a3, (sp, 4)
psrset ee
1:
ldw a3, (a2)
cmpne a0, a3
bt16 3f
2:
stw a1, (a2)
3:
mvc a0
ldw a3, (sp, 0)
mtcr a3, epc
ldw a3, (sp, 4)
mtcr a3, epsr
addi sp, 8
KSPTOUSP
rte
END(csky_cmpxchg)
/*
* Called from tlbmodified exception
*/
ENTRY(csky_cmpxchg_fixup)
mfcr a0, epc
lrw a1, 2b
cmpne a1, a0
bt 1f
subi a1, (2b - 1b)
stw a1, (sp, LSAVE_PC)
1:
rts
END(csky_cmpxchg_fixup)
#endif