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sh: Fix up futex implementation.

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SH is able to support a complete futex implementation on UP by way
of gUSA. However, IRQ toggling must be done for the old CPUs that
don't have movli.l/movco.l (LL/SC) instructions. Provide a default
implementation that does this, so it's possible to optimize for
newer CPUs.

Follows the same scheme as the current asm-sh/atomic-*.h headers.

Signed-off-by: Kaz Kojima <kkojima@rr.iij4u.or.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Kaz Kojima 2007-06-18 13:58:32 +09:00 committed by Paul Mundt
parent eee4c4694f
commit fc1d4c9c37
2 changed files with 186 additions and 4 deletions
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111
include/asm-sh/futex-irq.h Normal file
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@ -0,0 +1,111 @@
#ifndef __ASM_SH_FUTEX_IRQ_H
#define __ASM_SH_FUTEX_IRQ_H
#include <asm/system.h>
static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr,
int *oldval)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = get_user(*oldval, uaddr);
if (!ret)
ret = put_user(oparg, uaddr);
local_irq_restore(flags);
return ret;
}
static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr,
int *oldval)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = get_user(*oldval, uaddr);
if (!ret)
ret = put_user(*oldval + oparg, uaddr);
local_irq_restore(flags);
return ret;
}
static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr,
int *oldval)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = get_user(*oldval, uaddr);
if (!ret)
ret = put_user(*oldval | oparg, uaddr);
local_irq_restore(flags);
return ret;
}
static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr,
int *oldval)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = get_user(*oldval, uaddr);
if (!ret)
ret = put_user(*oldval & oparg, uaddr);
local_irq_restore(flags);
return ret;
}
static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr,
int *oldval)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = get_user(*oldval, uaddr);
if (!ret)
ret = put_user(*oldval ^ oparg, uaddr);
local_irq_restore(flags);
return ret;
}
static inline int atomic_futex_op_cmpxchg_inatomic(int __user *uaddr,
int oldval, int newval)
{
unsigned long flags;
int ret, prev = 0;
local_irq_save(flags);
ret = get_user(prev, uaddr);
if (!ret && oldval == prev)
ret = put_user(newval, uaddr);
local_irq_restore(flags);
if (ret)
return ret;
return prev;
}
#endif /* __ASM_SH_FUTEX_IRQ_H */

79
include/asm-sh/futex.h
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@ -1,6 +1,77 @@
#ifndef _ASM_FUTEX_H #ifndef __ASM_SH_FUTEX_H
#define _ASM_FUTEX_H #define __ASM_SH_FUTEX_H
#include <asm-generic/futex.h> #ifdef __KERNEL__
#endif #include <linux/futex.h>
#include <asm/errno.h>
#include <asm/uaccess.h>
/* XXX: UP variants, fix for SH-4A and SMP.. */
#include <asm/futex-irq.h>
static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
int oparg = (encoded_op << 8) >> 20;
int cmparg = (encoded_op << 20) >> 20;
int oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
ret = atomic_futex_op_xchg_set(oparg, uaddr, &oldval);
break;
case FUTEX_OP_ADD:
ret = atomic_futex_op_xchg_add(oparg, uaddr, &oldval);
break;
case FUTEX_OP_OR:
ret = atomic_futex_op_xchg_or(oparg, uaddr, &oldval);
break;
case FUTEX_OP_ANDN:
ret = atomic_futex_op_xchg_and(~oparg, uaddr, &oldval);
break;
case FUTEX_OP_XOR:
ret = atomic_futex_op_xchg_xor(oparg, uaddr, &oldval);
break;
default:
ret = -ENOSYS;
break;
}
pagefault_enable();
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
default: ret = -ENOSYS;
}
}
return ret;
}
static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
return atomic_futex_op_cmpxchg_inatomic(uaddr, oldval, newval);
}
#endif /* __KERNEL__ */
#endif /* __ASM_SH_FUTEX_H */