126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
#ifndef _ASM_ARM_FUTEX_H
|
|
#define _ASM_ARM_FUTEX_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
#include <asm-generic/futex.h>
|
|
|
|
#else /* !SMP, we can work around lack of atomic ops by disabling preemption */
|
|
|
|
#include <linux/futex.h>
|
|
#include <linux/preempt.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/domain.h>
|
|
|
|
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
|
|
__asm__ __volatile__( \
|
|
"1: " T(ldr) " %1, [%2]\n" \
|
|
" " insn "\n" \
|
|
"2: " T(str) " %0, [%2]\n" \
|
|
" mov %0, #0\n" \
|
|
"3:\n" \
|
|
" .pushsection __ex_table,\"a\"\n" \
|
|
" .align 3\n" \
|
|
" .long 1b, 4f, 2b, 4f\n" \
|
|
" .popsection\n" \
|
|
" .pushsection .fixup,\"ax\"\n" \
|
|
"4: mov %0, %4\n" \
|
|
" b 3b\n" \
|
|
" .popsection" \
|
|
: "=&r" (ret), "=&r" (oldval) \
|
|
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
|
|
: "cc", "memory")
|
|
|
|
static inline int
|
|
futex_atomic_op_inuser (int encoded_op, u32 __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(u32)))
|
|
return -EFAULT;
|
|
|
|
pagefault_disable(); /* implies preempt_disable() */
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
__futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
__futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
__futex_atomic_op("orr %0, %1, %3", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
__futex_atomic_op("and %0, %1, %3", ret, oldval, uaddr, ~oparg);
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
__futex_atomic_op("eor %0, %1, %3", ret, oldval, uaddr, oparg);
|
|
break;
|
|
default:
|
|
ret = -ENOSYS;
|
|
}
|
|
|
|
pagefault_enable(); /* subsumes preempt_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(u32 *uval, u32 __user *uaddr,
|
|
u32 oldval, u32 newval)
|
|
{
|
|
int ret = 0;
|
|
u32 val;
|
|
|
|
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
|
|
return -EFAULT;
|
|
|
|
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
|
|
"1: " T(ldr) " %1, [%4]\n"
|
|
" teq %1, %2\n"
|
|
" it eq @ explicit IT needed for the 2b label\n"
|
|
"2: " T(streq) " %3, [%4]\n"
|
|
"3:\n"
|
|
" .pushsection __ex_table,\"a\"\n"
|
|
" .align 3\n"
|
|
" .long 1b, 4f, 2b, 4f\n"
|
|
" .popsection\n"
|
|
" .pushsection .fixup,\"ax\"\n"
|
|
"4: mov %0, %5\n"
|
|
" b 3b\n"
|
|
" .popsection"
|
|
: "+r" (ret), "=&r" (val)
|
|
: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
|
|
: "cc", "memory");
|
|
|
|
*uval = val;
|
|
return ret;
|
|
}
|
|
|
|
#endif /* !SMP */
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_ARM_FUTEX_H */
|