[mirror_ubuntu-artful-kernel.git] / arch / arm / include / asm / futex.h

#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 */
Commit	Line	Data
e589ed23 MP	1	#ifndef _ASM_ARM_FUTEX_H
	2	#define _ASM_ARM_FUTEX_H
	3
	4	#ifdef __KERNEL__
	5
	6	#ifdef CONFIG_SMP
4732efbe	7
f8aaeace	8	#include <asm-generic/futex.h>
4732efbe	9
e589ed23 MP	10	#else /* !SMP, we can work around lack of atomic ops by disabling preemption */
	11
	12	#include <linux/futex.h>
	13	#include <linux/preempt.h>
	14	#include <linux/uaccess.h>
	15	#include <asm/errno.h>
247055aa	16	#include <asm/domain.h>
e589ed23 MP	17
	18	#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
	19	__asm__ __volatile__( \
247055aa	20	"1: " T(ldr) " %1, [%2]\n" \
e589ed23	21	" " insn "\n" \
247055aa	22	"2: " T(str) " %0, [%2]\n" \
e589ed23 MP	23	" mov %0, #0\n" \
e589ed23 MP	24	"3:\n" \
4260415f	25	" .pushsection __ex_table,\"a\"\n" \
e589ed23 MP	26	" .align 3\n" \
e589ed23 MP	27	" .long 1b, 4f, 2b, 4f\n" \
4260415f RK	28	" .popsection\n" \
4260415f RK	29	" .pushsection .fixup,\"ax\"\n" \
e589ed23 MP	30	"4: mov %0, %4\n" \
e589ed23 MP	31	" b 3b\n" \
4260415f	32	" .popsection" \
e589ed23 MP	33	: "=&r" (ret), "=&r" (oldval) \
	34	: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
	35	: "cc", "memory")
	36
	37	static inline int
8d7718aa	38	futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
e589ed23 MP	39	{
	40	int op = (encoded_op >> 28) & 7;
	41	int cmp = (encoded_op >> 24) & 15;
	42	int oparg = (encoded_op << 8) >> 20;
	43	int cmparg = (encoded_op << 20) >> 20;
	44	int oldval = 0, ret;
	45
	46	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
	47	oparg = 1 << oparg;
	48
8d7718aa	49	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
e589ed23 MP	50	return -EFAULT;
	51
	52	pagefault_disable(); /* implies preempt_disable() */
	53
	54	switch (op) {
	55	case FUTEX_OP_SET:
	56	__futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
	57	break;
	58	case FUTEX_OP_ADD:
	59	__futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
	60	break;
	61	case FUTEX_OP_OR:
	62	__futex_atomic_op("orr %0, %1, %3", ret, oldval, uaddr, oparg);
	63	break;
	64	case FUTEX_OP_ANDN:
	65	__futex_atomic_op("and %0, %1, %3", ret, oldval, uaddr, ~oparg);
	66	break;
	67	case FUTEX_OP_XOR:
	68	__futex_atomic_op("eor %0, %1, %3", ret, oldval, uaddr, oparg);
	69	break;
	70	default:
	71	ret = -ENOSYS;
	72	}
	73
	74	pagefault_enable(); /* subsumes preempt_enable() */
	75
	76	if (!ret) {
	77	switch (cmp) {
	78	case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
	79	case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
	80	case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
	81	case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
	82	case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
	83	case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
	84	default: ret = -ENOSYS;
	85	}
	86	}
	87	return ret;
	88	}
	89
	90	static inline int
8d7718aa ML	91	futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr,
8d7718aa ML	92	u32 oldval, u32 newval)
e589ed23	93	{
8d7718aa ML	94	int ret = 0;
8d7718aa ML	95	u32 val;
e589ed23	96
8d7718aa	97	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
e589ed23 MP	98	return -EFAULT;
e589ed23 MP	99
e589ed23	100	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
37a9d912 ML	101	"1: " T(ldr) " %1, [%4]\n"
37a9d912 ML	102	" teq %1, %2\n"
b86040a5	103	" it eq @ explicit IT needed for the 2b label\n"
37a9d912	104	"2: " T(streq) " %3, [%4]\n"
e589ed23	105	"3:\n"
4260415f	106	" .pushsection __ex_table,\"a\"\n"
e589ed23 MP	107	" .align 3\n"
e589ed23 MP	108	" .long 1b, 4f, 2b, 4f\n"
4260415f RK	109	" .popsection\n"
4260415f RK	110	" .pushsection .fixup,\"ax\"\n"
37a9d912	111	"4: mov %0, %5\n"
e589ed23	112	" b 3b\n"
4260415f	113	" .popsection"
37a9d912	114	: "+r" (ret), "=&r" (val)
e589ed23 MP	115	: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
	116	: "cc", "memory");
	117
37a9d912 ML	118	*uval = val;
37a9d912 ML	119	return ret;
e589ed23 MP	120	}
	121
	122	#endif /* !SMP */
	123
	124	#endif /* __KERNEL__ */
	125	#endif /* _ASM_ARM_FUTEX_H */