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

#ifndef _ASM_GENERIC_FUTEX_H
#define _ASM_GENERIC_FUTEX_H

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>

#ifndef CONFIG_SMP
/*
 * The following implementation only for uniprocessor machines.
 * For UP, it's relies on the fact that pagefault_disable() also disables
 * preemption to ensure mutual exclusion.
 *
 */

/**
 * futex_atomic_op_inuser() - Atomic arithmetic operation with constant
 *			  argument and comparison of the previous
 *			  futex value with another constant.
 *
 * @encoded_op:	encoded operation to execute
 * @uaddr:	pointer to user space address
 *
 * Return:
 * 0 - On success
 * <0 - On error
 */
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, ret;
	u32 tmp;

	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
		oparg = 1 << oparg;

	pagefault_disable();

	ret = -EFAULT;
	if (unlikely(get_user(oldval, uaddr) != 0))
		goto out_pagefault_enable;

	ret = 0;
	tmp = oldval;

	switch (op) {
	case FUTEX_OP_SET:
		tmp = oparg;
		break;
	case FUTEX_OP_ADD:
		tmp += oparg;
		break;
	case FUTEX_OP_OR:
		tmp |= oparg;
		break;
	case FUTEX_OP_ANDN:
		tmp &= ~oparg;
		break;
	case FUTEX_OP_XOR:
		tmp ^= oparg;
		break;
	default:
		ret = -ENOSYS;
	}

	if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
		ret = -EFAULT;

out_pagefault_enable:
	pagefault_enable();

	if (ret == 0) {
		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;
}

/**
 * futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the
 *				uaddr with newval if the current value is
 *				oldval.
 * @uval:	pointer to store content of @uaddr
 * @uaddr:	pointer to user space address
 * @oldval:	old value
 * @newval:	new value to store to @uaddr
 *
 * Return:
 * 0 - On success
 * <0 - On error
 */
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
			      u32 oldval, u32 newval)
{
	u32 val;

	if (unlikely(get_user(val, uaddr) != 0))
		return -EFAULT;

	if (val == oldval && unlikely(put_user(newval, uaddr) != 0))
		return -EFAULT;

	*uval = val;

	return 0;
}

#else
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();

	switch (op) {
	case FUTEX_OP_SET:
	case FUTEX_OP_ADD:
	case FUTEX_OP_OR:
	case FUTEX_OP_ANDN:
	case FUTEX_OP_XOR:
	default:
		ret = -ENOSYS;
	}

	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(u32 *uval, u32 __user *uaddr,
			      u32 oldval, u32 newval)
{
	return -ENOSYS;
}

#endif /* CONFIG_SMP */
#endif
Commit	Line	Data
f8aaeace JD	1	#ifndef _ASM_GENERIC_FUTEX_H
	2	#define _ASM_GENERIC_FUTEX_H
	3
f8aaeace	4	#include <linux/futex.h>
730f412c	5	#include <linux/uaccess.h>
f8aaeace	6	#include <asm/errno.h>
f8aaeace	7
00f634bc LFT	8	#ifndef CONFIG_SMP
	9	/*
	10	* The following implementation only for uniprocessor machines.
	11	* For UP, it's relies on the fact that pagefault_disable() also disables
	12	* preemption to ensure mutual exclusion.
	13	*
	14	*/
	15
	16	/**
	17	* futex_atomic_op_inuser() - Atomic arithmetic operation with constant
	18	* argument and comparison of the previous
	19	* futex value with another constant.
	20	*
	21	* @encoded_op: encoded operation to execute
	22	* @uaddr: pointer to user space address
	23	*
	24	* Return:
	25	* 0 - On success
	26	* <0 - On error
	27	*/
	28	static inline int
	29	futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
	30	{
	31	int op = (encoded_op >> 28) & 7;
	32	int cmp = (encoded_op >> 24) & 15;
	33	int oparg = (encoded_op << 8) >> 20;
	34	int cmparg = (encoded_op << 20) >> 20;
	35	int oldval, ret;
	36	u32 tmp;
	37
	38	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
	39	oparg = 1 << oparg;
	40
	41	pagefault_disable();
	42
	43	ret = -EFAULT;
	44	if (unlikely(get_user(oldval, uaddr) != 0))
	45	goto out_pagefault_enable;
	46
	47	ret = 0;
	48	tmp = oldval;
	49
	50	switch (op) {
	51	case FUTEX_OP_SET:
	52	tmp = oparg;
	53	break;
	54	case FUTEX_OP_ADD:
	55	tmp += oparg;
	56	break;
	57	case FUTEX_OP_OR:
	58	tmp \|= oparg;
	59	break;
	60	case FUTEX_OP_ANDN:
	61	tmp &= ~oparg;
	62	break;
	63	case FUTEX_OP_XOR:
	64	tmp ^= oparg;
	65	break;
	66	default:
	67	ret = -ENOSYS;
	68	}
	69
	70	if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
	71	ret = -EFAULT;
72
73	out_pagefault_enable:
74	pagefault_enable();
75
76	if (ret == 0) {
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	/**
91	* futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the
92	* uaddr with newval if the current value is
93	* oldval.
94	* @uval: pointer to store content of @uaddr
95	* @uaddr: pointer to user space address
96	* @oldval: old value
97	* @newval: new value to store to @uaddr
98	*
99	* Return:
100	* 0 - On success
101	* <0 - On error
102	*/
103	static inline int
104	futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr,
105	u32 oldval, u32 newval)
106	{
107	u32 val;
108
109	if (unlikely(get_user(val, uaddr) != 0))
110	return -EFAULT;
111
112	if (val == oldval && unlikely(put_user(newval, uaddr) != 0))
113	return -EFAULT;
114
115	*uval = val;
116
117	return 0;
118	}
119
120	#else
f8aaeace	121	static inline int
8d7718aa	122	futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
f8aaeace JD	123	{
	124	int op = (encoded_op >> 28) & 7;
	125	int cmp = (encoded_op >> 24) & 15;
	126	int oparg = (encoded_op << 8) >> 20;
	127	int cmparg = (encoded_op << 20) >> 20;
	128	int oldval = 0, ret;
	129	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
	130	oparg = 1 << oparg;
	131
8d7718aa	132	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
f8aaeace JD	133	return -EFAULT;
f8aaeace JD	134
a866374a	135	pagefault_disable();
f8aaeace JD	136
	137	switch (op) {
	138	case FUTEX_OP_SET:
	139	case FUTEX_OP_ADD:
	140	case FUTEX_OP_OR:
	141	case FUTEX_OP_ANDN:
	142	case FUTEX_OP_XOR:
	143	default:
	144	ret = -ENOSYS;
	145	}
	146
a866374a	147	pagefault_enable();
f8aaeace JD	148
	149	if (!ret) {
	150	switch (cmp) {
	151	case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
	152	case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
	153	case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
	154	case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
	155	case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
	156	case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
	157	default: ret = -ENOSYS;
	158	}
	159	}
	160	return ret;
	161	}
	162
e9056f13	163	static inline int
8d7718aa ML	164	futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr,
8d7718aa ML	165	u32 oldval, u32 newval)
e9056f13 IM	166	{
	167	return -ENOSYS;
	168	}
	169
00f634bc	170	#endif /* CONFIG_SMP */
f8aaeace	171	#endif