blob: dbc2ac7711e58e4c2ba4f3b42535c4a81c4afa75 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
// SPDX-License-Identifier: GPL-2.0
/*
* Functions for registration of I/O interruption subclasses on s390.
*
* Copyright IBM Corp. 2008
* Authors: Sebastian Ott <sebott@linux.vnet.ibm.com>
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <asm/isc.h>
static unsigned int isc_refs[MAX_ISC + 1];
static DEFINE_SPINLOCK(isc_ref_lock);
/**
* isc_register - register an I/O interruption subclass.
* @isc: I/O interruption subclass to register
*
* The number of users for @isc is increased. If this is the first user to
* register @isc, the corresponding I/O interruption subclass mask is enabled.
*
* Context:
* This function must not be called in interrupt context.
*/
void isc_register(unsigned int isc)
{
if (isc > MAX_ISC) {
WARN_ON(1);
return;
}
spin_lock(&isc_ref_lock);
if (isc_refs[isc] == 0)
system_ctl_set_bit(6, 31 - isc);
isc_refs[isc]++;
spin_unlock(&isc_ref_lock);
}
EXPORT_SYMBOL_GPL(isc_register);
/**
* isc_unregister - unregister an I/O interruption subclass.
* @isc: I/O interruption subclass to unregister
*
* The number of users for @isc is decreased. If this is the last user to
* unregister @isc, the corresponding I/O interruption subclass mask is
* disabled.
* Note: This function must not be called if isc_register() hasn't been called
* before by the driver for @isc.
*
* Context:
* This function must not be called in interrupt context.
*/
void isc_unregister(unsigned int isc)
{
spin_lock(&isc_ref_lock);
/* check for misuse */
if (isc > MAX_ISC || isc_refs[isc] == 0) {
WARN_ON(1);
goto out_unlock;
}
if (isc_refs[isc] == 1)
system_ctl_clear_bit(6, 31 - isc);
isc_refs[isc]--;
out_unlock:
spin_unlock(&isc_ref_lock);
}
EXPORT_SYMBOL_GPL(isc_unregister);
|
