70 lines
1.7 KiB
C
70 lines
1.7 KiB
C
|
// 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)
|
||
|
|
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)
|
||
|
|
ctl_clear_bit(6, 31 - isc);
|
||
|
|
isc_refs[isc]--;
|
||
|
|
out_unlock:
|
||
|
|
spin_unlock(&isc_ref_lock);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(isc_unregister);
|