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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/s390/cio/isc.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/s390/cio/isc.c')
-rw-r--r-- | drivers/s390/cio/isc.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/s390/cio/isc.c b/drivers/s390/cio/isc.c new file mode 100644 index 00000000..c592087b --- /dev/null +++ b/drivers/s390/cio/isc.c @@ -0,0 +1,68 @@ +/* + * 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); |