s390/kvm/interrupt.c

234  * gisa_set_iam - change the GISA interruption alert mask
239  * Change the IAM atomically with the next alert address and the IPM
240  * of the GISA if the GISA is not part of the GIB alert list. All three
244  *          -EBUSY in case the gisa is part of the alert list
265  * Clear the IPM atomically with the next alert address and the IAM
284  * Atomically restores the interruption alert mask if none of the
296 		alert_mask = READ_ONCE(gi->alert.mask);
3121 		 * If the NONE_GISA_ADDR is still stored in the alert list
3123 		 * been added to the alert list by millicode while processing
3124 		 * the current alert list.
3128 		 * Cut off the alert list and store the NONE_GISA_ADDR in the
3129 		 * alert list origin to avoid further GAL interruptions.
3130 		 * A new alert list can be build up by millicode in parallel
3131 		 * for guests not in the yet cut-off alert list. When in the
3138 		 * Loop through the just cut-off alert list and start the
3174 	gi->alert.mask = 0;
3175 	spin_lock_init(&gi->alert.ref_lock);
3214 	WARN(gi->alert.mask != 0x00,
3215 	     "unexpected non zero alert.mask 0x%02x",
3216 	     gi->alert.mask);
3217 	gi->alert.mask = 0x00;
3218 	if (gisa_set_iam(gi->origin, gi->alert.mask))
3249  * The function extends the vm specific alert mask to use.
3251  * in case the GISA is not part of the GIB alert list.
3255  * Returns: the nonspecific ISC (NISC) the gib alert mechanism
3269 	spin_lock(&gi->alert.ref_lock);
3270 	gi->alert.ref_count[gisc]++;
3271 	if (gi->alert.ref_count[gisc] == 1) {
3272 		gi->alert.mask |= 0x80 >> gisc;
3273 		gisa_set_iam(gi->origin, gi->alert.mask);
3275 	spin_unlock(&gi->alert.ref_lock);
3287  * The function reduces the vm specific alert mask to use.
3289  * in case the GISA is not part of the GIB alert list.
3293  * Returns: the nonspecific ISC (NISC) the gib alert mechanism
3309 	spin_lock(&gi->alert.ref_lock);
3310 	if (gi->alert.ref_count[gisc] == 0) {
3314 	gi->alert.ref_count[gisc]--;
3315 	if (gi->alert.ref_count[gisc] == 0) {
3316 		gi->alert.mask &= ~(0x80 >> gisc);
3317 		gisa_set_iam(gi->origin, gi->alert.mask);
3320 	spin_unlock(&gi->alert.ref_lock);
3446 		pr_err("Registering the GIB alert interruption handler failed\n");