+static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
+{
+ int rc;
+
+ pgm_check_occured = 0;
+ s390_reset_pgm_handler = cio_reset_pgm_check_handler;
+ rc = stsch(schid, addr);
+ s390_reset_pgm_handler = NULL;
+
+ /* The program check handler could have changed pgm_check_occured */
+ barrier();
+
+ if (pgm_check_occured)
+ return -EIO;
+ else
+ return rc;
+}
+
+static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
+{
+ struct schib schib;
+
+ if (stsch_reset(schid, &schib))
+ return -ENXIO;
+ if (!schib.pmcw.ena)
+ return 0;
+ switch(__disable_subchannel_easy(schid, &schib)) {
+ case 0:
+ case -ENODEV:
+ break;
+ default: /* -EBUSY */
+ if (__clear_subchannel_easy(schid))
+ break; /* give up... */
+ stsch(schid, &schib);
+ __disable_subchannel_easy(schid, &schib);
+ }
+ return 0;
+}
+
+static atomic_t chpid_reset_count;
+
+static void s390_reset_chpids_mcck_handler(void)
+{
+ struct crw crw;
+ struct mci *mci;
+
+ /* Check for pending channel report word. */
+ mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
+ if (!mci->cp)
+ return;
+ /* Process channel report words. */
+ while (stcrw(&crw) == 0) {
+ /* Check for responses to RCHP. */
+ if (crw.slct && crw.rsc == CRW_RSC_CPATH)
+ atomic_dec(&chpid_reset_count);
+ }
+}
+
+#define RCHP_TIMEOUT (30 * USEC_PER_SEC)
+static void css_reset(void)
+{
+ int i, ret;
+ unsigned long long timeout;
+
+ /* Reset subchannels. */
+ for_each_subchannel(__shutdown_subchannel_easy, NULL);
+ /* Reset channel paths. */
+ s390_reset_mcck_handler = s390_reset_chpids_mcck_handler;
+ /* Enable channel report machine checks. */
+ __ctl_set_bit(14, 28);
+ /* Temporarily reenable machine checks. */
+ local_mcck_enable();
+ for (i = 0; i <= __MAX_CHPID; i++) {
+ ret = rchp(i);
+ if ((ret == 0) || (ret == 2))
+ /*
+ * rchp either succeeded, or another rchp is already
+ * in progress. In either case, we'll get a crw.
+ */
+ atomic_inc(&chpid_reset_count);
+ }
+ /* Wait for machine check for all channel paths. */
+ timeout = get_clock() + (RCHP_TIMEOUT << 12);
+ while (atomic_read(&chpid_reset_count) != 0) {
+ if (get_clock() > timeout)