v4.19.13 snapshot.
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
new file mode 100644
index 0000000..07dea60
--- /dev/null
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2000, 2009
+ * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
+ * Cornelia Huck <cornelia.huck@de.ibm.com>
+ * Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/kernel_stat.h>
+#include <linux/atomic.h>
+#include <linux/rculist.h>
+
+#include <asm/debug.h>
+#include <asm/qdio.h>
+#include <asm/airq.h>
+#include <asm/isc.h>
+
+#include "cio.h"
+#include "ioasm.h"
+#include "qdio.h"
+#include "qdio_debug.h"
+
+/*
+ * Restriction: only 63 iqdio subchannels would have its own indicator,
+ * after that, subsequent subchannels share one indicator
+ */
+#define TIQDIO_NR_NONSHARED_IND 63
+#define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
+#define TIQDIO_SHARED_IND 63
+
+/* device state change indicators */
+struct indicator_t {
+ u32 ind; /* u32 because of compare-and-swap performance */
+ atomic_t count; /* use count, 0 or 1 for non-shared indicators */
+};
+
+/* list of thin interrupt input queues */
+static LIST_HEAD(tiq_list);
+static DEFINE_MUTEX(tiq_list_lock);
+
+/* Adapter interrupt definitions */
+static void tiqdio_thinint_handler(struct airq_struct *airq);
+
+static struct airq_struct tiqdio_airq = {
+ .handler = tiqdio_thinint_handler,
+ .isc = QDIO_AIRQ_ISC,
+};
+
+static struct indicator_t *q_indicators;
+
+u64 last_ai_time;
+
+/* returns addr for the device state change indicator */
+static u32 *get_indicator(void)
+{
+ int i;
+
+ for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
+ if (!atomic_cmpxchg(&q_indicators[i].count, 0, 1))
+ return &q_indicators[i].ind;
+
+ /* use the shared indicator */
+ atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
+ return &q_indicators[TIQDIO_SHARED_IND].ind;
+}
+
+static void put_indicator(u32 *addr)
+{
+ struct indicator_t *ind = container_of(addr, struct indicator_t, ind);
+
+ if (!addr)
+ return;
+ atomic_dec(&ind->count);
+}
+
+void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
+{
+ mutex_lock(&tiq_list_lock);
+ list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
+ mutex_unlock(&tiq_list_lock);
+ xchg(irq_ptr->dsci, 1 << 7);
+}
+
+void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
+{
+ struct qdio_q *q;
+
+ q = irq_ptr->input_qs[0];
+ /* if establish triggered an error */
+ if (!q || !q->entry.prev || !q->entry.next)
+ return;
+
+ mutex_lock(&tiq_list_lock);
+ list_del_rcu(&q->entry);
+ mutex_unlock(&tiq_list_lock);
+ synchronize_rcu();
+}
+
+static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)
+{
+ return irq_ptr->nr_input_qs > 1;
+}
+
+static inline int references_shared_dsci(struct qdio_irq *irq_ptr)
+{
+ return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
+}
+
+static inline int shared_ind(struct qdio_irq *irq_ptr)
+{
+ return references_shared_dsci(irq_ptr) ||
+ has_multiple_inq_on_dsci(irq_ptr);
+}
+
+void clear_nonshared_ind(struct qdio_irq *irq_ptr)
+{
+ if (!is_thinint_irq(irq_ptr))
+ return;
+ if (shared_ind(irq_ptr))
+ return;
+ xchg(irq_ptr->dsci, 0);
+}
+
+int test_nonshared_ind(struct qdio_irq *irq_ptr)
+{
+ if (!is_thinint_irq(irq_ptr))
+ return 0;
+ if (shared_ind(irq_ptr))
+ return 0;
+ if (*irq_ptr->dsci)
+ return 1;
+ else
+ return 0;
+}
+
+static inline u32 clear_shared_ind(void)
+{
+ if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count))
+ return 0;
+ return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
+}
+
+static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
+{
+ struct qdio_q *q;
+ int i;
+
+ if (!references_shared_dsci(irq) &&
+ has_multiple_inq_on_dsci(irq))
+ xchg(irq->dsci, 0);
+
+ for_each_input_queue(irq, q, i) {
+ if (q->u.in.queue_start_poll) {
+ /* skip if polling is enabled or already in work */
+ if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
+ &q->u.in.queue_irq_state)) {
+ qperf_inc(q, int_discarded);
+ continue;
+ }
+
+ /* avoid dsci clear here, done after processing */
+ q->u.in.queue_start_poll(irq->cdev, q->nr,
+ irq->int_parm);
+ } else {
+ if (!shared_ind(irq))
+ xchg(irq->dsci, 0);
+
+ /*
+ * Call inbound processing but not directly
+ * since that could starve other thinint queues.
+ */
+ tasklet_schedule(&q->tasklet);
+ }
+ }
+}
+
+/**
+ * tiqdio_thinint_handler - thin interrupt handler for qdio
+ * @airq: pointer to adapter interrupt descriptor
+ */
+static void tiqdio_thinint_handler(struct airq_struct *airq)
+{
+ u32 si_used = clear_shared_ind();
+ struct qdio_q *q;
+
+ last_ai_time = S390_lowcore.int_clock;
+ inc_irq_stat(IRQIO_QAI);
+
+ /* protect tiq_list entries, only changed in activate or shutdown */
+ rcu_read_lock();
+
+ /* check for work on all inbound thinint queues */
+ list_for_each_entry_rcu(q, &tiq_list, entry) {
+ struct qdio_irq *irq;
+
+ /* only process queues from changed sets */
+ irq = q->irq_ptr;
+ if (unlikely(references_shared_dsci(irq))) {
+ if (!si_used)
+ continue;
+ } else if (!*irq->dsci)
+ continue;
+
+ tiqdio_call_inq_handlers(irq);
+
+ qperf_inc(q, adapter_int);
+ }
+ rcu_read_unlock();
+}
+
+static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
+{
+ struct chsc_scssc_area *scssc = (void *)irq_ptr->chsc_page;
+ u64 summary_indicator_addr, subchannel_indicator_addr;
+ int rc;
+
+ if (reset) {
+ summary_indicator_addr = 0;
+ subchannel_indicator_addr = 0;
+ } else {
+ summary_indicator_addr = virt_to_phys(tiqdio_airq.lsi_ptr);
+ subchannel_indicator_addr = virt_to_phys(irq_ptr->dsci);
+ }
+
+ rc = chsc_sadc(irq_ptr->schid, scssc, summary_indicator_addr,
+ subchannel_indicator_addr);
+ if (rc) {
+ DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
+ scssc->response.code);
+ goto out;
+ }
+
+ DBF_EVENT("setscind");
+ DBF_HEX(&summary_indicator_addr, sizeof(summary_indicator_addr));
+ DBF_HEX(&subchannel_indicator_addr, sizeof(subchannel_indicator_addr));
+out:
+ return rc;
+}
+
+/* allocate non-shared indicators and shared indicator */
+int __init tiqdio_allocate_memory(void)
+{
+ q_indicators = kcalloc(TIQDIO_NR_INDICATORS,
+ sizeof(struct indicator_t),
+ GFP_KERNEL);
+ if (!q_indicators)
+ return -ENOMEM;
+ return 0;
+}
+
+void tiqdio_free_memory(void)
+{
+ kfree(q_indicators);
+}
+
+int __init tiqdio_register_thinints(void)
+{
+ int rc;
+
+ rc = register_adapter_interrupt(&tiqdio_airq);
+ if (rc) {
+ DBF_EVENT("RTI:%x", rc);
+ return rc;
+ }
+ return 0;
+}
+
+int qdio_establish_thinint(struct qdio_irq *irq_ptr)
+{
+ if (!is_thinint_irq(irq_ptr))
+ return 0;
+ return set_subchannel_ind(irq_ptr, 0);
+}
+
+void qdio_setup_thinint(struct qdio_irq *irq_ptr)
+{
+ if (!is_thinint_irq(irq_ptr))
+ return;
+ irq_ptr->dsci = get_indicator();
+ DBF_HEX(&irq_ptr->dsci, sizeof(void *));
+}
+
+void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
+{
+ if (!is_thinint_irq(irq_ptr))
+ return;
+
+ /* reset adapter interrupt indicators */
+ set_subchannel_ind(irq_ptr, 1);
+ put_indicator(irq_ptr->dsci);
+}
+
+void __exit tiqdio_unregister_thinints(void)
+{
+ WARN_ON(!list_empty(&tiq_list));
+ unregister_adapter_interrupt(&tiqdio_airq);
+}