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authorSrikant Patnaik2015-01-13 15:08:24 +0530
committerSrikant Patnaik2015-01-13 15:08:24 +0530
commit97327692361306d1e6259021bc425e32832fdb50 (patch)
treefe9088f3248ec61e24f404f21b9793cb644b7f01 /drivers/s390/cio/qdio_thinint.c
parent2d05a8f663478a44e088d122e0d62109bbc801d0 (diff)
parenta3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff)
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dirty fix to merging
Diffstat (limited to 'drivers/s390/cio/qdio_thinint.c')
-rw-r--r--drivers/s390/cio/qdio_thinint.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
new file mode 100644
index 00000000..011eadea
--- /dev/null
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -0,0 +1,324 @@
+/*
+ * linux/drivers/s390/cio/thinint_qdio.c
+ *
+ * Copyright 2000,2009 IBM Corp.
+ * 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 <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 local summary indicator */
+static u8 *tiqdio_alsi;
+
+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_read(&q_indicators[i].count)) {
+ atomic_set(&q_indicators[i].count, 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)
+{
+ int i;
+
+ if (!addr)
+ return;
+ i = ((unsigned long)addr - (unsigned long)q_indicators) /
+ sizeof(struct indicator_t);
+ atomic_dec(&q_indicators[i].count);
+}
+
+void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
+{
+ mutex_lock(&tiq_list_lock);
+ BUG_ON(irq_ptr->nr_input_qs < 1);
+ 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;
+
+ BUG_ON(irq_ptr->nr_input_qs < 1);
+ 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;
+
+ for_each_input_queue(irq, q, i) {
+ if (!references_shared_dsci(irq) &&
+ has_multiple_inq_on_dsci(irq))
+ xchg(q->irq_ptr->dsci, 0);
+
+ 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(q->irq_ptr->cdev, q->nr,
+ q->irq_ptr->int_parm);
+ } else {
+ if (!shared_ind(q->irq_ptr))
+ xchg(q->irq_ptr->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
+ * @alsi: pointer to adapter local summary indicator
+ * @data: NULL
+ */
+static void tiqdio_thinint_handler(void *alsi, void *data)
+{
+ u32 si_used = clear_shared_ind();
+ struct qdio_q *q;
+
+ last_ai_time = S390_lowcore.int_clock;
+ kstat_cpu(smp_processor_id()).irqs[IOINT_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 scssc_area *scssc_area;
+ int rc;
+
+ scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
+ memset(scssc_area, 0, PAGE_SIZE);
+
+ if (reset) {
+ scssc_area->summary_indicator_addr = 0;
+ scssc_area->subchannel_indicator_addr = 0;
+ } else {
+ scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
+ scssc_area->subchannel_indicator_addr =
+ virt_to_phys(irq_ptr->dsci);
+ }
+
+ scssc_area->request = (struct chsc_header) {
+ .length = 0x0fe0,
+ .code = 0x0021,
+ };
+ scssc_area->operation_code = 0;
+ scssc_area->ks = PAGE_DEFAULT_KEY >> 4;
+ scssc_area->kc = PAGE_DEFAULT_KEY >> 4;
+ scssc_area->isc = QDIO_AIRQ_ISC;
+ scssc_area->schid = irq_ptr->schid;
+
+ /* enable the time delay disablement facility */
+ if (css_general_characteristics.aif_tdd)
+ scssc_area->word_with_d_bit = 0x10000000;
+
+ rc = chsc(scssc_area);
+ if (rc)
+ return -EIO;
+
+ rc = chsc_error_from_response(scssc_area->response.code);
+ if (rc) {
+ DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
+ scssc_area->response.code);
+ DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
+ return rc;
+ }
+
+ DBF_EVENT("setscind");
+ DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
+ DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
+ return 0;
+}
+
+/* allocate non-shared indicators and shared indicator */
+int __init tiqdio_allocate_memory(void)
+{
+ q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
+ GFP_KERNEL);
+ if (!q_indicators)
+ return -ENOMEM;
+ return 0;
+}
+
+void tiqdio_free_memory(void)
+{
+ kfree(q_indicators);
+}
+
+int __init tiqdio_register_thinints(void)
+{
+ isc_register(QDIO_AIRQ_ISC);
+ tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
+ NULL, QDIO_AIRQ_ISC);
+ if (IS_ERR(tiqdio_alsi)) {
+ DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
+ tiqdio_alsi = NULL;
+ isc_unregister(QDIO_AIRQ_ISC);
+ return -ENOMEM;
+ }
+ 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));
+
+ if (tiqdio_alsi) {
+ s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
+ isc_unregister(QDIO_AIRQ_ISC);
+ }
+}