2 * Copyright IBM Corp. 2000, 2009
3 * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
4 * Cornelia Huck <cornelia.huck@de.ibm.com>
5 * Jan Glauber <jang@linux.vnet.ibm.com>
8 #include <linux/slab.h>
9 #include <linux/kernel_stat.h>
10 #include <linux/atomic.h>
11 #include <asm/debug.h>
19 #include "qdio_debug.h"
22 * Restriction: only 63 iqdio subchannels would have its own indicator,
23 * after that, subsequent subchannels share one indicator
25 #define TIQDIO_NR_NONSHARED_IND 63
26 #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
27 #define TIQDIO_SHARED_IND 63
29 /* device state change indicators */
31 u32 ind; /* u32 because of compare-and-swap performance */
32 atomic_t count; /* use count, 0 or 1 for non-shared indicators */
35 /* list of thin interrupt input queues */
36 static LIST_HEAD(tiq_list);
37 static DEFINE_MUTEX(tiq_list_lock);
39 /* Adapter interrupt definitions */
40 static void tiqdio_thinint_handler(struct airq_struct *airq);
42 static struct airq_struct tiqdio_airq = {
43 .handler = tiqdio_thinint_handler,
47 static struct indicator_t *q_indicators;
51 /* returns addr for the device state change indicator */
52 static u32 *get_indicator(void)
56 for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
57 if (!atomic_read(&q_indicators[i].count)) {
58 atomic_set(&q_indicators[i].count, 1);
59 return &q_indicators[i].ind;
62 /* use the shared indicator */
63 atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
64 return &q_indicators[TIQDIO_SHARED_IND].ind;
67 static void put_indicator(u32 *addr)
73 i = ((unsigned long)addr - (unsigned long)q_indicators) /
74 sizeof(struct indicator_t);
75 atomic_dec(&q_indicators[i].count);
78 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
80 mutex_lock(&tiq_list_lock);
81 list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
82 mutex_unlock(&tiq_list_lock);
83 xchg(irq_ptr->dsci, 1 << 7);
86 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
90 q = irq_ptr->input_qs[0];
91 /* if establish triggered an error */
92 if (!q || !q->entry.prev || !q->entry.next)
95 mutex_lock(&tiq_list_lock);
96 list_del_rcu(&q->entry);
97 mutex_unlock(&tiq_list_lock);
101 static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)
103 return irq_ptr->nr_input_qs > 1;
106 static inline int references_shared_dsci(struct qdio_irq *irq_ptr)
108 return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
111 static inline int shared_ind(struct qdio_irq *irq_ptr)
113 return references_shared_dsci(irq_ptr) ||
114 has_multiple_inq_on_dsci(irq_ptr);
117 void clear_nonshared_ind(struct qdio_irq *irq_ptr)
119 if (!is_thinint_irq(irq_ptr))
121 if (shared_ind(irq_ptr))
123 xchg(irq_ptr->dsci, 0);
126 int test_nonshared_ind(struct qdio_irq *irq_ptr)
128 if (!is_thinint_irq(irq_ptr))
130 if (shared_ind(irq_ptr))
138 static inline u32 clear_shared_ind(void)
140 if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count))
142 return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
145 static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
150 for_each_input_queue(irq, q, i) {
151 if (!references_shared_dsci(irq) &&
152 has_multiple_inq_on_dsci(irq))
153 xchg(q->irq_ptr->dsci, 0);
155 if (q->u.in.queue_start_poll) {
156 /* skip if polling is enabled or already in work */
157 if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
158 &q->u.in.queue_irq_state)) {
159 qperf_inc(q, int_discarded);
163 /* avoid dsci clear here, done after processing */
164 q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
165 q->irq_ptr->int_parm);
167 if (!shared_ind(q->irq_ptr))
168 xchg(q->irq_ptr->dsci, 0);
171 * Call inbound processing but not directly
172 * since that could starve other thinint queues.
174 tasklet_schedule(&q->tasklet);
180 * tiqdio_thinint_handler - thin interrupt handler for qdio
181 * @alsi: pointer to adapter local summary indicator
184 static void tiqdio_thinint_handler(struct airq_struct *airq)
186 u32 si_used = clear_shared_ind();
189 last_ai_time = S390_lowcore.int_clock;
190 inc_irq_stat(IRQIO_QAI);
192 /* protect tiq_list entries, only changed in activate or shutdown */
195 /* check for work on all inbound thinint queues */
196 list_for_each_entry_rcu(q, &tiq_list, entry) {
197 struct qdio_irq *irq;
199 /* only process queues from changed sets */
201 if (unlikely(references_shared_dsci(irq))) {
204 } else if (!*irq->dsci)
207 tiqdio_call_inq_handlers(irq);
209 qperf_inc(q, adapter_int);
214 static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
216 struct chsc_scssc_area *scssc = (void *)irq_ptr->chsc_page;
217 u64 summary_indicator_addr, subchannel_indicator_addr;
221 summary_indicator_addr = 0;
222 subchannel_indicator_addr = 0;
224 summary_indicator_addr = virt_to_phys(tiqdio_airq.lsi_ptr);
225 subchannel_indicator_addr = virt_to_phys(irq_ptr->dsci);
228 rc = chsc_sadc(irq_ptr->schid, scssc, summary_indicator_addr,
229 subchannel_indicator_addr);
231 DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
232 scssc->response.code);
236 DBF_EVENT("setscind");
237 DBF_HEX(&summary_indicator_addr, sizeof(summary_indicator_addr));
238 DBF_HEX(&subchannel_indicator_addr, sizeof(subchannel_indicator_addr));
243 /* allocate non-shared indicators and shared indicator */
244 int __init tiqdio_allocate_memory(void)
246 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
253 void tiqdio_free_memory(void)
258 int __init tiqdio_register_thinints(void)
262 rc = register_adapter_interrupt(&tiqdio_airq);
264 DBF_EVENT("RTI:%x", rc);
270 int qdio_establish_thinint(struct qdio_irq *irq_ptr)
272 if (!is_thinint_irq(irq_ptr))
274 return set_subchannel_ind(irq_ptr, 0);
277 void qdio_setup_thinint(struct qdio_irq *irq_ptr)
279 if (!is_thinint_irq(irq_ptr))
281 irq_ptr->dsci = get_indicator();
282 DBF_HEX(&irq_ptr->dsci, sizeof(void *));
285 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
287 if (!is_thinint_irq(irq_ptr))
290 /* reset adapter interrupt indicators */
291 set_subchannel_ind(irq_ptr, 1);
292 put_indicator(irq_ptr->dsci);
295 void __exit tiqdio_unregister_thinints(void)
297 WARN_ON(!list_empty(&tiq_list));
298 unregister_adapter_interrupt(&tiqdio_airq);