2 * linux/drivers/s390/cio/thinint_qdio.c
4 * Copyright 2000,2009 IBM Corp.
5 * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
6 * Cornelia Huck <cornelia.huck@de.ibm.com>
7 * Jan Glauber <jang@linux.vnet.ibm.com>
10 #include <linux/slab.h>
11 #include <linux/kernel_stat.h>
12 #include <linux/atomic.h>
13 #include <asm/debug.h>
21 #include "qdio_debug.h"
24 * Restriction: only 63 iqdio subchannels would have its own indicator,
25 * after that, subsequent subchannels share one indicator
27 #define TIQDIO_NR_NONSHARED_IND 63
28 #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
30 /* list of thin interrupt input queues */
31 static LIST_HEAD(tiq_list);
32 DEFINE_MUTEX(tiq_list_lock);
34 /* adapter local summary indicator */
35 static u8 *tiqdio_alsi;
37 struct indicator_t *q_indicators;
39 static u64 last_ai_time;
41 /* returns addr for the device state change indicator */
42 static u32 *get_indicator(void)
46 for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
47 if (!atomic_read(&q_indicators[i].count)) {
48 atomic_set(&q_indicators[i].count, 1);
49 return &q_indicators[i].ind;
52 /* use the shared indicator */
53 atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
54 return &q_indicators[TIQDIO_SHARED_IND].ind;
57 static void put_indicator(u32 *addr)
63 i = ((unsigned long)addr - (unsigned long)q_indicators) /
64 sizeof(struct indicator_t);
65 atomic_dec(&q_indicators[i].count);
68 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
73 mutex_lock(&tiq_list_lock);
74 for_each_input_queue(irq_ptr, q, i)
75 list_add_rcu(&q->entry, &tiq_list);
76 mutex_unlock(&tiq_list_lock);
77 xchg(irq_ptr->dsci, 1 << 7);
80 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
85 for (i = 0; i < irq_ptr->nr_input_qs; i++) {
86 q = irq_ptr->input_qs[i];
87 /* if establish triggered an error */
88 if (!q || !q->entry.prev || !q->entry.next)
91 mutex_lock(&tiq_list_lock);
92 list_del_rcu(&q->entry);
93 mutex_unlock(&tiq_list_lock);
98 static inline u32 clear_shared_ind(void)
100 if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count))
102 return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
106 * tiqdio_thinint_handler - thin interrupt handler for qdio
107 * @alsi: pointer to adapter local summary indicator
110 static void tiqdio_thinint_handler(void *alsi, void *data)
112 u32 si_used = clear_shared_ind();
115 last_ai_time = S390_lowcore.int_clock;
116 kstat_cpu(smp_processor_id()).irqs[IOINT_QAI]++;
118 /* protect tiq_list entries, only changed in activate or shutdown */
121 /* check for work on all inbound thinint queues */
122 list_for_each_entry_rcu(q, &tiq_list, entry) {
124 /* only process queues from changed sets */
125 if (unlikely(shared_ind(q->irq_ptr->dsci))) {
128 } else if (!*q->irq_ptr->dsci)
131 if (q->u.in.queue_start_poll) {
132 /* skip if polling is enabled or already in work */
133 if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
134 &q->u.in.queue_irq_state)) {
135 qperf_inc(q, int_discarded);
139 /* avoid dsci clear here, done after processing */
140 q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
141 q->irq_ptr->int_parm);
143 /* only clear it if the indicator is non-shared */
144 if (!shared_ind(q->irq_ptr->dsci))
145 xchg(q->irq_ptr->dsci, 0);
147 * Call inbound processing but not directly
148 * since that could starve other thinint queues.
150 tasklet_schedule(&q->tasklet);
152 qperf_inc(q, adapter_int);
157 static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
159 struct scssc_area *scssc_area;
162 scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
163 memset(scssc_area, 0, PAGE_SIZE);
166 scssc_area->summary_indicator_addr = 0;
167 scssc_area->subchannel_indicator_addr = 0;
169 scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
170 scssc_area->subchannel_indicator_addr =
171 virt_to_phys(irq_ptr->dsci);
174 scssc_area->request = (struct chsc_header) {
178 scssc_area->operation_code = 0;
179 scssc_area->ks = PAGE_DEFAULT_KEY >> 4;
180 scssc_area->kc = PAGE_DEFAULT_KEY >> 4;
181 scssc_area->isc = QDIO_AIRQ_ISC;
182 scssc_area->schid = irq_ptr->schid;
184 /* enable the time delay disablement facility */
185 if (css_general_characteristics.aif_tdd)
186 scssc_area->word_with_d_bit = 0x10000000;
188 rc = chsc(scssc_area);
192 rc = chsc_error_from_response(scssc_area->response.code);
194 DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
195 scssc_area->response.code);
196 DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
200 DBF_EVENT("setscind");
201 DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
202 DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
206 /* allocate non-shared indicators and shared indicator */
207 int __init tiqdio_allocate_memory(void)
209 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
216 void tiqdio_free_memory(void)
221 int __init tiqdio_register_thinints(void)
223 isc_register(QDIO_AIRQ_ISC);
224 tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
225 NULL, QDIO_AIRQ_ISC);
226 if (IS_ERR(tiqdio_alsi)) {
227 DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
229 isc_unregister(QDIO_AIRQ_ISC);
235 int qdio_establish_thinint(struct qdio_irq *irq_ptr)
237 if (!is_thinint_irq(irq_ptr))
239 return set_subchannel_ind(irq_ptr, 0);
242 void qdio_setup_thinint(struct qdio_irq *irq_ptr)
244 if (!is_thinint_irq(irq_ptr))
246 irq_ptr->dsci = get_indicator();
247 DBF_HEX(&irq_ptr->dsci, sizeof(void *));
250 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
252 if (!is_thinint_irq(irq_ptr))
255 /* reset adapter interrupt indicators */
256 set_subchannel_ind(irq_ptr, 1);
257 put_indicator(irq_ptr->dsci);
260 void __exit tiqdio_unregister_thinints(void)
262 WARN_ON(!list_empty(&tiq_list));
265 s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
266 isc_unregister(QDIO_AIRQ_ISC);