1 /*
2 * linux/drivers/s390/cio/thinint_qdio.c
3 *
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>
8 */
9 #include <linux/io.h>
10 #include <linux/slab.h>
11 #include <linux/kernel_stat.h>
12 #include <asm/atomic.h>
13 #include <asm/debug.h>
14 #include <asm/qdio.h>
15 #include <asm/airq.h>
16 #include <asm/isc.h>
17
18 #include "cio.h"
19 #include "ioasm.h"
20 #include "qdio.h"
21 #include "qdio_debug.h"
22
23 /*
24 * Restriction: only 63 iqdio subchannels would have its own indicator,
25 * after that, subsequent subchannels share one indicator
26 */
27 #define TIQDIO_NR_NONSHARED_IND 63
28 #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
29
30 /* list of thin interrupt input queues */
31 static LIST_HEAD(tiq_list);
32 DEFINE_MUTEX(tiq_list_lock);
33
34 /* adapter local summary indicator */
35 static u8 *tiqdio_alsi;
36
37 struct indicator_t *q_indicators;
38
39 static u64 last_ai_time;
40
41 /* returns addr for the device state change indicator */
get_indicator(void)42 static u32 *get_indicator(void)
43 {
44 int i;
45
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;
50 }
51
52 /* use the shared indicator */
53 atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
54 return &q_indicators[TIQDIO_SHARED_IND].ind;
55 }
56
put_indicator(u32 * addr)57 static void put_indicator(u32 *addr)
58 {
59 int i;
60
61 if (!addr)
62 return;
63 i = ((unsigned long)addr - (unsigned long)q_indicators) /
64 sizeof(struct indicator_t);
65 atomic_dec(&q_indicators[i].count);
66 }
67
tiqdio_add_input_queues(struct qdio_irq * irq_ptr)68 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
69 {
70 struct qdio_q *q;
71 int i;
72
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);
78 }
79
tiqdio_remove_input_queues(struct qdio_irq * irq_ptr)80 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
81 {
82 struct qdio_q *q;
83 int i;
84
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)
89 continue;
90
91 mutex_lock(&tiq_list_lock);
92 list_del_rcu(&q->entry);
93 mutex_unlock(&tiq_list_lock);
94 synchronize_rcu();
95 }
96 }
97
shared_ind_set(void)98 static inline u32 shared_ind_set(void)
99 {
100 return q_indicators[TIQDIO_SHARED_IND].ind;
101 }
102
103 /**
104 * tiqdio_thinint_handler - thin interrupt handler for qdio
105 * @alsi: pointer to adapter local summary indicator
106 * @data: NULL
107 */
tiqdio_thinint_handler(void * alsi,void * data)108 static void tiqdio_thinint_handler(void *alsi, void *data)
109 {
110 u32 si_used = shared_ind_set();
111 struct qdio_q *q;
112
113 last_ai_time = S390_lowcore.int_clock;
114 kstat_cpu(smp_processor_id()).irqs[IOINT_QAI]++;
115
116 /* protect tiq_list entries, only changed in activate or shutdown */
117 rcu_read_lock();
118
119 /* check for work on all inbound thinint queues */
120 list_for_each_entry_rcu(q, &tiq_list, entry) {
121
122 /* only process queues from changed sets */
123 if (unlikely(shared_ind(q->irq_ptr->dsci))) {
124 if (!si_used)
125 continue;
126 } else if (!*q->irq_ptr->dsci)
127 continue;
128
129 if (q->u.in.queue_start_poll) {
130 /* skip if polling is enabled or already in work */
131 if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
132 &q->u.in.queue_irq_state)) {
133 qperf_inc(q, int_discarded);
134 continue;
135 }
136
137 /* avoid dsci clear here, done after processing */
138 q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
139 q->irq_ptr->int_parm);
140 } else {
141 /* only clear it if the indicator is non-shared */
142 if (!shared_ind(q->irq_ptr->dsci))
143 xchg(q->irq_ptr->dsci, 0);
144 /*
145 * Call inbound processing but not directly
146 * since that could starve other thinint queues.
147 */
148 tasklet_schedule(&q->tasklet);
149 }
150 qperf_inc(q, adapter_int);
151 }
152 rcu_read_unlock();
153
154 /*
155 * If the shared indicator was used clear it now after all queues
156 * were processed.
157 */
158 if (si_used && shared_ind_set())
159 xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
160 }
161
set_subchannel_ind(struct qdio_irq * irq_ptr,int reset)162 static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
163 {
164 struct scssc_area *scssc_area;
165 int rc;
166
167 scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
168 memset(scssc_area, 0, PAGE_SIZE);
169
170 if (reset) {
171 scssc_area->summary_indicator_addr = 0;
172 scssc_area->subchannel_indicator_addr = 0;
173 } else {
174 scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
175 scssc_area->subchannel_indicator_addr =
176 virt_to_phys(irq_ptr->dsci);
177 }
178
179 scssc_area->request = (struct chsc_header) {
180 .length = 0x0fe0,
181 .code = 0x0021,
182 };
183 scssc_area->operation_code = 0;
184 scssc_area->ks = PAGE_DEFAULT_KEY >> 4;
185 scssc_area->kc = PAGE_DEFAULT_KEY >> 4;
186 scssc_area->isc = QDIO_AIRQ_ISC;
187 scssc_area->schid = irq_ptr->schid;
188
189 /* enable the time delay disablement facility */
190 if (css_general_characteristics.aif_tdd)
191 scssc_area->word_with_d_bit = 0x10000000;
192
193 rc = chsc(scssc_area);
194 if (rc)
195 return -EIO;
196
197 rc = chsc_error_from_response(scssc_area->response.code);
198 if (rc) {
199 DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
200 scssc_area->response.code);
201 DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
202 return rc;
203 }
204
205 DBF_EVENT("setscind");
206 DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
207 DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
208 return 0;
209 }
210
211 /* allocate non-shared indicators and shared indicator */
tiqdio_allocate_memory(void)212 int __init tiqdio_allocate_memory(void)
213 {
214 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
215 GFP_KERNEL);
216 if (!q_indicators)
217 return -ENOMEM;
218 return 0;
219 }
220
tiqdio_free_memory(void)221 void tiqdio_free_memory(void)
222 {
223 kfree(q_indicators);
224 }
225
tiqdio_register_thinints(void)226 int __init tiqdio_register_thinints(void)
227 {
228 isc_register(QDIO_AIRQ_ISC);
229 tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
230 NULL, QDIO_AIRQ_ISC);
231 if (IS_ERR(tiqdio_alsi)) {
232 DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
233 tiqdio_alsi = NULL;
234 isc_unregister(QDIO_AIRQ_ISC);
235 return -ENOMEM;
236 }
237 return 0;
238 }
239
qdio_establish_thinint(struct qdio_irq * irq_ptr)240 int qdio_establish_thinint(struct qdio_irq *irq_ptr)
241 {
242 if (!is_thinint_irq(irq_ptr))
243 return 0;
244 return set_subchannel_ind(irq_ptr, 0);
245 }
246
qdio_setup_thinint(struct qdio_irq * irq_ptr)247 void qdio_setup_thinint(struct qdio_irq *irq_ptr)
248 {
249 if (!is_thinint_irq(irq_ptr))
250 return;
251 irq_ptr->dsci = get_indicator();
252 DBF_HEX(&irq_ptr->dsci, sizeof(void *));
253 }
254
qdio_shutdown_thinint(struct qdio_irq * irq_ptr)255 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
256 {
257 if (!is_thinint_irq(irq_ptr))
258 return;
259
260 /* reset adapter interrupt indicators */
261 set_subchannel_ind(irq_ptr, 1);
262 put_indicator(irq_ptr->dsci);
263 }
264
tiqdio_unregister_thinints(void)265 void __exit tiqdio_unregister_thinints(void)
266 {
267 WARN_ON(!list_empty(&tiq_list));
268
269 if (tiqdio_alsi) {
270 s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
271 isc_unregister(QDIO_AIRQ_ISC);
272 }
273 }
274