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-rw-r--r--drivers/s390/cio/qdio_thinint.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
new file mode 100644
index 000000000000..9291a771d812
--- /dev/null
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -0,0 +1,380 @@
1/*
2 * linux/drivers/s390/cio/thinint_qdio.c
3 *
4 * thin interrupt support for qdio
5 *
6 * Copyright 2000-2008 IBM Corp.
7 * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
8 * Cornelia Huck <cornelia.huck@de.ibm.com>
9 * Jan Glauber <jang@linux.vnet.ibm.com>
10 */
11#include <linux/io.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#include "qdio_perf.h"
23
24/*
25 * Restriction: only 63 iqdio subchannels would have its own indicator,
26 * after that, subsequent subchannels share one indicator
27 */
28#define TIQDIO_NR_NONSHARED_IND 63
29#define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
30#define TIQDIO_SHARED_IND 63
31
32/* list of thin interrupt input queues */
33static LIST_HEAD(tiq_list);
34
35/* adapter local summary indicator */
36static unsigned char *tiqdio_alsi;
37
38/* device state change indicators */
39struct indicator_t {
40 u32 ind; /* u32 because of compare-and-swap performance */
41 atomic_t count; /* use count, 0 or 1 for non-shared indicators */
42};
43static struct indicator_t *q_indicators;
44
45static void tiqdio_tasklet_fn(unsigned long data);
46static DECLARE_TASKLET(tiqdio_tasklet, tiqdio_tasklet_fn, 0);
47
48static int css_qdio_omit_svs;
49
50static inline unsigned long do_clear_global_summary(void)
51{
52 register unsigned long __fn asm("1") = 3;
53 register unsigned long __tmp asm("2");
54 register unsigned long __time asm("3");
55
56 asm volatile(
57 " .insn rre,0xb2650000,2,0"
58 : "+d" (__fn), "=d" (__tmp), "=d" (__time));
59 return __time;
60}
61
62/* returns addr for the device state change indicator */
63static u32 *get_indicator(void)
64{
65 int i;
66
67 for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
68 if (!atomic_read(&q_indicators[i].count)) {
69 atomic_set(&q_indicators[i].count, 1);
70 return &q_indicators[i].ind;
71 }
72
73 /* use the shared indicator */
74 atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
75 return &q_indicators[TIQDIO_SHARED_IND].ind;
76}
77
78static void put_indicator(u32 *addr)
79{
80 int i;
81
82 if (!addr)
83 return;
84 i = ((unsigned long)addr - (unsigned long)q_indicators) /
85 sizeof(struct indicator_t);
86 atomic_dec(&q_indicators[i].count);
87}
88
89void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
90{
91 struct qdio_q *q;
92 int i;
93
94 /* No TDD facility? If we must use SIGA-s we can also omit SVS. */
95 if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync)
96 css_qdio_omit_svs = 1;
97
98 for_each_input_queue(irq_ptr, q, i) {
99 list_add_rcu(&q->entry, &tiq_list);
100 synchronize_rcu();
101 }
102 xchg(irq_ptr->dsci, 1);
103 tasklet_schedule(&tiqdio_tasklet);
104}
105
106/*
107 * we cannot stop the tiqdio tasklet here since it is for all
108 * thinint qdio devices and it must run as long as there is a
109 * thinint device left
110 */
111void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
112{
113 struct qdio_q *q;
114 int i;
115
116 for_each_input_queue(irq_ptr, q, i) {
117 list_del_rcu(&q->entry);
118 synchronize_rcu();
119 }
120}
121
122static inline int tiqdio_inbound_q_done(struct qdio_q *q)
123{
124 unsigned char state;
125
126 if (!atomic_read(&q->nr_buf_used))
127 return 1;
128
129 qdio_siga_sync_q(q);
130 get_buf_state(q, q->first_to_check, &state);
131
132 if (state == SLSB_P_INPUT_PRIMED)
133 /* more work coming */
134 return 0;
135 return 1;
136}
137
138static inline int shared_ind(struct qdio_irq *irq_ptr)
139{
140 return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
141}
142
143static void __tiqdio_inbound_processing(struct qdio_q *q)
144{
145 qdio_perf_stat_inc(&perf_stats.thinint_inbound);
146 qdio_sync_after_thinint(q);
147
148 /*
149 * Maybe we have work on our outbound queues... at least
150 * we have to check the PCI capable queues.
151 */
152 qdio_check_outbound_after_thinint(q);
153
154again:
155 if (!qdio_inbound_q_moved(q))
156 return;
157
158 qdio_kick_inbound_handler(q);
159
160 if (!tiqdio_inbound_q_done(q)) {
161 qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop);
162 goto again;
163 }
164
165 qdio_stop_polling(q);
166 /*
167 * We need to check again to not lose initiative after
168 * resetting the ACK state.
169 */
170 if (!tiqdio_inbound_q_done(q)) {
171 qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop2);
172 goto again;
173 }
174}
175
176void tiqdio_inbound_processing(unsigned long data)
177{
178 struct qdio_q *q = (struct qdio_q *)data;
179
180 __tiqdio_inbound_processing(q);
181}
182
183/* check for work on all inbound thinint queues */
184static void tiqdio_tasklet_fn(unsigned long data)
185{
186 struct qdio_q *q;
187
188 qdio_perf_stat_inc(&perf_stats.tasklet_thinint);
189again:
190
191 /* protect tiq_list entries, only changed in activate or shutdown */
192 rcu_read_lock();
193
194 list_for_each_entry_rcu(q, &tiq_list, entry)
195 /* only process queues from changed sets */
196 if (*q->irq_ptr->dsci) {
197
198 /* only clear it if the indicator is non-shared */
199 if (!shared_ind(q->irq_ptr))
200 xchg(q->irq_ptr->dsci, 0);
201 /*
202 * don't call inbound processing directly since
203 * that could starve other thinint queues
204 */
205 tasklet_schedule(&q->tasklet);
206 }
207
208 rcu_read_unlock();
209
210 /*
211 * if we used the shared indicator clear it now after all queues
212 * were processed
213 */
214 if (atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) {
215 xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
216
217 /* prevent racing */
218 if (*tiqdio_alsi)
219 xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1);
220 }
221
222 /* check for more work */
223 if (*tiqdio_alsi) {
224 xchg(tiqdio_alsi, 0);
225 qdio_perf_stat_inc(&perf_stats.tasklet_thinint_loop);
226 goto again;
227 }
228}
229
230/**
231 * tiqdio_thinint_handler - thin interrupt handler for qdio
232 * @ind: pointer to adapter local summary indicator
233 * @drv_data: NULL
234 */
235static void tiqdio_thinint_handler(void *ind, void *drv_data)
236{
237 qdio_perf_stat_inc(&perf_stats.thin_int);
238
239 /*
240 * SVS only when needed: issue SVS to benefit from iqdio interrupt
241 * avoidance (SVS clears adapter interrupt suppression overwrite)
242 */
243 if (!css_qdio_omit_svs)
244 do_clear_global_summary();
245
246 /*
247 * reset local summary indicator (tiqdio_alsi) to stop adapter
248 * interrupts for now, the tasklet will clean all dsci's
249 */
250 xchg((u8 *)ind, 0);
251 tasklet_hi_schedule(&tiqdio_tasklet);
252}
253
254static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
255{
256 struct scssc_area *scssc_area;
257 char dbf_text[15];
258 void *ptr;
259 int rc;
260
261 scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
262 memset(scssc_area, 0, PAGE_SIZE);
263
264 if (reset) {
265 scssc_area->summary_indicator_addr = 0;
266 scssc_area->subchannel_indicator_addr = 0;
267 } else {
268 scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
269 scssc_area->subchannel_indicator_addr =
270 virt_to_phys(irq_ptr->dsci);
271 }
272
273 scssc_area->request = (struct chsc_header) {
274 .length = 0x0fe0,
275 .code = 0x0021,
276 };
277 scssc_area->operation_code = 0;
278 scssc_area->ks = PAGE_DEFAULT_KEY;
279 scssc_area->kc = PAGE_DEFAULT_KEY;
280 scssc_area->isc = QDIO_AIRQ_ISC;
281 scssc_area->schid = irq_ptr->schid;
282
283 /* enable the time delay disablement facility */
284 if (css_general_characteristics.aif_tdd)
285 scssc_area->word_with_d_bit = 0x10000000;
286
287 rc = chsc(scssc_area);
288 if (rc)
289 return -EIO;
290
291 rc = chsc_error_from_response(scssc_area->response.code);
292 if (rc) {
293 sprintf(dbf_text, "sidR%4x", scssc_area->response.code);
294 QDIO_DBF_TEXT1(0, trace, dbf_text);
295 QDIO_DBF_TEXT1(0, setup, dbf_text);
296 ptr = &scssc_area->response;
297 QDIO_DBF_HEX2(1, setup, &ptr, QDIO_DBF_SETUP_LEN);
298 return rc;
299 }
300
301 QDIO_DBF_TEXT2(0, setup, "setscind");
302 QDIO_DBF_HEX2(0, setup, &scssc_area->summary_indicator_addr,
303 sizeof(unsigned long));
304 QDIO_DBF_HEX2(0, setup, &scssc_area->subchannel_indicator_addr,
305 sizeof(unsigned long));
306 return 0;
307}
308
309/* allocate non-shared indicators and shared indicator */
310int __init tiqdio_allocate_memory(void)
311{
312 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
313 GFP_KERNEL);
314 if (!q_indicators)
315 return -ENOMEM;
316 return 0;
317}
318
319void tiqdio_free_memory(void)
320{
321 kfree(q_indicators);
322}
323
324int __init tiqdio_register_thinints(void)
325{
326 char dbf_text[20];
327
328 isc_register(QDIO_AIRQ_ISC);
329 tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
330 NULL, QDIO_AIRQ_ISC);
331 if (IS_ERR(tiqdio_alsi)) {
332 sprintf(dbf_text, "regthn%lx", PTR_ERR(tiqdio_alsi));
333 QDIO_DBF_TEXT0(0, setup, dbf_text);
334 tiqdio_alsi = NULL;
335 isc_unregister(QDIO_AIRQ_ISC);
336 return -ENOMEM;
337 }
338 return 0;
339}
340
341int qdio_establish_thinint(struct qdio_irq *irq_ptr)
342{
343 if (!is_thinint_irq(irq_ptr))
344 return 0;
345
346 /* Check for aif time delay disablement. If installed,
347 * omit SVS even under LPAR
348 */
349 if (css_general_characteristics.aif_tdd)
350 css_qdio_omit_svs = 1;
351 return set_subchannel_ind(irq_ptr, 0);
352}
353
354void qdio_setup_thinint(struct qdio_irq *irq_ptr)
355{
356 if (!is_thinint_irq(irq_ptr))
357 return;
358 irq_ptr->dsci = get_indicator();
359 QDIO_DBF_HEX1(0, setup, &irq_ptr->dsci, sizeof(void *));
360}
361
362void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
363{
364 if (!is_thinint_irq(irq_ptr))
365 return;
366
367 /* reset adapter interrupt indicators */
368 put_indicator(irq_ptr->dsci);
369 set_subchannel_ind(irq_ptr, 1);
370}
371
372void __exit tiqdio_unregister_thinints(void)
373{
374 tasklet_disable(&tiqdio_tasklet);
375
376 if (tiqdio_alsi) {
377 s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
378 isc_unregister(QDIO_AIRQ_ISC);
379 }
380}