[IA64-SGI] abstract force_interrupt() mechanism
[linux-2.6.git] / arch / ia64 / sn / kernel / irq.c
1 /*
2  * Platform dependent support for SGI SN
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
9  */
10
11 #include <linux/irq.h>
12 #include <linux/spinlock.h>
13 #include <asm/sn/addrs.h>
14 #include <asm/sn/arch.h>
15 #include <asm/sn/intr.h>
16 #include <asm/sn/pcibr_provider.h>
17 #include <asm/sn/pcibus_provider_defs.h>
18 #include <asm/sn/pcidev.h>
19 #include <asm/sn/shub_mmr.h>
20 #include <asm/sn/sn_sal.h>
21
22 static void force_interrupt(int irq);
23 static void register_intr_pda(struct sn_irq_info *sn_irq_info);
24 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
25
26 extern int sn_force_interrupt_flag;
27 extern int sn_ioif_inited;
28 static struct list_head **sn_irq_lh;
29 static spinlock_t sn_irq_info_lock = SPIN_LOCK_UNLOCKED; /* non-IRQ lock */
30
31 static inline uint64_t sn_intr_alloc(nasid_t local_nasid, int local_widget,
32                                      u64 sn_irq_info,
33                                      int req_irq, nasid_t req_nasid,
34                                      int req_slice)
35 {
36         struct ia64_sal_retval ret_stuff;
37         ret_stuff.status = 0;
38         ret_stuff.v0 = 0;
39
40         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
41                         (u64) SAL_INTR_ALLOC, (u64) local_nasid,
42                         (u64) local_widget, (u64) sn_irq_info, (u64) req_irq,
43                         (u64) req_nasid, (u64) req_slice);
44         return ret_stuff.status;
45 }
46
47 static inline void sn_intr_free(nasid_t local_nasid, int local_widget,
48                                 struct sn_irq_info *sn_irq_info)
49 {
50         struct ia64_sal_retval ret_stuff;
51         ret_stuff.status = 0;
52         ret_stuff.v0 = 0;
53
54         SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,
55                         (u64) SAL_INTR_FREE, (u64) local_nasid,
56                         (u64) local_widget, (u64) sn_irq_info->irq_irq,
57                         (u64) sn_irq_info->irq_cookie, 0, 0);
58 }
59
60 static unsigned int sn_startup_irq(unsigned int irq)
61 {
62         return 0;
63 }
64
65 static void sn_shutdown_irq(unsigned int irq)
66 {
67 }
68
69 static void sn_disable_irq(unsigned int irq)
70 {
71 }
72
73 static void sn_enable_irq(unsigned int irq)
74 {
75 }
76
77 static void sn_ack_irq(unsigned int irq)
78 {
79         uint64_t event_occurred, mask = 0;
80         int nasid;
81
82         irq = irq & 0xff;
83         nasid = get_nasid();
84         event_occurred =
85             HUB_L((uint64_t *) GLOBAL_MMR_ADDR(nasid, SH_EVENT_OCCURRED));
86         mask = event_occurred & SH_ALL_INT_MASK;
87         HUB_S((uint64_t *) GLOBAL_MMR_ADDR(nasid, SH_EVENT_OCCURRED_ALIAS),
88                  mask);
89         __set_bit(irq, (volatile void *)pda->sn_in_service_ivecs);
90
91         move_irq(irq);
92 }
93
94 static void sn_end_irq(unsigned int irq)
95 {
96         int nasid;
97         int ivec;
98         uint64_t event_occurred;
99
100         ivec = irq & 0xff;
101         if (ivec == SGI_UART_VECTOR) {
102                 nasid = get_nasid();
103                 event_occurred = HUB_L((uint64_t *) GLOBAL_MMR_ADDR
104                                        (nasid, SH_EVENT_OCCURRED));
105                 /* If the UART bit is set here, we may have received an
106                  * interrupt from the UART that the driver missed.  To
107                  * make sure, we IPI ourselves to force us to look again.
108                  */
109                 if (event_occurred & SH_EVENT_OCCURRED_UART_INT_MASK) {
110                         platform_send_ipi(smp_processor_id(), SGI_UART_VECTOR,
111                                           IA64_IPI_DM_INT, 0);
112                 }
113         }
114         __clear_bit(ivec, (volatile void *)pda->sn_in_service_ivecs);
115         if (sn_force_interrupt_flag)
116                 force_interrupt(irq);
117 }
118
119 static void sn_irq_info_free(struct rcu_head *head);
120
121 static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
122 {
123         struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
124         int cpuid, cpuphys;
125
126         cpuid = first_cpu(mask);
127         cpuphys = cpu_physical_id(cpuid);
128
129         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
130                                  sn_irq_lh[irq], list) {
131                 uint64_t bridge;
132                 int local_widget, status;
133                 nasid_t local_nasid;
134                 struct sn_irq_info *new_irq_info;
135
136                 new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
137                 if (new_irq_info == NULL)
138                         break;
139                 memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
140
141                 bridge = (uint64_t) new_irq_info->irq_bridge;
142                 if (!bridge) {
143                         kfree(new_irq_info);
144                         break; /* irq is not a device interrupt */
145                 }
146
147                 local_nasid = NASID_GET(bridge);
148
149                 if (local_nasid & 1)
150                         local_widget = TIO_SWIN_WIDGETNUM(bridge);
151                 else
152                         local_widget = SWIN_WIDGETNUM(bridge);
153
154                 /* Free the old PROM new_irq_info structure */
155                 sn_intr_free(local_nasid, local_widget, new_irq_info);
156                 /* Update kernels new_irq_info with new target info */
157                 unregister_intr_pda(new_irq_info);
158
159                 /* allocate a new PROM new_irq_info struct */
160                 status = sn_intr_alloc(local_nasid, local_widget,
161                                        __pa(new_irq_info), irq,
162                                        cpuid_to_nasid(cpuid),
163                                        cpuid_to_slice(cpuid));
164
165                 /* SAL call failed */
166                 if (status) {
167                         kfree(new_irq_info);
168                         break;
169                 }
170
171                 new_irq_info->irq_cpuid = cpuid;
172                 register_intr_pda(new_irq_info);
173
174                 if (IS_PCI_BRIDGE_ASIC(new_irq_info->irq_bridge_type))
175                         pcibr_change_devices_irq(new_irq_info);
176
177                 spin_lock(&sn_irq_info_lock);
178                 list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
179                 spin_unlock(&sn_irq_info_lock);
180                 call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
181
182 #ifdef CONFIG_SMP
183                 set_irq_affinity_info((irq & 0xff), cpuphys, 0);
184 #endif
185         }
186 }
187
188 struct hw_interrupt_type irq_type_sn = {
189         .typename       = "SN hub",
190         .startup        = sn_startup_irq,
191         .shutdown       = sn_shutdown_irq,
192         .enable         = sn_enable_irq,
193         .disable        = sn_disable_irq,
194         .ack            = sn_ack_irq,
195         .end            = sn_end_irq,
196         .set_affinity   = sn_set_affinity_irq
197 };
198
199 unsigned int sn_local_vector_to_irq(u8 vector)
200 {
201         return (CPU_VECTOR_TO_IRQ(smp_processor_id(), vector));
202 }
203
204 void sn_irq_init(void)
205 {
206         int i;
207         irq_desc_t *base_desc = irq_desc;
208
209         for (i = 0; i < NR_IRQS; i++) {
210                 if (base_desc[i].handler == &no_irq_type) {
211                         base_desc[i].handler = &irq_type_sn;
212                 }
213         }
214 }
215
216 static void register_intr_pda(struct sn_irq_info *sn_irq_info)
217 {
218         int irq = sn_irq_info->irq_irq;
219         int cpu = sn_irq_info->irq_cpuid;
220
221         if (pdacpu(cpu)->sn_last_irq < irq) {
222                 pdacpu(cpu)->sn_last_irq = irq;
223         }
224
225         if (pdacpu(cpu)->sn_first_irq == 0 || pdacpu(cpu)->sn_first_irq > irq) {
226                 pdacpu(cpu)->sn_first_irq = irq;
227         }
228 }
229
230 static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
231 {
232         int irq = sn_irq_info->irq_irq;
233         int cpu = sn_irq_info->irq_cpuid;
234         struct sn_irq_info *tmp_irq_info;
235         int i, foundmatch;
236
237         rcu_read_lock();
238         if (pdacpu(cpu)->sn_last_irq == irq) {
239                 foundmatch = 0;
240                 for (i = pdacpu(cpu)->sn_last_irq - 1;
241                      i && !foundmatch; i--) {
242                         list_for_each_entry_rcu(tmp_irq_info,
243                                                 sn_irq_lh[i],
244                                                 list) {
245                                 if (tmp_irq_info->irq_cpuid == cpu) {
246                                         foundmatch = 1;
247                                         break;
248                                 }
249                         }
250                 }
251                 pdacpu(cpu)->sn_last_irq = i;
252         }
253
254         if (pdacpu(cpu)->sn_first_irq == irq) {
255                 foundmatch = 0;
256                 for (i = pdacpu(cpu)->sn_first_irq + 1;
257                      i < NR_IRQS && !foundmatch; i++) {
258                         list_for_each_entry_rcu(tmp_irq_info,
259                                                 sn_irq_lh[i],
260                                                 list) {
261                                 if (tmp_irq_info->irq_cpuid == cpu) {
262                                         foundmatch = 1;
263                                         break;
264                                 }
265                         }
266                 }
267                 pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
268         }
269         rcu_read_unlock();
270 }
271
272 static void sn_irq_info_free(struct rcu_head *head)
273 {
274         struct sn_irq_info *sn_irq_info;
275
276         sn_irq_info = container_of(head, struct sn_irq_info, rcu);
277         kfree(sn_irq_info);
278 }
279
280 void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
281 {
282         nasid_t nasid = sn_irq_info->irq_nasid;
283         int slice = sn_irq_info->irq_slice;
284         int cpu = nasid_slice_to_cpuid(nasid, slice);
285
286         pci_dev_get(pci_dev);
287         sn_irq_info->irq_cpuid = cpu;
288         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
289
290         /* link it into the sn_irq[irq] list */
291         spin_lock(&sn_irq_info_lock);
292         list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
293         spin_unlock(&sn_irq_info_lock);
294
295         (void)register_intr_pda(sn_irq_info);
296 }
297
298 void sn_irq_unfixup(struct pci_dev *pci_dev)
299 {
300         struct sn_irq_info *sn_irq_info;
301
302         /* Only cleanup IRQ stuff if this device has a host bus context */
303         if (!SN_PCIDEV_BUSSOFT(pci_dev))
304                 return;
305
306         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
307         if (!sn_irq_info || !sn_irq_info->irq_irq) {
308                 kfree(sn_irq_info);
309                 return;
310         }
311
312         unregister_intr_pda(sn_irq_info);
313         spin_lock(&sn_irq_info_lock);
314         list_del_rcu(&sn_irq_info->list);
315         spin_unlock(&sn_irq_info_lock);
316         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
317         pci_dev_put(pci_dev);
318 }
319
320 static inline void
321 sn_call_force_intr_provider(struct sn_irq_info *sn_irq_info)
322 {
323         struct sn_pcibus_provider *pci_provider;
324
325         pci_provider = sn_pci_provider[sn_irq_info->irq_bridge_type];
326         if (pci_provider && pci_provider->force_interrupt)
327                 (*pci_provider->force_interrupt)(sn_irq_info);
328 }
329
330 static void force_interrupt(int irq)
331 {
332         struct sn_irq_info *sn_irq_info;
333
334         if (!sn_ioif_inited)
335                 return;
336
337         rcu_read_lock();
338         list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list)
339                 sn_call_force_intr_provider(sn_irq_info);
340
341         rcu_read_unlock();
342 }
343
344 /*
345  * Check for lost interrupts.  If the PIC int_status reg. says that
346  * an interrupt has been sent, but not handled, and the interrupt
347  * is not pending in either the cpu irr regs or in the soft irr regs,
348  * and the interrupt is not in service, then the interrupt may have
349  * been lost.  Force an interrupt on that pin.  It is possible that
350  * the interrupt is in flight, so we may generate a spurious interrupt,
351  * but we should never miss a real lost interrupt.
352  */
353 static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
354 {
355         uint64_t regval;
356         int irr_reg_num;
357         int irr_bit;
358         uint64_t irr_reg;
359         struct pcidev_info *pcidev_info;
360         struct pcibus_info *pcibus_info;
361
362         /*
363          * Bridge types attached to TIO (anything but PIC) do not need this WAR
364          * since they do not target Shub II interrupt registers.  If that
365          * ever changes, this check needs to accomodate.
366          */
367         if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_PIC)
368                 return;
369
370         pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
371         if (!pcidev_info)
372                 return;
373
374         pcibus_info =
375             (struct pcibus_info *)pcidev_info->pdi_host_pcidev_info->
376             pdi_pcibus_info;
377         regval = pcireg_intr_status_get(pcibus_info);
378
379         irr_reg_num = irq_to_vector(irq) / 64;
380         irr_bit = irq_to_vector(irq) % 64;
381         switch (irr_reg_num) {
382         case 0:
383                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR0);
384                 break;
385         case 1:
386                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR1);
387                 break;
388         case 2:
389                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR2);
390                 break;
391         case 3:
392                 irr_reg = ia64_getreg(_IA64_REG_CR_IRR3);
393                 break;
394         }
395         if (!test_bit(irr_bit, &irr_reg)) {
396                 if (!test_bit(irq, pda->sn_in_service_ivecs)) {
397                         regval &= 0xff;
398                         if (sn_irq_info->irq_int_bit & regval &
399                             sn_irq_info->irq_last_intr) {
400                                 regval &= ~(sn_irq_info->irq_int_bit & regval);
401                                 sn_call_force_intr_provider(sn_irq_info);
402                         }
403                 }
404         }
405         sn_irq_info->irq_last_intr = regval;
406 }
407
408 void sn_lb_int_war_check(void)
409 {
410         struct sn_irq_info *sn_irq_info;
411         int i;
412
413         if (!sn_ioif_inited || pda->sn_first_irq == 0)
414                 return;
415
416         rcu_read_lock();
417         for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
418                 list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
419                         sn_check_intr(i, sn_irq_info);
420                 }
421         }
422         rcu_read_unlock();
423 }
424
425 void sn_irq_lh_init(void)
426 {
427         int i;
428
429         sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
430         if (!sn_irq_lh)
431                 panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
432
433         for (i = 0; i < NR_IRQS; i++) {
434                 sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
435                 if (!sn_irq_lh[i])
436                         panic("SN PCI INIT: Failed IRQ memory allocation\n");
437
438                 INIT_LIST_HEAD(sn_irq_lh[i]);
439         }
440
441 }