[POWERPC] pasemi: Implement NMI support
[linux-2.6] / arch / powerpc / platforms / iseries / irq.c
1 /*
2  * This module supports the iSeries PCI bus interrupt handling
3  * Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>
4  * Copyright (C) 2004-2005 IBM Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the:
18  * Free Software Foundation, Inc.,
19  * 59 Temple Place, Suite 330,
20  * Boston, MA  02111-1307  USA
21  *
22  * Change Activity:
23  *   Created, December 13, 2000 by Wayne Holm
24  * End Change Activity
25  */
26 #include <linux/pci.h>
27 #include <linux/init.h>
28 #include <linux/threads.h>
29 #include <linux/smp.h>
30 #include <linux/param.h>
31 #include <linux/string.h>
32 #include <linux/bootmem.h>
33 #include <linux/irq.h>
34 #include <linux/spinlock.h>
35
36 #include <asm/paca.h>
37 #include <asm/iseries/hv_types.h>
38 #include <asm/iseries/hv_lp_event.h>
39 #include <asm/iseries/hv_call_xm.h>
40 #include <asm/iseries/it_lp_queue.h>
41
42 #include "irq.h"
43 #include "pci.h"
44 #include "call_pci.h"
45 #include "smp.h"
46
47 #ifdef CONFIG_PCI
48
49 enum pci_event_type {
50         pe_bus_created          = 0,    /* PHB has been created */
51         pe_bus_error            = 1,    /* PHB has failed */
52         pe_bus_failed           = 2,    /* Msg to Secondary, Primary failed bus */
53         pe_node_failed          = 4,    /* Multi-adapter bridge has failed */
54         pe_node_recovered       = 5,    /* Multi-adapter bridge has recovered */
55         pe_bus_recovered        = 12,   /* PHB has been recovered */
56         pe_unquiese_bus         = 18,   /* Secondary bus unqiescing */
57         pe_bridge_error         = 21,   /* Bridge Error */
58         pe_slot_interrupt       = 22    /* Slot interrupt */
59 };
60
61 struct pci_event {
62         struct HvLpEvent event;
63         union {
64                 u64 __align;            /* Align on an 8-byte boundary */
65                 struct {
66                         u32             fisr;
67                         HvBusNumber     bus_number;
68                         HvSubBusNumber  sub_bus_number;
69                         HvAgentId       dev_id;
70                 } slot;
71                 struct {
72                         HvBusNumber     bus_number;
73                         HvSubBusNumber  sub_bus_number;
74                 } bus;
75                 struct {
76                         HvBusNumber     bus_number;
77                         HvSubBusNumber  sub_bus_number;
78                         HvAgentId       dev_id;
79                 } node;
80         } data;
81 };
82
83 static DEFINE_SPINLOCK(pending_irqs_lock);
84 static int num_pending_irqs;
85 static int pending_irqs[NR_IRQS];
86
87 static void int_received(struct pci_event *event)
88 {
89         int irq;
90
91         switch (event->event.xSubtype) {
92         case pe_slot_interrupt:
93                 irq = event->event.xCorrelationToken;
94                 if (irq < NR_IRQS) {
95                         spin_lock(&pending_irqs_lock);
96                         pending_irqs[irq]++;
97                         num_pending_irqs++;
98                         spin_unlock(&pending_irqs_lock);
99                 } else {
100                         printk(KERN_WARNING "int_received: bad irq number %d\n",
101                                         irq);
102                         HvCallPci_eoi(event->data.slot.bus_number,
103                                         event->data.slot.sub_bus_number,
104                                         event->data.slot.dev_id);
105                 }
106                 break;
107                 /* Ignore error recovery events for now */
108         case pe_bus_created:
109                 printk(KERN_INFO "int_received: system bus %d created\n",
110                         event->data.bus.bus_number);
111                 break;
112         case pe_bus_error:
113         case pe_bus_failed:
114                 printk(KERN_INFO "int_received: system bus %d failed\n",
115                         event->data.bus.bus_number);
116                 break;
117         case pe_bus_recovered:
118         case pe_unquiese_bus:
119                 printk(KERN_INFO "int_received: system bus %d recovered\n",
120                         event->data.bus.bus_number);
121                 break;
122         case pe_node_failed:
123         case pe_bridge_error:
124                 printk(KERN_INFO
125                         "int_received: multi-adapter bridge %d/%d/%d failed\n",
126                         event->data.node.bus_number,
127                         event->data.node.sub_bus_number,
128                         event->data.node.dev_id);
129                 break;
130         case pe_node_recovered:
131                 printk(KERN_INFO
132                         "int_received: multi-adapter bridge %d/%d/%d recovered\n",
133                         event->data.node.bus_number,
134                         event->data.node.sub_bus_number,
135                         event->data.node.dev_id);
136                 break;
137         default:
138                 printk(KERN_ERR
139                         "int_received: unrecognized event subtype 0x%x\n",
140                         event->event.xSubtype);
141                 break;
142         }
143 }
144
145 static void pci_event_handler(struct HvLpEvent *event)
146 {
147         if (event && (event->xType == HvLpEvent_Type_PciIo)) {
148                 if (hvlpevent_is_int(event))
149                         int_received((struct pci_event *)event);
150                 else
151                         printk(KERN_ERR
152                                 "pci_event_handler: unexpected ack received\n");
153         } else if (event)
154                 printk(KERN_ERR
155                         "pci_event_handler: Unrecognized PCI event type 0x%x\n",
156                         (int)event->xType);
157         else
158                 printk(KERN_ERR "pci_event_handler: NULL event received\n");
159 }
160
161 #define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
162 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
163 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
164 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
165
166 /*
167  * This will be called by device drivers (via enable_IRQ)
168  * to enable INTA in the bridge interrupt status register.
169  */
170 static void iseries_enable_IRQ(unsigned int irq)
171 {
172         u32 bus, dev_id, function, mask;
173         const u32 sub_bus = 0;
174         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
175
176         /* The IRQ has already been locked by the caller */
177         bus = REAL_IRQ_TO_BUS(rirq);
178         function = REAL_IRQ_TO_FUNC(rirq);
179         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
180
181         /* Unmask secondary INTA */
182         mask = 0x80000000;
183         HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
184 }
185
186 /* This is called by iseries_activate_IRQs */
187 static unsigned int iseries_startup_IRQ(unsigned int irq)
188 {
189         u32 bus, dev_id, function, mask;
190         const u32 sub_bus = 0;
191         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
192
193         bus = REAL_IRQ_TO_BUS(rirq);
194         function = REAL_IRQ_TO_FUNC(rirq);
195         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
196
197         /* Link the IRQ number to the bridge */
198         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, irq);
199
200         /* Unmask bridge interrupts in the FISR */
201         mask = 0x01010000 << function;
202         HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
203         iseries_enable_IRQ(irq);
204         return 0;
205 }
206
207 /*
208  * This is called out of iSeries_fixup to activate interrupt
209  * generation for usable slots
210  */
211 void __init iSeries_activate_IRQs()
212 {
213         int irq;
214         unsigned long flags;
215
216         for_each_irq (irq) {
217                 irq_desc_t *desc = get_irq_desc(irq);
218
219                 if (desc && desc->chip && desc->chip->startup) {
220                         spin_lock_irqsave(&desc->lock, flags);
221                         desc->chip->startup(irq);
222                         spin_unlock_irqrestore(&desc->lock, flags);
223                 }
224         }
225 }
226
227 /*  this is not called anywhere currently */
228 static void iseries_shutdown_IRQ(unsigned int irq)
229 {
230         u32 bus, dev_id, function, mask;
231         const u32 sub_bus = 0;
232         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
233
234         /* irq should be locked by the caller */
235         bus = REAL_IRQ_TO_BUS(rirq);
236         function = REAL_IRQ_TO_FUNC(rirq);
237         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
238
239         /* Invalidate the IRQ number in the bridge */
240         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, 0);
241
242         /* Mask bridge interrupts in the FISR */
243         mask = 0x01010000 << function;
244         HvCallPci_maskFisr(bus, sub_bus, dev_id, mask);
245 }
246
247 /*
248  * This will be called by device drivers (via disable_IRQ)
249  * to disable INTA in the bridge interrupt status register.
250  */
251 static void iseries_disable_IRQ(unsigned int irq)
252 {
253         u32 bus, dev_id, function, mask;
254         const u32 sub_bus = 0;
255         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
256
257         /* The IRQ has already been locked by the caller */
258         bus = REAL_IRQ_TO_BUS(rirq);
259         function = REAL_IRQ_TO_FUNC(rirq);
260         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
261
262         /* Mask secondary INTA   */
263         mask = 0x80000000;
264         HvCallPci_maskInterrupts(bus, sub_bus, dev_id, mask);
265 }
266
267 static void iseries_end_IRQ(unsigned int irq)
268 {
269         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
270
271         HvCallPci_eoi(REAL_IRQ_TO_BUS(rirq), REAL_IRQ_TO_SUBBUS(rirq),
272                 (REAL_IRQ_TO_IDSEL(rirq) << 4) + REAL_IRQ_TO_FUNC(rirq));
273 }
274
275 static struct irq_chip iseries_pic = {
276         .typename       = "iSeries irq controller",
277         .startup        = iseries_startup_IRQ,
278         .shutdown       = iseries_shutdown_IRQ,
279         .unmask         = iseries_enable_IRQ,
280         .mask           = iseries_disable_IRQ,
281         .eoi            = iseries_end_IRQ
282 };
283
284 /*
285  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
286  * It calculates the irq value for the slot.
287  * Note that sub_bus is always 0 (at the moment at least).
288  */
289 int __init iSeries_allocate_IRQ(HvBusNumber bus,
290                 HvSubBusNumber sub_bus, u32 bsubbus)
291 {
292         unsigned int realirq;
293         u8 idsel = ISERIES_GET_DEVICE_FROM_SUBBUS(bsubbus);
294         u8 function = ISERIES_GET_FUNCTION_FROM_SUBBUS(bsubbus);
295
296         realirq = (((((sub_bus << 8) + (bus - 1)) << 3) + (idsel - 1)) << 3)
297                 + function;
298
299         return irq_create_mapping(NULL, realirq);
300 }
301
302 #endif /* CONFIG_PCI */
303
304 /*
305  * Get the next pending IRQ.
306  */
307 unsigned int iSeries_get_irq(void)
308 {
309         int irq = NO_IRQ_IGNORE;
310
311 #ifdef CONFIG_SMP
312         if (get_lppaca()->int_dword.fields.ipi_cnt) {
313                 get_lppaca()->int_dword.fields.ipi_cnt = 0;
314                 iSeries_smp_message_recv();
315         }
316 #endif /* CONFIG_SMP */
317         if (hvlpevent_is_pending())
318                 process_hvlpevents();
319
320 #ifdef CONFIG_PCI
321         if (num_pending_irqs) {
322                 spin_lock(&pending_irqs_lock);
323                 for (irq = 0; irq < NR_IRQS; irq++) {
324                         if (pending_irqs[irq]) {
325                                 pending_irqs[irq]--;
326                                 num_pending_irqs--;
327                                 break;
328                         }
329                 }
330                 spin_unlock(&pending_irqs_lock);
331                 if (irq >= NR_IRQS)
332                         irq = NO_IRQ_IGNORE;
333         }
334 #endif
335
336         return irq;
337 }
338
339 #ifdef CONFIG_PCI
340
341 static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
342                                 irq_hw_number_t hw)
343 {
344         set_irq_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
345
346         return 0;
347 }
348
349 static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
350 {
351         /* Match all */
352         return 1;
353 }
354
355 static struct irq_host_ops iseries_irq_host_ops = {
356         .map = iseries_irq_host_map,
357         .match = iseries_irq_host_match,
358 };
359
360 /*
361  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
362  * It must be called before the bus walk.
363  */
364 void __init iSeries_init_IRQ(void)
365 {
366         /* Register PCI event handler and open an event path */
367         struct irq_host *host;
368         int ret;
369
370         /*
371          * The Hypervisor only allows us up to 256 interrupt
372          * sources (the irq number is passed in a u8).
373          */
374         irq_set_virq_count(256);
375
376         /* Create irq host. No need for a revmap since HV will give us
377          * back our virtual irq number
378          */
379         host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
380                               &iseries_irq_host_ops, 0);
381         BUG_ON(host == NULL);
382         irq_set_default_host(host);
383
384         ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
385                         &pci_event_handler);
386         if (ret == 0) {
387                 ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
388                 if (ret != 0)
389                         printk(KERN_ERR "iseries_init_IRQ: open event path "
390                                         "failed with rc 0x%x\n", ret);
391         } else
392                 printk(KERN_ERR "iseries_init_IRQ: register handler "
393                                 "failed with rc 0x%x\n", ret);
394 }
395
396 #endif  /* CONFIG_PCI */