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
46 #ifdef CONFIG_PCI
47
48 enum pci_event_type {
49 pe_bus_created = 0, /* PHB has been created */
50 pe_bus_error = 1, /* PHB has failed */
51 pe_bus_failed = 2, /* Msg to Secondary, Primary failed bus */
52 pe_node_failed = 4, /* Multi-adapter bridge has failed */
53 pe_node_recovered = 5, /* Multi-adapter bridge has recovered */
54 pe_bus_recovered = 12, /* PHB has been recovered */
55 pe_unquiese_bus = 18, /* Secondary bus unqiescing */
56 pe_bridge_error = 21, /* Bridge Error */
57 pe_slot_interrupt = 22 /* Slot interrupt */
58 };
59
60 struct pci_event {
61 struct HvLpEvent event;
62 union {
63 u64 __align; /* Align on an 8-byte boundary */
64 struct {
65 u32 fisr;
66 HvBusNumber bus_number;
67 HvSubBusNumber sub_bus_number;
68 HvAgentId dev_id;
69 } slot;
70 struct {
71 HvBusNumber bus_number;
72 HvSubBusNumber sub_bus_number;
73 } bus;
74 struct {
75 HvBusNumber bus_number;
76 HvSubBusNumber sub_bus_number;
77 HvAgentId dev_id;
78 } node;
79 } data;
80 };
81
82 static DEFINE_SPINLOCK(pending_irqs_lock);
83 static int num_pending_irqs;
84 static int pending_irqs[NR_IRQS];
85
int_received(struct pci_event * event)86 static void int_received(struct pci_event *event)
87 {
88 int irq;
89
90 switch (event->event.xSubtype) {
91 case pe_slot_interrupt:
92 irq = event->event.xCorrelationToken;
93 if (irq < NR_IRQS) {
94 spin_lock(&pending_irqs_lock);
95 pending_irqs[irq]++;
96 num_pending_irqs++;
97 spin_unlock(&pending_irqs_lock);
98 } else {
99 printk(KERN_WARNING "int_received: bad irq number %d\n",
100 irq);
101 HvCallPci_eoi(event->data.slot.bus_number,
102 event->data.slot.sub_bus_number,
103 event->data.slot.dev_id);
104 }
105 break;
106 /* Ignore error recovery events for now */
107 case pe_bus_created:
108 printk(KERN_INFO "int_received: system bus %d created\n",
109 event->data.bus.bus_number);
110 break;
111 case pe_bus_error:
112 case pe_bus_failed:
113 printk(KERN_INFO "int_received: system bus %d failed\n",
114 event->data.bus.bus_number);
115 break;
116 case pe_bus_recovered:
117 case pe_unquiese_bus:
118 printk(KERN_INFO "int_received: system bus %d recovered\n",
119 event->data.bus.bus_number);
120 break;
121 case pe_node_failed:
122 case pe_bridge_error:
123 printk(KERN_INFO
124 "int_received: multi-adapter bridge %d/%d/%d failed\n",
125 event->data.node.bus_number,
126 event->data.node.sub_bus_number,
127 event->data.node.dev_id);
128 break;
129 case pe_node_recovered:
130 printk(KERN_INFO
131 "int_received: multi-adapter bridge %d/%d/%d recovered\n",
132 event->data.node.bus_number,
133 event->data.node.sub_bus_number,
134 event->data.node.dev_id);
135 break;
136 default:
137 printk(KERN_ERR
138 "int_received: unrecognized event subtype 0x%x\n",
139 event->event.xSubtype);
140 break;
141 }
142 }
143
pci_event_handler(struct HvLpEvent * event)144 static void pci_event_handler(struct HvLpEvent *event)
145 {
146 if (event && (event->xType == HvLpEvent_Type_PciIo)) {
147 if (hvlpevent_is_int(event))
148 int_received((struct pci_event *)event);
149 else
150 printk(KERN_ERR
151 "pci_event_handler: unexpected ack received\n");
152 } else if (event)
153 printk(KERN_ERR
154 "pci_event_handler: Unrecognized PCI event type 0x%x\n",
155 (int)event->xType);
156 else
157 printk(KERN_ERR "pci_event_handler: NULL event received\n");
158 }
159
160 #define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
161 #define REAL_IRQ_TO_BUS(irq) ((((irq) >> 6) & 0xff) + 1)
162 #define REAL_IRQ_TO_IDSEL(irq) ((((irq) >> 3) & 7) + 1)
163 #define REAL_IRQ_TO_FUNC(irq) ((irq) & 7)
164
165 /*
166 * This will be called by device drivers (via enable_IRQ)
167 * to enable INTA in the bridge interrupt status register.
168 */
iseries_enable_IRQ(struct irq_data * d)169 static void iseries_enable_IRQ(struct irq_data *d)
170 {
171 u32 bus, dev_id, function, mask;
172 const u32 sub_bus = 0;
173 unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
174
175 /* The IRQ has already been locked by the caller */
176 bus = REAL_IRQ_TO_BUS(rirq);
177 function = REAL_IRQ_TO_FUNC(rirq);
178 dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
179
180 /* Unmask secondary INTA */
181 mask = 0x80000000;
182 HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
183 }
184
185 /* This is called by iseries_activate_IRQs */
iseries_startup_IRQ(struct irq_data * d)186 static unsigned int iseries_startup_IRQ(struct irq_data *d)
187 {
188 u32 bus, dev_id, function, mask;
189 const u32 sub_bus = 0;
190 unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
191
192 bus = REAL_IRQ_TO_BUS(rirq);
193 function = REAL_IRQ_TO_FUNC(rirq);
194 dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
195
196 /* Link the IRQ number to the bridge */
197 HvCallXm_connectBusUnit(bus, sub_bus, dev_id, d->irq);
198
199 /* Unmask bridge interrupts in the FISR */
200 mask = 0x01010000 << function;
201 HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
202 iseries_enable_IRQ(d);
203 return 0;
204 }
205
206 /*
207 * This is called out of iSeries_fixup to activate interrupt
208 * generation for usable slots
209 */
iSeries_activate_IRQs()210 void __init iSeries_activate_IRQs()
211 {
212 int irq;
213 unsigned long flags;
214
215 for_each_irq (irq) {
216 struct irq_desc *desc = irq_to_desc(irq);
217 struct irq_chip *chip;
218
219 if (!desc)
220 continue;
221
222 chip = irq_desc_get_chip(desc);
223 if (chip && chip->irq_startup) {
224 raw_spin_lock_irqsave(&desc->lock, flags);
225 chip->irq_startup(&desc->irq_data);
226 raw_spin_unlock_irqrestore(&desc->lock, flags);
227 }
228 }
229 }
230
231 /* this is not called anywhere currently */
iseries_shutdown_IRQ(struct irq_data * d)232 static void iseries_shutdown_IRQ(struct irq_data *d)
233 {
234 u32 bus, dev_id, function, mask;
235 const u32 sub_bus = 0;
236 unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
237
238 /* irq should be locked by the caller */
239 bus = REAL_IRQ_TO_BUS(rirq);
240 function = REAL_IRQ_TO_FUNC(rirq);
241 dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
242
243 /* Invalidate the IRQ number in the bridge */
244 HvCallXm_connectBusUnit(bus, sub_bus, dev_id, 0);
245
246 /* Mask bridge interrupts in the FISR */
247 mask = 0x01010000 << function;
248 HvCallPci_maskFisr(bus, sub_bus, dev_id, mask);
249 }
250
251 /*
252 * This will be called by device drivers (via disable_IRQ)
253 * to disable INTA in the bridge interrupt status register.
254 */
iseries_disable_IRQ(struct irq_data * d)255 static void iseries_disable_IRQ(struct irq_data *d)
256 {
257 u32 bus, dev_id, function, mask;
258 const u32 sub_bus = 0;
259 unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
260
261 /* The IRQ has already been locked by the caller */
262 bus = REAL_IRQ_TO_BUS(rirq);
263 function = REAL_IRQ_TO_FUNC(rirq);
264 dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
265
266 /* Mask secondary INTA */
267 mask = 0x80000000;
268 HvCallPci_maskInterrupts(bus, sub_bus, dev_id, mask);
269 }
270
iseries_end_IRQ(struct irq_data * d)271 static void iseries_end_IRQ(struct irq_data *d)
272 {
273 unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
274
275 HvCallPci_eoi(REAL_IRQ_TO_BUS(rirq), REAL_IRQ_TO_SUBBUS(rirq),
276 (REAL_IRQ_TO_IDSEL(rirq) << 4) + REAL_IRQ_TO_FUNC(rirq));
277 }
278
279 static struct irq_chip iseries_pic = {
280 .name = "iSeries",
281 .irq_startup = iseries_startup_IRQ,
282 .irq_shutdown = iseries_shutdown_IRQ,
283 .irq_unmask = iseries_enable_IRQ,
284 .irq_mask = iseries_disable_IRQ,
285 .irq_eoi = iseries_end_IRQ
286 };
287
288 /*
289 * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
290 * It calculates the irq value for the slot.
291 * Note that sub_bus is always 0 (at the moment at least).
292 */
iSeries_allocate_IRQ(HvBusNumber bus,HvSubBusNumber sub_bus,u32 bsubbus)293 int __init iSeries_allocate_IRQ(HvBusNumber bus,
294 HvSubBusNumber sub_bus, u32 bsubbus)
295 {
296 unsigned int realirq;
297 u8 idsel = ISERIES_GET_DEVICE_FROM_SUBBUS(bsubbus);
298 u8 function = ISERIES_GET_FUNCTION_FROM_SUBBUS(bsubbus);
299
300 realirq = (((((sub_bus << 8) + (bus - 1)) << 3) + (idsel - 1)) << 3)
301 + function;
302
303 return irq_create_mapping(NULL, realirq);
304 }
305
306 #endif /* CONFIG_PCI */
307
308 /*
309 * Get the next pending IRQ.
310 */
iSeries_get_irq(void)311 unsigned int iSeries_get_irq(void)
312 {
313 int irq = NO_IRQ_IGNORE;
314
315 #ifdef CONFIG_SMP
316 if (get_lppaca()->int_dword.fields.ipi_cnt) {
317 get_lppaca()->int_dword.fields.ipi_cnt = 0;
318 smp_ipi_demux();
319 }
320 #endif /* CONFIG_SMP */
321 if (hvlpevent_is_pending())
322 process_hvlpevents();
323
324 #ifdef CONFIG_PCI
325 if (num_pending_irqs) {
326 spin_lock(&pending_irqs_lock);
327 for (irq = 0; irq < NR_IRQS; irq++) {
328 if (pending_irqs[irq]) {
329 pending_irqs[irq]--;
330 num_pending_irqs--;
331 break;
332 }
333 }
334 spin_unlock(&pending_irqs_lock);
335 if (irq >= NR_IRQS)
336 irq = NO_IRQ_IGNORE;
337 }
338 #endif
339
340 return irq;
341 }
342
343 #ifdef CONFIG_PCI
344
iseries_irq_host_map(struct irq_host * h,unsigned int virq,irq_hw_number_t hw)345 static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
346 irq_hw_number_t hw)
347 {
348 irq_set_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
349
350 return 0;
351 }
352
iseries_irq_host_match(struct irq_host * h,struct device_node * np)353 static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
354 {
355 /* Match all */
356 return 1;
357 }
358
359 static struct irq_host_ops iseries_irq_host_ops = {
360 .map = iseries_irq_host_map,
361 .match = iseries_irq_host_match,
362 };
363
364 /*
365 * This is called by init_IRQ. set in ppc_md.init_IRQ by iSeries_setup.c
366 * It must be called before the bus walk.
367 */
iSeries_init_IRQ(void)368 void __init iSeries_init_IRQ(void)
369 {
370 /* Register PCI event handler and open an event path */
371 struct irq_host *host;
372 int ret;
373
374 /*
375 * The Hypervisor only allows us up to 256 interrupt
376 * sources (the irq number is passed in a u8).
377 */
378 irq_set_virq_count(256);
379
380 /* Create irq host. No need for a revmap since HV will give us
381 * back our virtual irq number
382 */
383 host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
384 &iseries_irq_host_ops, 0);
385 BUG_ON(host == NULL);
386 irq_set_default_host(host);
387
388 ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
389 &pci_event_handler);
390 if (ret == 0) {
391 ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
392 if (ret != 0)
393 printk(KERN_ERR "iseries_init_IRQ: open event path "
394 "failed with rc 0x%x\n", ret);
395 } else
396 printk(KERN_ERR "iseries_init_IRQ: register handler "
397 "failed with rc 0x%x\n", ret);
398 }
399
400 #endif /* CONFIG_PCI */
401