ppc64: allow iSeries to use IRQSTACKS again
[karo-tx-linux.git] / 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/config.h>
27 #include <linux/pci.h>
28 #include <linux/init.h>
29 #include <linux/threads.h>
30 #include <linux/smp.h>
31 #include <linux/param.h>
32 #include <linux/string.h>
33 #include <linux/bootmem.h>
34 #include <linux/ide.h>
35 #include <linux/irq.h>
36 #include <linux/spinlock.h>
37
38 #include <asm/iseries/hv_types.h>
39 #include <asm/iseries/hv_lp_event.h>
40 #include <asm/iseries/hv_call_xm.h>
41
42 #include "irq.h"
43 #include "call_pci.h"
44
45 /* This maps virtual irq numbers to real irqs */
46 unsigned int virt_irq_to_real_map[NR_IRQS];
47
48 /* The next available virtual irq number */
49 /* Note: the pcnet32 driver assumes irq numbers < 2 aren't valid. :( */
50 static int next_virtual_irq = 2;
51
52 static long Pci_Interrupt_Count;
53 static long Pci_Event_Count;
54
55 enum XmPciLpEvent_Subtype {
56         XmPciLpEvent_BusCreated         = 0,    // PHB has been created
57         XmPciLpEvent_BusError           = 1,    // PHB has failed
58         XmPciLpEvent_BusFailed          = 2,    // Msg to Secondary, Primary failed bus
59         XmPciLpEvent_NodeFailed         = 4,    // Multi-adapter bridge has failed
60         XmPciLpEvent_NodeRecovered      = 5,    // Multi-adapter bridge has recovered
61         XmPciLpEvent_BusRecovered       = 12,   // PHB has been recovered
62         XmPciLpEvent_UnQuiesceBus       = 18,   // Secondary bus unqiescing
63         XmPciLpEvent_BridgeError        = 21,   // Bridge Error
64         XmPciLpEvent_SlotInterrupt      = 22    // Slot interrupt
65 };
66
67 struct XmPciLpEvent_BusInterrupt {
68         HvBusNumber     busNumber;
69         HvSubBusNumber  subBusNumber;
70 };
71
72 struct XmPciLpEvent_NodeInterrupt {
73         HvBusNumber     busNumber;
74         HvSubBusNumber  subBusNumber;
75         HvAgentId       deviceId;
76 };
77
78 struct XmPciLpEvent {
79         struct HvLpEvent hvLpEvent;
80
81         union {
82                 u64 alignData;                  // Align on an 8-byte boundary
83
84                 struct {
85                         u32             fisr;
86                         HvBusNumber     busNumber;
87                         HvSubBusNumber  subBusNumber;
88                         HvAgentId       deviceId;
89                 } slotInterrupt;
90
91                 struct XmPciLpEvent_BusInterrupt busFailed;
92                 struct XmPciLpEvent_BusInterrupt busRecovered;
93                 struct XmPciLpEvent_BusInterrupt busCreated;
94
95                 struct XmPciLpEvent_NodeInterrupt nodeFailed;
96                 struct XmPciLpEvent_NodeInterrupt nodeRecovered;
97
98         } eventData;
99
100 };
101
102 static void intReceived(struct XmPciLpEvent *eventParm,
103                 struct pt_regs *regsParm)
104 {
105         int irq;
106 #ifdef CONFIG_IRQSTACKS
107         struct thread_info *curtp, *irqtp;
108 #endif
109
110         ++Pci_Interrupt_Count;
111
112         switch (eventParm->hvLpEvent.xSubtype) {
113         case XmPciLpEvent_SlotInterrupt:
114                 irq = eventParm->hvLpEvent.xCorrelationToken;
115                 /* Dispatch the interrupt handlers for this irq */
116 #ifdef CONFIG_IRQSTACKS
117                 /* Switch to the irq stack to handle this */
118                 curtp = current_thread_info();
119                 irqtp = hardirq_ctx[smp_processor_id()];
120                 if (curtp != irqtp) {
121                         irqtp->task = curtp->task;
122                         irqtp->flags = 0;
123                         call_ppc_irq_dispatch_handler(regsParm, irq, irqtp);
124                         irqtp->task = NULL;
125                         if (irqtp->flags)
126                                 set_bits(irqtp->flags, &curtp->flags);
127                 } else
128 #endif
129                         ppc_irq_dispatch_handler(regsParm, irq);
130                 HvCallPci_eoi(eventParm->eventData.slotInterrupt.busNumber,
131                         eventParm->eventData.slotInterrupt.subBusNumber,
132                         eventParm->eventData.slotInterrupt.deviceId);
133                 break;
134                 /* Ignore error recovery events for now */
135         case XmPciLpEvent_BusCreated:
136                 printk(KERN_INFO "intReceived: system bus %d created\n",
137                         eventParm->eventData.busCreated.busNumber);
138                 break;
139         case XmPciLpEvent_BusError:
140         case XmPciLpEvent_BusFailed:
141                 printk(KERN_INFO "intReceived: system bus %d failed\n",
142                         eventParm->eventData.busFailed.busNumber);
143                 break;
144         case XmPciLpEvent_BusRecovered:
145         case XmPciLpEvent_UnQuiesceBus:
146                 printk(KERN_INFO "intReceived: system bus %d recovered\n",
147                         eventParm->eventData.busRecovered.busNumber);
148                 break;
149         case XmPciLpEvent_NodeFailed:
150         case XmPciLpEvent_BridgeError:
151                 printk(KERN_INFO
152                         "intReceived: multi-adapter bridge %d/%d/%d failed\n",
153                         eventParm->eventData.nodeFailed.busNumber,
154                         eventParm->eventData.nodeFailed.subBusNumber,
155                         eventParm->eventData.nodeFailed.deviceId);
156                 break;
157         case XmPciLpEvent_NodeRecovered:
158                 printk(KERN_INFO
159                         "intReceived: multi-adapter bridge %d/%d/%d recovered\n",
160                         eventParm->eventData.nodeRecovered.busNumber,
161                         eventParm->eventData.nodeRecovered.subBusNumber,
162                         eventParm->eventData.nodeRecovered.deviceId);
163                 break;
164         default:
165                 printk(KERN_ERR
166                         "intReceived: unrecognized event subtype 0x%x\n",
167                         eventParm->hvLpEvent.xSubtype);
168                 break;
169         }
170 }
171
172 static void XmPciLpEvent_handler(struct HvLpEvent *eventParm,
173                 struct pt_regs *regsParm)
174 {
175 #ifdef CONFIG_PCI
176         ++Pci_Event_Count;
177
178         if (eventParm && (eventParm->xType == HvLpEvent_Type_PciIo)) {
179                 switch (eventParm->xFlags.xFunction) {
180                 case HvLpEvent_Function_Int:
181                         intReceived((struct XmPciLpEvent *)eventParm, regsParm);
182                         break;
183                 case HvLpEvent_Function_Ack:
184                         printk(KERN_ERR
185                                 "XmPciLpEvent_handler: unexpected ack received\n");
186                         break;
187                 default:
188                         printk(KERN_ERR
189                                 "XmPciLpEvent_handler: unexpected event function %d\n",
190                                 (int)eventParm->xFlags.xFunction);
191                         break;
192                 }
193         } else if (eventParm)
194                 printk(KERN_ERR
195                         "XmPciLpEvent_handler: Unrecognized PCI event type 0x%x\n",
196                         (int)eventParm->xType);
197         else
198                 printk(KERN_ERR "XmPciLpEvent_handler: NULL event received\n");
199 #endif
200 }
201
202 /*
203  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
204  * It must be called before the bus walk.
205  */
206 void __init iSeries_init_IRQ(void)
207 {
208         /* Register PCI event handler and open an event path */
209         int xRc;
210
211         xRc = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
212                         &XmPciLpEvent_handler);
213         if (xRc == 0) {
214                 xRc = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
215                 if (xRc != 0)
216                         printk(KERN_ERR "iSeries_init_IRQ: open event path "
217                                         "failed with rc 0x%x\n", xRc);
218         } else
219                 printk(KERN_ERR "iSeries_init_IRQ: register handler "
220                                 "failed with rc 0x%x\n", xRc);
221 }
222
223 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
224 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
225 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
226
227 /*
228  * This will be called by device drivers (via enable_IRQ)
229  * to enable INTA in the bridge interrupt status register.
230  */
231 static void iSeries_enable_IRQ(unsigned int irq)
232 {
233         u32 bus, deviceId, function, mask;
234         const u32 subBus = 0;
235         unsigned int rirq = virt_irq_to_real_map[irq];
236
237         /* The IRQ has already been locked by the caller */
238         bus = REAL_IRQ_TO_BUS(rirq);
239         function = REAL_IRQ_TO_FUNC(rirq);
240         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
241
242         /* Unmask secondary INTA */
243         mask = 0x80000000;
244         HvCallPci_unmaskInterrupts(bus, subBus, deviceId, mask);
245 }
246
247 /* This is called by iSeries_activate_IRQs */
248 static unsigned int iSeries_startup_IRQ(unsigned int irq)
249 {
250         u32 bus, deviceId, function, mask;
251         const u32 subBus = 0;
252         unsigned int rirq = virt_irq_to_real_map[irq];
253
254         bus = REAL_IRQ_TO_BUS(rirq);
255         function = REAL_IRQ_TO_FUNC(rirq);
256         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
257
258         /* Link the IRQ number to the bridge */
259         HvCallXm_connectBusUnit(bus, subBus, deviceId, irq);
260
261         /* Unmask bridge interrupts in the FISR */
262         mask = 0x01010000 << function;
263         HvCallPci_unmaskFisr(bus, subBus, deviceId, mask);
264         iSeries_enable_IRQ(irq);
265         return 0;
266 }
267
268 /*
269  * This is called out of iSeries_fixup to activate interrupt
270  * generation for usable slots
271  */
272 void __init iSeries_activate_IRQs()
273 {
274         int irq;
275         unsigned long flags;
276
277         for_each_irq (irq) {
278                 irq_desc_t *desc = get_irq_desc(irq);
279
280                 if (desc && desc->handler && desc->handler->startup) {
281                         spin_lock_irqsave(&desc->lock, flags);
282                         desc->handler->startup(irq);
283                         spin_unlock_irqrestore(&desc->lock, flags);
284                 }
285         }
286 }
287
288 /*  this is not called anywhere currently */
289 static void iSeries_shutdown_IRQ(unsigned int irq)
290 {
291         u32 bus, deviceId, function, mask;
292         const u32 subBus = 0;
293         unsigned int rirq = virt_irq_to_real_map[irq];
294
295         /* irq should be locked by the caller */
296         bus = REAL_IRQ_TO_BUS(rirq);
297         function = REAL_IRQ_TO_FUNC(rirq);
298         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
299
300         /* Invalidate the IRQ number in the bridge */
301         HvCallXm_connectBusUnit(bus, subBus, deviceId, 0);
302
303         /* Mask bridge interrupts in the FISR */
304         mask = 0x01010000 << function;
305         HvCallPci_maskFisr(bus, subBus, deviceId, mask);
306 }
307
308 /*
309  * This will be called by device drivers (via disable_IRQ)
310  * to disable INTA in the bridge interrupt status register.
311  */
312 static void iSeries_disable_IRQ(unsigned int irq)
313 {
314         u32 bus, deviceId, function, mask;
315         const u32 subBus = 0;
316         unsigned int rirq = virt_irq_to_real_map[irq];
317
318         /* The IRQ has already been locked by the caller */
319         bus = REAL_IRQ_TO_BUS(rirq);
320         function = REAL_IRQ_TO_FUNC(rirq);
321         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
322
323         /* Mask secondary INTA   */
324         mask = 0x80000000;
325         HvCallPci_maskInterrupts(bus, subBus, deviceId, mask);
326 }
327
328 /*
329  * Need to define this so ppc_irq_dispatch_handler will NOT call
330  * enable_IRQ at the end of interrupt handling.  However, this does
331  * nothing because there is not enough information provided to do
332  * the EOI HvCall.  This is done by XmPciLpEvent.c
333  */
334 static void iSeries_end_IRQ(unsigned int irq)
335 {
336 }
337
338 static hw_irq_controller iSeries_IRQ_handler = {
339         .typename = "iSeries irq controller",
340         .startup = iSeries_startup_IRQ,
341         .shutdown = iSeries_shutdown_IRQ,
342         .enable = iSeries_enable_IRQ,
343         .disable = iSeries_disable_IRQ,
344         .end = iSeries_end_IRQ
345 };
346
347 /*
348  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
349  * It calculates the irq value for the slot.
350  * Note that subBusNumber is always 0 (at the moment at least).
351  */
352 int __init iSeries_allocate_IRQ(HvBusNumber busNumber,
353                 HvSubBusNumber subBusNumber, HvAgentId deviceId)
354 {
355         unsigned int realirq, virtirq;
356         u8 idsel = (deviceId >> 4);
357         u8 function = deviceId & 7;
358
359         virtirq = next_virtual_irq++;
360         realirq = ((busNumber - 1) << 6) + ((idsel - 1) << 3) + function;
361         virt_irq_to_real_map[virtirq] = realirq;
362
363         irq_desc[virtirq].handler = &iSeries_IRQ_handler;
364         return virtirq;
365 }
366
367 int virt_irq_create_mapping(unsigned int real_irq)
368 {
369         BUG(); /* Don't call this on iSeries, yet */
370
371         return 0;
372 }
373
374 void virt_irq_init(void)
375 {
376         return;
377 }