xref: /linux/drivers/parisc/iosapic.c (revision 1f2367a39f17bd553a75e179a747f9b257bc9478)
1 /*
2 ** I/O Sapic Driver - PCI interrupt line support
3 **
4 **      (c) Copyright 1999 Grant Grundler
5 **      (c) Copyright 1999 Hewlett-Packard Company
6 **
7 **      This program is free software; you can redistribute it and/or modify
8 **      it under the terms of the GNU General Public License as published by
9 **      the Free Software Foundation; either version 2 of the License, or
10 **      (at your option) any later version.
11 **
12 ** The I/O sapic driver manages the Interrupt Redirection Table which is
13 ** the control logic to convert PCI line based interrupts into a Message
14 ** Signaled Interrupt (aka Transaction Based Interrupt, TBI).
15 **
16 ** Acronyms
17 ** --------
18 ** HPA  Hard Physical Address (aka MMIO address)
19 ** IRQ  Interrupt ReQuest. Implies Line based interrupt.
20 ** IRT	Interrupt Routing Table (provided by PAT firmware)
21 ** IRdT Interrupt Redirection Table. IRQ line to TXN ADDR/DATA
22 **      table which is implemented in I/O SAPIC.
23 ** ISR  Interrupt Service Routine. aka Interrupt handler.
24 ** MSI	Message Signaled Interrupt. PCI 2.2 functionality.
25 **      aka Transaction Based Interrupt (or TBI).
26 ** PA   Precision Architecture. HP's RISC architecture.
27 ** RISC Reduced Instruction Set Computer.
28 **
29 **
30 ** What's a Message Signalled Interrupt?
31 ** -------------------------------------
32 ** MSI is a write transaction which targets a processor and is similar
33 ** to a processor write to memory or MMIO. MSIs can be generated by I/O
34 ** devices as well as processors and require *architecture* to work.
35 **
36 ** PA only supports MSI. So I/O subsystems must either natively generate
37 ** MSIs (e.g. GSC or HP-PB) or convert line based interrupts into MSIs
38 ** (e.g. PCI and EISA).  IA64 supports MSIs via a "local SAPIC" which
39 ** acts on behalf of a processor.
40 **
41 ** MSI allows any I/O device to interrupt any processor. This makes
42 ** load balancing of the interrupt processing possible on an SMP platform.
43 ** Interrupts are also ordered WRT to DMA data.  It's possible on I/O
44 ** coherent systems to completely eliminate PIO reads from the interrupt
45 ** path. The device and driver must be designed and implemented to
46 ** guarantee all DMA has been issued (issues about atomicity here)
47 ** before the MSI is issued. I/O status can then safely be read from
48 ** DMA'd data by the ISR.
49 **
50 **
51 ** PA Firmware
52 ** -----------
53 ** PA-RISC platforms have two fundamentally different types of firmware.
54 ** For PCI devices, "Legacy" PDC initializes the "INTERRUPT_LINE" register
55 ** and BARs similar to a traditional PC BIOS.
56 ** The newer "PAT" firmware supports PDC calls which return tables.
57 ** PAT firmware only initializes the PCI Console and Boot interface.
58 ** With these tables, the OS can program all other PCI devices.
59 **
60 ** One such PAT PDC call returns the "Interrupt Routing Table" (IRT).
61 ** The IRT maps each PCI slot's INTA-D "output" line to an I/O SAPIC
62 ** input line.  If the IRT is not available, this driver assumes
63 ** INTERRUPT_LINE register has been programmed by firmware. The latter
64 ** case also means online addition of PCI cards can NOT be supported
65 ** even if HW support is present.
66 **
67 ** All platforms with PAT firmware to date (Oct 1999) use one Interrupt
68 ** Routing Table for the entire platform.
69 **
70 ** Where's the iosapic?
71 ** --------------------
72 ** I/O sapic is part of the "Core Electronics Complex". And on HP platforms
73 ** it's integrated as part of the PCI bus adapter, "lba".  So no bus walk
74 ** will discover I/O Sapic. I/O Sapic driver learns about each device
75 ** when lba driver advertises the presence of the I/O sapic by calling
76 ** iosapic_register().
77 **
78 **
79 ** IRQ handling notes
80 ** ------------------
81 ** The IO-SAPIC can indicate to the CPU which interrupt was asserted.
82 ** So, unlike the GSC-ASIC and Dino, we allocate one CPU interrupt per
83 ** IO-SAPIC interrupt and call the device driver's handler directly.
84 ** The IO-SAPIC driver hijacks the CPU interrupt handler so it can
85 ** issue the End Of Interrupt command to the IO-SAPIC.
86 **
87 ** Overview of exported iosapic functions
88 ** --------------------------------------
89 ** (caveat: code isn't finished yet - this is just the plan)
90 **
91 ** iosapic_init:
92 **   o initialize globals (lock, etc)
93 **   o try to read IRT. Presence of IRT determines if this is
94 **     a PAT platform or not.
95 **
96 ** iosapic_register():
97 **   o create iosapic_info instance data structure
98 **   o allocate vector_info array for this iosapic
99 **   o initialize vector_info - read corresponding IRdT?
100 **
101 ** iosapic_xlate_pin: (only called by fixup_irq for PAT platform)
102 **   o intr_pin = read cfg (INTERRUPT_PIN);
103 **   o if (device under PCI-PCI bridge)
104 **               translate slot/pin
105 **
106 ** iosapic_fixup_irq:
107 **   o if PAT platform (IRT present)
108 **	   intr_pin = iosapic_xlate_pin(isi,pcidev):
109 **         intr_line = find IRT entry(isi, PCI_SLOT(pcidev), intr_pin)
110 **         save IRT entry into vector_info later
111 **         write cfg INTERRUPT_LINE (with intr_line)?
112 **     else
113 **         intr_line = pcidev->irq
114 **         IRT pointer = NULL
115 **     endif
116 **   o locate vector_info (needs: isi, intr_line)
117 **   o allocate processor "irq" and get txn_addr/data
118 **   o request_irq(processor_irq,  iosapic_interrupt, vector_info,...)
119 **
120 ** iosapic_enable_irq:
121 **   o clear any pending IRQ on that line
122 **   o enable IRdT - call enable_irq(vector[line]->processor_irq)
123 **   o write EOI in case line is already asserted.
124 **
125 ** iosapic_disable_irq:
126 **   o disable IRdT - call disable_irq(vector[line]->processor_irq)
127 */
128 
129 #include <linux/pci.h>
130 
131 #include <asm/pdc.h>
132 #include <asm/pdcpat.h>
133 #ifdef CONFIG_SUPERIO
134 #include <asm/superio.h>
135 #endif
136 
137 #include <asm/ropes.h>
138 #include "iosapic_private.h"
139 
140 #define MODULE_NAME "iosapic"
141 
142 /* "local" compile flags */
143 #undef PCI_BRIDGE_FUNCS
144 #undef DEBUG_IOSAPIC
145 #undef DEBUG_IOSAPIC_IRT
146 
147 
148 #ifdef DEBUG_IOSAPIC
149 #define DBG(x...) printk(x)
150 #else /* DEBUG_IOSAPIC */
151 #define DBG(x...)
152 #endif /* DEBUG_IOSAPIC */
153 
154 #ifdef DEBUG_IOSAPIC_IRT
155 #define DBG_IRT(x...) printk(x)
156 #else
157 #define DBG_IRT(x...)
158 #endif
159 
160 #define COMPARE_IRTE_ADDR(irte, hpa)	\
161 		((irte)->dest_iosapic_addr == F_EXTEND(hpa))
162 
163 #define IOSAPIC_REG_SELECT              0x00
164 #define IOSAPIC_REG_WINDOW              0x10
165 #define IOSAPIC_REG_EOI                 0x40
166 
167 #define IOSAPIC_REG_VERSION		0x1
168 
169 #define IOSAPIC_IRDT_ENTRY(idx)		(0x10+(idx)*2)
170 #define IOSAPIC_IRDT_ENTRY_HI(idx)	(0x11+(idx)*2)
171 
172 static inline unsigned int iosapic_read(void __iomem *iosapic, unsigned int reg)
173 {
174 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
175 	return readl(iosapic + IOSAPIC_REG_WINDOW);
176 }
177 
178 static inline void iosapic_write(void __iomem *iosapic, unsigned int reg, u32 val)
179 {
180 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
181 	writel(val, iosapic + IOSAPIC_REG_WINDOW);
182 }
183 
184 #define IOSAPIC_VERSION_MASK	0x000000ff
185 #define	IOSAPIC_VERSION(ver)	((int) (ver & IOSAPIC_VERSION_MASK))
186 
187 #define IOSAPIC_MAX_ENTRY_MASK          0x00ff0000
188 #define IOSAPIC_MAX_ENTRY_SHIFT         0x10
189 #define	IOSAPIC_IRDT_MAX_ENTRY(ver)	\
190 	(int) (((ver) & IOSAPIC_MAX_ENTRY_MASK) >> IOSAPIC_MAX_ENTRY_SHIFT)
191 
192 /* bits in the "low" I/O Sapic IRdT entry */
193 #define IOSAPIC_IRDT_ENABLE       0x10000
194 #define IOSAPIC_IRDT_PO_LOW       0x02000
195 #define IOSAPIC_IRDT_LEVEL_TRIG   0x08000
196 #define IOSAPIC_IRDT_MODE_LPRI    0x00100
197 
198 /* bits in the "high" I/O Sapic IRdT entry */
199 #define IOSAPIC_IRDT_ID_EID_SHIFT              0x10
200 
201 
202 static DEFINE_SPINLOCK(iosapic_lock);
203 
204 static inline void iosapic_eoi(void __iomem *addr, unsigned int data)
205 {
206 	__raw_writel(data, addr);
207 }
208 
209 /*
210 ** REVISIT: future platforms may have more than one IRT.
211 ** If so, the following three fields form a structure which
212 ** then be linked into a list. Names are chosen to make searching
213 ** for them easy - not necessarily accurate (eg "cell").
214 **
215 ** Alternative: iosapic_info could point to the IRT it's in.
216 ** iosapic_register() could search a list of IRT's.
217 */
218 static struct irt_entry *irt_cell;
219 static size_t irt_num_entry;
220 
221 static struct irt_entry *iosapic_alloc_irt(int num_entries)
222 {
223 	unsigned long a;
224 
225 	/* The IRT needs to be 8-byte aligned for the PDC call.
226 	 * Normally kmalloc would guarantee larger alignment, but
227 	 * if CONFIG_DEBUG_SLAB is enabled, then we can get only
228 	 * 4-byte alignment on 32-bit kernels
229 	 */
230 	a = (unsigned long)kmalloc(sizeof(struct irt_entry) * num_entries + 8, GFP_KERNEL);
231 	a = (a + 7UL) & ~7UL;
232 	return (struct irt_entry *)a;
233 }
234 
235 /**
236  * iosapic_load_irt - Fill in the interrupt routing table
237  * @cell_num: The cell number of the CPU we're currently executing on
238  * @irt: The address to place the new IRT at
239  * @return The number of entries found
240  *
241  * The "Get PCI INT Routing Table Size" option returns the number of
242  * entries in the PCI interrupt routing table for the cell specified
243  * in the cell_number argument.  The cell number must be for a cell
244  * within the caller's protection domain.
245  *
246  * The "Get PCI INT Routing Table" option returns, for the cell
247  * specified in the cell_number argument, the PCI interrupt routing
248  * table in the caller allocated memory pointed to by mem_addr.
249  * We assume the IRT only contains entries for I/O SAPIC and
250  * calculate the size based on the size of I/O sapic entries.
251  *
252  * The PCI interrupt routing table entry format is derived from the
253  * IA64 SAL Specification 2.4.   The PCI interrupt routing table defines
254  * the routing of PCI interrupt signals between the PCI device output
255  * "pins" and the IO SAPICs' input "lines" (including core I/O PCI
256  * devices).  This table does NOT include information for devices/slots
257  * behind PCI to PCI bridges. See PCI to PCI Bridge Architecture Spec.
258  * for the architected method of routing of IRQ's behind PPB's.
259  */
260 
261 
262 static int __init
263 iosapic_load_irt(unsigned long cell_num, struct irt_entry **irt)
264 {
265 	long status;              /* PDC return value status */
266 	struct irt_entry *table;  /* start of interrupt routing tbl */
267 	unsigned long num_entries = 0UL;
268 
269 	BUG_ON(!irt);
270 
271 	if (is_pdc_pat()) {
272 		/* Use pat pdc routine to get interrupt routing table size */
273 		DBG("calling get_irt_size (cell %ld)\n", cell_num);
274 		status = pdc_pat_get_irt_size(&num_entries, cell_num);
275 		DBG("get_irt_size: %ld\n", status);
276 
277 		BUG_ON(status != PDC_OK);
278 		BUG_ON(num_entries == 0);
279 
280 		/*
281 		** allocate memory for interrupt routing table
282 		** This interface isn't really right. We are assuming
283 		** the contents of the table are exclusively
284 		** for I/O sapic devices.
285 		*/
286 		table = iosapic_alloc_irt(num_entries);
287 		if (table == NULL) {
288 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
289 					"not alloc mem for IRT\n");
290 			return 0;
291 		}
292 
293 		/* get PCI INT routing table */
294 		status = pdc_pat_get_irt(table, cell_num);
295 		DBG("pdc_pat_get_irt: %ld\n", status);
296 		WARN_ON(status != PDC_OK);
297 	} else {
298 		/*
299 		** C3000/J5000 (and similar) platforms with Sprockets PDC
300 		** will return exactly one IRT for all iosapics.
301 		** So if we have one, don't need to get it again.
302 		*/
303 		if (irt_cell)
304 			return 0;
305 
306 		/* Should be using the Elroy's HPA, but it's ignored anyway */
307 		status = pdc_pci_irt_size(&num_entries, 0);
308 		DBG("pdc_pci_irt_size: %ld\n", status);
309 
310 		if (status != PDC_OK) {
311 			/* Not a "legacy" system with I/O SAPIC either */
312 			return 0;
313 		}
314 
315 		BUG_ON(num_entries == 0);
316 
317 		table = iosapic_alloc_irt(num_entries);
318 		if (!table) {
319 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
320 					"not alloc mem for IRT\n");
321 			return 0;
322 		}
323 
324 		/* HPA ignored by this call too. */
325 		status = pdc_pci_irt(num_entries, 0, table);
326 		BUG_ON(status != PDC_OK);
327 	}
328 
329 	/* return interrupt table address */
330 	*irt = table;
331 
332 #ifdef DEBUG_IOSAPIC_IRT
333 {
334 	struct irt_entry *p = table;
335 	int i;
336 
337 	printk(MODULE_NAME " Interrupt Routing Table (cell %ld)\n", cell_num);
338 	printk(MODULE_NAME " start = 0x%p num_entries %ld entry_size %d\n",
339 		table,
340 		num_entries,
341 		(int) sizeof(struct irt_entry));
342 
343 	for (i = 0 ; i < num_entries ; i++, p++) {
344 		printk(MODULE_NAME " %02x %02x %02x %02x %02x %02x %02x %02x %08x%08x\n",
345 		p->entry_type, p->entry_length, p->interrupt_type,
346 		p->polarity_trigger, p->src_bus_irq_devno, p->src_bus_id,
347 		p->src_seg_id, p->dest_iosapic_intin,
348 		((u32 *) p)[2],
349 		((u32 *) p)[3]
350 		);
351 	}
352 }
353 #endif /* DEBUG_IOSAPIC_IRT */
354 
355 	return num_entries;
356 }
357 
358 
359 
360 void __init iosapic_init(void)
361 {
362 	unsigned long cell = 0;
363 
364 	DBG("iosapic_init()\n");
365 
366 #ifdef __LP64__
367 	if (is_pdc_pat()) {
368 		int status;
369 		struct pdc_pat_cell_num cell_info;
370 
371 		status = pdc_pat_cell_get_number(&cell_info);
372 		if (status == PDC_OK) {
373 			cell = cell_info.cell_num;
374 		}
375 	}
376 #endif
377 
378 	/* get interrupt routing table for this cell */
379 	irt_num_entry = iosapic_load_irt(cell, &irt_cell);
380 	if (irt_num_entry == 0)
381 		irt_cell = NULL;	/* old PDC w/o iosapic */
382 }
383 
384 
385 /*
386 ** Return the IRT entry in case we need to look something else up.
387 */
388 static struct irt_entry *
389 irt_find_irqline(struct iosapic_info *isi, u8 slot, u8 intr_pin)
390 {
391 	struct irt_entry *i = irt_cell;
392 	int cnt;	/* track how many entries we've looked at */
393 	u8 irq_devno = (slot << IRT_DEV_SHIFT) | (intr_pin-1);
394 
395 	DBG_IRT("irt_find_irqline() SLOT %d pin %d\n", slot, intr_pin);
396 
397 	for (cnt=0; cnt < irt_num_entry; cnt++, i++) {
398 
399 		/*
400 		** Validate: entry_type, entry_length, interrupt_type
401 		**
402 		** Difference between validate vs compare is the former
403 		** should print debug info and is not expected to "fail"
404 		** on current platforms.
405 		*/
406 		if (i->entry_type != IRT_IOSAPIC_TYPE) {
407 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d type %d\n", i, cnt, i->entry_type);
408 			continue;
409 		}
410 
411 		if (i->entry_length != IRT_IOSAPIC_LENGTH) {
412 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d  length %d\n", i, cnt, i->entry_length);
413 			continue;
414 		}
415 
416 		if (i->interrupt_type != IRT_VECTORED_INTR) {
417 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry  %d interrupt_type %d\n", i, cnt, i->interrupt_type);
418 			continue;
419 		}
420 
421 		if (!COMPARE_IRTE_ADDR(i, isi->isi_hpa))
422 			continue;
423 
424 		if ((i->src_bus_irq_devno & IRT_IRQ_DEVNO_MASK) != irq_devno)
425 			continue;
426 
427 		/*
428 		** Ignore: src_bus_id and rc_seg_id correlate with
429 		**         iosapic_info->isi_hpa on HP platforms.
430 		**         If needed, pass in "PFA" (aka config space addr)
431 		**         instead of slot.
432 		*/
433 
434 		/* Found it! */
435 		return i;
436 	}
437 
438 	printk(KERN_WARNING MODULE_NAME ": 0x%lx : no IRT entry for slot %d, pin %d\n",
439 			isi->isi_hpa, slot, intr_pin);
440 	return NULL;
441 }
442 
443 
444 /*
445 ** xlate_pin() supports the skewing of IRQ lines done by subsidiary bridges.
446 ** Legacy PDC already does this translation for us and stores it in INTR_LINE.
447 **
448 ** PAT PDC needs to basically do what legacy PDC does:
449 ** o read PIN
450 ** o adjust PIN in case device is "behind" a PPB
451 **     (eg 4-port 100BT and SCSI/LAN "Combo Card")
452 ** o convert slot/pin to I/O SAPIC input line.
453 **
454 ** HP platforms only support:
455 ** o one level of skewing for any number of PPBs
456 ** o only support PCI-PCI Bridges.
457 */
458 static struct irt_entry *
459 iosapic_xlate_pin(struct iosapic_info *isi, struct pci_dev *pcidev)
460 {
461 	u8 intr_pin, intr_slot;
462 
463 	pci_read_config_byte(pcidev, PCI_INTERRUPT_PIN, &intr_pin);
464 
465 	DBG_IRT("iosapic_xlate_pin(%s) SLOT %d pin %d\n",
466 		pcidev->slot_name, PCI_SLOT(pcidev->devfn), intr_pin);
467 
468 	if (intr_pin == 0) {
469 		/* The device does NOT support/use IRQ lines.  */
470 		return NULL;
471 	}
472 
473 	/* Check if pcidev behind a PPB */
474 	if (pcidev->bus->parent) {
475 		/* Convert pcidev INTR_PIN into something we
476 		** can lookup in the IRT.
477 		*/
478 #ifdef PCI_BRIDGE_FUNCS
479 		/*
480 		** Proposal #1:
481 		**
482 		** call implementation specific translation function
483 		** This is architecturally "cleaner". HP-UX doesn't
484 		** support other secondary bus types (eg. E/ISA) directly.
485 		** May be needed for other processor (eg IA64) architectures
486 		** or by some ambitous soul who wants to watch TV.
487 		*/
488 		if (pci_bridge_funcs->xlate_intr_line) {
489 			intr_pin = pci_bridge_funcs->xlate_intr_line(pcidev);
490 		}
491 #else	/* PCI_BRIDGE_FUNCS */
492 		struct pci_bus *p = pcidev->bus;
493 		/*
494 		** Proposal #2:
495 		** The "pin" is skewed ((pin + dev - 1) % 4).
496 		**
497 		** This isn't very clean since I/O SAPIC must assume:
498 		**   - all platforms only have PCI busses.
499 		**   - only PCI-PCI bridge (eg not PCI-EISA, PCI-PCMCIA)
500 		**   - IRQ routing is only skewed once regardless of
501 		**     the number of PPB's between iosapic and device.
502 		**     (Bit3 expansion chassis follows this rule)
503 		**
504 		** Advantage is it's really easy to implement.
505 		*/
506 		intr_pin = pci_swizzle_interrupt_pin(pcidev, intr_pin);
507 #endif /* PCI_BRIDGE_FUNCS */
508 
509 		/*
510 		 * Locate the host slot of the PPB.
511 		 */
512 		while (p->parent->parent)
513 			p = p->parent;
514 
515 		intr_slot = PCI_SLOT(p->self->devfn);
516 	} else {
517 		intr_slot = PCI_SLOT(pcidev->devfn);
518 	}
519 	DBG_IRT("iosapic_xlate_pin:  bus %d slot %d pin %d\n",
520 			pcidev->bus->busn_res.start, intr_slot, intr_pin);
521 
522 	return irt_find_irqline(isi, intr_slot, intr_pin);
523 }
524 
525 static void iosapic_rd_irt_entry(struct vector_info *vi , u32 *dp0, u32 *dp1)
526 {
527 	struct iosapic_info *isp = vi->iosapic;
528 	u8 idx = vi->irqline;
529 
530 	*dp0 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY(idx));
531 	*dp1 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY_HI(idx));
532 }
533 
534 
535 static void iosapic_wr_irt_entry(struct vector_info *vi, u32 dp0, u32 dp1)
536 {
537 	struct iosapic_info *isp = vi->iosapic;
538 
539 	DBG_IRT("iosapic_wr_irt_entry(): irq %d hpa %lx 0x%x 0x%x\n",
540 		vi->irqline, isp->isi_hpa, dp0, dp1);
541 
542 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY(vi->irqline), dp0);
543 
544 	/* Read the window register to flush the writes down to HW  */
545 	dp0 = readl(isp->addr+IOSAPIC_REG_WINDOW);
546 
547 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY_HI(vi->irqline), dp1);
548 
549 	/* Read the window register to flush the writes down to HW  */
550 	dp1 = readl(isp->addr+IOSAPIC_REG_WINDOW);
551 }
552 
553 /*
554 ** set_irt prepares the data (dp0, dp1) according to the vector_info
555 ** and target cpu (id_eid).  dp0/dp1 are then used to program I/O SAPIC
556 ** IRdT for the given "vector" (aka IRQ line).
557 */
558 static void
559 iosapic_set_irt_data( struct vector_info *vi, u32 *dp0, u32 *dp1)
560 {
561 	u32 mode = 0;
562 	struct irt_entry *p = vi->irte;
563 
564 	if ((p->polarity_trigger & IRT_PO_MASK) == IRT_ACTIVE_LO)
565 		mode |= IOSAPIC_IRDT_PO_LOW;
566 
567 	if (((p->polarity_trigger >> IRT_EL_SHIFT) & IRT_EL_MASK) == IRT_LEVEL_TRIG)
568 		mode |= IOSAPIC_IRDT_LEVEL_TRIG;
569 
570 	/*
571 	** IA64 REVISIT
572 	** PA doesn't support EXTINT or LPRIO bits.
573 	*/
574 
575 	*dp0 = mode | (u32) vi->txn_data;
576 
577 	/*
578 	** Extracting id_eid isn't a real clean way of getting it.
579 	** But the encoding is the same for both PA and IA64 platforms.
580 	*/
581 	if (is_pdc_pat()) {
582 		/*
583 		** PAT PDC just hands it to us "right".
584 		** txn_addr comes from cpu_data[x].txn_addr.
585 		*/
586 		*dp1 = (u32) (vi->txn_addr);
587 	} else {
588 		/*
589 		** eg if base_addr == 0xfffa0000),
590 		**    we want to get 0xa0ff0000.
591 		**
592 		** eid	0x0ff00000 -> 0x00ff0000
593 		** id	0x000ff000 -> 0xff000000
594 		*/
595 		*dp1 = (((u32)vi->txn_addr & 0x0ff00000) >> 4) |
596 			(((u32)vi->txn_addr & 0x000ff000) << 12);
597 	}
598 	DBG_IRT("iosapic_set_irt_data(): 0x%x 0x%x\n", *dp0, *dp1);
599 }
600 
601 
602 static void iosapic_mask_irq(struct irq_data *d)
603 {
604 	unsigned long flags;
605 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
606 	u32 d0, d1;
607 
608 	spin_lock_irqsave(&iosapic_lock, flags);
609 	iosapic_rd_irt_entry(vi, &d0, &d1);
610 	d0 |= IOSAPIC_IRDT_ENABLE;
611 	iosapic_wr_irt_entry(vi, d0, d1);
612 	spin_unlock_irqrestore(&iosapic_lock, flags);
613 }
614 
615 static void iosapic_unmask_irq(struct irq_data *d)
616 {
617 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
618 	u32 d0, d1;
619 
620 	/* data is initialized by fixup_irq */
621 	WARN_ON(vi->txn_irq  == 0);
622 
623 	iosapic_set_irt_data(vi, &d0, &d1);
624 	iosapic_wr_irt_entry(vi, d0, d1);
625 
626 #ifdef DEBUG_IOSAPIC_IRT
627 {
628 	u32 *t = (u32 *) ((ulong) vi->eoi_addr & ~0xffUL);
629 	printk("iosapic_enable_irq(): regs %p", vi->eoi_addr);
630 	for ( ; t < vi->eoi_addr; t++)
631 		printk(" %x", readl(t));
632 	printk("\n");
633 }
634 
635 printk("iosapic_enable_irq(): sel ");
636 {
637 	struct iosapic_info *isp = vi->iosapic;
638 
639 	for (d0=0x10; d0<0x1e; d0++) {
640 		d1 = iosapic_read(isp->addr, d0);
641 		printk(" %x", d1);
642 	}
643 }
644 printk("\n");
645 #endif
646 
647 	/*
648 	 * Issuing I/O SAPIC an EOI causes an interrupt IFF IRQ line is
649 	 * asserted.  IRQ generally should not be asserted when a driver
650 	 * enables their IRQ. It can lead to "interesting" race conditions
651 	 * in the driver initialization sequence.
652 	 */
653 	DBG(KERN_DEBUG "enable_irq(%d): eoi(%p, 0x%x)\n", d->irq,
654 			vi->eoi_addr, vi->eoi_data);
655 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
656 }
657 
658 static void iosapic_eoi_irq(struct irq_data *d)
659 {
660 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
661 
662 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
663 	cpu_eoi_irq(d);
664 }
665 
666 #ifdef CONFIG_SMP
667 static int iosapic_set_affinity_irq(struct irq_data *d,
668 				    const struct cpumask *dest, bool force)
669 {
670 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
671 	u32 d0, d1, dummy_d0;
672 	unsigned long flags;
673 	int dest_cpu;
674 
675 	dest_cpu = cpu_check_affinity(d, dest);
676 	if (dest_cpu < 0)
677 		return -1;
678 
679 	cpumask_copy(irq_data_get_affinity_mask(d), cpumask_of(dest_cpu));
680 	vi->txn_addr = txn_affinity_addr(d->irq, dest_cpu);
681 
682 	spin_lock_irqsave(&iosapic_lock, flags);
683 	/* d1 contains the destination CPU, so only want to set that
684 	 * entry */
685 	iosapic_rd_irt_entry(vi, &d0, &d1);
686 	iosapic_set_irt_data(vi, &dummy_d0, &d1);
687 	iosapic_wr_irt_entry(vi, d0, d1);
688 	spin_unlock_irqrestore(&iosapic_lock, flags);
689 
690 	return 0;
691 }
692 #endif
693 
694 static struct irq_chip iosapic_interrupt_type = {
695 	.name		=	"IO-SAPIC-level",
696 	.irq_unmask	=	iosapic_unmask_irq,
697 	.irq_mask	=	iosapic_mask_irq,
698 	.irq_ack	=	cpu_ack_irq,
699 	.irq_eoi	=	iosapic_eoi_irq,
700 #ifdef CONFIG_SMP
701 	.irq_set_affinity =	iosapic_set_affinity_irq,
702 #endif
703 };
704 
705 int iosapic_fixup_irq(void *isi_obj, struct pci_dev *pcidev)
706 {
707 	struct iosapic_info *isi = isi_obj;
708 	struct irt_entry *irte = NULL;  /* only used if PAT PDC */
709 	struct vector_info *vi;
710 	int isi_line;	/* line used by device */
711 
712 	if (!isi) {
713 		printk(KERN_WARNING MODULE_NAME ": hpa not registered for %s\n",
714 			pci_name(pcidev));
715 		return -1;
716 	}
717 
718 #ifdef CONFIG_SUPERIO
719 	/*
720 	 * HACK ALERT! (non-compliant PCI device support)
721 	 *
722 	 * All SuckyIO interrupts are routed through the PIC's on function 1.
723 	 * But SuckyIO OHCI USB controller gets an IRT entry anyway because
724 	 * it advertises INT D for INT_PIN.  Use that IRT entry to get the
725 	 * SuckyIO interrupt routing for PICs on function 1 (*BLEECCHH*).
726 	 */
727 	if (is_superio_device(pcidev)) {
728 		/* We must call superio_fixup_irq() to register the pdev */
729 		pcidev->irq = superio_fixup_irq(pcidev);
730 
731 		/* Don't return if need to program the IOSAPIC's IRT... */
732 		if (PCI_FUNC(pcidev->devfn) != SUPERIO_USB_FN)
733 			return pcidev->irq;
734 	}
735 #endif /* CONFIG_SUPERIO */
736 
737 	/* lookup IRT entry for isi/slot/pin set */
738 	irte = iosapic_xlate_pin(isi, pcidev);
739 	if (!irte) {
740 		printk("iosapic: no IRTE for %s (IRQ not connected?)\n",
741 				pci_name(pcidev));
742 		return -1;
743 	}
744 	DBG_IRT("iosapic_fixup_irq(): irte %p %x %x %x %x %x %x %x %x\n",
745 		irte,
746 		irte->entry_type,
747 		irte->entry_length,
748 		irte->polarity_trigger,
749 		irte->src_bus_irq_devno,
750 		irte->src_bus_id,
751 		irte->src_seg_id,
752 		irte->dest_iosapic_intin,
753 		(u32) irte->dest_iosapic_addr);
754 	isi_line = irte->dest_iosapic_intin;
755 
756 	/* get vector info for this input line */
757 	vi = isi->isi_vector + isi_line;
758 	DBG_IRT("iosapic_fixup_irq:  line %d vi 0x%p\n", isi_line, vi);
759 
760 	/* If this IRQ line has already been setup, skip it */
761 	if (vi->irte)
762 		goto out;
763 
764 	vi->irte = irte;
765 
766 	/*
767 	 * Allocate processor IRQ
768 	 *
769 	 * XXX/FIXME The txn_alloc_irq() code and related code should be
770 	 * moved to enable_irq(). That way we only allocate processor IRQ
771 	 * bits for devices that actually have drivers claiming them.
772 	 * Right now we assign an IRQ to every PCI device present,
773 	 * regardless of whether it's used or not.
774 	 */
775 	vi->txn_irq = txn_alloc_irq(8);
776 
777 	if (vi->txn_irq < 0)
778 		panic("I/O sapic: couldn't get TXN IRQ\n");
779 
780 	/* enable_irq() will use txn_* to program IRdT */
781 	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
782 	vi->txn_data = txn_alloc_data(vi->txn_irq);
783 
784 	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
785 	vi->eoi_data = cpu_to_le32(vi->txn_data);
786 
787 	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
788 
789  out:
790 	pcidev->irq = vi->txn_irq;
791 
792 	DBG_IRT("iosapic_fixup_irq() %d:%d %x %x line %d irq %d\n",
793 		PCI_SLOT(pcidev->devfn), PCI_FUNC(pcidev->devfn),
794 		pcidev->vendor, pcidev->device, isi_line, pcidev->irq);
795 
796 	return pcidev->irq;
797 }
798 
799 static struct iosapic_info *iosapic_list;
800 
801 #ifdef CONFIG_64BIT
802 int iosapic_serial_irq(struct parisc_device *dev)
803 {
804 	struct iosapic_info *isi;
805 	struct irt_entry *irte;
806 	struct vector_info *vi;
807 	int cnt;
808 	int intin;
809 
810 	intin = (dev->mod_info >> 24) & 15;
811 
812 	/* lookup IRT entry for isi/slot/pin set */
813 	for (cnt = 0; cnt < irt_num_entry; cnt++) {
814 		irte = &irt_cell[cnt];
815 		if (COMPARE_IRTE_ADDR(irte, dev->mod0) &&
816 		    irte->dest_iosapic_intin == intin)
817 			break;
818 	}
819 	if (cnt >= irt_num_entry)
820 		return 0; /* no irq found, force polling */
821 
822 	DBG_IRT("iosapic_serial_irq(): irte %p %x %x %x %x %x %x %x %x\n",
823 		irte,
824 		irte->entry_type,
825 		irte->entry_length,
826 		irte->polarity_trigger,
827 		irte->src_bus_irq_devno,
828 		irte->src_bus_id,
829 		irte->src_seg_id,
830 		irte->dest_iosapic_intin,
831 		(u32) irte->dest_iosapic_addr);
832 
833 	/* search for iosapic */
834 	for (isi = iosapic_list; isi; isi = isi->isi_next)
835 		if (isi->isi_hpa == dev->mod0)
836 			break;
837 	if (!isi)
838 		return 0; /* no iosapic found, force polling */
839 
840 	/* get vector info for this input line */
841 	vi = isi->isi_vector + intin;
842 	DBG_IRT("iosapic_serial_irq:  line %d vi 0x%p\n", iosapic_intin, vi);
843 
844 	/* If this IRQ line has already been setup, skip it */
845 	if (vi->irte)
846 		goto out;
847 
848 	vi->irte = irte;
849 
850 	/*
851 	 * Allocate processor IRQ
852 	 *
853 	 * XXX/FIXME The txn_alloc_irq() code and related code should be
854 	 * moved to enable_irq(). That way we only allocate processor IRQ
855 	 * bits for devices that actually have drivers claiming them.
856 	 * Right now we assign an IRQ to every PCI device present,
857 	 * regardless of whether it's used or not.
858 	 */
859 	vi->txn_irq = txn_alloc_irq(8);
860 
861 	if (vi->txn_irq < 0)
862 		panic("I/O sapic: couldn't get TXN IRQ\n");
863 
864 	/* enable_irq() will use txn_* to program IRdT */
865 	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
866 	vi->txn_data = txn_alloc_data(vi->txn_irq);
867 
868 	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
869 	vi->eoi_data = cpu_to_le32(vi->txn_data);
870 
871 	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
872 
873  out:
874 
875 	return vi->txn_irq;
876 }
877 #endif
878 
879 
880 /*
881 ** squirrel away the I/O Sapic Version
882 */
883 static unsigned int
884 iosapic_rd_version(struct iosapic_info *isi)
885 {
886 	return iosapic_read(isi->addr, IOSAPIC_REG_VERSION);
887 }
888 
889 
890 /*
891 ** iosapic_register() is called by "drivers" with an integrated I/O SAPIC.
892 ** Caller must be certain they have an I/O SAPIC and know its MMIO address.
893 **
894 **	o allocate iosapic_info and add it to the list
895 **	o read iosapic version and squirrel that away
896 **	o read size of IRdT.
897 **	o allocate and initialize isi_vector[]
898 **	o allocate irq region
899 */
900 void *iosapic_register(unsigned long hpa)
901 {
902 	struct iosapic_info *isi = NULL;
903 	struct irt_entry *irte = irt_cell;
904 	struct vector_info *vip;
905 	int cnt;	/* track how many entries we've looked at */
906 
907 	/*
908 	 * Astro based platforms can only support PCI OLARD if they implement
909 	 * PAT PDC.  Legacy PDC omits LBAs with no PCI devices from the IRT.
910 	 * Search the IRT and ignore iosapic's which aren't in the IRT.
911 	 */
912 	for (cnt=0; cnt < irt_num_entry; cnt++, irte++) {
913 		WARN_ON(IRT_IOSAPIC_TYPE != irte->entry_type);
914 		if (COMPARE_IRTE_ADDR(irte, hpa))
915 			break;
916 	}
917 
918 	if (cnt >= irt_num_entry) {
919 		DBG("iosapic_register() ignoring 0x%lx (NOT FOUND)\n", hpa);
920 		return NULL;
921 	}
922 
923 	isi = kzalloc(sizeof(struct iosapic_info), GFP_KERNEL);
924 	if (!isi) {
925 		BUG();
926 		return NULL;
927 	}
928 
929 	isi->addr = ioremap_nocache(hpa, 4096);
930 	isi->isi_hpa = hpa;
931 	isi->isi_version = iosapic_rd_version(isi);
932 	isi->isi_num_vectors = IOSAPIC_IRDT_MAX_ENTRY(isi->isi_version) + 1;
933 
934 	vip = isi->isi_vector = kcalloc(isi->isi_num_vectors,
935 					sizeof(struct vector_info), GFP_KERNEL);
936 	if (vip == NULL) {
937 		kfree(isi);
938 		return NULL;
939 	}
940 
941 	for (cnt=0; cnt < isi->isi_num_vectors; cnt++, vip++) {
942 		vip->irqline = (unsigned char) cnt;
943 		vip->iosapic = isi;
944 	}
945 	isi->isi_next = iosapic_list;
946 	iosapic_list = isi;
947 	return isi;
948 }
949 
950 
951 #ifdef DEBUG_IOSAPIC
952 
953 static void
954 iosapic_prt_irt(void *irt, long num_entry)
955 {
956 	unsigned int i, *irp = (unsigned int *) irt;
957 
958 
959 	printk(KERN_DEBUG MODULE_NAME ": Interrupt Routing Table (%lx entries)\n", num_entry);
960 
961 	for (i=0; i<num_entry; i++, irp += 4) {
962 		printk(KERN_DEBUG "%p : %2d %.8x %.8x %.8x %.8x\n",
963 					irp, i, irp[0], irp[1], irp[2], irp[3]);
964 	}
965 }
966 
967 
968 static void
969 iosapic_prt_vi(struct vector_info *vi)
970 {
971 	printk(KERN_DEBUG MODULE_NAME ": vector_info[%d] is at %p\n", vi->irqline, vi);
972 	printk(KERN_DEBUG "\t\tstatus:	 %.4x\n", vi->status);
973 	printk(KERN_DEBUG "\t\ttxn_irq:  %d\n",  vi->txn_irq);
974 	printk(KERN_DEBUG "\t\ttxn_addr: %lx\n", vi->txn_addr);
975 	printk(KERN_DEBUG "\t\ttxn_data: %lx\n", vi->txn_data);
976 	printk(KERN_DEBUG "\t\teoi_addr: %p\n",  vi->eoi_addr);
977 	printk(KERN_DEBUG "\t\teoi_data: %x\n",  vi->eoi_data);
978 }
979 
980 
981 static void
982 iosapic_prt_isi(struct iosapic_info *isi)
983 {
984 	printk(KERN_DEBUG MODULE_NAME ": io_sapic_info at %p\n", isi);
985 	printk(KERN_DEBUG "\t\tisi_hpa:       %lx\n", isi->isi_hpa);
986 	printk(KERN_DEBUG "\t\tisi_status:    %x\n", isi->isi_status);
987 	printk(KERN_DEBUG "\t\tisi_version:   %x\n", isi->isi_version);
988 	printk(KERN_DEBUG "\t\tisi_vector:    %p\n", isi->isi_vector);
989 }
990 #endif /* DEBUG_IOSAPIC */
991