aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/parisc/iosapic.c
blob: a3120a09c43dd603d9b96b0c5926e77ceebb8095 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
/*
** I/O Sapic Driver - PCI interrupt line support
**
**      (c) Copyright 1999 Grant Grundler
**      (c) Copyright 1999 Hewlett-Packard Company
**
**      This program is free software; you can redistribute it and/or modify
**      it under the terms of the GNU General Public License as published by
**      the Free Software Foundation; either version 2 of the License, or
**      (at your option) any later version.
**
** The I/O sapic driver manages the Interrupt Redirection Table which is
** the control logic to convert PCI line based interrupts into a Message
** Signaled Interrupt (aka Transaction Based Interrupt, TBI).
**
** Acronyms
** --------
** HPA  Hard Physical Address (aka MMIO address)
** IRQ  Interrupt ReQuest. Implies Line based interrupt.
** IRT	Interrupt Routing Table (provided by PAT firmware)
** IRdT Interrupt Redirection Table. IRQ line to TXN ADDR/DATA
**      table which is implemented in I/O SAPIC.
** ISR  Interrupt Service Routine. aka Interrupt handler.
** MSI	Message Signaled Interrupt. PCI 2.2 functionality.
**      aka Transaction Based Interrupt (or TBI).
** PA   Precision Architecture. HP's RISC architecture.
** RISC Reduced Instruction Set Computer.
**
**
** What's a Message Signalled Interrupt?
** -------------------------------------
** MSI is a write transaction which targets a processor and is similar
** to a processor write to memory or MMIO. MSIs can be generated by I/O
** devices as well as processors and require *architecture* to work.
**
** PA only supports MSI. So I/O subsystems must either natively generate
** MSIs (e.g. GSC or HP-PB) or convert line based interrupts into MSIs
** (e.g. PCI and EISA).  IA64 supports MSIs via a "local SAPIC" which
** acts on behalf of a processor.
**
** MSI allows any I/O device to interrupt any processor. This makes
** load balancing of the interrupt processing possible on an SMP platform.
** Interrupts are also ordered WRT to DMA data.  It's possible on I/O
** coherent systems to completely eliminate PIO reads from the interrupt
** path. The device and driver must be designed and implemented to
** guarantee all DMA has been issued (issues about atomicity here)
** before the MSI is issued. I/O status can then safely be read from
** DMA'd data by the ISR.
**
**
** PA Firmware
** -----------
** PA-RISC platforms have two fundamentally different types of firmware.
** For PCI devices, "Legacy" PDC initializes the "INTERRUPT_LINE" register
** and BARs similar to a traditional PC BIOS.
** The newer "PAT" firmware supports PDC calls which return tables.
** PAT firmware only initializes the PCI Console and Boot interface.
** With these tables, the OS can program all other PCI devices.
**
** One such PAT PDC call returns the "Interrupt Routing Table" (IRT).
** The IRT maps each PCI slot's INTA-D "output" line to an I/O SAPIC
** input line.  If the IRT is not available, this driver assumes
** INTERRUPT_LINE register has been programmed by firmware. The latter
** case also means online addition of PCI cards can NOT be supported
** even if HW support is present.
**
** All platforms with PAT firmware to date (Oct 1999) use one Interrupt
** Routing Table for the entire platform.
**
** Where's the iosapic?
** --------------------
** I/O sapic is part of the "Core Electronics Complex". And on HP platforms
** it's integrated as part of the PCI bus adapter, "lba".  So no bus walk
** will discover I/O Sapic. I/O Sapic driver learns about each device
** when lba driver advertises the presence of the I/O sapic by calling
** iosapic_register().
**
**
** IRQ handling notes
** ------------------
** The IO-SAPIC can indicate to the CPU which interrupt was asserted.
** So, unlike the GSC-ASIC and Dino, we allocate one CPU interrupt per
** IO-SAPIC interrupt and call the device driver's handler directly.
** The IO-SAPIC driver hijacks the CPU interrupt handler so it can
** issue the End Of Interrupt command to the IO-SAPIC.
**
** Overview of exported iosapic functions
** --------------------------------------
** (caveat: code isn't finished yet - this is just the plan)
**
** iosapic_init:
**   o initialize globals (lock, etc)
**   o try to read IRT. Presence of IRT determines if this is
**     a PAT platform or not.
**
** iosapic_register():
**   o create iosapic_info instance data structure
**   o allocate vector_info array for this iosapic
**   o initialize vector_info - read corresponding IRdT?
**
** iosapic_xlate_pin: (only called by fixup_irq for PAT platform)
**   o intr_pin = read cfg (INTERRUPT_PIN);
**   o if (device under PCI-PCI bridge)
**               translate slot/pin
**
** iosapic_fixup_irq:
**   o if PAT platform (IRT present)
**	   intr_pin = iosapic_xlate_pin(isi,pcidev):
**         intr_line = find IRT entry(isi, PCI_SLOT(pcidev), intr_pin)
**         save IRT entry into vector_info later
**         write cfg INTERRUPT_LINE (with intr_line)?
**     else
**         intr_line = pcidev->irq
**         IRT pointer = NULL
**     endif
**   o locate vector_info (needs: isi, intr_line)
**   o allocate processor "irq" and get txn_addr/data
**   o request_irq(processor_irq,  iosapic_interrupt, vector_info,...)
**
** iosapic_enable_irq:
**   o clear any pending IRQ on that line
**   o enable IRdT - call enable_irq(vector[line]->processor_irq)
**   o write EOI in case line is already asserted.
**
** iosapic_disable_irq:
**   o disable IRdT - call disable_irq(vector[line]->processor_irq)
*/


/* FIXME: determine which include files are really needed */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

#include <asm/byteorder.h>	/* get in-line asm for swab */
#include <asm/pdc.h>
#include <asm/pdcpat.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/io.h>		/* read/write functions */
#ifdef CONFIG_SUPERIO
#include <asm/superio.h>
#endif

#include <asm/ropes.h>
#include "./iosapic_private.h"

#define MODULE_NAME "iosapic"

/* "local" compile flags */
#undef PCI_BRIDGE_FUNCS
#undef DEBUG_IOSAPIC
#undef DEBUG_IOSAPIC_IRT


#ifdef DEBUG_IOSAPIC
#define DBG(x...) printk(x)
#else /* DEBUG_IOSAPIC */
#define DBG(x...)
#endif /* DEBUG_IOSAPIC */

#ifdef DEBUG_IOSAPIC_IRT
#define DBG_IRT(x...) printk(x)
#else
#define DBG_IRT(x...)
#endif

#ifdef CONFIG_64BIT
#define COMPARE_IRTE_ADDR(irte, hpa)	((irte)->dest_iosapic_addr == (hpa))
#else
#define COMPARE_IRTE_ADDR(irte, hpa)	\
		((irte)->dest_iosapic_addr == ((hpa) | 0xffffffff00000000ULL))
#endif

#define IOSAPIC_REG_SELECT              0x00
#define IOSAPIC_REG_WINDOW              0x10
#define IOSAPIC_REG_EOI                 0x40

#define IOSAPIC_REG_VERSION		0x1

#define IOSAPIC_IRDT_ENTRY(idx)		(0x10+(idx)*2)
#define IOSAPIC_IRDT_ENTRY_HI(idx)	(0x11+(idx)*2)

static inline unsigned int iosapic_read(void __iomem *iosapic, unsigned int reg)
{
	writel(reg, iosapic + IOSAPIC_REG_SELECT);
	return readl(iosapic + IOSAPIC_REG_WINDOW);
}

static inline void iosapic_write(void __iomem *iosapic, unsigned int reg, u32 val)
{
	writel(reg, iosapic + IOSAPIC_REG_SELECT);
	writel(val, iosapic + IOSAPIC_REG_WINDOW);
}

#define IOSAPIC_VERSION_MASK	0x000000ff
#define	IOSAPIC_VERSION(ver)	((int) (ver & IOSAPIC_VERSION_MASK))

#define IOSAPIC_MAX_ENTRY_MASK          0x00ff0000
#define IOSAPIC_MAX_ENTRY_SHIFT         0x10
#define	IOSAPIC_IRDT_MAX_ENTRY(ver)	\
	(int) (((ver) & IOSAPIC_MAX_ENTRY_MASK) >> IOSAPIC_MAX_ENTRY_SHIFT)

/* bits in the "low" I/O Sapic IRdT entry */
#define IOSAPIC_IRDT_ENABLE       0x10000
#define IOSAPIC_IRDT_PO_LOW       0x02000
#define IOSAPIC_IRDT_LEVEL_TRIG   0x08000
#define IOSAPIC_IRDT_MODE_LPRI    0x00100

/* bits in the "high" I/O Sapic IRdT entry */
#define IOSAPIC_IRDT_ID_EID_SHIFT              0x10


static DEFINE_SPINLOCK(iosapic_lock);

static inline void iosapic_eoi(void __iomem *addr, unsigned int data)
{
	__raw_writel(data, addr);
}

/*
** REVISIT: future platforms may have more than one IRT.
** If so, the following three fields form a structure which
** then be linked into a list. Names are chosen to make searching
** for them easy - not necessarily accurate (eg "cell").
**
** Alternative: iosapic_info could point to the IRT it's in.
** iosapic_register() could search a list of IRT's.
*/
static struct irt_entry *irt_cell;
static size_t irt_num_entry;

static struct irt_entry *iosapic_alloc_irt(int num_entries)
{
	unsigned long a;

	/* The IRT needs to be 8-byte aligned for the PDC call. 
	 * Normally kmalloc would guarantee larger alignment, but
	 * if CONFIG_DEBUG_SLAB is enabled, then we can get only
	 * 4-byte alignment on 32-bit kernels
	 */
	a = (unsigned long)kmalloc(sizeof(struct irt_entry) * num_entries + 8, GFP_KERNEL);
	a = (a + 7UL) & ~7UL;
	return (struct irt_entry *)a;
}

/**
 * iosapic_load_irt - Fill in the interrupt routing table
 * @cell_num: The cell number of the CPU we're currently executing on
 * @irt: The address to place the new IRT at
 * @return The number of entries found
 *
 * The "Get PCI INT Routing Table Size" option returns the number of 
 * entries in the PCI interrupt routing table for the cell specified 
 * in the cell_number argument.  The cell number must be for a cell 
 * within the caller's protection domain.
 *
 * The "Get PCI INT Routing Table" option returns, for the cell 
 * specified in the cell_number argument, the PCI interrupt routing 
 * table in the caller allocated memory pointed to by mem_addr.
 * We assume the IRT only contains entries for I/O SAPIC and
 * calculate the size based on the size of I/O sapic entries.
 *
 * The PCI interrupt routing table entry format is derived from the
 * IA64 SAL Specification 2.4.   The PCI interrupt routing table defines
 * the routing of PCI interrupt signals between the PCI device output
 * "pins" and the IO SAPICs' input "lines" (including core I/O PCI
 * devices).  This table does NOT include information for devices/slots
 * behind PCI to PCI bridges. See PCI to PCI Bridge Architecture Spec.
 * for the architected method of routing of IRQ's behind PPB's.
 */


static int __init
iosapic_load_irt(unsigned long cell_num, struct irt_entry **irt)
{
	long status;              /* PDC return value status */
	struct irt_entry *table;  /* start of interrupt routing tbl */
	unsigned long num_entries = 0UL;

	BUG_ON(!irt);

	if (is_pdc_pat()) {
		/* Use pat pdc routine to get interrupt routing table size */
		DBG("calling get_irt_size (cell %ld)\n", cell_num);
		status = pdc_pat_get_irt_size(&num_entries, cell_num);
		DBG("get_irt_size: %ld\n", status);

		BUG_ON(status != PDC_OK);
		BUG_ON(num_entries == 0);

		/*
		** allocate memory for interrupt routing table
		** This interface isn't really right. We are assuming
		** the contents of the table are exclusively
		** for I/O sapic devices.
		*/
		table = iosapic_alloc_irt(num_entries);
		if (table == NULL) {
			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
					"not alloc mem for IRT\n");
			return 0;
		}

		/* get PCI INT routing table */
		status = pdc_pat_get_irt(table, cell_num);
		DBG("pdc_pat_get_irt: %ld\n", status);
		WARN_ON(status != PDC_OK);
	} else {
		/*
		** C3000/J5000 (and similar) platforms with Sprockets PDC
		** will return exactly one IRT for all iosapics.
		** So if we have one, don't need to get it again.
		*/
		if (irt_cell)
			return 0;

		/* Should be using the Elroy's HPA, but it's ignored anyway */
		status = pdc_pci_irt_size(&num_entries, 0);
		DBG("pdc_pci_irt_size: %ld\n", status);

		if (status != PDC_OK) {
			/* Not a "legacy" system with I/O SAPIC either */
			return 0;
		}

		BUG_ON(num_entries == 0);

		table = iosapic_alloc_irt(num_entries);
		if (!table) {
			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
					"not alloc mem for IRT\n");
			return 0;
		}

		/* HPA ignored by this call too. */
		status = pdc_pci_irt(num_entries, 0, table);
		BUG_ON(status != PDC_OK);
	}

	/* return interrupt table address */
	*irt = table;

#ifdef DEBUG_IOSAPIC_IRT
{
	struct irt_entry *p = table;
	int i;

	printk(MODULE_NAME " Interrupt Routing Table (cell %ld)\n", cell_num);
	printk(MODULE_NAME " start = 0x%p num_entries %ld entry_size %d\n",
		table,
		num_entries,
		(int) sizeof(struct irt_entry));

	for (i = 0 ; i < num_entries ; i++, p++) {
		printk(MODULE_NAME " %02x %02x %02x %02x %02x %02x %02x %02x %08x%08x\n",
		p->entry_type, p->entry_length, p->interrupt_type,
		p->polarity_trigger, p->src_bus_irq_devno, p->src_bus_id,
		p->src_seg_id, p->dest_iosapic_intin,
		((u32 *) p)[2],
		((u32 *) p)[3]
		);
	}
}
#endif /* DEBUG_IOSAPIC_IRT */

	return num_entries;
}



void __init iosapic_init(void)
{
	unsigned long cell = 0;

	DBG("iosapic_init()\n");

#ifdef __LP64__
	if (is_pdc_pat()) {
		int status;
		struct pdc_pat_cell_num cell_info;

		status = pdc_pat_cell_get_number(&cell_info);
		if (status == PDC_OK) {
			cell = cell_info.cell_num;
		}
	}
#endif

	/* get interrupt routing table for this cell */
	irt_num_entry = iosapic_load_irt(cell, &irt_cell);
	if (irt_num_entry == 0)
		irt_cell = NULL;	/* old PDC w/o iosapic */
}


/*
** Return the IRT entry in case we need to look something else up.
*/
static struct irt_entry *
irt_find_irqline(struct iosapic_info *isi, u8 slot, u8 intr_pin)
{
	struct irt_entry *i = irt_cell;
	int cnt;	/* track how many entries we've looked at */
	u8 irq_devno = (slot << IRT_DEV_SHIFT) | (intr_pin-1);

	DBG_IRT("irt_find_irqline() SLOT %d pin %d\n", slot, intr_pin);

	for (cnt=0; cnt < irt_num_entry; cnt++, i++) {

		/*
		** Validate: entry_type, entry_length, interrupt_type
		**
		** Difference between validate vs compare is the former
		** should print debug info and is not expected to "fail"
		** on current platforms.
		*/
		if (i->entry_type != IRT_IOSAPIC_TYPE) {
			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d type %d\n", i, cnt, i->entry_type);
			continue;
		}
		
		if (i->entry_length != IRT_IOSAPIC_LENGTH) {
			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d  length %d\n", i, cnt, i->entry_length);
			continue;
		}

		if (i->interrupt_type != IRT_VECTORED_INTR) {
			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry  %d interrupt_type %d\n", i, cnt, i->interrupt_type);
			continue;
		}

		if (!COMPARE_IRTE_ADDR(i, isi->isi_hpa))
			continue;

		if ((i->src_bus_irq_devno & IRT_IRQ_DEVNO_MASK) != irq_devno)
			continue;

		/*
		** Ignore: src_bus_id and rc_seg_id correlate with
		**         iosapic_info->isi_hpa on HP platforms.
		**         If needed, pass in "PFA" (aka config space addr)
		**         instead of slot.
		*/

		/* Found it! */
		return i;
	}

	printk(KERN_WARNING MODULE_NAME ": 0x%lx : no IRT entry for slot %d, pin %d\n",
			isi->isi_hpa, slot, intr_pin);
	return NULL;
}


/*
** xlate_pin() supports the skewing of IRQ lines done by subsidiary bridges.
** Legacy PDC already does this translation for us and stores it in INTR_LINE.
**
** PAT PDC needs to basically do what legacy PDC does:
** o read PIN
** o adjust PIN in case device is "behind" a PPB
**     (eg 4-port 100BT and SCSI/LAN "Combo Card")
** o convert slot/pin to I/O SAPIC input line.
**
** HP platforms only support:
** o one level of skewing for any number of PPBs
** o only support PCI-PCI Bridges.
*/
static struct irt_entry *
iosapic_xlate_pin(struct iosapic_info *isi, struct pci_dev *pcidev)
{
	u8 intr_pin, intr_slot;

	pci_read_config_byte(pcidev, PCI_INTERRUPT_PIN, &intr_pin);

	DBG_IRT("iosapic_xlate_pin(%s) SLOT %d pin %d\n",
		pcidev->slot_name, PCI_SLOT(pcidev->devfn), intr_pin);

	if (intr_pin == 0) {
		/* The device does NOT support/use IRQ lines.  */
		return NULL;
	}

	/* Check if pcidev behind a PPB */
	if (pcidev->bus->parent) {
		/* Convert pcidev INTR_PIN into something we
		** can lookup in the IRT.
		*/
#ifdef PCI_BRIDGE_FUNCS
		/*
		** Proposal #1:
		**
		** call implementation specific translation function
		** This is architecturally "cleaner". HP-UX doesn't
		** support other secondary bus types (eg. E/ISA) directly.
		** May be needed for other processor (eg IA64) architectures
		** or by some ambitous soul who wants to watch TV.
		*/
		if (pci_bridge_funcs->xlate_intr_line) {
			intr_pin = pci_bridge_funcs->xlate_intr_line(pcidev);
		}
#else	/* PCI_BRIDGE_FUNCS */
		struct pci_bus *p = pcidev->bus;
		/*
		** Proposal #2:
		** The "pin" is skewed ((pin + dev - 1) % 4).
		**
		** This isn't very clean since I/O SAPIC must assume:
		**   - all platforms only have PCI busses.
		**   - only PCI-PCI bridge (eg not PCI-EISA, PCI-PCMCIA)
		**   - IRQ routing is only skewed once regardless of
		**     the number of PPB's between iosapic and device.
		**     (Bit3 expansion chassis follows this rule)
		**
		** Advantage is it's really easy to implement.
		*/
		intr_pin = pci_swizzle_interrupt_pin(pcidev, intr_pin);
#endif /* PCI_BRIDGE_FUNCS */

		/*
		 * Locate the host slot of the PPB.
		 */
		while (p->parent->parent)
			p = p->parent;

		intr_slot = PCI_SLOT(p->self->devfn);
	} else {
		intr_slot = PCI_SLOT(pcidev->devfn);
	}
	DBG_IRT("iosapic_xlate_pin:  bus %d slot %d pin %d\n",
				pcidev->bus->secondary, intr_slot, intr_pin);

	return irt_find_irqline(isi, intr_slot, intr_pin);
}

static void iosapic_rd_irt_entry(struct vector_info *vi , u32 *dp0, u32 *dp1)
{
	struct iosapic_info *isp = vi->iosapic;
	u8 idx = vi->irqline;

	*dp0 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY(idx));
	*dp1 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY_HI(idx));
}


static void iosapic_wr_irt_entry(struct vector_info *vi, u32 dp0, u32 dp1)
{
	struct iosapic_info *isp = vi->iosapic;

	DBG_IRT("iosapic_wr_irt_entry(): irq %d hpa %lx 0x%x 0x%x\n",
		vi->irqline, isp->isi_hpa, dp0, dp1);

	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY(vi->irqline), dp0);

	/* Read the window register to flush the writes down to HW  */
	dp0 = readl(isp->addr+IOSAPIC_REG_WINDOW);

	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY_HI(vi->irqline), dp1);

	/* Read the window register to flush the writes down to HW  */
	dp1 = readl(isp->addr+IOSAPIC_REG_WINDOW);
}

/*
** set_irt prepares the data (dp0, dp1) according to the vector_info
** and target cpu (id_eid).  dp0/dp1 are then used to program I/O SAPIC
** IRdT for the given "vector" (aka IRQ line).
*/
static void
iosapic_set_irt_data( struct vector_info *vi, u32 *dp0, u32 *dp1)
{
	u32 mode = 0;
	struct irt_entry *p = vi->irte;

	if ((p->polarity_trigger & IRT_PO_MASK) == IRT_ACTIVE_LO)
		mode |= IOSAPIC_IRDT_PO_LOW;

	if (((p->polarity_trigger >> IRT_EL_SHIFT) & IRT_EL_MASK) == IRT_LEVEL_TRIG)
		mode |= IOSAPIC_IRDT_LEVEL_TRIG;

	/*
	** IA64 REVISIT
	** PA doesn't support EXTINT or LPRIO bits.
	*/

	*dp0 = mode | (u32) vi->txn_data;

	/*
	** Extracting id_eid isn't a real clean way of getting it.
	** But the encoding is the same for both PA and IA64 platforms.
	*/
	if (is_pdc_pat()) {
		/*
		** PAT PDC just hands it to us "right".
		** txn_addr comes from cpu_data[x].txn_addr.
		*/
		*dp1 = (u32) (vi->txn_addr);
	} else {
		/* 
		** eg if base_addr == 0xfffa0000),
		**    we want to get 0xa0ff0000.
		**
		** eid	0x0ff00000 -> 0x00ff0000
		** id	0x000ff000 -> 0xff000000
		*/
		*dp1 = (((u32)vi->txn_addr & 0x0ff00000) >> 4) |
			(((u32)vi->txn_addr & 0x000ff000) << 12);
	}
	DBG_IRT("iosapic_set_irt_data(): 0x%x 0x%x\n", *dp0, *dp1);
}


static void iosapic_mask_irq(unsigned int irq)
{
	unsigned long flags;
	struct vector_info *vi = get_irq_chip_data(irq);
	u32 d0, d1;

	spin_lock_irqsave(&iosapic_lock, flags);
	iosapic_rd_irt_entry(vi, &d0, &d1);
	d0 |= IOSAPIC_IRDT_ENABLE;
	iosapic_wr_irt_entry(vi, d0, d1);
	spin_unlock_irqrestore(&iosapic_lock, flags);
}

static void iosapic_unmask_irq(unsigned int irq)
{
	struct vector_info *vi = get_irq_chip_data(irq);
	u32 d0, d1;

	/* data is initialized by fixup_irq */
	WARN_ON(vi->txn_irq  == 0);

	iosapic_set_irt_data(vi, &d0, &d1);
	iosapic_wr_irt_entry(vi, d0, d1);

#ifdef DEBUG_IOSAPIC_IRT
{
	u32 *t = (u32 *) ((ulong) vi->eoi_addr & ~0xffUL);
	printk("iosapic_enable_irq(): regs %p", vi->eoi_addr);
	for ( ; t < vi->eoi_addr; t++)
		printk(" %x", readl(t));
	printk("\n");
}

printk("iosapic_enable_irq(): sel ");
{
	struct iosapic_info *isp = vi->iosapic;

	for (d0=0x10; d0<0x1e; d0++) {
		d1 = iosapic_read(isp->addr, d0);
		printk(" %x", d1);
	}
}
printk("\n");
#endif

	/*
	 * Issuing I/O SAPIC an EOI causes an interrupt IFF IRQ line is
	 * asserted.  IRQ generally should not be asserted when a driver
	 * enables their IRQ. It can lead to "interesting" race conditions
	 * in the driver initialization sequence.
	 */
	DBG(KERN_DEBUG "enable_irq(%d): eoi(%p, 0x%x)\n", irq,
			vi->eoi_addr, vi->eoi_data);
	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
	cpu_eoi_irq(irq);
}

#ifdef CONFIG_SMP
static int iosapic_set_affinity_irq(unsigned int irq,
				     const struct cpumask *dest)
{
	struct vector_info *vi = get_irq_chip_data(irq);
	u32 d0, d1, dummy_d0;
	unsigned long flags;
	int dest_cpu;

	dest_cpu = cpu_check_affinity(irq, dest);
	if (dest_cpu < 0)
		return -1;

	cpumask_copy(irq_desc[irq].affinity, cpumask_of(dest_cpu));
	vi->txn_addr = txn_affinity_addr(irq, dest_cpu);

	spin_lock_irqsave(&iosapic_lock, flags);
	/* d1 contains the destination CPU, so only want to set that
	 * entry */
	iosapic_rd_irt_entry(vi, &d0, &d1);
	iosapic_set_irt_data(vi, &dummy_d0, &d1);
	iosapic_wr_irt_entry(vi, d0, d1);
	spin_unlock_irqrestore(&iosapic_lock, flags);

	return 0;
}
#endif

static struct irq_chip iosapic_interrupt_type = {
	.name	=	"IO-SAPIC-level",
	.unmask	=	iosapic_unmask_irq,
	.mask	=	iosapic_mask_irq,
	.ack	=	cpu_ack_irq,
#ifdef CONFIG_SMP
	.set_affinity =	iosapic_set_affinity_irq,
#endif
};

int iosapic_fixup_irq(void *isi_obj, struct pci_dev *pcidev)
{
	struct iosapic_info *isi = isi_obj;
	struct irt_entry *irte = NULL;  /* only used if PAT PDC */
	struct vector_info *vi;
	int isi_line;	/* line used by device */

	if (!isi) {
		printk(KERN_WARNING MODULE_NAME ": hpa not registered for %s\n",
			pci_name(pcidev));
		return -1;
	}

#ifdef CONFIG_SUPERIO
	/*
	 * HACK ALERT! (non-compliant PCI device support)
	 *
	 * All SuckyIO interrupts are routed through the PIC's on function 1.
	 * But SuckyIO OHCI USB controller gets an IRT entry anyway because
	 * it advertises INT D for INT_PIN.  Use that IRT entry to get the
	 * SuckyIO interrupt routing for PICs on function 1 (*BLEECCHH*).
	 */
	if (is_superio_device(pcidev)) {
		/* We must call superio_fixup_irq() to register the pdev */
		pcidev->irq = superio_fixup_irq(pcidev);

		/* Don't return if need to program the IOSAPIC's IRT... */
		if (PCI_FUNC(pcidev->devfn) != SUPERIO_USB_FN)
			return pcidev->irq;
	}
#endif /* CONFIG_SUPERIO */

	/* lookup IRT entry for isi/slot/pin set */
	irte = iosapic_xlate_pin(isi, pcidev);
	if (!irte) {
		printk("iosapic: no IRTE for %s (IRQ not connected?)\n",
				pci_name(pcidev));
		return -1;
	}
	DBG_IRT("iosapic_fixup_irq(): irte %p %x %x %x %x %x %x %x %x\n",
		irte,
		irte->entry_type,
		irte->entry_length,
		irte->polarity_trigger,
		irte->src_bus_irq_devno,
		irte->src_bus_id,
		irte->src_seg_id,
		irte->dest_iosapic_intin,
		(u32) irte->dest_iosapic_addr);
	isi_line = irte->dest_iosapic_intin;

	/* get vector info for this input line */
	vi = isi->isi_vector + isi_line;
	DBG_IRT("iosapic_fixup_irq:  line %d vi 0x%p\n", isi_line, vi);

	/* If this IRQ line has already been setup, skip it */
	if (vi->irte)
		goto out;

	vi->irte = irte;

	/*
	 * Allocate processor IRQ
	 *
	 * XXX/FIXME The txn_alloc_irq() code and related code should be
	 * moved to enable_irq(). That way we only allocate processor IRQ
	 * bits for devices that actually have drivers claiming them.
	 * Right now we assign an IRQ to every PCI device present,
	 * regardless of whether it's used or not.
	 */
	vi->txn_irq = txn_alloc_irq(8);

	if (vi->txn_irq < 0)
		panic("I/O sapic: couldn't get TXN IRQ\n");

	/* enable_irq() will use txn_* to program IRdT */
	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
	vi->txn_data = txn_alloc_data(vi->txn_irq);

	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
	vi->eoi_data = cpu_to_le32(vi->txn_data);

	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);

 out:
	pcidev->irq = vi->txn_irq;

	DBG_IRT("iosapic_fixup_irq() %d:%d %x %x line %d irq %d\n",
		PCI_SLOT(pcidev->devfn), PCI_FUNC(pcidev->devfn),
		pcidev->vendor, pcidev->device, isi_line, pcidev->irq);

	return pcidev->irq;
}


/*
** squirrel away the I/O Sapic Version
*/
static unsigned int
iosapic_rd_version(struct iosapic_info *isi)
{
	return iosapic_read(isi->addr, IOSAPIC_REG_VERSION);
}


/*
** iosapic_register() is called by "drivers" with an integrated I/O SAPIC.
** Caller must be certain they have an I/O SAPIC and know its MMIO address.
**
**	o allocate iosapic_info and add it to the list
**	o read iosapic version and squirrel that away
**	o read size of IRdT.
**	o allocate and initialize isi_vector[]
**	o allocate irq region
*/
void *iosapic_register(unsigned long hpa)
{
	struct iosapic_info *isi = NULL;
	struct irt_entry *irte = irt_cell;
	struct vector_info *vip;
	int cnt;	/* track how many entries we've looked at */

	/*
	 * Astro based platforms can only support PCI OLARD if they implement
	 * PAT PDC.  Legacy PDC omits LBAs with no PCI devices from the IRT.
	 * Search the IRT and ignore iosapic's which aren't in the IRT.
	 */
	for (cnt=0; cnt < irt_num_entry; cnt++, irte++) {
		WARN_ON(IRT_IOSAPIC_TYPE != irte->entry_type);
		if (COMPARE_IRTE_ADDR(irte, hpa))
			break;
	}

	if (cnt >= irt_num_entry) {
		DBG("iosapic_register() ignoring 0x%lx (NOT FOUND)\n", hpa);
		return NULL;
	}

	isi = kzalloc(sizeof(struct iosapic_info), GFP_KERNEL);
	if (!isi) {
		BUG();
		return NULL;
	}

	isi->addr = ioremap_nocache(hpa, 4096);
	isi->isi_hpa = hpa;
	isi->isi_version = iosapic_rd_version(isi);
	isi->isi_num_vectors = IOSAPIC_IRDT_MAX_ENTRY(isi->isi_version) + 1;

	vip = isi->isi_vector = kcalloc(isi->isi_num_vectors,
					sizeof(struct vector_info), GFP_KERNEL);
	if (vip == NULL) {
		kfree(isi);
		return NULL;
	}

	for (cnt=0; cnt < isi->isi_num_vectors; cnt++, vip++) {
		vip->irqline = (unsigned char) cnt;
		vip->iosapic = isi;
	}
	return isi;
}


#ifdef DEBUG_IOSAPIC

static void
iosapic_prt_irt(void *irt, long num_entry)
{
	unsigned int i, *irp = (unsigned int *) irt;


	printk(KERN_DEBUG MODULE_NAME ": Interrupt Routing Table (%lx entries)\n", num_entry);

	for (i=0; i<num_entry; i++, irp += 4) {
		printk(KERN_DEBUG "%p : %2d %.8x %.8x %.8x %.8x\n",
					irp, i, irp[0], irp[1], irp[2], irp[3]);
	}
}


static void
iosapic_prt_vi(struct vector_info *vi)
{
	printk(KERN_DEBUG MODULE_NAME ": vector_info[%d] is at %p\n", vi->irqline, vi);
	printk(KERN_DEBUG "\t\tstatus:	 %.4x\n", vi->status);
	printk(KERN_DEBUG "\t\ttxn_irq:  %d\n",  vi->txn_irq);
	printk(KERN_DEBUG "\t\ttxn_addr: %lx\n", vi->txn_addr);
	printk(KERN_DEBUG "\t\ttxn_data: %lx\n", vi->txn_data);
	printk(KERN_DEBUG "\t\teoi_addr: %p\n",  vi->eoi_addr);
	printk(KERN_DEBUG "\t\teoi_data: %x\n",  vi->eoi_data);
}


static void
iosapic_prt_isi(struct iosapic_info *isi)
{
	printk(KERN_DEBUG MODULE_NAME ": io_sapic_info at %p\n", isi);
	printk(KERN_DEBUG "\t\tisi_hpa:       %lx\n", isi->isi_hpa);
	printk(KERN_DEBUG "\t\tisi_status:    %x\n", isi->isi_status);
	printk(KERN_DEBUG "\t\tisi_version:   %x\n", isi->isi_version);
	printk(KERN_DEBUG "\t\tisi_vector:    %p\n", isi->isi_vector);
}
#endif /* DEBUG_IOSAPIC */