xref: /openbmc/linux/drivers/parisc/iosapic.c (revision ae213c44)
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 #ifdef CONFIG_64BIT
161 #define COMPARE_IRTE_ADDR(irte, hpa)	((irte)->dest_iosapic_addr == (hpa))
162 #else
163 #define COMPARE_IRTE_ADDR(irte, hpa)	\
164 		((irte)->dest_iosapic_addr == ((hpa) | 0xffffffff00000000ULL))
165 #endif
166 
167 #define IOSAPIC_REG_SELECT              0x00
168 #define IOSAPIC_REG_WINDOW              0x10
169 #define IOSAPIC_REG_EOI                 0x40
170 
171 #define IOSAPIC_REG_VERSION		0x1
172 
173 #define IOSAPIC_IRDT_ENTRY(idx)		(0x10+(idx)*2)
174 #define IOSAPIC_IRDT_ENTRY_HI(idx)	(0x11+(idx)*2)
175 
176 static inline unsigned int iosapic_read(void __iomem *iosapic, unsigned int reg)
177 {
178 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
179 	return readl(iosapic + IOSAPIC_REG_WINDOW);
180 }
181 
182 static inline void iosapic_write(void __iomem *iosapic, unsigned int reg, u32 val)
183 {
184 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
185 	writel(val, iosapic + IOSAPIC_REG_WINDOW);
186 }
187 
188 #define IOSAPIC_VERSION_MASK	0x000000ff
189 #define	IOSAPIC_VERSION(ver)	((int) (ver & IOSAPIC_VERSION_MASK))
190 
191 #define IOSAPIC_MAX_ENTRY_MASK          0x00ff0000
192 #define IOSAPIC_MAX_ENTRY_SHIFT         0x10
193 #define	IOSAPIC_IRDT_MAX_ENTRY(ver)	\
194 	(int) (((ver) & IOSAPIC_MAX_ENTRY_MASK) >> IOSAPIC_MAX_ENTRY_SHIFT)
195 
196 /* bits in the "low" I/O Sapic IRdT entry */
197 #define IOSAPIC_IRDT_ENABLE       0x10000
198 #define IOSAPIC_IRDT_PO_LOW       0x02000
199 #define IOSAPIC_IRDT_LEVEL_TRIG   0x08000
200 #define IOSAPIC_IRDT_MODE_LPRI    0x00100
201 
202 /* bits in the "high" I/O Sapic IRdT entry */
203 #define IOSAPIC_IRDT_ID_EID_SHIFT              0x10
204 
205 
206 static DEFINE_SPINLOCK(iosapic_lock);
207 
208 static inline void iosapic_eoi(void __iomem *addr, unsigned int data)
209 {
210 	__raw_writel(data, addr);
211 }
212 
213 /*
214 ** REVISIT: future platforms may have more than one IRT.
215 ** If so, the following three fields form a structure which
216 ** then be linked into a list. Names are chosen to make searching
217 ** for them easy - not necessarily accurate (eg "cell").
218 **
219 ** Alternative: iosapic_info could point to the IRT it's in.
220 ** iosapic_register() could search a list of IRT's.
221 */
222 static struct irt_entry *irt_cell;
223 static size_t irt_num_entry;
224 
225 static struct irt_entry *iosapic_alloc_irt(int num_entries)
226 {
227 	unsigned long a;
228 
229 	/* The IRT needs to be 8-byte aligned for the PDC call.
230 	 * Normally kmalloc would guarantee larger alignment, but
231 	 * if CONFIG_DEBUG_SLAB is enabled, then we can get only
232 	 * 4-byte alignment on 32-bit kernels
233 	 */
234 	a = (unsigned long)kmalloc(sizeof(struct irt_entry) * num_entries + 8, GFP_KERNEL);
235 	a = (a + 7UL) & ~7UL;
236 	return (struct irt_entry *)a;
237 }
238 
239 /**
240  * iosapic_load_irt - Fill in the interrupt routing table
241  * @cell_num: The cell number of the CPU we're currently executing on
242  * @irt: The address to place the new IRT at
243  * @return The number of entries found
244  *
245  * The "Get PCI INT Routing Table Size" option returns the number of
246  * entries in the PCI interrupt routing table for the cell specified
247  * in the cell_number argument.  The cell number must be for a cell
248  * within the caller's protection domain.
249  *
250  * The "Get PCI INT Routing Table" option returns, for the cell
251  * specified in the cell_number argument, the PCI interrupt routing
252  * table in the caller allocated memory pointed to by mem_addr.
253  * We assume the IRT only contains entries for I/O SAPIC and
254  * calculate the size based on the size of I/O sapic entries.
255  *
256  * The PCI interrupt routing table entry format is derived from the
257  * IA64 SAL Specification 2.4.   The PCI interrupt routing table defines
258  * the routing of PCI interrupt signals between the PCI device output
259  * "pins" and the IO SAPICs' input "lines" (including core I/O PCI
260  * devices).  This table does NOT include information for devices/slots
261  * behind PCI to PCI bridges. See PCI to PCI Bridge Architecture Spec.
262  * for the architected method of routing of IRQ's behind PPB's.
263  */
264 
265 
266 static int __init
267 iosapic_load_irt(unsigned long cell_num, struct irt_entry **irt)
268 {
269 	long status;              /* PDC return value status */
270 	struct irt_entry *table;  /* start of interrupt routing tbl */
271 	unsigned long num_entries = 0UL;
272 
273 	BUG_ON(!irt);
274 
275 	if (is_pdc_pat()) {
276 		/* Use pat pdc routine to get interrupt routing table size */
277 		DBG("calling get_irt_size (cell %ld)\n", cell_num);
278 		status = pdc_pat_get_irt_size(&num_entries, cell_num);
279 		DBG("get_irt_size: %ld\n", status);
280 
281 		BUG_ON(status != PDC_OK);
282 		BUG_ON(num_entries == 0);
283 
284 		/*
285 		** allocate memory for interrupt routing table
286 		** This interface isn't really right. We are assuming
287 		** the contents of the table are exclusively
288 		** for I/O sapic devices.
289 		*/
290 		table = iosapic_alloc_irt(num_entries);
291 		if (table == NULL) {
292 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
293 					"not alloc mem for IRT\n");
294 			return 0;
295 		}
296 
297 		/* get PCI INT routing table */
298 		status = pdc_pat_get_irt(table, cell_num);
299 		DBG("pdc_pat_get_irt: %ld\n", status);
300 		WARN_ON(status != PDC_OK);
301 	} else {
302 		/*
303 		** C3000/J5000 (and similar) platforms with Sprockets PDC
304 		** will return exactly one IRT for all iosapics.
305 		** So if we have one, don't need to get it again.
306 		*/
307 		if (irt_cell)
308 			return 0;
309 
310 		/* Should be using the Elroy's HPA, but it's ignored anyway */
311 		status = pdc_pci_irt_size(&num_entries, 0);
312 		DBG("pdc_pci_irt_size: %ld\n", status);
313 
314 		if (status != PDC_OK) {
315 			/* Not a "legacy" system with I/O SAPIC either */
316 			return 0;
317 		}
318 
319 		BUG_ON(num_entries == 0);
320 
321 		table = iosapic_alloc_irt(num_entries);
322 		if (!table) {
323 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
324 					"not alloc mem for IRT\n");
325 			return 0;
326 		}
327 
328 		/* HPA ignored by this call too. */
329 		status = pdc_pci_irt(num_entries, 0, table);
330 		BUG_ON(status != PDC_OK);
331 	}
332 
333 	/* return interrupt table address */
334 	*irt = table;
335 
336 #ifdef DEBUG_IOSAPIC_IRT
337 {
338 	struct irt_entry *p = table;
339 	int i;
340 
341 	printk(MODULE_NAME " Interrupt Routing Table (cell %ld)\n", cell_num);
342 	printk(MODULE_NAME " start = 0x%p num_entries %ld entry_size %d\n",
343 		table,
344 		num_entries,
345 		(int) sizeof(struct irt_entry));
346 
347 	for (i = 0 ; i < num_entries ; i++, p++) {
348 		printk(MODULE_NAME " %02x %02x %02x %02x %02x %02x %02x %02x %08x%08x\n",
349 		p->entry_type, p->entry_length, p->interrupt_type,
350 		p->polarity_trigger, p->src_bus_irq_devno, p->src_bus_id,
351 		p->src_seg_id, p->dest_iosapic_intin,
352 		((u32 *) p)[2],
353 		((u32 *) p)[3]
354 		);
355 	}
356 }
357 #endif /* DEBUG_IOSAPIC_IRT */
358 
359 	return num_entries;
360 }
361 
362 
363 
364 void __init iosapic_init(void)
365 {
366 	unsigned long cell = 0;
367 
368 	DBG("iosapic_init()\n");
369 
370 #ifdef __LP64__
371 	if (is_pdc_pat()) {
372 		int status;
373 		struct pdc_pat_cell_num cell_info;
374 
375 		status = pdc_pat_cell_get_number(&cell_info);
376 		if (status == PDC_OK) {
377 			cell = cell_info.cell_num;
378 		}
379 	}
380 #endif
381 
382 	/* get interrupt routing table for this cell */
383 	irt_num_entry = iosapic_load_irt(cell, &irt_cell);
384 	if (irt_num_entry == 0)
385 		irt_cell = NULL;	/* old PDC w/o iosapic */
386 }
387 
388 
389 /*
390 ** Return the IRT entry in case we need to look something else up.
391 */
392 static struct irt_entry *
393 irt_find_irqline(struct iosapic_info *isi, u8 slot, u8 intr_pin)
394 {
395 	struct irt_entry *i = irt_cell;
396 	int cnt;	/* track how many entries we've looked at */
397 	u8 irq_devno = (slot << IRT_DEV_SHIFT) | (intr_pin-1);
398 
399 	DBG_IRT("irt_find_irqline() SLOT %d pin %d\n", slot, intr_pin);
400 
401 	for (cnt=0; cnt < irt_num_entry; cnt++, i++) {
402 
403 		/*
404 		** Validate: entry_type, entry_length, interrupt_type
405 		**
406 		** Difference between validate vs compare is the former
407 		** should print debug info and is not expected to "fail"
408 		** on current platforms.
409 		*/
410 		if (i->entry_type != IRT_IOSAPIC_TYPE) {
411 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d type %d\n", i, cnt, i->entry_type);
412 			continue;
413 		}
414 
415 		if (i->entry_length != IRT_IOSAPIC_LENGTH) {
416 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d  length %d\n", i, cnt, i->entry_length);
417 			continue;
418 		}
419 
420 		if (i->interrupt_type != IRT_VECTORED_INTR) {
421 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry  %d interrupt_type %d\n", i, cnt, i->interrupt_type);
422 			continue;
423 		}
424 
425 		if (!COMPARE_IRTE_ADDR(i, isi->isi_hpa))
426 			continue;
427 
428 		if ((i->src_bus_irq_devno & IRT_IRQ_DEVNO_MASK) != irq_devno)
429 			continue;
430 
431 		/*
432 		** Ignore: src_bus_id and rc_seg_id correlate with
433 		**         iosapic_info->isi_hpa on HP platforms.
434 		**         If needed, pass in "PFA" (aka config space addr)
435 		**         instead of slot.
436 		*/
437 
438 		/* Found it! */
439 		return i;
440 	}
441 
442 	printk(KERN_WARNING MODULE_NAME ": 0x%lx : no IRT entry for slot %d, pin %d\n",
443 			isi->isi_hpa, slot, intr_pin);
444 	return NULL;
445 }
446 
447 
448 /*
449 ** xlate_pin() supports the skewing of IRQ lines done by subsidiary bridges.
450 ** Legacy PDC already does this translation for us and stores it in INTR_LINE.
451 **
452 ** PAT PDC needs to basically do what legacy PDC does:
453 ** o read PIN
454 ** o adjust PIN in case device is "behind" a PPB
455 **     (eg 4-port 100BT and SCSI/LAN "Combo Card")
456 ** o convert slot/pin to I/O SAPIC input line.
457 **
458 ** HP platforms only support:
459 ** o one level of skewing for any number of PPBs
460 ** o only support PCI-PCI Bridges.
461 */
462 static struct irt_entry *
463 iosapic_xlate_pin(struct iosapic_info *isi, struct pci_dev *pcidev)
464 {
465 	u8 intr_pin, intr_slot;
466 
467 	pci_read_config_byte(pcidev, PCI_INTERRUPT_PIN, &intr_pin);
468 
469 	DBG_IRT("iosapic_xlate_pin(%s) SLOT %d pin %d\n",
470 		pcidev->slot_name, PCI_SLOT(pcidev->devfn), intr_pin);
471 
472 	if (intr_pin == 0) {
473 		/* The device does NOT support/use IRQ lines.  */
474 		return NULL;
475 	}
476 
477 	/* Check if pcidev behind a PPB */
478 	if (pcidev->bus->parent) {
479 		/* Convert pcidev INTR_PIN into something we
480 		** can lookup in the IRT.
481 		*/
482 #ifdef PCI_BRIDGE_FUNCS
483 		/*
484 		** Proposal #1:
485 		**
486 		** call implementation specific translation function
487 		** This is architecturally "cleaner". HP-UX doesn't
488 		** support other secondary bus types (eg. E/ISA) directly.
489 		** May be needed for other processor (eg IA64) architectures
490 		** or by some ambitous soul who wants to watch TV.
491 		*/
492 		if (pci_bridge_funcs->xlate_intr_line) {
493 			intr_pin = pci_bridge_funcs->xlate_intr_line(pcidev);
494 		}
495 #else	/* PCI_BRIDGE_FUNCS */
496 		struct pci_bus *p = pcidev->bus;
497 		/*
498 		** Proposal #2:
499 		** The "pin" is skewed ((pin + dev - 1) % 4).
500 		**
501 		** This isn't very clean since I/O SAPIC must assume:
502 		**   - all platforms only have PCI busses.
503 		**   - only PCI-PCI bridge (eg not PCI-EISA, PCI-PCMCIA)
504 		**   - IRQ routing is only skewed once regardless of
505 		**     the number of PPB's between iosapic and device.
506 		**     (Bit3 expansion chassis follows this rule)
507 		**
508 		** Advantage is it's really easy to implement.
509 		*/
510 		intr_pin = pci_swizzle_interrupt_pin(pcidev, intr_pin);
511 #endif /* PCI_BRIDGE_FUNCS */
512 
513 		/*
514 		 * Locate the host slot of the PPB.
515 		 */
516 		while (p->parent->parent)
517 			p = p->parent;
518 
519 		intr_slot = PCI_SLOT(p->self->devfn);
520 	} else {
521 		intr_slot = PCI_SLOT(pcidev->devfn);
522 	}
523 	DBG_IRT("iosapic_xlate_pin:  bus %d slot %d pin %d\n",
524 			pcidev->bus->busn_res.start, intr_slot, intr_pin);
525 
526 	return irt_find_irqline(isi, intr_slot, intr_pin);
527 }
528 
529 static void iosapic_rd_irt_entry(struct vector_info *vi , u32 *dp0, u32 *dp1)
530 {
531 	struct iosapic_info *isp = vi->iosapic;
532 	u8 idx = vi->irqline;
533 
534 	*dp0 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY(idx));
535 	*dp1 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY_HI(idx));
536 }
537 
538 
539 static void iosapic_wr_irt_entry(struct vector_info *vi, u32 dp0, u32 dp1)
540 {
541 	struct iosapic_info *isp = vi->iosapic;
542 
543 	DBG_IRT("iosapic_wr_irt_entry(): irq %d hpa %lx 0x%x 0x%x\n",
544 		vi->irqline, isp->isi_hpa, dp0, dp1);
545 
546 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY(vi->irqline), dp0);
547 
548 	/* Read the window register to flush the writes down to HW  */
549 	dp0 = readl(isp->addr+IOSAPIC_REG_WINDOW);
550 
551 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY_HI(vi->irqline), dp1);
552 
553 	/* Read the window register to flush the writes down to HW  */
554 	dp1 = readl(isp->addr+IOSAPIC_REG_WINDOW);
555 }
556 
557 /*
558 ** set_irt prepares the data (dp0, dp1) according to the vector_info
559 ** and target cpu (id_eid).  dp0/dp1 are then used to program I/O SAPIC
560 ** IRdT for the given "vector" (aka IRQ line).
561 */
562 static void
563 iosapic_set_irt_data( struct vector_info *vi, u32 *dp0, u32 *dp1)
564 {
565 	u32 mode = 0;
566 	struct irt_entry *p = vi->irte;
567 
568 	if ((p->polarity_trigger & IRT_PO_MASK) == IRT_ACTIVE_LO)
569 		mode |= IOSAPIC_IRDT_PO_LOW;
570 
571 	if (((p->polarity_trigger >> IRT_EL_SHIFT) & IRT_EL_MASK) == IRT_LEVEL_TRIG)
572 		mode |= IOSAPIC_IRDT_LEVEL_TRIG;
573 
574 	/*
575 	** IA64 REVISIT
576 	** PA doesn't support EXTINT or LPRIO bits.
577 	*/
578 
579 	*dp0 = mode | (u32) vi->txn_data;
580 
581 	/*
582 	** Extracting id_eid isn't a real clean way of getting it.
583 	** But the encoding is the same for both PA and IA64 platforms.
584 	*/
585 	if (is_pdc_pat()) {
586 		/*
587 		** PAT PDC just hands it to us "right".
588 		** txn_addr comes from cpu_data[x].txn_addr.
589 		*/
590 		*dp1 = (u32) (vi->txn_addr);
591 	} else {
592 		/*
593 		** eg if base_addr == 0xfffa0000),
594 		**    we want to get 0xa0ff0000.
595 		**
596 		** eid	0x0ff00000 -> 0x00ff0000
597 		** id	0x000ff000 -> 0xff000000
598 		*/
599 		*dp1 = (((u32)vi->txn_addr & 0x0ff00000) >> 4) |
600 			(((u32)vi->txn_addr & 0x000ff000) << 12);
601 	}
602 	DBG_IRT("iosapic_set_irt_data(): 0x%x 0x%x\n", *dp0, *dp1);
603 }
604 
605 
606 static void iosapic_mask_irq(struct irq_data *d)
607 {
608 	unsigned long flags;
609 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
610 	u32 d0, d1;
611 
612 	spin_lock_irqsave(&iosapic_lock, flags);
613 	iosapic_rd_irt_entry(vi, &d0, &d1);
614 	d0 |= IOSAPIC_IRDT_ENABLE;
615 	iosapic_wr_irt_entry(vi, d0, d1);
616 	spin_unlock_irqrestore(&iosapic_lock, flags);
617 }
618 
619 static void iosapic_unmask_irq(struct irq_data *d)
620 {
621 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
622 	u32 d0, d1;
623 
624 	/* data is initialized by fixup_irq */
625 	WARN_ON(vi->txn_irq  == 0);
626 
627 	iosapic_set_irt_data(vi, &d0, &d1);
628 	iosapic_wr_irt_entry(vi, d0, d1);
629 
630 #ifdef DEBUG_IOSAPIC_IRT
631 {
632 	u32 *t = (u32 *) ((ulong) vi->eoi_addr & ~0xffUL);
633 	printk("iosapic_enable_irq(): regs %p", vi->eoi_addr);
634 	for ( ; t < vi->eoi_addr; t++)
635 		printk(" %x", readl(t));
636 	printk("\n");
637 }
638 
639 printk("iosapic_enable_irq(): sel ");
640 {
641 	struct iosapic_info *isp = vi->iosapic;
642 
643 	for (d0=0x10; d0<0x1e; d0++) {
644 		d1 = iosapic_read(isp->addr, d0);
645 		printk(" %x", d1);
646 	}
647 }
648 printk("\n");
649 #endif
650 
651 	/*
652 	 * Issuing I/O SAPIC an EOI causes an interrupt IFF IRQ line is
653 	 * asserted.  IRQ generally should not be asserted when a driver
654 	 * enables their IRQ. It can lead to "interesting" race conditions
655 	 * in the driver initialization sequence.
656 	 */
657 	DBG(KERN_DEBUG "enable_irq(%d): eoi(%p, 0x%x)\n", d->irq,
658 			vi->eoi_addr, vi->eoi_data);
659 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
660 }
661 
662 static void iosapic_eoi_irq(struct irq_data *d)
663 {
664 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
665 
666 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
667 	cpu_eoi_irq(d);
668 }
669 
670 #ifdef CONFIG_SMP
671 static int iosapic_set_affinity_irq(struct irq_data *d,
672 				    const struct cpumask *dest, bool force)
673 {
674 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
675 	u32 d0, d1, dummy_d0;
676 	unsigned long flags;
677 	int dest_cpu;
678 
679 	dest_cpu = cpu_check_affinity(d, dest);
680 	if (dest_cpu < 0)
681 		return -1;
682 
683 	cpumask_copy(irq_data_get_affinity_mask(d), cpumask_of(dest_cpu));
684 	vi->txn_addr = txn_affinity_addr(d->irq, dest_cpu);
685 
686 	spin_lock_irqsave(&iosapic_lock, flags);
687 	/* d1 contains the destination CPU, so only want to set that
688 	 * entry */
689 	iosapic_rd_irt_entry(vi, &d0, &d1);
690 	iosapic_set_irt_data(vi, &dummy_d0, &d1);
691 	iosapic_wr_irt_entry(vi, d0, d1);
692 	spin_unlock_irqrestore(&iosapic_lock, flags);
693 
694 	return 0;
695 }
696 #endif
697 
698 static struct irq_chip iosapic_interrupt_type = {
699 	.name		=	"IO-SAPIC-level",
700 	.irq_unmask	=	iosapic_unmask_irq,
701 	.irq_mask	=	iosapic_mask_irq,
702 	.irq_ack	=	cpu_ack_irq,
703 	.irq_eoi	=	iosapic_eoi_irq,
704 #ifdef CONFIG_SMP
705 	.irq_set_affinity =	iosapic_set_affinity_irq,
706 #endif
707 };
708 
709 int iosapic_fixup_irq(void *isi_obj, struct pci_dev *pcidev)
710 {
711 	struct iosapic_info *isi = isi_obj;
712 	struct irt_entry *irte = NULL;  /* only used if PAT PDC */
713 	struct vector_info *vi;
714 	int isi_line;	/* line used by device */
715 
716 	if (!isi) {
717 		printk(KERN_WARNING MODULE_NAME ": hpa not registered for %s\n",
718 			pci_name(pcidev));
719 		return -1;
720 	}
721 
722 #ifdef CONFIG_SUPERIO
723 	/*
724 	 * HACK ALERT! (non-compliant PCI device support)
725 	 *
726 	 * All SuckyIO interrupts are routed through the PIC's on function 1.
727 	 * But SuckyIO OHCI USB controller gets an IRT entry anyway because
728 	 * it advertises INT D for INT_PIN.  Use that IRT entry to get the
729 	 * SuckyIO interrupt routing for PICs on function 1 (*BLEECCHH*).
730 	 */
731 	if (is_superio_device(pcidev)) {
732 		/* We must call superio_fixup_irq() to register the pdev */
733 		pcidev->irq = superio_fixup_irq(pcidev);
734 
735 		/* Don't return if need to program the IOSAPIC's IRT... */
736 		if (PCI_FUNC(pcidev->devfn) != SUPERIO_USB_FN)
737 			return pcidev->irq;
738 	}
739 #endif /* CONFIG_SUPERIO */
740 
741 	/* lookup IRT entry for isi/slot/pin set */
742 	irte = iosapic_xlate_pin(isi, pcidev);
743 	if (!irte) {
744 		printk("iosapic: no IRTE for %s (IRQ not connected?)\n",
745 				pci_name(pcidev));
746 		return -1;
747 	}
748 	DBG_IRT("iosapic_fixup_irq(): irte %p %x %x %x %x %x %x %x %x\n",
749 		irte,
750 		irte->entry_type,
751 		irte->entry_length,
752 		irte->polarity_trigger,
753 		irte->src_bus_irq_devno,
754 		irte->src_bus_id,
755 		irte->src_seg_id,
756 		irte->dest_iosapic_intin,
757 		(u32) irte->dest_iosapic_addr);
758 	isi_line = irte->dest_iosapic_intin;
759 
760 	/* get vector info for this input line */
761 	vi = isi->isi_vector + isi_line;
762 	DBG_IRT("iosapic_fixup_irq:  line %d vi 0x%p\n", isi_line, vi);
763 
764 	/* If this IRQ line has already been setup, skip it */
765 	if (vi->irte)
766 		goto out;
767 
768 	vi->irte = irte;
769 
770 	/*
771 	 * Allocate processor IRQ
772 	 *
773 	 * XXX/FIXME The txn_alloc_irq() code and related code should be
774 	 * moved to enable_irq(). That way we only allocate processor IRQ
775 	 * bits for devices that actually have drivers claiming them.
776 	 * Right now we assign an IRQ to every PCI device present,
777 	 * regardless of whether it's used or not.
778 	 */
779 	vi->txn_irq = txn_alloc_irq(8);
780 
781 	if (vi->txn_irq < 0)
782 		panic("I/O sapic: couldn't get TXN IRQ\n");
783 
784 	/* enable_irq() will use txn_* to program IRdT */
785 	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
786 	vi->txn_data = txn_alloc_data(vi->txn_irq);
787 
788 	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
789 	vi->eoi_data = cpu_to_le32(vi->txn_data);
790 
791 	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
792 
793  out:
794 	pcidev->irq = vi->txn_irq;
795 
796 	DBG_IRT("iosapic_fixup_irq() %d:%d %x %x line %d irq %d\n",
797 		PCI_SLOT(pcidev->devfn), PCI_FUNC(pcidev->devfn),
798 		pcidev->vendor, pcidev->device, isi_line, pcidev->irq);
799 
800 	return pcidev->irq;
801 }
802 
803 static struct iosapic_info *iosapic_list;
804 
805 #ifdef CONFIG_64BIT
806 int iosapic_serial_irq(struct parisc_device *dev)
807 {
808 	struct iosapic_info *isi;
809 	struct irt_entry *irte;
810 	struct vector_info *vi;
811 	int cnt;
812 	int intin;
813 
814 	intin = (dev->mod_info >> 24) & 15;
815 
816 	/* lookup IRT entry for isi/slot/pin set */
817 	for (cnt = 0; cnt < irt_num_entry; cnt++) {
818 		irte = &irt_cell[cnt];
819 		if (COMPARE_IRTE_ADDR(irte, dev->mod0) &&
820 		    irte->dest_iosapic_intin == intin)
821 			break;
822 	}
823 	if (cnt >= irt_num_entry)
824 		return 0; /* no irq found, force polling */
825 
826 	DBG_IRT("iosapic_serial_irq(): irte %p %x %x %x %x %x %x %x %x\n",
827 		irte,
828 		irte->entry_type,
829 		irte->entry_length,
830 		irte->polarity_trigger,
831 		irte->src_bus_irq_devno,
832 		irte->src_bus_id,
833 		irte->src_seg_id,
834 		irte->dest_iosapic_intin,
835 		(u32) irte->dest_iosapic_addr);
836 
837 	/* search for iosapic */
838 	for (isi = iosapic_list; isi; isi = isi->isi_next)
839 		if (isi->isi_hpa == dev->mod0)
840 			break;
841 	if (!isi)
842 		return 0; /* no iosapic found, force polling */
843 
844 	/* get vector info for this input line */
845 	vi = isi->isi_vector + intin;
846 	DBG_IRT("iosapic_serial_irq:  line %d vi 0x%p\n", iosapic_intin, vi);
847 
848 	/* If this IRQ line has already been setup, skip it */
849 	if (vi->irte)
850 		goto out;
851 
852 	vi->irte = irte;
853 
854 	/*
855 	 * Allocate processor IRQ
856 	 *
857 	 * XXX/FIXME The txn_alloc_irq() code and related code should be
858 	 * moved to enable_irq(). That way we only allocate processor IRQ
859 	 * bits for devices that actually have drivers claiming them.
860 	 * Right now we assign an IRQ to every PCI device present,
861 	 * regardless of whether it's used or not.
862 	 */
863 	vi->txn_irq = txn_alloc_irq(8);
864 
865 	if (vi->txn_irq < 0)
866 		panic("I/O sapic: couldn't get TXN IRQ\n");
867 
868 	/* enable_irq() will use txn_* to program IRdT */
869 	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
870 	vi->txn_data = txn_alloc_data(vi->txn_irq);
871 
872 	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
873 	vi->eoi_data = cpu_to_le32(vi->txn_data);
874 
875 	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
876 
877  out:
878 
879 	return vi->txn_irq;
880 }
881 #endif
882 
883 
884 /*
885 ** squirrel away the I/O Sapic Version
886 */
887 static unsigned int
888 iosapic_rd_version(struct iosapic_info *isi)
889 {
890 	return iosapic_read(isi->addr, IOSAPIC_REG_VERSION);
891 }
892 
893 
894 /*
895 ** iosapic_register() is called by "drivers" with an integrated I/O SAPIC.
896 ** Caller must be certain they have an I/O SAPIC and know its MMIO address.
897 **
898 **	o allocate iosapic_info and add it to the list
899 **	o read iosapic version and squirrel that away
900 **	o read size of IRdT.
901 **	o allocate and initialize isi_vector[]
902 **	o allocate irq region
903 */
904 void *iosapic_register(unsigned long hpa)
905 {
906 	struct iosapic_info *isi = NULL;
907 	struct irt_entry *irte = irt_cell;
908 	struct vector_info *vip;
909 	int cnt;	/* track how many entries we've looked at */
910 
911 	/*
912 	 * Astro based platforms can only support PCI OLARD if they implement
913 	 * PAT PDC.  Legacy PDC omits LBAs with no PCI devices from the IRT.
914 	 * Search the IRT and ignore iosapic's which aren't in the IRT.
915 	 */
916 	for (cnt=0; cnt < irt_num_entry; cnt++, irte++) {
917 		WARN_ON(IRT_IOSAPIC_TYPE != irte->entry_type);
918 		if (COMPARE_IRTE_ADDR(irte, hpa))
919 			break;
920 	}
921 
922 	if (cnt >= irt_num_entry) {
923 		DBG("iosapic_register() ignoring 0x%lx (NOT FOUND)\n", hpa);
924 		return NULL;
925 	}
926 
927 	isi = kzalloc(sizeof(struct iosapic_info), GFP_KERNEL);
928 	if (!isi) {
929 		BUG();
930 		return NULL;
931 	}
932 
933 	isi->addr = ioremap_nocache(hpa, 4096);
934 	isi->isi_hpa = hpa;
935 	isi->isi_version = iosapic_rd_version(isi);
936 	isi->isi_num_vectors = IOSAPIC_IRDT_MAX_ENTRY(isi->isi_version) + 1;
937 
938 	vip = isi->isi_vector = kcalloc(isi->isi_num_vectors,
939 					sizeof(struct vector_info), GFP_KERNEL);
940 	if (vip == NULL) {
941 		kfree(isi);
942 		return NULL;
943 	}
944 
945 	for (cnt=0; cnt < isi->isi_num_vectors; cnt++, vip++) {
946 		vip->irqline = (unsigned char) cnt;
947 		vip->iosapic = isi;
948 	}
949 	isi->isi_next = iosapic_list;
950 	iosapic_list = isi;
951 	return isi;
952 }
953 
954 
955 #ifdef DEBUG_IOSAPIC
956 
957 static void
958 iosapic_prt_irt(void *irt, long num_entry)
959 {
960 	unsigned int i, *irp = (unsigned int *) irt;
961 
962 
963 	printk(KERN_DEBUG MODULE_NAME ": Interrupt Routing Table (%lx entries)\n", num_entry);
964 
965 	for (i=0; i<num_entry; i++, irp += 4) {
966 		printk(KERN_DEBUG "%p : %2d %.8x %.8x %.8x %.8x\n",
967 					irp, i, irp[0], irp[1], irp[2], irp[3]);
968 	}
969 }
970 
971 
972 static void
973 iosapic_prt_vi(struct vector_info *vi)
974 {
975 	printk(KERN_DEBUG MODULE_NAME ": vector_info[%d] is at %p\n", vi->irqline, vi);
976 	printk(KERN_DEBUG "\t\tstatus:	 %.4x\n", vi->status);
977 	printk(KERN_DEBUG "\t\ttxn_irq:  %d\n",  vi->txn_irq);
978 	printk(KERN_DEBUG "\t\ttxn_addr: %lx\n", vi->txn_addr);
979 	printk(KERN_DEBUG "\t\ttxn_data: %lx\n", vi->txn_data);
980 	printk(KERN_DEBUG "\t\teoi_addr: %p\n",  vi->eoi_addr);
981 	printk(KERN_DEBUG "\t\teoi_data: %x\n",  vi->eoi_data);
982 }
983 
984 
985 static void
986 iosapic_prt_isi(struct iosapic_info *isi)
987 {
988 	printk(KERN_DEBUG MODULE_NAME ": io_sapic_info at %p\n", isi);
989 	printk(KERN_DEBUG "\t\tisi_hpa:       %lx\n", isi->isi_hpa);
990 	printk(KERN_DEBUG "\t\tisi_status:    %x\n", isi->isi_status);
991 	printk(KERN_DEBUG "\t\tisi_version:   %x\n", isi->isi_version);
992 	printk(KERN_DEBUG "\t\tisi_vector:    %p\n", isi->isi_vector);
993 }
994 #endif /* DEBUG_IOSAPIC */
995