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 
130 /* FIXME: determine which include files are really needed */
131 #include <linux/types.h>
132 #include <linux/kernel.h>
133 #include <linux/spinlock.h>
134 #include <linux/pci.h>
135 #include <linux/init.h>
136 #include <linux/slab.h>
137 #include <linux/interrupt.h>
138 
139 #include <asm/byteorder.h>	/* get in-line asm for swab */
140 #include <asm/pdc.h>
141 #include <asm/pdcpat.h>
142 #include <asm/page.h>
143 #include <asm/system.h>
144 #include <asm/io.h>		/* read/write functions */
145 #ifdef CONFIG_SUPERIO
146 #include <asm/superio.h>
147 #endif
148 
149 #include <asm/ropes.h>
150 #include "./iosapic_private.h"
151 
152 #define MODULE_NAME "iosapic"
153 
154 /* "local" compile flags */
155 #undef PCI_BRIDGE_FUNCS
156 #undef DEBUG_IOSAPIC
157 #undef DEBUG_IOSAPIC_IRT
158 
159 
160 #ifdef DEBUG_IOSAPIC
161 #define DBG(x...) printk(x)
162 #else /* DEBUG_IOSAPIC */
163 #define DBG(x...)
164 #endif /* DEBUG_IOSAPIC */
165 
166 #ifdef DEBUG_IOSAPIC_IRT
167 #define DBG_IRT(x...) printk(x)
168 #else
169 #define DBG_IRT(x...)
170 #endif
171 
172 #ifdef CONFIG_64BIT
173 #define COMPARE_IRTE_ADDR(irte, hpa)	((irte)->dest_iosapic_addr == (hpa))
174 #else
175 #define COMPARE_IRTE_ADDR(irte, hpa)	\
176 		((irte)->dest_iosapic_addr == ((hpa) | 0xffffffff00000000ULL))
177 #endif
178 
179 #define IOSAPIC_REG_SELECT              0x00
180 #define IOSAPIC_REG_WINDOW              0x10
181 #define IOSAPIC_REG_EOI                 0x40
182 
183 #define IOSAPIC_REG_VERSION		0x1
184 
185 #define IOSAPIC_IRDT_ENTRY(idx)		(0x10+(idx)*2)
186 #define IOSAPIC_IRDT_ENTRY_HI(idx)	(0x11+(idx)*2)
187 
iosapic_read(void __iomem * iosapic,unsigned int reg)188 static inline unsigned int iosapic_read(void __iomem *iosapic, unsigned int reg)
189 {
190 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
191 	return readl(iosapic + IOSAPIC_REG_WINDOW);
192 }
193 
iosapic_write(void __iomem * iosapic,unsigned int reg,u32 val)194 static inline void iosapic_write(void __iomem *iosapic, unsigned int reg, u32 val)
195 {
196 	writel(reg, iosapic + IOSAPIC_REG_SELECT);
197 	writel(val, iosapic + IOSAPIC_REG_WINDOW);
198 }
199 
200 #define IOSAPIC_VERSION_MASK	0x000000ff
201 #define	IOSAPIC_VERSION(ver)	((int) (ver & IOSAPIC_VERSION_MASK))
202 
203 #define IOSAPIC_MAX_ENTRY_MASK          0x00ff0000
204 #define IOSAPIC_MAX_ENTRY_SHIFT         0x10
205 #define	IOSAPIC_IRDT_MAX_ENTRY(ver)	\
206 	(int) (((ver) & IOSAPIC_MAX_ENTRY_MASK) >> IOSAPIC_MAX_ENTRY_SHIFT)
207 
208 /* bits in the "low" I/O Sapic IRdT entry */
209 #define IOSAPIC_IRDT_ENABLE       0x10000
210 #define IOSAPIC_IRDT_PO_LOW       0x02000
211 #define IOSAPIC_IRDT_LEVEL_TRIG   0x08000
212 #define IOSAPIC_IRDT_MODE_LPRI    0x00100
213 
214 /* bits in the "high" I/O Sapic IRdT entry */
215 #define IOSAPIC_IRDT_ID_EID_SHIFT              0x10
216 
217 
218 static DEFINE_SPINLOCK(iosapic_lock);
219 
iosapic_eoi(void __iomem * addr,unsigned int data)220 static inline void iosapic_eoi(void __iomem *addr, unsigned int data)
221 {
222 	__raw_writel(data, addr);
223 }
224 
225 /*
226 ** REVISIT: future platforms may have more than one IRT.
227 ** If so, the following three fields form a structure which
228 ** then be linked into a list. Names are chosen to make searching
229 ** for them easy - not necessarily accurate (eg "cell").
230 **
231 ** Alternative: iosapic_info could point to the IRT it's in.
232 ** iosapic_register() could search a list of IRT's.
233 */
234 static struct irt_entry *irt_cell;
235 static size_t irt_num_entry;
236 
iosapic_alloc_irt(int num_entries)237 static struct irt_entry *iosapic_alloc_irt(int num_entries)
238 {
239 	unsigned long a;
240 
241 	/* The IRT needs to be 8-byte aligned for the PDC call.
242 	 * Normally kmalloc would guarantee larger alignment, but
243 	 * if CONFIG_DEBUG_SLAB is enabled, then we can get only
244 	 * 4-byte alignment on 32-bit kernels
245 	 */
246 	a = (unsigned long)kmalloc(sizeof(struct irt_entry) * num_entries + 8, GFP_KERNEL);
247 	a = (a + 7UL) & ~7UL;
248 	return (struct irt_entry *)a;
249 }
250 
251 /**
252  * iosapic_load_irt - Fill in the interrupt routing table
253  * @cell_num: The cell number of the CPU we're currently executing on
254  * @irt: The address to place the new IRT at
255  * @return The number of entries found
256  *
257  * The "Get PCI INT Routing Table Size" option returns the number of
258  * entries in the PCI interrupt routing table for the cell specified
259  * in the cell_number argument.  The cell number must be for a cell
260  * within the caller's protection domain.
261  *
262  * The "Get PCI INT Routing Table" option returns, for the cell
263  * specified in the cell_number argument, the PCI interrupt routing
264  * table in the caller allocated memory pointed to by mem_addr.
265  * We assume the IRT only contains entries for I/O SAPIC and
266  * calculate the size based on the size of I/O sapic entries.
267  *
268  * The PCI interrupt routing table entry format is derived from the
269  * IA64 SAL Specification 2.4.   The PCI interrupt routing table defines
270  * the routing of PCI interrupt signals between the PCI device output
271  * "pins" and the IO SAPICs' input "lines" (including core I/O PCI
272  * devices).  This table does NOT include information for devices/slots
273  * behind PCI to PCI bridges. See PCI to PCI Bridge Architecture Spec.
274  * for the architected method of routing of IRQ's behind PPB's.
275  */
276 
277 
278 static int __init
iosapic_load_irt(unsigned long cell_num,struct irt_entry ** irt)279 iosapic_load_irt(unsigned long cell_num, struct irt_entry **irt)
280 {
281 	long status;              /* PDC return value status */
282 	struct irt_entry *table;  /* start of interrupt routing tbl */
283 	unsigned long num_entries = 0UL;
284 
285 	BUG_ON(!irt);
286 
287 	if (is_pdc_pat()) {
288 		/* Use pat pdc routine to get interrupt routing table size */
289 		DBG("calling get_irt_size (cell %ld)\n", cell_num);
290 		status = pdc_pat_get_irt_size(&num_entries, cell_num);
291 		DBG("get_irt_size: %ld\n", status);
292 
293 		BUG_ON(status != PDC_OK);
294 		BUG_ON(num_entries == 0);
295 
296 		/*
297 		** allocate memory for interrupt routing table
298 		** This interface isn't really right. We are assuming
299 		** the contents of the table are exclusively
300 		** for I/O sapic devices.
301 		*/
302 		table = iosapic_alloc_irt(num_entries);
303 		if (table == NULL) {
304 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
305 					"not alloc mem for IRT\n");
306 			return 0;
307 		}
308 
309 		/* get PCI INT routing table */
310 		status = pdc_pat_get_irt(table, cell_num);
311 		DBG("pdc_pat_get_irt: %ld\n", status);
312 		WARN_ON(status != PDC_OK);
313 	} else {
314 		/*
315 		** C3000/J5000 (and similar) platforms with Sprockets PDC
316 		** will return exactly one IRT for all iosapics.
317 		** So if we have one, don't need to get it again.
318 		*/
319 		if (irt_cell)
320 			return 0;
321 
322 		/* Should be using the Elroy's HPA, but it's ignored anyway */
323 		status = pdc_pci_irt_size(&num_entries, 0);
324 		DBG("pdc_pci_irt_size: %ld\n", status);
325 
326 		if (status != PDC_OK) {
327 			/* Not a "legacy" system with I/O SAPIC either */
328 			return 0;
329 		}
330 
331 		BUG_ON(num_entries == 0);
332 
333 		table = iosapic_alloc_irt(num_entries);
334 		if (!table) {
335 			printk(KERN_WARNING MODULE_NAME ": read_irt : can "
336 					"not alloc mem for IRT\n");
337 			return 0;
338 		}
339 
340 		/* HPA ignored by this call too. */
341 		status = pdc_pci_irt(num_entries, 0, table);
342 		BUG_ON(status != PDC_OK);
343 	}
344 
345 	/* return interrupt table address */
346 	*irt = table;
347 
348 #ifdef DEBUG_IOSAPIC_IRT
349 {
350 	struct irt_entry *p = table;
351 	int i;
352 
353 	printk(MODULE_NAME " Interrupt Routing Table (cell %ld)\n", cell_num);
354 	printk(MODULE_NAME " start = 0x%p num_entries %ld entry_size %d\n",
355 		table,
356 		num_entries,
357 		(int) sizeof(struct irt_entry));
358 
359 	for (i = 0 ; i < num_entries ; i++, p++) {
360 		printk(MODULE_NAME " %02x %02x %02x %02x %02x %02x %02x %02x %08x%08x\n",
361 		p->entry_type, p->entry_length, p->interrupt_type,
362 		p->polarity_trigger, p->src_bus_irq_devno, p->src_bus_id,
363 		p->src_seg_id, p->dest_iosapic_intin,
364 		((u32 *) p)[2],
365 		((u32 *) p)[3]
366 		);
367 	}
368 }
369 #endif /* DEBUG_IOSAPIC_IRT */
370 
371 	return num_entries;
372 }
373 
374 
375 
iosapic_init(void)376 void __init iosapic_init(void)
377 {
378 	unsigned long cell = 0;
379 
380 	DBG("iosapic_init()\n");
381 
382 #ifdef __LP64__
383 	if (is_pdc_pat()) {
384 		int status;
385 		struct pdc_pat_cell_num cell_info;
386 
387 		status = pdc_pat_cell_get_number(&cell_info);
388 		if (status == PDC_OK) {
389 			cell = cell_info.cell_num;
390 		}
391 	}
392 #endif
393 
394 	/* get interrupt routing table for this cell */
395 	irt_num_entry = iosapic_load_irt(cell, &irt_cell);
396 	if (irt_num_entry == 0)
397 		irt_cell = NULL;	/* old PDC w/o iosapic */
398 }
399 
400 
401 /*
402 ** Return the IRT entry in case we need to look something else up.
403 */
404 static struct irt_entry *
irt_find_irqline(struct iosapic_info * isi,u8 slot,u8 intr_pin)405 irt_find_irqline(struct iosapic_info *isi, u8 slot, u8 intr_pin)
406 {
407 	struct irt_entry *i = irt_cell;
408 	int cnt;	/* track how many entries we've looked at */
409 	u8 irq_devno = (slot << IRT_DEV_SHIFT) | (intr_pin-1);
410 
411 	DBG_IRT("irt_find_irqline() SLOT %d pin %d\n", slot, intr_pin);
412 
413 	for (cnt=0; cnt < irt_num_entry; cnt++, i++) {
414 
415 		/*
416 		** Validate: entry_type, entry_length, interrupt_type
417 		**
418 		** Difference between validate vs compare is the former
419 		** should print debug info and is not expected to "fail"
420 		** on current platforms.
421 		*/
422 		if (i->entry_type != IRT_IOSAPIC_TYPE) {
423 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d type %d\n", i, cnt, i->entry_type);
424 			continue;
425 		}
426 
427 		if (i->entry_length != IRT_IOSAPIC_LENGTH) {
428 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry %d  length %d\n", i, cnt, i->entry_length);
429 			continue;
430 		}
431 
432 		if (i->interrupt_type != IRT_VECTORED_INTR) {
433 			DBG_IRT(KERN_WARNING MODULE_NAME ":find_irqline(0x%p): skipping entry  %d interrupt_type %d\n", i, cnt, i->interrupt_type);
434 			continue;
435 		}
436 
437 		if (!COMPARE_IRTE_ADDR(i, isi->isi_hpa))
438 			continue;
439 
440 		if ((i->src_bus_irq_devno & IRT_IRQ_DEVNO_MASK) != irq_devno)
441 			continue;
442 
443 		/*
444 		** Ignore: src_bus_id and rc_seg_id correlate with
445 		**         iosapic_info->isi_hpa on HP platforms.
446 		**         If needed, pass in "PFA" (aka config space addr)
447 		**         instead of slot.
448 		*/
449 
450 		/* Found it! */
451 		return i;
452 	}
453 
454 	printk(KERN_WARNING MODULE_NAME ": 0x%lx : no IRT entry for slot %d, pin %d\n",
455 			isi->isi_hpa, slot, intr_pin);
456 	return NULL;
457 }
458 
459 
460 /*
461 ** xlate_pin() supports the skewing of IRQ lines done by subsidiary bridges.
462 ** Legacy PDC already does this translation for us and stores it in INTR_LINE.
463 **
464 ** PAT PDC needs to basically do what legacy PDC does:
465 ** o read PIN
466 ** o adjust PIN in case device is "behind" a PPB
467 **     (eg 4-port 100BT and SCSI/LAN "Combo Card")
468 ** o convert slot/pin to I/O SAPIC input line.
469 **
470 ** HP platforms only support:
471 ** o one level of skewing for any number of PPBs
472 ** o only support PCI-PCI Bridges.
473 */
474 static struct irt_entry *
iosapic_xlate_pin(struct iosapic_info * isi,struct pci_dev * pcidev)475 iosapic_xlate_pin(struct iosapic_info *isi, struct pci_dev *pcidev)
476 {
477 	u8 intr_pin, intr_slot;
478 
479 	pci_read_config_byte(pcidev, PCI_INTERRUPT_PIN, &intr_pin);
480 
481 	DBG_IRT("iosapic_xlate_pin(%s) SLOT %d pin %d\n",
482 		pcidev->slot_name, PCI_SLOT(pcidev->devfn), intr_pin);
483 
484 	if (intr_pin == 0) {
485 		/* The device does NOT support/use IRQ lines.  */
486 		return NULL;
487 	}
488 
489 	/* Check if pcidev behind a PPB */
490 	if (pcidev->bus->parent) {
491 		/* Convert pcidev INTR_PIN into something we
492 		** can lookup in the IRT.
493 		*/
494 #ifdef PCI_BRIDGE_FUNCS
495 		/*
496 		** Proposal #1:
497 		**
498 		** call implementation specific translation function
499 		** This is architecturally "cleaner". HP-UX doesn't
500 		** support other secondary bus types (eg. E/ISA) directly.
501 		** May be needed for other processor (eg IA64) architectures
502 		** or by some ambitous soul who wants to watch TV.
503 		*/
504 		if (pci_bridge_funcs->xlate_intr_line) {
505 			intr_pin = pci_bridge_funcs->xlate_intr_line(pcidev);
506 		}
507 #else	/* PCI_BRIDGE_FUNCS */
508 		struct pci_bus *p = pcidev->bus;
509 		/*
510 		** Proposal #2:
511 		** The "pin" is skewed ((pin + dev - 1) % 4).
512 		**
513 		** This isn't very clean since I/O SAPIC must assume:
514 		**   - all platforms only have PCI busses.
515 		**   - only PCI-PCI bridge (eg not PCI-EISA, PCI-PCMCIA)
516 		**   - IRQ routing is only skewed once regardless of
517 		**     the number of PPB's between iosapic and device.
518 		**     (Bit3 expansion chassis follows this rule)
519 		**
520 		** Advantage is it's really easy to implement.
521 		*/
522 		intr_pin = pci_swizzle_interrupt_pin(pcidev, intr_pin);
523 #endif /* PCI_BRIDGE_FUNCS */
524 
525 		/*
526 		 * Locate the host slot of the PPB.
527 		 */
528 		while (p->parent->parent)
529 			p = p->parent;
530 
531 		intr_slot = PCI_SLOT(p->self->devfn);
532 	} else {
533 		intr_slot = PCI_SLOT(pcidev->devfn);
534 	}
535 	DBG_IRT("iosapic_xlate_pin:  bus %d slot %d pin %d\n",
536 				pcidev->bus->secondary, intr_slot, intr_pin);
537 
538 	return irt_find_irqline(isi, intr_slot, intr_pin);
539 }
540 
iosapic_rd_irt_entry(struct vector_info * vi,u32 * dp0,u32 * dp1)541 static void iosapic_rd_irt_entry(struct vector_info *vi , u32 *dp0, u32 *dp1)
542 {
543 	struct iosapic_info *isp = vi->iosapic;
544 	u8 idx = vi->irqline;
545 
546 	*dp0 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY(idx));
547 	*dp1 = iosapic_read(isp->addr, IOSAPIC_IRDT_ENTRY_HI(idx));
548 }
549 
550 
iosapic_wr_irt_entry(struct vector_info * vi,u32 dp0,u32 dp1)551 static void iosapic_wr_irt_entry(struct vector_info *vi, u32 dp0, u32 dp1)
552 {
553 	struct iosapic_info *isp = vi->iosapic;
554 
555 	DBG_IRT("iosapic_wr_irt_entry(): irq %d hpa %lx 0x%x 0x%x\n",
556 		vi->irqline, isp->isi_hpa, dp0, dp1);
557 
558 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY(vi->irqline), dp0);
559 
560 	/* Read the window register to flush the writes down to HW  */
561 	dp0 = readl(isp->addr+IOSAPIC_REG_WINDOW);
562 
563 	iosapic_write(isp->addr, IOSAPIC_IRDT_ENTRY_HI(vi->irqline), dp1);
564 
565 	/* Read the window register to flush the writes down to HW  */
566 	dp1 = readl(isp->addr+IOSAPIC_REG_WINDOW);
567 }
568 
569 /*
570 ** set_irt prepares the data (dp0, dp1) according to the vector_info
571 ** and target cpu (id_eid).  dp0/dp1 are then used to program I/O SAPIC
572 ** IRdT for the given "vector" (aka IRQ line).
573 */
574 static void
iosapic_set_irt_data(struct vector_info * vi,u32 * dp0,u32 * dp1)575 iosapic_set_irt_data( struct vector_info *vi, u32 *dp0, u32 *dp1)
576 {
577 	u32 mode = 0;
578 	struct irt_entry *p = vi->irte;
579 
580 	if ((p->polarity_trigger & IRT_PO_MASK) == IRT_ACTIVE_LO)
581 		mode |= IOSAPIC_IRDT_PO_LOW;
582 
583 	if (((p->polarity_trigger >> IRT_EL_SHIFT) & IRT_EL_MASK) == IRT_LEVEL_TRIG)
584 		mode |= IOSAPIC_IRDT_LEVEL_TRIG;
585 
586 	/*
587 	** IA64 REVISIT
588 	** PA doesn't support EXTINT or LPRIO bits.
589 	*/
590 
591 	*dp0 = mode | (u32) vi->txn_data;
592 
593 	/*
594 	** Extracting id_eid isn't a real clean way of getting it.
595 	** But the encoding is the same for both PA and IA64 platforms.
596 	*/
597 	if (is_pdc_pat()) {
598 		/*
599 		** PAT PDC just hands it to us "right".
600 		** txn_addr comes from cpu_data[x].txn_addr.
601 		*/
602 		*dp1 = (u32) (vi->txn_addr);
603 	} else {
604 		/*
605 		** eg if base_addr == 0xfffa0000),
606 		**    we want to get 0xa0ff0000.
607 		**
608 		** eid	0x0ff00000 -> 0x00ff0000
609 		** id	0x000ff000 -> 0xff000000
610 		*/
611 		*dp1 = (((u32)vi->txn_addr & 0x0ff00000) >> 4) |
612 			(((u32)vi->txn_addr & 0x000ff000) << 12);
613 	}
614 	DBG_IRT("iosapic_set_irt_data(): 0x%x 0x%x\n", *dp0, *dp1);
615 }
616 
617 
iosapic_mask_irq(struct irq_data * d)618 static void iosapic_mask_irq(struct irq_data *d)
619 {
620 	unsigned long flags;
621 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
622 	u32 d0, d1;
623 
624 	spin_lock_irqsave(&iosapic_lock, flags);
625 	iosapic_rd_irt_entry(vi, &d0, &d1);
626 	d0 |= IOSAPIC_IRDT_ENABLE;
627 	iosapic_wr_irt_entry(vi, d0, d1);
628 	spin_unlock_irqrestore(&iosapic_lock, flags);
629 }
630 
iosapic_unmask_irq(struct irq_data * d)631 static void iosapic_unmask_irq(struct irq_data *d)
632 {
633 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
634 	u32 d0, d1;
635 
636 	/* data is initialized by fixup_irq */
637 	WARN_ON(vi->txn_irq  == 0);
638 
639 	iosapic_set_irt_data(vi, &d0, &d1);
640 	iosapic_wr_irt_entry(vi, d0, d1);
641 
642 #ifdef DEBUG_IOSAPIC_IRT
643 {
644 	u32 *t = (u32 *) ((ulong) vi->eoi_addr & ~0xffUL);
645 	printk("iosapic_enable_irq(): regs %p", vi->eoi_addr);
646 	for ( ; t < vi->eoi_addr; t++)
647 		printk(" %x", readl(t));
648 	printk("\n");
649 }
650 
651 printk("iosapic_enable_irq(): sel ");
652 {
653 	struct iosapic_info *isp = vi->iosapic;
654 
655 	for (d0=0x10; d0<0x1e; d0++) {
656 		d1 = iosapic_read(isp->addr, d0);
657 		printk(" %x", d1);
658 	}
659 }
660 printk("\n");
661 #endif
662 
663 	/*
664 	 * Issuing I/O SAPIC an EOI causes an interrupt IFF IRQ line is
665 	 * asserted.  IRQ generally should not be asserted when a driver
666 	 * enables their IRQ. It can lead to "interesting" race conditions
667 	 * in the driver initialization sequence.
668 	 */
669 	DBG(KERN_DEBUG "enable_irq(%d): eoi(%p, 0x%x)\n", d->irq,
670 			vi->eoi_addr, vi->eoi_data);
671 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
672 }
673 
iosapic_eoi_irq(struct irq_data * d)674 static void iosapic_eoi_irq(struct irq_data *d)
675 {
676 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
677 
678 	iosapic_eoi(vi->eoi_addr, vi->eoi_data);
679 	cpu_eoi_irq(d);
680 }
681 
682 #ifdef CONFIG_SMP
iosapic_set_affinity_irq(struct irq_data * d,const struct cpumask * dest,bool force)683 static int iosapic_set_affinity_irq(struct irq_data *d,
684 				    const struct cpumask *dest, bool force)
685 {
686 	struct vector_info *vi = irq_data_get_irq_chip_data(d);
687 	u32 d0, d1, dummy_d0;
688 	unsigned long flags;
689 	int dest_cpu;
690 
691 	dest_cpu = cpu_check_affinity(d, dest);
692 	if (dest_cpu < 0)
693 		return -1;
694 
695 	cpumask_copy(d->affinity, cpumask_of(dest_cpu));
696 	vi->txn_addr = txn_affinity_addr(d->irq, dest_cpu);
697 
698 	spin_lock_irqsave(&iosapic_lock, flags);
699 	/* d1 contains the destination CPU, so only want to set that
700 	 * entry */
701 	iosapic_rd_irt_entry(vi, &d0, &d1);
702 	iosapic_set_irt_data(vi, &dummy_d0, &d1);
703 	iosapic_wr_irt_entry(vi, d0, d1);
704 	spin_unlock_irqrestore(&iosapic_lock, flags);
705 
706 	return 0;
707 }
708 #endif
709 
710 static struct irq_chip iosapic_interrupt_type = {
711 	.name		=	"IO-SAPIC-level",
712 	.irq_unmask	=	iosapic_unmask_irq,
713 	.irq_mask	=	iosapic_mask_irq,
714 	.irq_ack	=	cpu_ack_irq,
715 	.irq_eoi	=	iosapic_eoi_irq,
716 #ifdef CONFIG_SMP
717 	.irq_set_affinity =	iosapic_set_affinity_irq,
718 #endif
719 };
720 
iosapic_fixup_irq(void * isi_obj,struct pci_dev * pcidev)721 int iosapic_fixup_irq(void *isi_obj, struct pci_dev *pcidev)
722 {
723 	struct iosapic_info *isi = isi_obj;
724 	struct irt_entry *irte = NULL;  /* only used if PAT PDC */
725 	struct vector_info *vi;
726 	int isi_line;	/* line used by device */
727 
728 	if (!isi) {
729 		printk(KERN_WARNING MODULE_NAME ": hpa not registered for %s\n",
730 			pci_name(pcidev));
731 		return -1;
732 	}
733 
734 #ifdef CONFIG_SUPERIO
735 	/*
736 	 * HACK ALERT! (non-compliant PCI device support)
737 	 *
738 	 * All SuckyIO interrupts are routed through the PIC's on function 1.
739 	 * But SuckyIO OHCI USB controller gets an IRT entry anyway because
740 	 * it advertises INT D for INT_PIN.  Use that IRT entry to get the
741 	 * SuckyIO interrupt routing for PICs on function 1 (*BLEECCHH*).
742 	 */
743 	if (is_superio_device(pcidev)) {
744 		/* We must call superio_fixup_irq() to register the pdev */
745 		pcidev->irq = superio_fixup_irq(pcidev);
746 
747 		/* Don't return if need to program the IOSAPIC's IRT... */
748 		if (PCI_FUNC(pcidev->devfn) != SUPERIO_USB_FN)
749 			return pcidev->irq;
750 	}
751 #endif /* CONFIG_SUPERIO */
752 
753 	/* lookup IRT entry for isi/slot/pin set */
754 	irte = iosapic_xlate_pin(isi, pcidev);
755 	if (!irte) {
756 		printk("iosapic: no IRTE for %s (IRQ not connected?)\n",
757 				pci_name(pcidev));
758 		return -1;
759 	}
760 	DBG_IRT("iosapic_fixup_irq(): irte %p %x %x %x %x %x %x %x %x\n",
761 		irte,
762 		irte->entry_type,
763 		irte->entry_length,
764 		irte->polarity_trigger,
765 		irte->src_bus_irq_devno,
766 		irte->src_bus_id,
767 		irte->src_seg_id,
768 		irte->dest_iosapic_intin,
769 		(u32) irte->dest_iosapic_addr);
770 	isi_line = irte->dest_iosapic_intin;
771 
772 	/* get vector info for this input line */
773 	vi = isi->isi_vector + isi_line;
774 	DBG_IRT("iosapic_fixup_irq:  line %d vi 0x%p\n", isi_line, vi);
775 
776 	/* If this IRQ line has already been setup, skip it */
777 	if (vi->irte)
778 		goto out;
779 
780 	vi->irte = irte;
781 
782 	/*
783 	 * Allocate processor IRQ
784 	 *
785 	 * XXX/FIXME The txn_alloc_irq() code and related code should be
786 	 * moved to enable_irq(). That way we only allocate processor IRQ
787 	 * bits for devices that actually have drivers claiming them.
788 	 * Right now we assign an IRQ to every PCI device present,
789 	 * regardless of whether it's used or not.
790 	 */
791 	vi->txn_irq = txn_alloc_irq(8);
792 
793 	if (vi->txn_irq < 0)
794 		panic("I/O sapic: couldn't get TXN IRQ\n");
795 
796 	/* enable_irq() will use txn_* to program IRdT */
797 	vi->txn_addr = txn_alloc_addr(vi->txn_irq);
798 	vi->txn_data = txn_alloc_data(vi->txn_irq);
799 
800 	vi->eoi_addr = isi->addr + IOSAPIC_REG_EOI;
801 	vi->eoi_data = cpu_to_le32(vi->txn_data);
802 
803 	cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
804 
805  out:
806 	pcidev->irq = vi->txn_irq;
807 
808 	DBG_IRT("iosapic_fixup_irq() %d:%d %x %x line %d irq %d\n",
809 		PCI_SLOT(pcidev->devfn), PCI_FUNC(pcidev->devfn),
810 		pcidev->vendor, pcidev->device, isi_line, pcidev->irq);
811 
812 	return pcidev->irq;
813 }
814 
815 
816 /*
817 ** squirrel away the I/O Sapic Version
818 */
819 static unsigned int
iosapic_rd_version(struct iosapic_info * isi)820 iosapic_rd_version(struct iosapic_info *isi)
821 {
822 	return iosapic_read(isi->addr, IOSAPIC_REG_VERSION);
823 }
824 
825 
826 /*
827 ** iosapic_register() is called by "drivers" with an integrated I/O SAPIC.
828 ** Caller must be certain they have an I/O SAPIC and know its MMIO address.
829 **
830 **	o allocate iosapic_info and add it to the list
831 **	o read iosapic version and squirrel that away
832 **	o read size of IRdT.
833 **	o allocate and initialize isi_vector[]
834 **	o allocate irq region
835 */
iosapic_register(unsigned long hpa)836 void *iosapic_register(unsigned long hpa)
837 {
838 	struct iosapic_info *isi = NULL;
839 	struct irt_entry *irte = irt_cell;
840 	struct vector_info *vip;
841 	int cnt;	/* track how many entries we've looked at */
842 
843 	/*
844 	 * Astro based platforms can only support PCI OLARD if they implement
845 	 * PAT PDC.  Legacy PDC omits LBAs with no PCI devices from the IRT.
846 	 * Search the IRT and ignore iosapic's which aren't in the IRT.
847 	 */
848 	for (cnt=0; cnt < irt_num_entry; cnt++, irte++) {
849 		WARN_ON(IRT_IOSAPIC_TYPE != irte->entry_type);
850 		if (COMPARE_IRTE_ADDR(irte, hpa))
851 			break;
852 	}
853 
854 	if (cnt >= irt_num_entry) {
855 		DBG("iosapic_register() ignoring 0x%lx (NOT FOUND)\n", hpa);
856 		return NULL;
857 	}
858 
859 	isi = kzalloc(sizeof(struct iosapic_info), GFP_KERNEL);
860 	if (!isi) {
861 		BUG();
862 		return NULL;
863 	}
864 
865 	isi->addr = ioremap_nocache(hpa, 4096);
866 	isi->isi_hpa = hpa;
867 	isi->isi_version = iosapic_rd_version(isi);
868 	isi->isi_num_vectors = IOSAPIC_IRDT_MAX_ENTRY(isi->isi_version) + 1;
869 
870 	vip = isi->isi_vector = kcalloc(isi->isi_num_vectors,
871 					sizeof(struct vector_info), GFP_KERNEL);
872 	if (vip == NULL) {
873 		kfree(isi);
874 		return NULL;
875 	}
876 
877 	for (cnt=0; cnt < isi->isi_num_vectors; cnt++, vip++) {
878 		vip->irqline = (unsigned char) cnt;
879 		vip->iosapic = isi;
880 	}
881 	return isi;
882 }
883 
884 
885 #ifdef DEBUG_IOSAPIC
886 
887 static void
iosapic_prt_irt(void * irt,long num_entry)888 iosapic_prt_irt(void *irt, long num_entry)
889 {
890 	unsigned int i, *irp = (unsigned int *) irt;
891 
892 
893 	printk(KERN_DEBUG MODULE_NAME ": Interrupt Routing Table (%lx entries)\n", num_entry);
894 
895 	for (i=0; i<num_entry; i++, irp += 4) {
896 		printk(KERN_DEBUG "%p : %2d %.8x %.8x %.8x %.8x\n",
897 					irp, i, irp[0], irp[1], irp[2], irp[3]);
898 	}
899 }
900 
901 
902 static void
iosapic_prt_vi(struct vector_info * vi)903 iosapic_prt_vi(struct vector_info *vi)
904 {
905 	printk(KERN_DEBUG MODULE_NAME ": vector_info[%d] is at %p\n", vi->irqline, vi);
906 	printk(KERN_DEBUG "\t\tstatus:	 %.4x\n", vi->status);
907 	printk(KERN_DEBUG "\t\ttxn_irq:  %d\n",  vi->txn_irq);
908 	printk(KERN_DEBUG "\t\ttxn_addr: %lx\n", vi->txn_addr);
909 	printk(KERN_DEBUG "\t\ttxn_data: %lx\n", vi->txn_data);
910 	printk(KERN_DEBUG "\t\teoi_addr: %p\n",  vi->eoi_addr);
911 	printk(KERN_DEBUG "\t\teoi_data: %x\n",  vi->eoi_data);
912 }
913 
914 
915 static void
iosapic_prt_isi(struct iosapic_info * isi)916 iosapic_prt_isi(struct iosapic_info *isi)
917 {
918 	printk(KERN_DEBUG MODULE_NAME ": io_sapic_info at %p\n", isi);
919 	printk(KERN_DEBUG "\t\tisi_hpa:       %lx\n", isi->isi_hpa);
920 	printk(KERN_DEBUG "\t\tisi_status:    %x\n", isi->isi_status);
921 	printk(KERN_DEBUG "\t\tisi_version:   %x\n", isi->isi_version);
922 	printk(KERN_DEBUG "\t\tisi_vector:    %p\n", isi->isi_vector);
923 }
924 #endif /* DEBUG_IOSAPIC */
925