xref: /openbmc/linux/arch/arm/kernel/bios32.c (revision e9e8bcb8)
1 /*
2  *  linux/arch/arm/kernel/bios32.c
3  *
4  *  PCI bios-type initialisation for PCI machines
5  *
6  *  Bits taken from various places.
7  */
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/pci.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/io.h>
14 
15 #include <asm/mach-types.h>
16 #include <asm/mach/pci.h>
17 
18 static int debug_pci;
19 static int use_firmware;
20 
21 /*
22  * We can't use pci_find_device() here since we are
23  * called from interrupt context.
24  */
25 static void pcibios_bus_report_status(struct pci_bus *bus, u_int status_mask, int warn)
26 {
27 	struct pci_dev *dev;
28 
29 	list_for_each_entry(dev, &bus->devices, bus_list) {
30 		u16 status;
31 
32 		/*
33 		 * ignore host bridge - we handle
34 		 * that separately
35 		 */
36 		if (dev->bus->number == 0 && dev->devfn == 0)
37 			continue;
38 
39 		pci_read_config_word(dev, PCI_STATUS, &status);
40 		if (status == 0xffff)
41 			continue;
42 
43 		if ((status & status_mask) == 0)
44 			continue;
45 
46 		/* clear the status errors */
47 		pci_write_config_word(dev, PCI_STATUS, status & status_mask);
48 
49 		if (warn)
50 			printk("(%s: %04X) ", pci_name(dev), status);
51 	}
52 
53 	list_for_each_entry(dev, &bus->devices, bus_list)
54 		if (dev->subordinate)
55 			pcibios_bus_report_status(dev->subordinate, status_mask, warn);
56 }
57 
58 void pcibios_report_status(u_int status_mask, int warn)
59 {
60 	struct list_head *l;
61 
62 	list_for_each(l, &pci_root_buses) {
63 		struct pci_bus *bus = pci_bus_b(l);
64 
65 		pcibios_bus_report_status(bus, status_mask, warn);
66 	}
67 }
68 
69 /*
70  * We don't use this to fix the device, but initialisation of it.
71  * It's not the correct use for this, but it works.
72  * Note that the arbiter/ISA bridge appears to be buggy, specifically in
73  * the following area:
74  * 1. park on CPU
75  * 2. ISA bridge ping-pong
76  * 3. ISA bridge master handling of target RETRY
77  *
78  * Bug 3 is responsible for the sound DMA grinding to a halt.  We now
79  * live with bug 2.
80  */
81 static void __devinit pci_fixup_83c553(struct pci_dev *dev)
82 {
83 	/*
84 	 * Set memory region to start at address 0, and enable IO
85 	 */
86 	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_SPACE_MEMORY);
87 	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_IO);
88 
89 	dev->resource[0].end -= dev->resource[0].start;
90 	dev->resource[0].start = 0;
91 
92 	/*
93 	 * All memory requests from ISA to be channelled to PCI
94 	 */
95 	pci_write_config_byte(dev, 0x48, 0xff);
96 
97 	/*
98 	 * Enable ping-pong on bus master to ISA bridge transactions.
99 	 * This improves the sound DMA substantially.  The fixed
100 	 * priority arbiter also helps (see below).
101 	 */
102 	pci_write_config_byte(dev, 0x42, 0x01);
103 
104 	/*
105 	 * Enable PCI retry
106 	 */
107 	pci_write_config_byte(dev, 0x40, 0x22);
108 
109 	/*
110 	 * We used to set the arbiter to "park on last master" (bit
111 	 * 1 set), but unfortunately the CyberPro does not park the
112 	 * bus.  We must therefore park on CPU.  Unfortunately, this
113 	 * may trigger yet another bug in the 553.
114 	 */
115 	pci_write_config_byte(dev, 0x83, 0x02);
116 
117 	/*
118 	 * Make the ISA DMA request lowest priority, and disable
119 	 * rotating priorities completely.
120 	 */
121 	pci_write_config_byte(dev, 0x80, 0x11);
122 	pci_write_config_byte(dev, 0x81, 0x00);
123 
124 	/*
125 	 * Route INTA input to IRQ 11, and set IRQ11 to be level
126 	 * sensitive.
127 	 */
128 	pci_write_config_word(dev, 0x44, 0xb000);
129 	outb(0x08, 0x4d1);
130 }
131 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_83C553, pci_fixup_83c553);
132 
133 static void __devinit pci_fixup_unassign(struct pci_dev *dev)
134 {
135 	dev->resource[0].end -= dev->resource[0].start;
136 	dev->resource[0].start = 0;
137 }
138 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND2, PCI_DEVICE_ID_WINBOND2_89C940F, pci_fixup_unassign);
139 
140 /*
141  * Prevent the PCI layer from seeing the resources allocated to this device
142  * if it is the host bridge by marking it as such.  These resources are of
143  * no consequence to the PCI layer (they are handled elsewhere).
144  */
145 static void __devinit pci_fixup_dec21285(struct pci_dev *dev)
146 {
147 	int i;
148 
149 	if (dev->devfn == 0) {
150 		dev->class &= 0xff;
151 		dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
152 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
153 			dev->resource[i].start = 0;
154 			dev->resource[i].end   = 0;
155 			dev->resource[i].flags = 0;
156 		}
157 	}
158 }
159 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21285, pci_fixup_dec21285);
160 
161 /*
162  * PCI IDE controllers use non-standard I/O port decoding, respect it.
163  */
164 static void __devinit pci_fixup_ide_bases(struct pci_dev *dev)
165 {
166 	struct resource *r;
167 	int i;
168 
169 	if ((dev->class >> 8) != PCI_CLASS_STORAGE_IDE)
170 		return;
171 
172 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
173 		r = dev->resource + i;
174 		if ((r->start & ~0x80) == 0x374) {
175 			r->start |= 2;
176 			r->end = r->start;
177 		}
178 	}
179 }
180 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_ide_bases);
181 
182 /*
183  * Put the DEC21142 to sleep
184  */
185 static void __devinit pci_fixup_dec21142(struct pci_dev *dev)
186 {
187 	pci_write_config_dword(dev, 0x40, 0x80000000);
188 }
189 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21142, pci_fixup_dec21142);
190 
191 /*
192  * The CY82C693 needs some rather major fixups to ensure that it does
193  * the right thing.  Idea from the Alpha people, with a few additions.
194  *
195  * We ensure that the IDE base registers are set to 1f0/3f4 for the
196  * primary bus, and 170/374 for the secondary bus.  Also, hide them
197  * from the PCI subsystem view as well so we won't try to perform
198  * our own auto-configuration on them.
199  *
200  * In addition, we ensure that the PCI IDE interrupts are routed to
201  * IRQ 14 and IRQ 15 respectively.
202  *
203  * The above gets us to a point where the IDE on this device is
204  * functional.  However, The CY82C693U _does not work_ in bus
205  * master mode without locking the PCI bus solid.
206  */
207 static void __devinit pci_fixup_cy82c693(struct pci_dev *dev)
208 {
209 	if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
210 		u32 base0, base1;
211 
212 		if (dev->class & 0x80) {	/* primary */
213 			base0 = 0x1f0;
214 			base1 = 0x3f4;
215 		} else {			/* secondary */
216 			base0 = 0x170;
217 			base1 = 0x374;
218 		}
219 
220 		pci_write_config_dword(dev, PCI_BASE_ADDRESS_0,
221 				       base0 | PCI_BASE_ADDRESS_SPACE_IO);
222 		pci_write_config_dword(dev, PCI_BASE_ADDRESS_1,
223 				       base1 | PCI_BASE_ADDRESS_SPACE_IO);
224 
225 		dev->resource[0].start = 0;
226 		dev->resource[0].end   = 0;
227 		dev->resource[0].flags = 0;
228 
229 		dev->resource[1].start = 0;
230 		dev->resource[1].end   = 0;
231 		dev->resource[1].flags = 0;
232 	} else if (PCI_FUNC(dev->devfn) == 0) {
233 		/*
234 		 * Setup IDE IRQ routing.
235 		 */
236 		pci_write_config_byte(dev, 0x4b, 14);
237 		pci_write_config_byte(dev, 0x4c, 15);
238 
239 		/*
240 		 * Disable FREQACK handshake, enable USB.
241 		 */
242 		pci_write_config_byte(dev, 0x4d, 0x41);
243 
244 		/*
245 		 * Enable PCI retry, and PCI post-write buffer.
246 		 */
247 		pci_write_config_byte(dev, 0x44, 0x17);
248 
249 		/*
250 		 * Enable ISA master and DMA post write buffering.
251 		 */
252 		pci_write_config_byte(dev, 0x45, 0x03);
253 	}
254 }
255 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693, pci_fixup_cy82c693);
256 
257 static void __init pci_fixup_it8152(struct pci_dev *dev)
258 {
259 	int i;
260 	/* fixup for ITE 8152 devices */
261 	/* FIXME: add defines for class 0x68000 and 0x80103 */
262 	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_HOST ||
263 	    dev->class == 0x68000 ||
264 	    dev->class == 0x80103) {
265 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
266 			dev->resource[i].start = 0;
267 			dev->resource[i].end   = 0;
268 			dev->resource[i].flags = 0;
269 		}
270 	}
271 }
272 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ITE, PCI_DEVICE_ID_ITE_8152, pci_fixup_it8152);
273 
274 
275 
276 void __devinit pcibios_update_irq(struct pci_dev *dev, int irq)
277 {
278 	if (debug_pci)
279 		printk("PCI: Assigning IRQ %02d to %s\n", irq, pci_name(dev));
280 	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
281 }
282 
283 /*
284  * If the bus contains any of these devices, then we must not turn on
285  * parity checking of any kind.  Currently this is CyberPro 20x0 only.
286  */
287 static inline int pdev_bad_for_parity(struct pci_dev *dev)
288 {
289 	return ((dev->vendor == PCI_VENDOR_ID_INTERG &&
290 		 (dev->device == PCI_DEVICE_ID_INTERG_2000 ||
291 		  dev->device == PCI_DEVICE_ID_INTERG_2010)) ||
292 		(dev->vendor == PCI_VENDOR_ID_ITE &&
293 		 dev->device == PCI_DEVICE_ID_ITE_8152));
294 
295 }
296 
297 /*
298  * Adjust the device resources from bus-centric to Linux-centric.
299  */
300 static void __devinit
301 pdev_fixup_device_resources(struct pci_sys_data *root, struct pci_dev *dev)
302 {
303 	resource_size_t offset;
304 	int i;
305 
306 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
307 		if (dev->resource[i].start == 0)
308 			continue;
309 		if (dev->resource[i].flags & IORESOURCE_MEM)
310 			offset = root->mem_offset;
311 		else
312 			offset = root->io_offset;
313 
314 		dev->resource[i].start += offset;
315 		dev->resource[i].end   += offset;
316 	}
317 }
318 
319 static void __devinit
320 pbus_assign_bus_resources(struct pci_bus *bus, struct pci_sys_data *root)
321 {
322 	struct pci_dev *dev = bus->self;
323 	int i;
324 
325 	if (!dev) {
326 		/*
327 		 * Assign root bus resources.
328 		 */
329 		for (i = 0; i < 3; i++)
330 			bus->resource[i] = root->resource[i];
331 	}
332 }
333 
334 /*
335  * pcibios_fixup_bus - Called after each bus is probed,
336  * but before its children are examined.
337  */
338 void pcibios_fixup_bus(struct pci_bus *bus)
339 {
340 	struct pci_sys_data *root = bus->sysdata;
341 	struct pci_dev *dev;
342 	u16 features = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_FAST_BACK;
343 
344 	pbus_assign_bus_resources(bus, root);
345 
346 	/*
347 	 * Walk the devices on this bus, working out what we can
348 	 * and can't support.
349 	 */
350 	list_for_each_entry(dev, &bus->devices, bus_list) {
351 		u16 status;
352 
353 		pdev_fixup_device_resources(root, dev);
354 
355 		pci_read_config_word(dev, PCI_STATUS, &status);
356 
357 		/*
358 		 * If any device on this bus does not support fast back
359 		 * to back transfers, then the bus as a whole is not able
360 		 * to support them.  Having fast back to back transfers
361 		 * on saves us one PCI cycle per transaction.
362 		 */
363 		if (!(status & PCI_STATUS_FAST_BACK))
364 			features &= ~PCI_COMMAND_FAST_BACK;
365 
366 		if (pdev_bad_for_parity(dev))
367 			features &= ~(PCI_COMMAND_SERR | PCI_COMMAND_PARITY);
368 
369 		switch (dev->class >> 8) {
370 		case PCI_CLASS_BRIDGE_PCI:
371 			pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &status);
372 			status |= PCI_BRIDGE_CTL_PARITY|PCI_BRIDGE_CTL_MASTER_ABORT;
373 			status &= ~(PCI_BRIDGE_CTL_BUS_RESET|PCI_BRIDGE_CTL_FAST_BACK);
374 			pci_write_config_word(dev, PCI_BRIDGE_CONTROL, status);
375 			break;
376 
377 		case PCI_CLASS_BRIDGE_CARDBUS:
378 			pci_read_config_word(dev, PCI_CB_BRIDGE_CONTROL, &status);
379 			status |= PCI_CB_BRIDGE_CTL_PARITY|PCI_CB_BRIDGE_CTL_MASTER_ABORT;
380 			pci_write_config_word(dev, PCI_CB_BRIDGE_CONTROL, status);
381 			break;
382 		}
383 	}
384 
385 	/*
386 	 * Now walk the devices again, this time setting them up.
387 	 */
388 	list_for_each_entry(dev, &bus->devices, bus_list) {
389 		u16 cmd;
390 
391 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
392 		cmd |= features;
393 		pci_write_config_word(dev, PCI_COMMAND, cmd);
394 
395 		pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE,
396 				      L1_CACHE_BYTES >> 2);
397 	}
398 
399 	/*
400 	 * Propagate the flags to the PCI bridge.
401 	 */
402 	if (bus->self && bus->self->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
403 		if (features & PCI_COMMAND_FAST_BACK)
404 			bus->bridge_ctl |= PCI_BRIDGE_CTL_FAST_BACK;
405 		if (features & PCI_COMMAND_PARITY)
406 			bus->bridge_ctl |= PCI_BRIDGE_CTL_PARITY;
407 	}
408 
409 	/*
410 	 * Report what we did for this bus
411 	 */
412 	printk(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
413 		bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
414 }
415 
416 /*
417  * Convert from Linux-centric to bus-centric addresses for bridge devices.
418  */
419 void
420 pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
421 			 struct resource *res)
422 {
423 	struct pci_sys_data *root = dev->sysdata;
424 	unsigned long offset = 0;
425 
426 	if (res->flags & IORESOURCE_IO)
427 		offset = root->io_offset;
428 	if (res->flags & IORESOURCE_MEM)
429 		offset = root->mem_offset;
430 
431 	region->start = res->start - offset;
432 	region->end   = res->end - offset;
433 }
434 
435 void __devinit
436 pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
437 			struct pci_bus_region *region)
438 {
439 	struct pci_sys_data *root = dev->sysdata;
440 	unsigned long offset = 0;
441 
442 	if (res->flags & IORESOURCE_IO)
443 		offset = root->io_offset;
444 	if (res->flags & IORESOURCE_MEM)
445 		offset = root->mem_offset;
446 
447 	res->start = region->start + offset;
448 	res->end   = region->end + offset;
449 }
450 
451 #ifdef CONFIG_HOTPLUG
452 EXPORT_SYMBOL(pcibios_fixup_bus);
453 EXPORT_SYMBOL(pcibios_resource_to_bus);
454 EXPORT_SYMBOL(pcibios_bus_to_resource);
455 #endif
456 
457 /*
458  * Swizzle the device pin each time we cross a bridge.
459  * This might update pin and returns the slot number.
460  */
461 static u8 __devinit pcibios_swizzle(struct pci_dev *dev, u8 *pin)
462 {
463 	struct pci_sys_data *sys = dev->sysdata;
464 	int slot = 0, oldpin = *pin;
465 
466 	if (sys->swizzle)
467 		slot = sys->swizzle(dev, pin);
468 
469 	if (debug_pci)
470 		printk("PCI: %s swizzling pin %d => pin %d slot %d\n",
471 			pci_name(dev), oldpin, *pin, slot);
472 
473 	return slot;
474 }
475 
476 /*
477  * Map a slot/pin to an IRQ.
478  */
479 static int pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
480 {
481 	struct pci_sys_data *sys = dev->sysdata;
482 	int irq = -1;
483 
484 	if (sys->map_irq)
485 		irq = sys->map_irq(dev, slot, pin);
486 
487 	if (debug_pci)
488 		printk("PCI: %s mapping slot %d pin %d => irq %d\n",
489 			pci_name(dev), slot, pin, irq);
490 
491 	return irq;
492 }
493 
494 static void __init pcibios_init_hw(struct hw_pci *hw)
495 {
496 	struct pci_sys_data *sys = NULL;
497 	int ret;
498 	int nr, busnr;
499 
500 	for (nr = busnr = 0; nr < hw->nr_controllers; nr++) {
501 		sys = kzalloc(sizeof(struct pci_sys_data), GFP_KERNEL);
502 		if (!sys)
503 			panic("PCI: unable to allocate sys data!");
504 
505 #ifdef CONFIG_PCI_DOMAINS
506 		sys->domain  = hw->domain;
507 #endif
508 		sys->hw      = hw;
509 		sys->busnr   = busnr;
510 		sys->swizzle = hw->swizzle;
511 		sys->map_irq = hw->map_irq;
512 		sys->resource[0] = &ioport_resource;
513 		sys->resource[1] = &iomem_resource;
514 
515 		ret = hw->setup(nr, sys);
516 
517 		if (ret > 0) {
518 			sys->bus = hw->scan(nr, sys);
519 
520 			if (!sys->bus)
521 				panic("PCI: unable to scan bus!");
522 
523 			busnr = sys->bus->subordinate + 1;
524 
525 			list_add(&sys->node, &hw->buses);
526 		} else {
527 			kfree(sys);
528 			if (ret < 0)
529 				break;
530 		}
531 	}
532 }
533 
534 void __init pci_common_init(struct hw_pci *hw)
535 {
536 	struct pci_sys_data *sys;
537 
538 	INIT_LIST_HEAD(&hw->buses);
539 
540 	if (hw->preinit)
541 		hw->preinit();
542 	pcibios_init_hw(hw);
543 	if (hw->postinit)
544 		hw->postinit();
545 
546 	pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq);
547 
548 	list_for_each_entry(sys, &hw->buses, node) {
549 		struct pci_bus *bus = sys->bus;
550 
551 		if (!use_firmware) {
552 			/*
553 			 * Size the bridge windows.
554 			 */
555 			pci_bus_size_bridges(bus);
556 
557 			/*
558 			 * Assign resources.
559 			 */
560 			pci_bus_assign_resources(bus);
561 
562 			/*
563 			 * Enable bridges
564 			 */
565 			pci_enable_bridges(bus);
566 		}
567 
568 		/*
569 		 * Tell drivers about devices found.
570 		 */
571 		pci_bus_add_devices(bus);
572 	}
573 }
574 
575 char * __init pcibios_setup(char *str)
576 {
577 	if (!strcmp(str, "debug")) {
578 		debug_pci = 1;
579 		return NULL;
580 	} else if (!strcmp(str, "firmware")) {
581 		use_firmware = 1;
582 		return NULL;
583 	}
584 	return str;
585 }
586 
587 /*
588  * From arch/i386/kernel/pci-i386.c:
589  *
590  * We need to avoid collisions with `mirrored' VGA ports
591  * and other strange ISA hardware, so we always want the
592  * addresses to be allocated in the 0x000-0x0ff region
593  * modulo 0x400.
594  *
595  * Why? Because some silly external IO cards only decode
596  * the low 10 bits of the IO address. The 0x00-0xff region
597  * is reserved for motherboard devices that decode all 16
598  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
599  * but we want to try to avoid allocating at 0x2900-0x2bff
600  * which might be mirrored at 0x0100-0x03ff..
601  */
602 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
603 				resource_size_t size, resource_size_t align)
604 {
605 	resource_size_t start = res->start;
606 
607 	if (res->flags & IORESOURCE_IO && start & 0x300)
608 		start = (start + 0x3ff) & ~0x3ff;
609 
610 	start = (start + align - 1) & ~(align - 1);
611 
612 	return start;
613 }
614 
615 /**
616  * pcibios_enable_device - Enable I/O and memory.
617  * @dev: PCI device to be enabled
618  */
619 int pcibios_enable_device(struct pci_dev *dev, int mask)
620 {
621 	u16 cmd, old_cmd;
622 	int idx;
623 	struct resource *r;
624 
625 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
626 	old_cmd = cmd;
627 	for (idx = 0; idx < 6; idx++) {
628 		/* Only set up the requested stuff */
629 		if (!(mask & (1 << idx)))
630 			continue;
631 
632 		r = dev->resource + idx;
633 		if (!r->start && r->end) {
634 			printk(KERN_ERR "PCI: Device %s not available because"
635 			       " of resource collisions\n", pci_name(dev));
636 			return -EINVAL;
637 		}
638 		if (r->flags & IORESOURCE_IO)
639 			cmd |= PCI_COMMAND_IO;
640 		if (r->flags & IORESOURCE_MEM)
641 			cmd |= PCI_COMMAND_MEMORY;
642 	}
643 
644 	/*
645 	 * Bridges (eg, cardbus bridges) need to be fully enabled
646 	 */
647 	if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
648 		cmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
649 
650 	if (cmd != old_cmd) {
651 		printk("PCI: enabling device %s (%04x -> %04x)\n",
652 		       pci_name(dev), old_cmd, cmd);
653 		pci_write_config_word(dev, PCI_COMMAND, cmd);
654 	}
655 	return 0;
656 }
657 
658 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
659 			enum pci_mmap_state mmap_state, int write_combine)
660 {
661 	struct pci_sys_data *root = dev->sysdata;
662 	unsigned long phys;
663 
664 	if (mmap_state == pci_mmap_io) {
665 		return -EINVAL;
666 	} else {
667 		phys = vma->vm_pgoff + (root->mem_offset >> PAGE_SHIFT);
668 	}
669 
670 	/*
671 	 * Mark this as IO
672 	 */
673 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
674 
675 	if (remap_pfn_range(vma, vma->vm_start, phys,
676 			     vma->vm_end - vma->vm_start,
677 			     vma->vm_page_prot))
678 		return -EAGAIN;
679 
680 	return 0;
681 }
682