1/*
2 * arch/xtensa/kernel/pci.c
3 *
4 * PCI bios-type initialisation for PCI machines
5 *
6 * This program is free software; you can redistribute  it and/or modify it
7 * under  the terms of  the GNU General  Public License as published by the
8 * Free Software Foundation;  either version 2 of the  License, or (at your
9 * option) any later version.
10 *
11 * Copyright (C) 2001-2005 Tensilica Inc.
12 *
13 * Based largely on work from Cort (ppc/kernel/pci.c)
14 * IO functions copied from sparc.
15 *
16 * Chris Zankel <chris@zankel.net>
17 *
18 */
19
20#include <linux/kernel.h>
21#include <linux/pci.h>
22#include <linux/delay.h>
23#include <linux/string.h>
24#include <linux/init.h>
25#include <linux/sched.h>
26#include <linux/errno.h>
27#include <linux/bootmem.h>
28
29#include <asm/pci-bridge.h>
30#include <asm/platform.h>
31
32#undef DEBUG
33
34#ifdef DEBUG
35#define DBG(x...) printk(x)
36#else
37#define DBG(x...)
38#endif
39
40/* PCI Controller */
41
42
43/*
44 * pcibios_alloc_controller
45 * pcibios_enable_device
46 * pcibios_fixups
47 * pcibios_align_resource
48 * pcibios_fixup_bus
49 * pcibios_setup
50 * pci_bus_add_device
51 * pci_mmap_page_range
52 */
53
54struct pci_controller* pci_ctrl_head;
55struct pci_controller** pci_ctrl_tail = &pci_ctrl_head;
56
57static int pci_bus_count;
58
59/*
60 * We need to avoid collisions with `mirrored' VGA ports
61 * and other strange ISA hardware, so we always want the
62 * addresses to be allocated in the 0x000-0x0ff region
63 * modulo 0x400.
64 *
65 * Why? Because some silly external IO cards only decode
66 * the low 10 bits of the IO address. The 0x00-0xff region
67 * is reserved for motherboard devices that decode all 16
68 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
69 * but we want to try to avoid allocating at 0x2900-0x2bff
70 * which might have be mirrored at 0x0100-0x03ff..
71 */
72void
73pcibios_align_resource(void *data, struct resource *res, resource_size_t size,
74    		       resource_size_t align)
75{
76	struct pci_dev *dev = data;
77
78	if (res->flags & IORESOURCE_IO) {
79		resource_size_t start = res->start;
80
81		if (size > 0x100) {
82			printk(KERN_ERR "PCI: I/O Region %s/%d too large"
83			       " (%ld bytes)\n", pci_name(dev),
84			       dev->resource - res, size);
85		}
86
87		if (start & 0x300) {
88			start = (start + 0x3ff) & ~0x3ff;
89			res->start = start;
90		}
91	}
92}
93
94int
95pcibios_enable_resources(struct pci_dev *dev, int mask)
96{
97	u16 cmd, old_cmd;
98	int idx;
99	struct resource *r;
100
101	pci_read_config_word(dev, PCI_COMMAND, &cmd);
102	old_cmd = cmd;
103	for(idx=0; idx<6; idx++) {
104		r = &dev->resource[idx];
105		if (!r->start && r->end) {
106			printk (KERN_ERR "PCI: Device %s not available because "
107				"of resource collisions\n", pci_name(dev));
108			return -EINVAL;
109		}
110		if (r->flags & IORESOURCE_IO)
111			cmd |= PCI_COMMAND_IO;
112		if (r->flags & IORESOURCE_MEM)
113			cmd |= PCI_COMMAND_MEMORY;
114	}
115	if (dev->resource[PCI_ROM_RESOURCE].start)
116		cmd |= PCI_COMMAND_MEMORY;
117	if (cmd != old_cmd) {
118		printk("PCI: Enabling device %s (%04x -> %04x)\n",
119			pci_name(dev), old_cmd, cmd);
120		pci_write_config_word(dev, PCI_COMMAND, cmd);
121	}
122	return 0;
123}
124
125struct pci_controller * __init pcibios_alloc_controller(void)
126{
127	struct pci_controller *pci_ctrl;
128
129	pci_ctrl = (struct pci_controller *)alloc_bootmem(sizeof(*pci_ctrl));
130	memset(pci_ctrl, 0, sizeof(struct pci_controller));
131
132	*pci_ctrl_tail = pci_ctrl;
133	pci_ctrl_tail = &pci_ctrl->next;
134
135	return pci_ctrl;
136}
137
138static int __init pcibios_init(void)
139{
140	struct pci_controller *pci_ctrl;
141	struct pci_bus *bus;
142	int next_busno = 0, i;
143
144	printk("PCI: Probing PCI hardware\n");
145
146	/* Scan all of the recorded PCI controllers.  */
147	for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
148		pci_ctrl->last_busno = 0xff;
149		bus = pci_scan_bus(pci_ctrl->first_busno, pci_ctrl->ops,
150				   pci_ctrl);
151		if (pci_ctrl->io_resource.flags) {
152			unsigned long offs;
153
154			offs = (unsigned long)pci_ctrl->io_space.base;
155			pci_ctrl->io_resource.start += offs;
156			pci_ctrl->io_resource.end += offs;
157			bus->resource[0] = &pci_ctrl->io_resource;
158		}
159		for (i = 0; i < 3; ++i)
160			if (pci_ctrl->mem_resources[i].flags)
161				bus->resource[i+1] =&pci_ctrl->mem_resources[i];
162		pci_ctrl->bus = bus;
163		pci_ctrl->last_busno = bus->subordinate;
164		if (next_busno <= pci_ctrl->last_busno)
165			next_busno = pci_ctrl->last_busno+1;
166	}
167	pci_bus_count = next_busno;
168
169	return platform_pcibios_fixup();
170}
171
172subsys_initcall(pcibios_init);
173
174void __init pcibios_fixup_bus(struct pci_bus *bus)
175{
176	struct pci_controller *pci_ctrl = bus->sysdata;
177	struct resource *res;
178	unsigned long io_offset;
179	int i;
180
181	io_offset = (unsigned long)pci_ctrl->io_space.base;
182	if (bus->parent == NULL) {
183		/* this is a host bridge - fill in its resources */
184		pci_ctrl->bus = bus;
185
186		bus->resource[0] = res = &pci_ctrl->io_resource;
187		if (!res->flags) {
188			if (io_offset)
189				printk (KERN_ERR "I/O resource not set for host"
190					" bridge %d\n", pci_ctrl->index);
191			res->start = 0;
192			res->end = IO_SPACE_LIMIT;
193			res->flags = IORESOURCE_IO;
194		}
195		res->start += io_offset;
196		res->end += io_offset;
197
198		for (i = 0; i < 3; i++) {
199			res = &pci_ctrl->mem_resources[i];
200			if (!res->flags) {
201				if (i > 0)
202					continue;
203				printk(KERN_ERR "Memory resource not set for "
204				       "host bridge %d\n", pci_ctrl->index);
205				res->start = 0;
206				res->end = ~0U;
207				res->flags = IORESOURCE_MEM;
208			}
209			bus->resource[i+1] = res;
210		}
211	} else {
212		/* This is a subordinate bridge */
213		pci_read_bridge_bases(bus);
214
215		for (i = 0; i < 4; i++) {
216			if ((res = bus->resource[i]) == NULL || !res->flags)
217				continue;
218			if (io_offset && (res->flags & IORESOURCE_IO)) {
219				res->start += io_offset;
220				res->end += io_offset;
221			}
222		}
223	}
224}
225
226char __init *pcibios_setup(char *str)
227{
228	return str;
229}
230
231/* the next one is stolen from the alpha port... */
232
233void __init
234pcibios_update_irq(struct pci_dev *dev, int irq)
235{
236	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
237}
238
239int pcibios_enable_device(struct pci_dev *dev, int mask)
240{
241	u16 cmd, old_cmd;
242	int idx;
243	struct resource *r;
244
245	pci_read_config_word(dev, PCI_COMMAND, &cmd);
246	old_cmd = cmd;
247	for (idx=0; idx<6; idx++) {
248		r = &dev->resource[idx];
249		if (!r->start && r->end) {
250			printk(KERN_ERR "PCI: Device %s not available because "
251			       "of resource collisions\n", pci_name(dev));
252			return -EINVAL;
253		}
254		if (r->flags & IORESOURCE_IO)
255			cmd |= PCI_COMMAND_IO;
256		if (r->flags & IORESOURCE_MEM)
257			cmd |= PCI_COMMAND_MEMORY;
258	}
259	if (cmd != old_cmd) {
260		printk("PCI: Enabling device %s (%04x -> %04x)\n",
261		       pci_name(dev), old_cmd, cmd);
262		pci_write_config_word(dev, PCI_COMMAND, cmd);
263	}
264
265	return 0;
266}
267
268#ifdef CONFIG_PROC_FS
269
270/*
271 * Return the index of the PCI controller for device pdev.
272 */
273
274int
275pci_controller_num(struct pci_dev *dev)
276{
277	struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
278	return pci_ctrl->index;
279}
280
281#endif /* CONFIG_PROC_FS */
282
283/*
284 * Platform support for /proc/bus/pci/X/Y mmap()s,
285 * modelled on the sparc64 implementation by Dave Miller.
286 *  -- paulus.
287 */
288
289static __inline__ int
290__pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma,
291		       enum pci_mmap_state mmap_state)
292{
293	struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
294	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
295	unsigned long io_offset = 0;
296	int i, res_bit;
297
298	if (pci_ctrl == 0)
299		return -EINVAL;		/* should never happen */
300
301	/* If memory, add on the PCI bridge address offset */
302	if (mmap_state == pci_mmap_mem) {
303		res_bit = IORESOURCE_MEM;
304	} else {
305		io_offset = (unsigned long)pci_ctrl->io_space.base;
306		offset += io_offset;
307		res_bit = IORESOURCE_IO;
308	}
309
310	/*
311	 * Check that the offset requested corresponds to one of the
312	 * resources of the device.
313	 */
314	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
315		struct resource *rp = &dev->resource[i];
316		int flags = rp->flags;
317
318		/* treat ROM as memory (should be already) */
319		if (i == PCI_ROM_RESOURCE)
320			flags |= IORESOURCE_MEM;
321
322		/* Active and same type? */
323		if ((flags & res_bit) == 0)
324			continue;
325
326		/* In the range of this resource? */
327		if (offset < (rp->start & PAGE_MASK) || offset > rp->end)
328			continue;
329
330		/* found it! construct the final physical address */
331		if (mmap_state == pci_mmap_io)
332			offset += pci_ctrl->io_space.start - io_offset;
333		vma->vm_pgoff = offset >> PAGE_SHIFT;
334		return 0;
335	}
336
337	return -EINVAL;
338}
339
340/*
341 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
342 * device mapping.
343 */
344static __inline__ void
345__pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
346		      enum pci_mmap_state mmap_state, int write_combine)
347{
348	int prot = pgprot_val(vma->vm_page_prot);
349
350	/* Set to write-through */
351	prot &= ~_PAGE_NO_CACHE;
352	vma->vm_page_prot = __pgprot(prot);
353}
354
355/*
356 * Perform the actual remap of the pages for a PCI device mapping, as
357 * appropriate for this architecture.  The region in the process to map
358 * is described by vm_start and vm_end members of VMA, the base physical
359 * address is found in vm_pgoff.
360 * The pci device structure is provided so that architectures may make mapping
361 * decisions on a per-device or per-bus basis.
362 *
363 * Returns a negative error code on failure, zero on success.
364 */
365int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
366			enum pci_mmap_state mmap_state,
367			int write_combine)
368{
369	int ret;
370
371	ret = __pci_mmap_make_offset(dev, vma, mmap_state);
372	if (ret < 0)
373		return ret;
374
375	__pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine);
376
377	ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
378			         vma->vm_end - vma->vm_start,vma->vm_page_prot);
379
380	return ret;
381}
382
383/*
384 * This probably belongs here rather than ioport.c because
385 * we do not want this crud linked into SBus kernels.
386 * Also, think for a moment about likes of floppy.c that
387 * include architecture specific parts. They may want to redefine ins/outs.
388 *
389 * We do not use horrible macros here because we want to
390 * advance pointer by sizeof(size).
391 */
392void outsb(unsigned long addr, const void *src, unsigned long count) {
393        while (count) {
394                count -= 1;
395                writeb(*(const char *)src, addr);
396                src += 1;
397                addr += 1;
398        }
399}
400
401void outsw(unsigned long addr, const void *src, unsigned long count) {
402        while (count) {
403                count -= 2;
404                writew(*(const short *)src, addr);
405                src += 2;
406                addr += 2;
407        }
408}
409
410void outsl(unsigned long addr, const void *src, unsigned long count) {
411        while (count) {
412                count -= 4;
413                writel(*(const long *)src, addr);
414                src += 4;
415                addr += 4;
416        }
417}
418
419void insb(unsigned long addr, void *dst, unsigned long count) {
420        while (count) {
421                count -= 1;
422                *(unsigned char *)dst = readb(addr);
423                dst += 1;
424                addr += 1;
425        }
426}
427
428void insw(unsigned long addr, void *dst, unsigned long count) {
429        while (count) {
430                count -= 2;
431                *(unsigned short *)dst = readw(addr);
432                dst += 2;
433                addr += 2;
434        }
435}
436
437void insl(unsigned long addr, void *dst, unsigned long count) {
438        while (count) {
439                count -= 4;
440                *(unsigned long *)dst = readl(addr);
441                dst += 4;
442                addr += 4;
443        }
444}
445