Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[linux-2.6] / arch / mn10300 / unit-asb2305 / pci-asb2305.c
1 /* ASB2305 PCI resource stuff
2  *
3  * Copyright (C) 2001 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  * - Derived from arch/i386/pci-i386.c
6  *   - Copyright 1997--2000 Martin Mares <mj@suse.cz>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public Licence
10  * as published by the Free Software Foundation; either version
11  * 2 of the Licence, or (at your option) any later version.
12  */
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/pci.h>
16 #include <linux/init.h>
17 #include <linux/ioport.h>
18 #include <linux/errno.h>
19 #include "pci-asb2305.h"
20
21 /*
22  * We need to avoid collisions with `mirrored' VGA ports
23  * and other strange ISA hardware, so we always want the
24  * addresses to be allocated in the 0x000-0x0ff region
25  * modulo 0x400.
26  *
27  * Why? Because some silly external IO cards only decode
28  * the low 10 bits of the IO address. The 0x00-0xff region
29  * is reserved for motherboard devices that decode all 16
30  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
31  * but we want to try to avoid allocating at 0x2900-0x2bff
32  * which might have be mirrored at 0x0100-0x03ff..
33  */
34 void pcibios_align_resource(void *data, struct resource *res,
35                             resource_size_t size, resource_size_t align)
36 {
37 #if 0
38         struct pci_dev *dev = data;
39
40         printk(KERN_DEBUG
41                "### PCIBIOS_ALIGN_RESOURCE(%s,,{%08lx-%08lx,%08lx},%lx)\n",
42                pci_name(dev),
43                res->start,
44                res->end,
45                res->flags,
46                size
47                );
48 #endif
49
50         if (res->flags & IORESOURCE_IO) {
51                 unsigned long start = res->start;
52
53                 if (start & 0x300) {
54                         start = (start + 0x3ff) & ~0x3ff;
55                         res->start = start;
56                 }
57         }
58 }
59
60
61 /*
62  *  Handle resources of PCI devices.  If the world were perfect, we could
63  *  just allocate all the resource regions and do nothing more.  It isn't.
64  *  On the other hand, we cannot just re-allocate all devices, as it would
65  *  require us to know lots of host bridge internals.  So we attempt to
66  *  keep as much of the original configuration as possible, but tweak it
67  *  when it's found to be wrong.
68  *
69  *  Known BIOS problems we have to work around:
70  *      - I/O or memory regions not configured
71  *      - regions configured, but not enabled in the command register
72  *      - bogus I/O addresses above 64K used
73  *      - expansion ROMs left enabled (this may sound harmless, but given
74  *        the fact the PCI specs explicitly allow address decoders to be
75  *        shared between expansion ROMs and other resource regions, it's
76  *        at least dangerous)
77  *
78  *  Our solution:
79  *      (1) Allocate resources for all buses behind PCI-to-PCI bridges.
80  *          This gives us fixed barriers on where we can allocate.
81  *      (2) Allocate resources for all enabled devices.  If there is
82  *          a collision, just mark the resource as unallocated. Also
83  *          disable expansion ROMs during this step.
84  *      (3) Try to allocate resources for disabled devices.  If the
85  *          resources were assigned correctly, everything goes well,
86  *          if they weren't, they won't disturb allocation of other
87  *          resources.
88  *      (4) Assign new addresses to resources which were either
89  *          not configured at all or misconfigured.  If explicitly
90  *          requested by the user, configure expansion ROM address
91  *          as well.
92  */
93 static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
94 {
95         struct pci_bus *bus;
96         struct pci_dev *dev;
97         int idx;
98         struct resource *r, *pr;
99
100         /* Depth-First Search on bus tree */
101         list_for_each_entry(bus, bus_list, node) {
102                 dev = bus->self;
103                 if (dev) {
104                         for (idx = PCI_BRIDGE_RESOURCES;
105                              idx < PCI_NUM_RESOURCES;
106                              idx++) {
107                                 r = &dev->resource[idx];
108                                 if (!r->flags)
109                                         continue;
110                                 pr = pci_find_parent_resource(dev, r);
111                                 if (!r->start ||
112                                     !pr ||
113                                     request_resource(pr, r) < 0) {
114                                         printk(KERN_ERR "PCI:"
115                                                " Cannot allocate resource"
116                                                " region %d of bridge %s\n",
117                                                idx, pci_name(dev));
118                                         /* Something is wrong with the region.
119                                          * Invalidate the resource to prevent
120                                          * child resource allocations in this
121                                          * range. */
122                                         r->flags = 0;
123                                 }
124                         }
125                 }
126                 pcibios_allocate_bus_resources(&bus->children);
127         }
128 }
129
130 static void __init pcibios_allocate_resources(int pass)
131 {
132         struct pci_dev *dev = NULL;
133         int idx, disabled;
134         u16 command;
135         struct resource *r, *pr;
136
137         for_each_pci_dev(dev) {
138                 pci_read_config_word(dev, PCI_COMMAND, &command);
139                 for (idx = 0; idx < 6; idx++) {
140                         r = &dev->resource[idx];
141                         if (r->parent)          /* Already allocated */
142                                 continue;
143                         if (!r->start)          /* Address not assigned */
144                                 continue;
145                         if (r->flags & IORESOURCE_IO)
146                                 disabled = !(command & PCI_COMMAND_IO);
147                         else
148                                 disabled = !(command & PCI_COMMAND_MEMORY);
149                         if (pass == disabled) {
150                                 DBG("PCI[%s]: Resource %08lx-%08lx"
151                                     " (f=%lx, d=%d, p=%d)\n",
152                                     pci_name(dev), r->start, r->end, r->flags,
153                                     disabled, pass);
154                                 pr = pci_find_parent_resource(dev, r);
155                                 if (!pr || request_resource(pr, r) < 0) {
156                                         printk(KERN_ERR "PCI:"
157                                                " Cannot allocate resource"
158                                                " region %d of device %s\n",
159                                                idx, pci_name(dev));
160                                         /* We'll assign a new address later */
161                                         r->end -= r->start;
162                                         r->start = 0;
163                                 }
164                         }
165                 }
166                 if (!pass) {
167                         r = &dev->resource[PCI_ROM_RESOURCE];
168                         if (r->flags & IORESOURCE_ROM_ENABLE) {
169                                 /* Turn the ROM off, leave the resource region,
170                                  * but keep it unregistered. */
171                                 u32 reg;
172                                 DBG("PCI: Switching off ROM of %s\n",
173                                     pci_name(dev));
174                                 r->flags &= ~IORESOURCE_ROM_ENABLE;
175                                 pci_read_config_dword(
176                                         dev, dev->rom_base_reg, &reg);
177                                 pci_write_config_dword(
178                                         dev, dev->rom_base_reg,
179                                         reg & ~PCI_ROM_ADDRESS_ENABLE);
180                         }
181                 }
182         }
183 }
184
185 static int __init pcibios_assign_resources(void)
186 {
187         struct pci_dev *dev = NULL;
188         struct resource *r, *pr;
189
190         if (!(pci_probe & PCI_ASSIGN_ROMS)) {
191                 /* Try to use BIOS settings for ROMs, otherwise let
192                    pci_assign_unassigned_resources() allocate the new
193                    addresses. */
194                 for_each_pci_dev(dev) {
195                         r = &dev->resource[PCI_ROM_RESOURCE];
196                         if (!r->flags || !r->start)
197                                 continue;
198                         pr = pci_find_parent_resource(dev, r);
199                         if (!pr || request_resource(pr, r) < 0) {
200                                 r->end -= r->start;
201                                 r->start = 0;
202                         }
203                 }
204         }
205
206         pci_assign_unassigned_resources();
207
208         return 0;
209 }
210
211 fs_initcall(pcibios_assign_resources);
212
213 void __init pcibios_resource_survey(void)
214 {
215         DBG("PCI: Allocating resources\n");
216         pcibios_allocate_bus_resources(&pci_root_buses);
217         pcibios_allocate_resources(0);
218         pcibios_allocate_resources(1);
219 }
220
221 int pcibios_enable_resources(struct pci_dev *dev, int mask)
222 {
223         u16 cmd, old_cmd;
224         int idx;
225         struct resource *r;
226
227         pci_read_config_word(dev, PCI_COMMAND, &cmd);
228         old_cmd = cmd;
229
230         for (idx = 0; idx < 6; idx++) {
231                 /* Only set up the requested stuff */
232                 if (!(mask & (1 << idx)))
233                         continue;
234
235                 r = &dev->resource[idx];
236
237                 if (!r->start && r->end) {
238                         printk(KERN_ERR
239                                "PCI: Device %s not available because of"
240                                " resource collisions\n",
241                                pci_name(dev));
242                         return -EINVAL;
243                 }
244
245                 if (r->flags & IORESOURCE_IO)
246                         cmd |= PCI_COMMAND_IO;
247                 if (r->flags & IORESOURCE_MEM)
248                         cmd |= PCI_COMMAND_MEMORY;
249         }
250
251         if (dev->resource[PCI_ROM_RESOURCE].start)
252                 cmd |= PCI_COMMAND_MEMORY;
253
254         if (cmd != old_cmd)
255                 pci_write_config_word(dev, PCI_COMMAND, cmd);
256
257         return 0;
258 }
259
260 /*
261  *  If we set up a device for bus mastering, we need to check the latency
262  *  timer as certain crappy BIOSes forget to set it properly.
263  */
264 unsigned int pcibios_max_latency = 255;
265
266 void pcibios_set_master(struct pci_dev *dev)
267 {
268         u8 lat;
269
270         pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
271
272         if (lat < 16)
273                 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
274         else if (lat > pcibios_max_latency)
275                 lat = pcibios_max_latency;
276         else
277                 return;
278
279         pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
280 }
281
282 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
283                         enum pci_mmap_state mmap_state, int write_combine)
284 {
285         unsigned long prot;
286
287         /* Leave vm_pgoff as-is, the PCI space address is the physical
288          * address on this platform.
289          */
290         vma->vm_flags |= VM_LOCKED | VM_IO;
291
292         prot = pgprot_val(vma->vm_page_prot);
293         prot &= ~_PAGE_CACHE;
294         vma->vm_page_prot = __pgprot(prot);
295
296         /* Write-combine setting is ignored */
297         if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
298                                vma->vm_end - vma->vm_start,
299                                vma->vm_page_prot))
300                 return -EAGAIN;
301
302         return 0;
303 }