1 /*
2 * arch/xtensa/lib/pci-auto.c
3 *
4 * PCI autoconfiguration library
5 *
6 * Copyright (C) 2001 - 2005 Tensilica Inc.
7 *
8 * Chris Zankel <zankel@tensilica.com, cez@zankel.net>
9 *
10 * Based on work from Matt Porter <mporter@mvista.com>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version.
16 */
17
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/pci.h>
21
22 #include <asm/pci-bridge.h>
23
24
25 /*
26 *
27 * Setting up a PCI
28 *
29 * pci_ctrl->first_busno = <first bus number (0)>
30 * pci_ctrl->last_busno = <last bus number (0xff)>
31 * pci_ctrl->ops = <PCI config operations>
32 * pci_ctrl->map_irq = <function to return the interrupt number for a device>
33 *
34 * pci_ctrl->io_space.start = <IO space start address (PCI view)>
35 * pci_ctrl->io_space.end = <IO space end address (PCI view)>
36 * pci_ctrl->io_space.base = <IO space offset: address 0 from CPU space>
37 * pci_ctrl->mem_space.start = <MEM space start address (PCI view)>
38 * pci_ctrl->mem_space.end = <MEM space end address (PCI view)>
39 * pci_ctrl->mem_space.base = <MEM space offset: address 0 from CPU space>
40 *
41 * pcibios_init_resource(&pci_ctrl->io_resource, <IO space start>,
42 * <IO space end>, IORESOURCE_IO, "PCI host bridge");
43 * pcibios_init_resource(&pci_ctrl->mem_resources[0], <MEM space start>,
44 * <MEM space end>, IORESOURCE_MEM, "PCI host bridge");
45 *
46 * pci_ctrl->last_busno = pciauto_bus_scan(pci_ctrl,pci_ctrl->first_busno);
47 *
48 * int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus)
49 *
50 */
51
52
53 /* define DEBUG to print some debugging messages. */
54
55 #undef DEBUG
56
57 #ifdef DEBUG
58 # define DBG(x...) printk(x)
59 #else
60 # define DBG(x...)
61 #endif
62
63 static int pciauto_upper_iospc;
64 static int pciauto_upper_memspc;
65
66 static struct pci_dev pciauto_dev;
67 static struct pci_bus pciauto_bus;
68
69 /*
70 * Helper functions
71 */
72
73 /* Initialize the bars of a PCI device. */
74
75 static void __init
pciauto_setup_bars(struct pci_dev * dev,int bar_limit)76 pciauto_setup_bars(struct pci_dev *dev, int bar_limit)
77 {
78 int bar_size;
79 int bar, bar_nr;
80 int *upper_limit;
81 int found_mem64 = 0;
82
83 for (bar = PCI_BASE_ADDRESS_0, bar_nr = 0;
84 bar <= bar_limit;
85 bar+=4, bar_nr++)
86 {
87 /* Tickle the BAR and get the size */
88 pci_write_config_dword(dev, bar, 0xffffffff);
89 pci_read_config_dword(dev, bar, &bar_size);
90
91 /* If BAR is not implemented go to the next BAR */
92 if (!bar_size)
93 continue;
94
95 /* Check the BAR type and set our address mask */
96 if (bar_size & PCI_BASE_ADDRESS_SPACE_IO)
97 {
98 bar_size &= PCI_BASE_ADDRESS_IO_MASK;
99 upper_limit = &pciauto_upper_iospc;
100 DBG("PCI Autoconfig: BAR %d, I/O, ", bar_nr);
101 }
102 else
103 {
104 if ((bar_size & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
105 PCI_BASE_ADDRESS_MEM_TYPE_64)
106 found_mem64 = 1;
107
108 bar_size &= PCI_BASE_ADDRESS_MEM_MASK;
109 upper_limit = &pciauto_upper_memspc;
110 DBG("PCI Autoconfig: BAR %d, Mem, ", bar_nr);
111 }
112
113 /* Allocate a base address (bar_size is negative!) */
114 *upper_limit = (*upper_limit + bar_size) & bar_size;
115
116 /* Write it out and update our limit */
117 pci_write_config_dword(dev, bar, *upper_limit);
118
119 /*
120 * If we are a 64-bit decoder then increment to the
121 * upper 32 bits of the bar and force it to locate
122 * in the lower 4GB of memory.
123 */
124
125 if (found_mem64)
126 pci_write_config_dword(dev, (bar+=4), 0x00000000);
127
128 DBG("size=0x%x, address=0x%x\n", ~bar_size + 1, *upper_limit);
129 }
130 }
131
132 /* Initialize the interrupt number. */
133
134 static void __init
pciauto_setup_irq(struct pci_controller * pci_ctrl,struct pci_dev * dev,int devfn)135 pciauto_setup_irq(struct pci_controller* pci_ctrl,struct pci_dev *dev,int devfn)
136 {
137 u8 pin;
138 int irq = 0;
139
140 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
141
142 /* Fix illegal pin numbers. */
143
144 if (pin == 0 || pin > 4)
145 pin = 1;
146
147 if (pci_ctrl->map_irq)
148 irq = pci_ctrl->map_irq(dev, PCI_SLOT(devfn), pin);
149
150 if (irq == -1)
151 irq = 0;
152
153 DBG("PCI Autoconfig: Interrupt %d, pin %d\n", irq, pin);
154
155 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
156 }
157
158
159 static void __init
pciauto_prescan_setup_bridge(struct pci_dev * dev,int current_bus,int sub_bus,int * iosave,int * memsave)160 pciauto_prescan_setup_bridge(struct pci_dev *dev, int current_bus,
161 int sub_bus, int *iosave, int *memsave)
162 {
163 /* Configure bus number registers */
164 pci_write_config_byte(dev, PCI_PRIMARY_BUS, current_bus);
165 pci_write_config_byte(dev, PCI_SECONDARY_BUS, sub_bus + 1);
166 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, 0xff);
167
168 /* Round memory allocator to 1MB boundary */
169 pciauto_upper_memspc &= ~(0x100000 - 1);
170 *memsave = pciauto_upper_memspc;
171
172 /* Round I/O allocator to 4KB boundary */
173 pciauto_upper_iospc &= ~(0x1000 - 1);
174 *iosave = pciauto_upper_iospc;
175
176 /* Set up memory and I/O filter limits, assume 32-bit I/O space */
177 pci_write_config_word(dev, PCI_MEMORY_LIMIT,
178 ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
179 pci_write_config_byte(dev, PCI_IO_LIMIT,
180 ((pciauto_upper_iospc - 1) & 0x0000f000) >> 8);
181 pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16,
182 ((pciauto_upper_iospc - 1) & 0xffff0000) >> 16);
183 }
184
185 static void __init
pciauto_postscan_setup_bridge(struct pci_dev * dev,int current_bus,int sub_bus,int * iosave,int * memsave)186 pciauto_postscan_setup_bridge(struct pci_dev *dev, int current_bus, int sub_bus,
187 int *iosave, int *memsave)
188 {
189 int cmdstat;
190
191 /* Configure bus number registers */
192 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, sub_bus);
193
194 /*
195 * Round memory allocator to 1MB boundary.
196 * If no space used, allocate minimum.
197 */
198 pciauto_upper_memspc &= ~(0x100000 - 1);
199 if (*memsave == pciauto_upper_memspc)
200 pciauto_upper_memspc -= 0x00100000;
201
202 pci_write_config_word(dev, PCI_MEMORY_BASE, pciauto_upper_memspc >> 16);
203
204 /* Allocate 1MB for pre-fretch */
205 pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT,
206 ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
207
208 pciauto_upper_memspc -= 0x100000;
209
210 pci_write_config_word(dev, PCI_PREF_MEMORY_BASE,
211 pciauto_upper_memspc >> 16);
212
213 /* Round I/O allocator to 4KB boundary */
214 pciauto_upper_iospc &= ~(0x1000 - 1);
215 if (*iosave == pciauto_upper_iospc)
216 pciauto_upper_iospc -= 0x1000;
217
218 pci_write_config_byte(dev, PCI_IO_BASE,
219 (pciauto_upper_iospc & 0x0000f000) >> 8);
220 pci_write_config_word(dev, PCI_IO_BASE_UPPER16,
221 pciauto_upper_iospc >> 16);
222
223 /* Enable memory and I/O accesses, enable bus master */
224 pci_read_config_dword(dev, PCI_COMMAND, &cmdstat);
225 pci_write_config_dword(dev, PCI_COMMAND,
226 cmdstat |
227 PCI_COMMAND_IO |
228 PCI_COMMAND_MEMORY |
229 PCI_COMMAND_MASTER);
230 }
231
232 /*
233 * Scan the current PCI bus.
234 */
235
236
pciauto_bus_scan(struct pci_controller * pci_ctrl,int current_bus)237 int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus)
238 {
239 int sub_bus, pci_devfn, pci_class, cmdstat, found_multi=0;
240 unsigned short vid;
241 unsigned char header_type;
242 struct pci_dev *dev = &pciauto_dev;
243
244 pciauto_dev.bus = &pciauto_bus;
245 pciauto_dev.sysdata = pci_ctrl;
246 pciauto_bus.ops = pci_ctrl->ops;
247
248 /*
249 * Fetch our I/O and memory space upper boundaries used
250 * to allocated base addresses on this pci_controller.
251 */
252
253 if (current_bus == pci_ctrl->first_busno)
254 {
255 pciauto_upper_iospc = pci_ctrl->io_resource.end + 1;
256 pciauto_upper_memspc = pci_ctrl->mem_resources[0].end + 1;
257 }
258
259 sub_bus = current_bus;
260
261 for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++)
262 {
263 /* Skip our host bridge */
264 if ((current_bus == pci_ctrl->first_busno) && (pci_devfn == 0))
265 continue;
266
267 if (PCI_FUNC(pci_devfn) && !found_multi)
268 continue;
269
270 pciauto_bus.number = current_bus;
271 pciauto_dev.devfn = pci_devfn;
272
273 /* If config space read fails from this device, move on */
274 if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type))
275 continue;
276
277 if (!PCI_FUNC(pci_devfn))
278 found_multi = header_type & 0x80;
279 pci_read_config_word(dev, PCI_VENDOR_ID, &vid);
280
281 if (vid == 0xffff || vid == 0x0000) {
282 found_multi = 0;
283 continue;
284 }
285
286 pci_read_config_dword(dev, PCI_CLASS_REVISION, &pci_class);
287
288 if ((pci_class >> 16) == PCI_CLASS_BRIDGE_PCI) {
289
290 int iosave, memsave;
291
292 DBG("PCI Autoconfig: Found P2P bridge, device %d\n",
293 PCI_SLOT(pci_devfn));
294
295 /* Allocate PCI I/O and/or memory space */
296 pciauto_setup_bars(dev, PCI_BASE_ADDRESS_1);
297
298 pciauto_prescan_setup_bridge(dev, current_bus, sub_bus,
299 &iosave, &memsave);
300 sub_bus = pciauto_bus_scan(pci_ctrl, sub_bus+1);
301 pciauto_postscan_setup_bridge(dev, current_bus, sub_bus,
302 &iosave, &memsave);
303 pciauto_bus.number = current_bus;
304
305 continue;
306
307 }
308
309
310 #if 0
311 /* Skip legacy mode IDE controller */
312
313 if ((pci_class >> 16) == PCI_CLASS_STORAGE_IDE) {
314
315 unsigned char prg_iface;
316 pci_read_config_byte(dev, PCI_CLASS_PROG, &prg_iface);
317
318 if (!(prg_iface & PCIAUTO_IDE_MODE_MASK)) {
319 DBG("PCI Autoconfig: Skipping legacy mode "
320 "IDE controller\n");
321 continue;
322 }
323 }
324 #endif
325
326 /*
327 * Found a peripheral, enable some standard
328 * settings
329 */
330
331 pci_read_config_dword(dev, PCI_COMMAND, &cmdstat);
332 pci_write_config_dword(dev, PCI_COMMAND,
333 cmdstat |
334 PCI_COMMAND_IO |
335 PCI_COMMAND_MEMORY |
336 PCI_COMMAND_MASTER);
337 pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x80);
338
339 /* Allocate PCI I/O and/or memory space */
340 DBG("PCI Autoconfig: Found Bus %d, Device %d, Function %d\n",
341 current_bus, PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn) );
342
343 pciauto_setup_bars(dev, PCI_BASE_ADDRESS_5);
344 pciauto_setup_irq(pci_ctrl, dev, pci_devfn);
345 }
346 return sub_bus;
347 }
348
349
350
351
352
353