1 /*
2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * Based in part on pci.c from Etherboot 5.4, by Ken Yap and David
5 * Munro, in turn based on the Linux kernel's PCI implementation.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22 FILE_LICENCE ( GPL2_OR_LATER );
23
24 #include <stdint.h>
25 #include <stdlib.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <gpxe/tables.h>
30 #include <gpxe/device.h>
31 #include <gpxe/pci.h>
32
33 /** @file
34 *
35 * PCI bus
36 *
37 */
38
39 static void pcibus_remove ( struct root_device *rootdev );
40
41 /**
42 * Read PCI BAR
43 *
44 * @v pci PCI device
45 * @v reg PCI register number
46 * @ret bar Base address register
47 *
48 * Reads the specified PCI base address register, including the flags
49 * portion. 64-bit BARs will be handled automatically. If the value
50 * of the 64-bit BAR exceeds the size of an unsigned long (i.e. if the
51 * high dword is non-zero on a 32-bit platform), then the value
52 * returned will be zero plus the flags for a 64-bit BAR. Unreachable
53 * 64-bit BARs are therefore returned as uninitialised 64-bit BARs.
54 */
pci_bar(struct pci_device * pci,unsigned int reg)55 static unsigned long pci_bar ( struct pci_device *pci, unsigned int reg ) {
56 uint32_t low;
57 uint32_t high;
58
59 pci_read_config_dword ( pci, reg, &low );
60 if ( ( low & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK) )
61 == (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64) ){
62 pci_read_config_dword ( pci, reg + 4, &high );
63 if ( high ) {
64 if ( sizeof ( unsigned long ) > sizeof ( uint32_t ) ) {
65 return ( ( ( uint64_t ) high << 32 ) | low );
66 } else {
67 DBG ( "Unhandled 64-bit BAR %08x%08x\n",
68 high, low );
69 return PCI_BASE_ADDRESS_MEM_TYPE_64;
70 }
71 }
72 }
73 return low;
74 }
75
76 /**
77 * Find the start of a PCI BAR
78 *
79 * @v pci PCI device
80 * @v reg PCI register number
81 * @ret start BAR start address
82 *
83 * Reads the specified PCI base address register, and returns the
84 * address portion of the BAR (i.e. without the flags).
85 *
86 * If the address exceeds the size of an unsigned long (i.e. if a
87 * 64-bit BAR has a non-zero high dword on a 32-bit machine), the
88 * return value will be zero.
89 */
pci_bar_start(struct pci_device * pci,unsigned int reg)90 unsigned long pci_bar_start ( struct pci_device *pci, unsigned int reg ) {
91 unsigned long bar;
92
93 bar = pci_bar ( pci, reg );
94 if ( (bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY ){
95 return ( bar & PCI_BASE_ADDRESS_MEM_MASK );
96 } else {
97 return ( bar & PCI_BASE_ADDRESS_IO_MASK );
98 }
99 }
100
101 /**
102 * Read membase and ioaddr for a PCI device
103 *
104 * @v pci PCI device
105 *
106 * This scans through all PCI BARs on the specified device. The first
107 * valid memory BAR is recorded as pci_device::membase, and the first
108 * valid IO BAR is recorded as pci_device::ioaddr.
109 *
110 * 64-bit BARs are handled automatically. On a 32-bit platform, if a
111 * 64-bit BAR has a non-zero high dword, it will be regarded as
112 * invalid.
113 */
pci_read_bases(struct pci_device * pci)114 static void pci_read_bases ( struct pci_device *pci ) {
115 unsigned long bar;
116 int reg;
117
118 for ( reg = PCI_BASE_ADDRESS_0; reg <= PCI_BASE_ADDRESS_5; reg += 4 ) {
119 bar = pci_bar ( pci, reg );
120 if ( bar & PCI_BASE_ADDRESS_SPACE_IO ) {
121 if ( ! pci->ioaddr )
122 pci->ioaddr =
123 ( bar & PCI_BASE_ADDRESS_IO_MASK );
124 } else {
125 if ( ! pci->membase )
126 pci->membase =
127 ( bar & PCI_BASE_ADDRESS_MEM_MASK );
128 /* Skip next BAR if 64-bit */
129 if ( bar & PCI_BASE_ADDRESS_MEM_TYPE_64 )
130 reg += 4;
131 }
132 }
133 }
134
135 /**
136 * Enable PCI device
137 *
138 * @v pci PCI device
139 *
140 * Set device to be a busmaster in case BIOS neglected to do so. Also
141 * adjust PCI latency timer to a reasonable value, 32.
142 */
adjust_pci_device(struct pci_device * pci)143 void adjust_pci_device ( struct pci_device *pci ) {
144 unsigned short new_command, pci_command;
145 unsigned char pci_latency;
146
147 pci_read_config_word ( pci, PCI_COMMAND, &pci_command );
148 new_command = ( pci_command | PCI_COMMAND_MASTER |
149 PCI_COMMAND_MEM | PCI_COMMAND_IO );
150 if ( pci_command != new_command ) {
151 DBG ( "PCI BIOS has not enabled device %02x:%02x.%x! "
152 "Updating PCI command %04x->%04x\n", pci->bus,
153 PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
154 pci_command, new_command );
155 pci_write_config_word ( pci, PCI_COMMAND, new_command );
156 }
157
158 pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency);
159 if ( pci_latency < 32 ) {
160 DBG ( "PCI device %02x:%02x.%x latency timer is unreasonably "
161 "low at %d. Setting to 32.\n", pci->bus,
162 PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
163 pci_latency );
164 pci_write_config_byte ( pci, PCI_LATENCY_TIMER, 32);
165 }
166 }
167
168 /**
169 * Probe a PCI device
170 *
171 * @v pci PCI device
172 * @ret rc Return status code
173 *
174 * Searches for a driver for the PCI device. If a driver is found,
175 * its probe() routine is called.
176 */
pci_probe(struct pci_device * pci)177 static int pci_probe ( struct pci_device *pci ) {
178 struct pci_driver *driver;
179 struct pci_device_id *id;
180 unsigned int i;
181 int rc;
182
183 DBG ( "Adding PCI device %02x:%02x.%x (%04x:%04x mem %lx io %lx "
184 "irq %d)\n", pci->bus, PCI_SLOT ( pci->devfn ),
185 PCI_FUNC ( pci->devfn ), pci->vendor, pci->device,
186 pci->membase, pci->ioaddr, pci->irq );
187
188 for_each_table_entry ( driver, PCI_DRIVERS ) {
189 for ( i = 0 ; i < driver->id_count ; i++ ) {
190 id = &driver->ids[i];
191 if ( ( id->vendor != PCI_ANY_ID ) &&
192 ( id->vendor != pci->vendor ) )
193 continue;
194 if ( ( id->device != PCI_ANY_ID ) &&
195 ( id->device != pci->device ) )
196 continue;
197 pci->driver = driver;
198 pci->driver_name = id->name;
199 DBG ( "...using driver %s\n", pci->driver_name );
200 if ( ( rc = driver->probe ( pci, id ) ) != 0 ) {
201 DBG ( "......probe failed\n" );
202 continue;
203 }
204 return 0;
205 }
206 }
207
208 DBG ( "...no driver found\n" );
209 return -ENOTTY;
210 }
211
212 /**
213 * Remove a PCI device
214 *
215 * @v pci PCI device
216 */
pci_remove(struct pci_device * pci)217 static void pci_remove ( struct pci_device *pci ) {
218 pci->driver->remove ( pci );
219 DBG ( "Removed PCI device %02x:%02x.%x\n", pci->bus,
220 PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ) );
221 }
222
223 /**
224 * Probe PCI root bus
225 *
226 * @v rootdev PCI bus root device
227 *
228 * Scans the PCI bus for devices and registers all devices it can
229 * find.
230 */
pcibus_probe(struct root_device * rootdev)231 static int pcibus_probe ( struct root_device *rootdev ) {
232 struct pci_device *pci = NULL;
233 unsigned int max_bus;
234 unsigned int bus;
235 unsigned int devfn;
236 uint8_t hdrtype = 0;
237 uint32_t tmp;
238 int rc;
239
240 max_bus = pci_max_bus();
241 for ( bus = 0 ; bus <= max_bus ; bus++ ) {
242 for ( devfn = 0 ; devfn <= 0xff ; devfn++ ) {
243
244 /* Allocate struct pci_device */
245 if ( ! pci )
246 pci = malloc ( sizeof ( *pci ) );
247 if ( ! pci ) {
248 rc = -ENOMEM;
249 goto err;
250 }
251 memset ( pci, 0, sizeof ( *pci ) );
252 pci->bus = bus;
253 pci->devfn = devfn;
254
255 /* Skip all but the first function on
256 * non-multifunction cards
257 */
258 if ( PCI_FUNC ( devfn ) == 0 ) {
259 pci_read_config_byte ( pci, PCI_HEADER_TYPE,
260 &hdrtype );
261 } else if ( ! ( hdrtype & 0x80 ) ) {
262 continue;
263 }
264
265 /* Check for physical device presence */
266 pci_read_config_dword ( pci, PCI_VENDOR_ID, &tmp );
267 if ( ( tmp == 0xffffffff ) || ( tmp == 0 ) )
268 continue;
269
270 /* Populate struct pci_device */
271 pci->vendor = ( tmp & 0xffff );
272 pci->device = ( tmp >> 16 );
273 pci_read_config_dword ( pci, PCI_REVISION, &tmp );
274 pci->class = ( tmp >> 8 );
275 pci_read_config_byte ( pci, PCI_INTERRUPT_LINE,
276 &pci->irq );
277 pci_read_bases ( pci );
278
279 /* Add to device hierarchy */
280 snprintf ( pci->dev.name, sizeof ( pci->dev.name ),
281 "PCI%02x:%02x.%x", bus,
282 PCI_SLOT ( devfn ), PCI_FUNC ( devfn ) );
283 pci->dev.desc.bus_type = BUS_TYPE_PCI;
284 pci->dev.desc.location = PCI_BUSDEVFN (bus, devfn);
285 pci->dev.desc.vendor = pci->vendor;
286 pci->dev.desc.device = pci->device;
287 pci->dev.desc.class = pci->class;
288 pci->dev.desc.ioaddr = pci->ioaddr;
289 pci->dev.desc.irq = pci->irq;
290 pci->dev.parent = &rootdev->dev;
291 list_add ( &pci->dev.siblings, &rootdev->dev.children);
292 INIT_LIST_HEAD ( &pci->dev.children );
293
294 /* Look for a driver */
295 if ( pci_probe ( pci ) == 0 ) {
296 /* pcidev registered, we can drop our ref */
297 pci = NULL;
298 } else {
299 /* Not registered; re-use struct pci_device */
300 list_del ( &pci->dev.siblings );
301 }
302 }
303 }
304
305 free ( pci );
306 return 0;
307
308 err:
309 free ( pci );
310 pcibus_remove ( rootdev );
311 return rc;
312 }
313
314 /**
315 * Remove PCI root bus
316 *
317 * @v rootdev PCI bus root device
318 */
pcibus_remove(struct root_device * rootdev)319 static void pcibus_remove ( struct root_device *rootdev ) {
320 struct pci_device *pci;
321 struct pci_device *tmp;
322
323 list_for_each_entry_safe ( pci, tmp, &rootdev->dev.children,
324 dev.siblings ) {
325 pci_remove ( pci );
326 list_del ( &pci->dev.siblings );
327 free ( pci );
328 }
329 }
330
331 /** PCI bus root device driver */
332 static struct root_driver pci_root_driver = {
333 .probe = pcibus_probe,
334 .remove = pcibus_remove,
335 };
336
337 /** PCI bus root device */
338 struct root_device pci_root_device __root_device = {
339 .dev = { .name = "PCI" },
340 .driver = &pci_root_driver,
341 };
342