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
22FILE_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
39static 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 */
55static 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 */
90unsigned 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 */
114static 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 */
143void 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 */
177static 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 */
217static 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 */
231static 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 */
319static 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 */
332static struct root_driver pci_root_driver = {
333	.probe = pcibus_probe,
334	.remove = pcibus_remove,
335};
336
337/** PCI bus root device */
338struct root_device pci_root_device __root_device = {
339	.dev = { .name = "PCI" },
340	.driver = &pci_root_driver,
341};
342