pci_subr.c revision 69783
1/*-
2 * Copyright (c) 1994,1995 Stefan Esser, Wolfgang StanglMeier
3 * Copyright (c) 2000 Michael Smith <msmith@freebsd.org>
4 * Copyright (c) 2000 BSDi
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 *	$FreeBSD: head/sys/dev/pci/pci_pci.c 69783 2000-12-08 22:11:23Z msmith $
31 */
32
33/*
34 * PCI:PCI bridge support.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/bus.h>
41
42#include <machine/resource.h>
43
44#include <pci/pcivar.h>
45#include <pci/pcireg.h>
46
47#include "pcib_if.h"
48
49/*
50 * Bridge-specific data.
51 */
52struct pcib_softc
53{
54    device_t	dev;
55    u_int8_t	secbus;		/* secondary bus number */
56    u_int8_t	subbus;		/* subordinate bus number */
57    pci_addr_t	pmembase;	/* base address of prefetchable memory */
58    pci_addr_t	pmemlimit;	/* topmost address of prefetchable memory */
59    u_int32_t	membase;	/* base address of memory window */
60    u_int32_t	memlimit;	/* topmost address of memory window */
61    u_int32_t	iobase;		/* base address of port window */
62    u_int32_t	iolimit;	/* topmost address of port window */
63    u_int16_t	secstat;	/* secondary bus status register */
64    u_int16_t	bridgectl;	/* bridge control register */
65    u_int8_t	seclat;		/* secondary bus latency timer */
66};
67
68static int		pcib_probe(device_t dev);
69static int		pcib_attach(device_t dev);
70static int		pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result);
71static int		pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value);
72static struct resource *pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
73					    u_long start, u_long end, u_long count, u_int flags);
74static int		pcib_maxslots(device_t dev);
75static u_int32_t	pcib_read_config(device_t dev, int b, int s, int f, int reg, int width);
76static void		pcib_write_config(device_t dev, int b, int s, int f, int reg, u_int32_t val, int width);
77static int		pcib_route_interrupt(device_t pcib, device_t dev, int pin);
78
79static device_method_t pcib_methods[] = {
80    /* Device interface */
81    DEVMETHOD(device_probe,		pcib_probe),
82    DEVMETHOD(device_attach,		pcib_attach),
83    DEVMETHOD(device_shutdown,		bus_generic_shutdown),
84    DEVMETHOD(device_suspend,		bus_generic_suspend),
85    DEVMETHOD(device_resume,		bus_generic_resume),
86
87    /* Bus interface */
88    DEVMETHOD(bus_print_child,		bus_generic_print_child),
89    DEVMETHOD(bus_read_ivar,		pcib_read_ivar),
90    DEVMETHOD(bus_write_ivar,		pcib_write_ivar),
91    DEVMETHOD(bus_alloc_resource,	pcib_alloc_resource),
92    DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
93    DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
94    DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
95    DEVMETHOD(bus_setup_intr,		bus_generic_setup_intr),
96    DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
97
98    /* pcib interface */
99    DEVMETHOD(pcib_maxslots,		pcib_maxslots),
100    DEVMETHOD(pcib_read_config,		pcib_read_config),
101    DEVMETHOD(pcib_write_config,	pcib_write_config),
102    DEVMETHOD(pcib_route_interrupt,	pcib_route_interrupt),
103
104    { 0, 0 }
105};
106
107static driver_t pcib_driver = {
108    "pcib",
109    pcib_methods,
110    sizeof(struct pcib_softc),
111};
112
113static devclass_t pcib_devclass;
114
115DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, 0, 0);
116
117/*
118 * Generic device interface
119 */
120static int
121pcib_probe(device_t dev)
122{
123    if ((pci_get_class(dev) == PCIC_BRIDGE) &&
124	(pci_get_subclass(dev) == PCIS_BRIDGE_PCI)) {
125	device_set_desc(dev, "PCI-PCI bridge");
126	return(-10000);
127    }
128    return(ENXIO);
129}
130
131static int
132pcib_attach(device_t dev)
133{
134    struct pcib_softc	*sc;
135    device_t		pcib, child;
136    int			b, s, f;
137
138    sc = device_get_softc(dev);
139    sc->dev = dev;
140    pcib = device_get_parent(dev);
141    b = pci_get_bus(dev);
142    s = pci_get_slot(dev);
143    f = pci_get_function(dev);
144
145    sc->secbus    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECBUS_1, 1);
146    sc->subbus    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SUBBUS_1, 1);
147    sc->secstat   = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECSTAT_1, 2);
148    sc->bridgectl = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_BRIDGECTL_1, 2);
149    sc->seclat    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECLAT_1, 1);
150    sc->iobase    = PCI_PPBIOBASE(PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOBASEH_1, 2),
151				  PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOBASEL_1, 1));
152    sc->iolimit   = PCI_PPBIOLIMIT(PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOLIMITH_1, 2),
153				   PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOLIMITL_1, 1));
154    sc->membase   = PCI_PPBMEMBASE(0, PCIB_READ_CONFIG(pcib, b, s, f, PCIR_MEMBASE_1, 2));
155    sc->memlimit  = PCI_PPBMEMLIMIT(0, PCIB_READ_CONFIG(pcib, b, s, f, PCIR_MEMLIMIT_1, 2));
156    sc->pmembase  = PCI_PPBMEMBASE((pci_addr_t)PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMBASEH_1, 4),
157				   PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMBASEL_1, 2));
158    sc->pmemlimit = PCI_PPBMEMLIMIT((pci_addr_t)PCIB_READ_CONFIG(pcib, b, s, f,PCIR_PMLIMITH_1, 4),
159				    PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMLIMITL_1, 2));
160
161    if (bootverbose) {
162	device_printf(dev, "  secondary bus     %d\n", sc->secbus);
163	device_printf(dev, "  subordinate bus   %d\n", sc->subbus);
164	device_printf(dev, "  I/O decode        0x%x-0x%x\n", sc->iobase, sc->iolimit);
165	device_printf(dev, "  memory decode     0x%x-0x%x\n", sc->membase, sc->memlimit);
166	device_printf(dev, "  prefetched decode 0x%x-0x%x\n", sc->pmembase, sc->pmemlimit);
167    }
168
169    /*
170     * XXX If the secondary bus number is zero, we should assign a bus number
171     *     since the BIOS hasn't, then initialise the bridge.
172     */
173
174    /*
175     * XXX If the subordinate bus number is less than the secondary bus number,
176     *     we should pick a better value.  One sensible alternative would be to
177     *     pick 255; the only tradeoff here is that configuration transactions
178     *     would be more widely routed than absolutely necessary.
179     */
180
181    if (sc->secbus != 0) {
182	child = device_add_child(dev, "pci", -1);
183	if (child != NULL)
184	    return(bus_generic_attach(dev));
185    }
186
187    /* no secondary bus; we should have fixed this */
188    return(0);
189}
190
191static int
192pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
193{
194    struct pcib_softc	*sc = device_get_softc(dev);
195
196    switch (which) {
197    case PCIB_IVAR_BUS:
198	*result = sc->secbus;
199	return(0);
200    }
201    return(ENOENT);
202}
203
204static int
205pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
206{
207    struct pcib_softc	*sc = device_get_softc(dev);
208
209    switch (which) {
210    case PCIB_IVAR_BUS:
211	sc->secbus = value;
212	break;
213    }
214    return(ENOENT);
215}
216
217/*
218 * We have to trap resource allocation requests and ensure that the bridge
219 * is set up to, or capable of handling them.
220 */
221static struct resource *
222pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
223		    u_long start, u_long end, u_long count, u_int flags)
224{
225    struct pcib_softc	*sc = device_get_softc(dev);
226
227    /*
228     * If this is a "default" allocation against this rid, we can't work
229     * out where it's coming from (we should actually never see these) so we
230     * just have to punt.
231     */
232    if ((start == 0) && (end == ~0)) {
233	device_printf(dev, "can't decode default resource id %d for %s%d, bypassing\n",
234		      *rid, device_get_name(child), device_get_unit(child));
235    } else {
236	/*
237	 * Fail the allocation for this range if it's not supported.
238	 *
239	 * XXX we should probably just fix up the bridge decode and soldier on.
240	 */
241	switch (type) {
242	case SYS_RES_IOPORT:
243	    if ((start < sc->iobase) || (end > sc->iolimit)) {
244		device_printf(dev, "device %s%d requested unsupported I/O range 0x%lx-0x%lx"
245			      " (decoding 0x%x-0x%x)\n",
246			      device_get_name(child), device_get_unit(child), start, end,
247			      sc->iobase, sc->iolimit);
248		return(NULL);
249	    }
250	    break;
251
252	    /*
253	     * XXX will have to decide whether the device making the request is asking
254	     *     for prefetchable memory or not.  If it's coming from another bridge
255	     *     down the line, do we assume not, or ask the bridge to pass in another
256	     *     flag as the request bubbles up?
257	     */
258	case SYS_RES_MEMORY:
259	    if (((start < sc->membase) || (end > sc->memlimit)) &&
260		((start < sc->pmembase) || (end > sc->pmemlimit))) {
261		device_printf(dev, "device %s%d requested unsupported memory range 0x%lx-0x%lx"
262			      " (decoding 0x%x-0x%x, 0x%x-0x%x)\n",
263			      device_get_name(child), device_get_unit(child), start, end,
264			      sc->membase, sc->memlimit, sc->pmembase, sc->pmemlimit);
265		return(NULL);
266	    }
267	default:
268	}
269    }
270    device_printf(sc->dev, "resource request type %d 0x%lx-0x%lx decodes OK\n",
271		  type, start, end);
272    /*
273     * Bridge is OK decoding this resource, so pass it up.
274     */
275    return(bus_generic_alloc_resource(dev, child, type, rid, start, end, count, flags));
276}
277
278/*
279 * PCIB interface.
280 */
281static int
282pcib_maxslots(device_t dev)
283{
284    return(31);
285}
286
287/*
288 * Since we are a child of a PCI bus, its parent must support the pcib interface.
289 */
290static u_int32_t
291pcib_read_config(device_t dev, int b, int s, int f, int reg, int width)
292{
293    return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, width));
294}
295
296static void
297pcib_write_config(device_t dev, int b, int s, int f, int reg, u_int32_t val, int width)
298{
299    PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, val, width);
300}
301
302/*
303 * Route an interrupt across a PCI bridge.
304 */
305static int
306pcib_route_interrupt(device_t pcib, device_t dev, int pin)
307{
308    device_t	bus;
309    int		parent_intpin;
310    int		intnum;
311
312    /*
313     *
314     * The PCI standard defines a swizzle of the child-side device/intpin to
315     * the parent-side intpin as follows.
316     *
317     * device = device on child bus
318     * child_intpin = intpin on child bus slot (0-3)
319     * parent_intpin = intpin on parent bus slot (0-3)
320     *
321     * parent_intpin = (device + child_intpin) % 4
322     */
323    parent_intpin = (pci_get_slot(pcib) + (pin - 1)) % 4;
324
325    /*
326     * Our parent is a PCI bus.  Its parent must export the pcib interface
327     * which includes the ability to route interrupts.
328     */
329    bus = device_get_parent(pcib);
330    intnum = PCIB_ROUTE_INTERRUPT(device_get_parent(bus), pcib, parent_intpin + 1);
331    device_printf(pcib, "routed slot %d INT%c to irq %d\n", pci_get_slot(dev),
332		  'A' + pin - 1, intnum);
333    return(intnum);
334}
335