xref: /freebsd/sys/powerpc/powermac/grackle.c (revision bc7512cc58af2e8bbe5bbf5ca0059b1daa1da897)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright 2003 by Peter Grehan. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/module.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/proc.h>
40 #include <sys/rman.h>
41 
42 #include <dev/ofw/openfirm.h>
43 #include <dev/ofw/ofw_pci.h>
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 #include <dev/ofw/ofwpci.h>
47 
48 #include <dev/pci/pcivar.h>
49 #include <dev/pci/pcireg.h>
50 
51 #include <machine/bus.h>
52 #include <machine/intr_machdep.h>
53 #include <machine/md_var.h>
54 #include <machine/pio.h>
55 #include <machine/resource.h>
56 
57 #include <powerpc/powermac/gracklevar.h>
58 
59 #include <vm/vm.h>
60 #include <vm/pmap.h>
61 
62 #include "pcib_if.h"
63 
64 /*
65  * Device interface.
66  */
67 static int		grackle_probe(device_t);
68 static int		grackle_attach(device_t);
69 
70 /*
71  * pcib interface.
72  */
73 static u_int32_t	grackle_read_config(device_t, u_int, u_int, u_int,
74 			    u_int, int);
75 static void		grackle_write_config(device_t, u_int, u_int, u_int,
76 			    u_int, u_int32_t, int);
77 
78 /*
79  * Local routines.
80  */
81 static int		grackle_enable_config(struct grackle_softc *, u_int,
82 			    u_int, u_int, u_int);
83 static void		grackle_disable_config(struct grackle_softc *);
84 static int		badaddr(void *, size_t);
85 
86 /*
87  * Driver methods.
88  */
89 static device_method_t	grackle_methods[] = {
90 	/* Device interface */
91 	DEVMETHOD(device_probe,		grackle_probe),
92 	DEVMETHOD(device_attach,	grackle_attach),
93 
94 	/* pcib interface */
95 	DEVMETHOD(pcib_read_config,	grackle_read_config),
96 	DEVMETHOD(pcib_write_config,	grackle_write_config),
97 
98 	DEVMETHOD_END
99 };
100 
101 DEFINE_CLASS_1(pcib, grackle_driver, grackle_methods,
102     sizeof(struct grackle_softc), ofw_pcib_driver);
103 DRIVER_MODULE(grackle, ofwbus, grackle_driver, 0, 0);
104 
105 static int
106 grackle_probe(device_t dev)
107 {
108 	const char	*type, *compatible;
109 
110 	type = ofw_bus_get_type(dev);
111 	compatible = ofw_bus_get_compat(dev);
112 
113 	if (type == NULL || compatible == NULL)
114 		return (ENXIO);
115 
116 	if (strcmp(type, "pci") != 0 || strcmp(compatible, "grackle") != 0)
117 		return (ENXIO);
118 
119 	device_set_desc(dev, "MPC106 (Grackle) Host-PCI bridge");
120 	return (0);
121 }
122 
123 static int
124 grackle_attach(device_t dev)
125 {
126 	struct		grackle_softc *sc;
127 
128 	sc = device_get_softc(dev);
129 
130 	/*
131 	 * The Grackle PCI config addr/data registers are actually in
132 	 * PCI space, but since they are needed to actually probe the
133 	 * PCI bus, use the fact that they are also available directly
134 	 * on the processor bus and map them
135 	 */
136 	sc->sc_addr = (vm_offset_t)pmap_mapdev(GRACKLE_ADDR, PAGE_SIZE);
137 	sc->sc_data = (vm_offset_t)pmap_mapdev(GRACKLE_DATA, PAGE_SIZE);
138 
139 	return (ofw_pcib_attach(dev));
140 }
141 
142 static u_int32_t
143 grackle_read_config(device_t dev, u_int bus, u_int slot, u_int func, u_int reg,
144     int width)
145 {
146 	struct		grackle_softc *sc;
147 	vm_offset_t	caoff;
148 	u_int32_t	retval = 0xffffffff;
149 
150 	sc = device_get_softc(dev);
151 	caoff = sc->sc_data + (reg & 0x03);
152 
153 	if (grackle_enable_config(sc, bus, slot, func, reg) != 0) {
154 		/*
155 		 * Config probes to non-existent devices on the
156 		 * secondary bus generates machine checks. Be sure
157 		 * to catch these.
158 		 */
159 		if (bus > 0) {
160 		  if (badaddr((void *)sc->sc_data, 4)) {
161 			  return (retval);
162 		  }
163 		}
164 
165 		switch (width) {
166 		case 1:
167 			retval = (in8rb(caoff));
168 			break;
169 		case 2:
170 			retval = (in16rb(caoff));
171 			break;
172 		case 4:
173 			retval = (in32rb(caoff));
174 			break;
175 		}
176 	}
177 	grackle_disable_config(sc);
178 
179 	return (retval);
180 }
181 
182 static void
183 grackle_write_config(device_t dev, u_int bus, u_int slot, u_int func,
184     u_int reg, u_int32_t val, int width)
185 {
186 	struct		grackle_softc *sc;
187 	vm_offset_t	caoff;
188 
189 	sc = device_get_softc(dev);
190 	caoff = sc->sc_data + (reg & 0x03);
191 
192 	if (grackle_enable_config(sc, bus, slot, func, reg)) {
193 		switch (width) {
194 		case 1:
195 			out8rb(caoff, val);
196 			(void)in8rb(caoff);
197 			break;
198 		case 2:
199 			out16rb(caoff, val);
200 			(void)in16rb(caoff);
201 			break;
202 		case 4:
203 			out32rb(caoff, val);
204 			(void)in32rb(caoff);
205 			break;
206 		}
207 	}
208 	grackle_disable_config(sc);
209 }
210 
211 static int
212 grackle_enable_config(struct grackle_softc *sc, u_int bus, u_int slot,
213     u_int func, u_int reg)
214 {
215 	u_int32_t	cfgval;
216 
217 	/*
218 	 * Unlike UniNorth, the format of the config word is the same
219 	 * for local (0) and remote busses.
220 	 */
221 	cfgval = (bus << 16) | (slot << 11) | (func << 8) | (reg & 0xFC)
222 	    | GRACKLE_CFG_ENABLE;
223 
224 	out32rb(sc->sc_addr, cfgval);
225 	(void) in32rb(sc->sc_addr);
226 
227 	return (1);
228 }
229 
230 static void
231 grackle_disable_config(struct grackle_softc *sc)
232 {
233 	/*
234 	 * Clear the GRACKLE_CFG_ENABLE bit to prevent stray
235 	 * accesses from causing config cycles
236 	 */
237 	out32rb(sc->sc_addr, 0);
238 }
239 
240 static int
241 badaddr(void *addr, size_t size)
242 {
243 	struct thread	*td;
244 	jmp_buf		env, *oldfaultbuf;
245 
246 	/* Get rid of any stale machine checks that have been waiting.  */
247 	__asm __volatile ("sync; isync");
248 
249 	td = curthread;
250 
251 	oldfaultbuf = td->td_pcb->pcb_onfault;
252 	td->td_pcb->pcb_onfault = &env;
253 	if (setjmp(env)) {
254 		td->td_pcb->pcb_onfault = oldfaultbuf;
255 		__asm __volatile ("sync");
256 		return 1;
257 	}
258 
259 	__asm __volatile ("sync");
260 
261 	switch (size) {
262 	case 1:
263 		(void)*(volatile int8_t *)addr;
264 		break;
265 	case 2:
266 		(void)*(volatile int16_t *)addr;
267 		break;
268 	case 4:
269 		(void)*(volatile int32_t *)addr;
270 		break;
271 	default:
272 		panic("badaddr: invalid size (%zd)", size);
273 	}
274 
275 	/* Make sure we took the machine check, if we caused one. */
276 	__asm __volatile ("sync; isync");
277 
278 	td->td_pcb->pcb_onfault = oldfaultbuf;
279 	__asm __volatile ("sync");	/* To be sure. */
280 
281 	return (0);
282 }
283 
284 /*
285  * Driver to swallow Grackle host bridges from the PCI bus side.
286  */
287 static int
288 grackle_hb_probe(device_t dev)
289 {
290 
291 	if (pci_get_devid(dev) == 0x00021057) {
292 		device_set_desc(dev, "Grackle Host to PCI bridge");
293 		device_quiet(dev);
294 		return (0);
295 	}
296 
297 	return (ENXIO);
298 }
299 
300 static int
301 grackle_hb_attach(device_t dev)
302 {
303 
304 	return (0);
305 }
306 
307 static device_method_t grackle_hb_methods[] = {
308 	/* Device interface */
309 	DEVMETHOD(device_probe,         grackle_hb_probe),
310 	DEVMETHOD(device_attach,        grackle_hb_attach),
311 	{ 0, 0 }
312 };
313 
314 static driver_t grackle_hb_driver = {
315 	"grackle_hb",
316 	grackle_hb_methods,
317 	1,
318 };
319 
320 DRIVER_MODULE(grackle_hb, pci, grackle_hb_driver, 0, 0);
321