xref: /freebsd/sys/powerpc/powermac/grackle.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/module.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/kernel.h>
36 #include <sys/proc.h>
37 #include <sys/rman.h>
38 
39 #include <dev/ofw/openfirm.h>
40 #include <dev/ofw/ofw_pci.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 #include <dev/ofw/ofwpci.h>
44 
45 #include <dev/pci/pcivar.h>
46 #include <dev/pci/pcireg.h>
47 
48 #include <machine/bus.h>
49 #include <machine/intr_machdep.h>
50 #include <machine/md_var.h>
51 #include <machine/pio.h>
52 #include <machine/resource.h>
53 
54 #include <powerpc/powermac/gracklevar.h>
55 
56 #include <vm/vm.h>
57 #include <vm/pmap.h>
58 
59 #include "pcib_if.h"
60 
61 /*
62  * Device interface.
63  */
64 static int		grackle_probe(device_t);
65 static int		grackle_attach(device_t);
66 
67 /*
68  * pcib interface.
69  */
70 static u_int32_t	grackle_read_config(device_t, u_int, u_int, u_int,
71 			    u_int, int);
72 static void		grackle_write_config(device_t, u_int, u_int, u_int,
73 			    u_int, u_int32_t, int);
74 
75 /*
76  * Local routines.
77  */
78 static int		grackle_enable_config(struct grackle_softc *, u_int,
79 			    u_int, u_int, u_int);
80 static void		grackle_disable_config(struct grackle_softc *);
81 static int		badaddr(void *, size_t);
82 
83 /*
84  * Driver methods.
85  */
86 static device_method_t	grackle_methods[] = {
87 	/* Device interface */
88 	DEVMETHOD(device_probe,		grackle_probe),
89 	DEVMETHOD(device_attach,	grackle_attach),
90 
91 	/* pcib interface */
92 	DEVMETHOD(pcib_read_config,	grackle_read_config),
93 	DEVMETHOD(pcib_write_config,	grackle_write_config),
94 
95 	DEVMETHOD_END
96 };
97 
98 DEFINE_CLASS_1(pcib, grackle_driver, grackle_methods,
99     sizeof(struct grackle_softc), ofw_pcib_driver);
100 DRIVER_MODULE(grackle, ofwbus, grackle_driver, 0, 0);
101 
102 static int
103 grackle_probe(device_t dev)
104 {
105 	const char	*type, *compatible;
106 
107 	type = ofw_bus_get_type(dev);
108 	compatible = ofw_bus_get_compat(dev);
109 
110 	if (type == NULL || compatible == NULL)
111 		return (ENXIO);
112 
113 	if (strcmp(type, "pci") != 0 || strcmp(compatible, "grackle") != 0)
114 		return (ENXIO);
115 
116 	device_set_desc(dev, "MPC106 (Grackle) Host-PCI bridge");
117 	return (0);
118 }
119 
120 static int
121 grackle_attach(device_t dev)
122 {
123 	struct		grackle_softc *sc;
124 
125 	sc = device_get_softc(dev);
126 
127 	/*
128 	 * The Grackle PCI config addr/data registers are actually in
129 	 * PCI space, but since they are needed to actually probe the
130 	 * PCI bus, use the fact that they are also available directly
131 	 * on the processor bus and map them
132 	 */
133 	sc->sc_addr = (vm_offset_t)pmap_mapdev(GRACKLE_ADDR, PAGE_SIZE);
134 	sc->sc_data = (vm_offset_t)pmap_mapdev(GRACKLE_DATA, PAGE_SIZE);
135 
136 	return (ofw_pcib_attach(dev));
137 }
138 
139 static u_int32_t
140 grackle_read_config(device_t dev, u_int bus, u_int slot, u_int func, u_int reg,
141     int width)
142 {
143 	struct		grackle_softc *sc;
144 	vm_offset_t	caoff;
145 	u_int32_t	retval = 0xffffffff;
146 
147 	sc = device_get_softc(dev);
148 	caoff = sc->sc_data + (reg & 0x03);
149 
150 	if (grackle_enable_config(sc, bus, slot, func, reg) != 0) {
151 		/*
152 		 * Config probes to non-existent devices on the
153 		 * secondary bus generates machine checks. Be sure
154 		 * to catch these.
155 		 */
156 		if (bus > 0) {
157 		  if (badaddr((void *)sc->sc_data, 4)) {
158 			  return (retval);
159 		  }
160 		}
161 
162 		switch (width) {
163 		case 1:
164 			retval = (in8rb(caoff));
165 			break;
166 		case 2:
167 			retval = (in16rb(caoff));
168 			break;
169 		case 4:
170 			retval = (in32rb(caoff));
171 			break;
172 		}
173 	}
174 	grackle_disable_config(sc);
175 
176 	return (retval);
177 }
178 
179 static void
180 grackle_write_config(device_t dev, u_int bus, u_int slot, u_int func,
181     u_int reg, u_int32_t val, int width)
182 {
183 	struct		grackle_softc *sc;
184 	vm_offset_t	caoff;
185 
186 	sc = device_get_softc(dev);
187 	caoff = sc->sc_data + (reg & 0x03);
188 
189 	if (grackle_enable_config(sc, bus, slot, func, reg)) {
190 		switch (width) {
191 		case 1:
192 			out8rb(caoff, val);
193 			(void)in8rb(caoff);
194 			break;
195 		case 2:
196 			out16rb(caoff, val);
197 			(void)in16rb(caoff);
198 			break;
199 		case 4:
200 			out32rb(caoff, val);
201 			(void)in32rb(caoff);
202 			break;
203 		}
204 	}
205 	grackle_disable_config(sc);
206 }
207 
208 static int
209 grackle_enable_config(struct grackle_softc *sc, u_int bus, u_int slot,
210     u_int func, u_int reg)
211 {
212 	u_int32_t	cfgval;
213 
214 	/*
215 	 * Unlike UniNorth, the format of the config word is the same
216 	 * for local (0) and remote busses.
217 	 */
218 	cfgval = (bus << 16) | (slot << 11) | (func << 8) | (reg & 0xFC)
219 	    | GRACKLE_CFG_ENABLE;
220 
221 	out32rb(sc->sc_addr, cfgval);
222 	(void) in32rb(sc->sc_addr);
223 
224 	return (1);
225 }
226 
227 static void
228 grackle_disable_config(struct grackle_softc *sc)
229 {
230 	/*
231 	 * Clear the GRACKLE_CFG_ENABLE bit to prevent stray
232 	 * accesses from causing config cycles
233 	 */
234 	out32rb(sc->sc_addr, 0);
235 }
236 
237 static int
238 badaddr(void *addr, size_t size)
239 {
240 	struct thread	*td;
241 	jmp_buf		env, *oldfaultbuf;
242 
243 	/* Get rid of any stale machine checks that have been waiting.  */
244 	__asm __volatile ("sync; isync");
245 
246 	td = curthread;
247 
248 	oldfaultbuf = td->td_pcb->pcb_onfault;
249 	td->td_pcb->pcb_onfault = &env;
250 	if (setjmp(env)) {
251 		td->td_pcb->pcb_onfault = oldfaultbuf;
252 		__asm __volatile ("sync");
253 		return 1;
254 	}
255 
256 	__asm __volatile ("sync");
257 
258 	switch (size) {
259 	case 1:
260 		(void)*(volatile int8_t *)addr;
261 		break;
262 	case 2:
263 		(void)*(volatile int16_t *)addr;
264 		break;
265 	case 4:
266 		(void)*(volatile int32_t *)addr;
267 		break;
268 	default:
269 		panic("badaddr: invalid size (%zd)", size);
270 	}
271 
272 	/* Make sure we took the machine check, if we caused one. */
273 	__asm __volatile ("sync; isync");
274 
275 	td->td_pcb->pcb_onfault = oldfaultbuf;
276 	__asm __volatile ("sync");	/* To be sure. */
277 
278 	return (0);
279 }
280 
281 /*
282  * Driver to swallow Grackle host bridges from the PCI bus side.
283  */
284 static int
285 grackle_hb_probe(device_t dev)
286 {
287 
288 	if (pci_get_devid(dev) == 0x00021057) {
289 		device_set_desc(dev, "Grackle Host to PCI bridge");
290 		device_quiet(dev);
291 		return (0);
292 	}
293 
294 	return (ENXIO);
295 }
296 
297 static int
298 grackle_hb_attach(device_t dev)
299 {
300 
301 	return (0);
302 }
303 
304 static device_method_t grackle_hb_methods[] = {
305 	/* Device interface */
306 	DEVMETHOD(device_probe,         grackle_hb_probe),
307 	DEVMETHOD(device_attach,        grackle_hb_attach),
308 	{ 0, 0 }
309 };
310 
311 static driver_t grackle_hb_driver = {
312 	"grackle_hb",
313 	grackle_hb_methods,
314 	1,
315 };
316 
317 DRIVER_MODULE(grackle_hb, pci, grackle_hb_driver, 0, 0);
318