xref: /illumos-gate/usr/src/uts/i86pc/os/pci_cfgspace.c (revision 9c88ac3ab4edaa5e8c0130ed1b4b376ea57c545a)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 /*
27  * PCI configuration space access routines
28  */
29 
30 #include <sys/systm.h>
31 #include <sys/psw.h>
32 #include <sys/bootconf.h>
33 #include <sys/reboot.h>
34 #include <sys/pci_impl.h>
35 #include <sys/pci_cfgspace.h>
36 #include <sys/pci_cfgspace_impl.h>
37 #include <sys/pci_cfgacc.h>
38 #if defined(__xpv)
39 #include <sys/hypervisor.h>
40 #endif
41 
42 #if defined(__xpv)
43 int pci_max_nbus = 0xFE;
44 #else
45 int pci_max_nbus = 0xFF;
46 #endif
47 int pci_bios_cfg_type = PCI_MECHANISM_UNKNOWN;
48 int pci_bios_maxbus;
49 int pci_bios_mech;
50 int pci_bios_vers;
51 
52 /*
53  * These two variables can be used to force a configuration mechanism or
54  * to force which function is used to probe for the presence of the PCI bus.
55  */
56 int	PCI_CFG_TYPE = 0;
57 int	PCI_PROBE_TYPE = 0;
58 
59 /*
60  * No valid mcfg_mem_base by default, and accessing pci config space
61  * in mem-mapped way is disabled.
62  */
63 uint64_t mcfg_mem_base = 0;
64 uint8_t mcfg_bus_start = 0;
65 uint8_t mcfg_bus_end = 0xff;
66 
67 /*
68  * Maximum offset in config space when not using MMIO
69  */
70 uint_t pci_iocfg_max_offset = 0xff;
71 
72 /*
73  * These function pointers lead to the actual implementation routines
74  * for configuration space access.  Normally they lead to either the
75  * pci_mech1_* or pci_mech2_* routines, but they can also lead to
76  * routines that work around chipset bugs.
77  * These functions are accessing pci config space via I/O way.
78  * Pci_cfgacc_get/put functions shoul be used as more common interfaces,
79  * which also provide accessing pci config space via mem-mapped way.
80  */
81 uint8_t (*pci_getb_func)(int bus, int dev, int func, int reg);
82 uint16_t (*pci_getw_func)(int bus, int dev, int func, int reg);
83 uint32_t (*pci_getl_func)(int bus, int dev, int func, int reg);
84 void (*pci_putb_func)(int bus, int dev, int func, int reg, uint8_t val);
85 void (*pci_putw_func)(int bus, int dev, int func, int reg, uint16_t val);
86 void (*pci_putl_func)(int bus, int dev, int func, int reg, uint32_t val);
87 
88 extern void (*pci_cfgacc_acc_p)(pci_cfgacc_req_t *req);
89 
90 /*
91  * Internal routines
92  */
93 static int pci_check(void);
94 
95 #if !defined(__xpv)
96 static int pci_check_bios(void);
97 static int pci_get_cfg_type(void);
98 #endif
99 
100 /* for legacy io-based config space access */
101 kmutex_t pcicfg_mutex;
102 
103 /* for mmio-based config space access */
104 kmutex_t pcicfg_mmio_mutex;
105 
106 /* ..except Orion and Neptune, which have to have their own */
107 kmutex_t pcicfg_chipset_mutex;
108 
109 void
110 pci_cfgspace_init(void)
111 {
112 	mutex_init(&pcicfg_mutex, NULL, MUTEX_SPIN,
113 	    (ddi_iblock_cookie_t)ipltospl(15));
114 	mutex_init(&pcicfg_mmio_mutex, NULL, MUTEX_SPIN,
115 	    (ddi_iblock_cookie_t)ipltospl(DISP_LEVEL));
116 	mutex_init(&pcicfg_chipset_mutex, NULL, MUTEX_SPIN,
117 	    (ddi_iblock_cookie_t)ipltospl(15));
118 	if (!pci_check()) {
119 		mutex_destroy(&pcicfg_mutex);
120 		mutex_destroy(&pcicfg_mmio_mutex);
121 		mutex_destroy(&pcicfg_chipset_mutex);
122 	}
123 }
124 
125 /*
126  * This code determines if this system supports PCI/PCIE and which
127  * type of configuration access method is used
128  */
129 static int
130 pci_check(void)
131 {
132 	uint64_t ecfginfo[4];
133 
134 	/*
135 	 * Only do this once.  NB:  If this is not a PCI system, and we
136 	 * get called twice, we can't detect it and will probably die
137 	 * horribly when we try to ask the BIOS whether PCI is present.
138 	 * This code is safe *ONLY* during system startup when the
139 	 * BIOS is still available.
140 	 */
141 	if (pci_bios_cfg_type != PCI_MECHANISM_UNKNOWN)
142 		return (TRUE);
143 
144 #if defined(__xpv)
145 	/*
146 	 * only support PCI config mechanism 1 in i86xpv. This should be fine
147 	 * since the other ones are workarounds for old broken H/W which won't
148 	 * be supported in i86xpv anyway.
149 	 */
150 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
151 		pci_bios_cfg_type = PCI_MECHANISM_1;
152 		pci_getb_func = pci_mech1_getb;
153 		pci_getw_func = pci_mech1_getw;
154 		pci_getl_func = pci_mech1_getl;
155 		pci_putb_func = pci_mech1_putb;
156 		pci_putw_func = pci_mech1_putw;
157 		pci_putl_func = pci_mech1_putl;
158 
159 		/*
160 		 * Since we can't get the BIOS info in i86xpv, we will do an
161 		 * exhaustive search of all PCI buses. We have to do this until
162 		 * we start using the PCI information in ACPI.
163 		 */
164 		pci_bios_maxbus = pci_max_nbus;
165 	}
166 #else /* !__xpv */
167 
168 	pci_bios_cfg_type = pci_check_bios();
169 
170 	if (pci_bios_cfg_type == PCI_MECHANISM_NONE)
171 		pci_bios_cfg_type = PCI_MECHANISM_1;	/* default to mech 1 */
172 
173 	switch (pci_get_cfg_type()) {
174 	case PCI_MECHANISM_1:
175 		if (pci_is_broken_orion()) {
176 			pci_getb_func = pci_orion_getb;
177 			pci_getw_func = pci_orion_getw;
178 			pci_getl_func = pci_orion_getl;
179 			pci_putb_func = pci_orion_putb;
180 			pci_putw_func = pci_orion_putw;
181 			pci_putl_func = pci_orion_putl;
182 		} else if (pci_check_amd_ioecs()) {
183 			pci_getb_func = pci_mech1_amd_getb;
184 			pci_getw_func = pci_mech1_amd_getw;
185 			pci_getl_func = pci_mech1_amd_getl;
186 			pci_putb_func = pci_mech1_amd_putb;
187 			pci_putw_func = pci_mech1_amd_putw;
188 			pci_putl_func = pci_mech1_amd_putl;
189 			pci_iocfg_max_offset = 0xfff;
190 		} else {
191 			pci_getb_func = pci_mech1_getb;
192 			pci_getw_func = pci_mech1_getw;
193 			pci_getl_func = pci_mech1_getl;
194 			pci_putb_func = pci_mech1_putb;
195 			pci_putw_func = pci_mech1_putw;
196 			pci_putl_func = pci_mech1_putl;
197 		}
198 		break;
199 
200 	case PCI_MECHANISM_2:
201 		if (pci_check_neptune()) {
202 			/*
203 			 * The BIOS for some systems with the Intel
204 			 * Neptune chipset seem to default to #2 even
205 			 * though the chipset can do #1.  Override
206 			 * the BIOS so that MP systems will work
207 			 * correctly.
208 			 */
209 
210 			pci_getb_func = pci_neptune_getb;
211 			pci_getw_func = pci_neptune_getw;
212 			pci_getl_func = pci_neptune_getl;
213 			pci_putb_func = pci_neptune_putb;
214 			pci_putw_func = pci_neptune_putw;
215 			pci_putl_func = pci_neptune_putl;
216 		} else {
217 			pci_getb_func = pci_mech2_getb;
218 			pci_getw_func = pci_mech2_getw;
219 			pci_getl_func = pci_mech2_getl;
220 			pci_putb_func = pci_mech2_putb;
221 			pci_putw_func = pci_mech2_putw;
222 			pci_putl_func = pci_mech2_putl;
223 		}
224 		break;
225 
226 	default:
227 		return (FALSE);
228 	}
229 #endif /* __xpv */
230 
231 	/*
232 	 * Try to get a valid mcfg_mem_base in early boot
233 	 * If failed, leave mem-mapped pci config space accessing disabled
234 	 * until pci boot code (pci_autoconfig) makes sure this is a PCIE
235 	 * platform.
236 	 */
237 	if (do_bsys_getprop(NULL, MCFG_PROPNAME, ecfginfo) != -1) {
238 		mcfg_mem_base = ecfginfo[0];
239 		mcfg_bus_start = ecfginfo[2];
240 		mcfg_bus_end = ecfginfo[3];
241 	}
242 
243 	/* See pci_cfgacc.c */
244 	pci_cfgacc_acc_p = pci_cfgacc_acc;
245 
246 	return (TRUE);
247 }
248 
249 #if !defined(__xpv)
250 
251 static int
252 pci_check_bios(void)
253 {
254 	struct bop_regs regs;
255 	uint32_t	carryflag;
256 	uint16_t	ax, dx;
257 
258 	/*
259 	 * This mechanism uses a legacy BIOS call to detect PCI configuration,
260 	 * but such calls are not available on systems with UEFI firmware.
261 	 * For UEFI systems we must assume some reasonable defaults and scan
262 	 * all possible buses.
263 	 */
264 	if (BOP_GETPROPLEN(bootops, "efi-systab") > 0) {
265 		pci_bios_mech = 1;
266 		pci_bios_vers = 0;
267 		pci_bios_maxbus = pci_max_nbus;
268 		return (PCI_MECHANISM_1);
269 	}
270 
271 	bzero(&regs, sizeof (regs));
272 	regs.eax.word.ax = (PCI_FUNCTION_ID << 8) | PCI_BIOS_PRESENT;
273 
274 	BOP_DOINT(bootops, 0x1a, &regs);
275 	carryflag = regs.eflags & PS_C;
276 	ax = regs.eax.word.ax;
277 	dx = regs.edx.word.dx;
278 
279 	/* the carry flag must not be set */
280 	if (carryflag != 0)
281 		return (PCI_MECHANISM_NONE);
282 
283 	if (dx != ('P' | 'C'<<8))
284 		return (PCI_MECHANISM_NONE);
285 
286 	/* ah (the high byte of ax) must be zero */
287 	if ((ax & 0xff00) != 0)
288 		return (PCI_MECHANISM_NONE);
289 
290 	pci_bios_mech = (ax & 0x3);
291 	pci_bios_vers = regs.ebx.word.bx;
292 	pci_bios_maxbus = (regs.ecx.word.cx & 0xff);
293 
294 	switch (pci_bios_mech) {
295 	default:	/* ?!? */
296 	case 0:		/* supports neither? */
297 		return (PCI_MECHANISM_NONE);
298 
299 	case 1:
300 	case 3:		/* supports both */
301 		return (PCI_MECHANISM_1);
302 
303 	case 2:
304 		return (PCI_MECHANISM_2);
305 	}
306 }
307 
308 static int
309 pci_get_cfg_type(void)
310 {
311 	/* Check to see if the config mechanism has been set in /etc/system */
312 	switch (PCI_CFG_TYPE) {
313 	default:
314 	case 0:
315 		break;
316 	case 1:
317 		return (PCI_MECHANISM_1);
318 	case 2:
319 		return (PCI_MECHANISM_2);
320 	case -1:
321 		return (PCI_MECHANISM_NONE);
322 	}
323 
324 	/* call one of the PCI detection algorithms */
325 	switch (PCI_PROBE_TYPE) {
326 	default:
327 	case 0:
328 		/* From pci_check() and pci_check_bios() */
329 		return (pci_bios_cfg_type);
330 	case -1:
331 		return (PCI_MECHANISM_NONE);
332 	}
333 }
334 
335 #endif	/* __xpv */
336