xref: /illumos-gate/usr/src/uts/i86pc/os/pci_bios.c (revision 014ec826f15c2551c9f84a5fe6f816ffb5bee7da)
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  * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
24  * Copyright 2022 Oxide Computer Company
25  */
26 
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <sys/sunndi.h>
30 #include <sys/pci.h>
31 #include <sys/pci_impl.h>
32 #include <sys/pci_cfgspace.h>
33 #include <sys/pci_cfgspace_impl.h>
34 #include <sys/memlist.h>
35 #include <sys/bootconf.h>
36 #include <sys/psw.h>
37 
38 /*
39  * pci irq routing information table
40  */
41 int				pci_irq_nroutes;
42 static pci_irq_route_t		*pci_irq_routes;
43 
44 
45 static int pci_bios_get_irq_routing(pci_irq_route_t *, int, int *);
46 static void pci_get_irq_routing_table(void);
47 
48 
49 /*
50  * Retrieve information from the bios needed for system
51  * configuration early during startup.
52  */
53 void
54 startup_pci_bios(void)
55 {
56 	pci_get_irq_routing_table();
57 }
58 
59 
60 /*
61  * Issue the bios get irq routing information table interrupt
62  *
63  * Despite the name, the information in the table is only
64  * used to derive slot names for some named pci hot-plug slots.
65  *
66  * Returns the number of irq routing table entries returned
67  * by the bios, or 0 and optionally, the number of entries required.
68  */
69 static int
70 pci_bios_get_irq_routing(pci_irq_route_t *routes, int nroutes, int *nneededp)
71 {
72 	struct bop_regs regs;
73 	uchar_t		*hdrp;
74 	uchar_t		*bufp;
75 	int		i, n;
76 	int		rval = 0;
77 
78 	if (nneededp)
79 		*nneededp = 0;
80 
81 	/* in UEFI system, there is no BIOS data */
82 	if (BOP_GETPROPLEN(bootops, "efi-systab") > 0)
83 		return (0);
84 
85 	/*
86 	 * Set up irq routing header with the size and address
87 	 * of some useable low-memory data addresses.  Initalize
88 	 * data area to zero, avoiding memcpy/bzero.
89 	 */
90 	hdrp = (uchar_t *)BIOS_IRQ_ROUTING_HDR;
91 	bufp = (uchar_t *)BIOS_IRQ_ROUTING_DATA;
92 
93 	n = nroutes * sizeof (pci_irq_route_t);
94 	for (i = 0; i < n; i++)
95 		bufp[i] = 0;
96 	((pci_irq_route_hdr_t *)hdrp)->pir_size = n;
97 	((pci_irq_route_hdr_t *)hdrp)->pir_addr = (uint32_t)(uintptr_t)bufp;
98 
99 	bzero(&regs, sizeof (regs));
100 	regs.eax.word.ax = (PCI_FUNCTION_ID << 8) | PCI_GET_IRQ_ROUTING;
101 
102 	regs.ds = 0xf000;
103 	regs.es = FP_SEG((uint_t)(uintptr_t)hdrp);
104 	regs.edi.word.di = FP_OFF((uint_t)(uintptr_t)hdrp);
105 
106 	BOP_DOINT(bootops, 0x1a, &regs);
107 
108 	n = (int)(((pci_irq_route_hdr_t *)hdrp)->pir_size /
109 	    sizeof (pci_irq_route_t));
110 
111 	if ((regs.eflags & PS_C) != 0) {
112 		if (nneededp)
113 			*nneededp = n;
114 	} else {
115 		/*
116 		 * Copy resulting irq routing data from low memory up to
117 		 * the kernel address space, avoiding memcpy as usual.
118 		 */
119 		if (n <= nroutes) {
120 			for (i = 0; i < n * sizeof (pci_irq_route_t); i++)
121 				((uchar_t *)routes)[i] = bufp[i];
122 			rval = n;
123 		}
124 	}
125 	return (rval);
126 }
127 
128 static void
129 pci_get_irq_routing_table(void)
130 {
131 	pci_irq_route_t	*routes;
132 	int		n = N_PCI_IRQ_ROUTES;
133 	int		nneeded = 0;
134 	int		nroutes;
135 
136 	/*
137 	 * Get irq routing table information.
138 	 * Allocate a buffer for an initial default number of entries.
139 	 * If the bios indicates it needs a larger buffer, try it again.
140 	 * Drive on if it still won't cooperate and play nice after that.
141 	 */
142 	routes = kmem_zalloc(n * sizeof (pci_irq_route_t), KM_SLEEP);
143 	nroutes = pci_bios_get_irq_routing(routes, n, &nneeded);
144 	if (nroutes == 0 && nneeded > n) {
145 		kmem_free(routes, n * sizeof (pci_irq_route_t));
146 		if (nneeded > N_PCI_IRQ_ROUTES_MAX) {
147 			cmn_err(CE_CONT,
148 			    "pci: unable to get IRQ routing information, "
149 			    "required buffer space of %d entries exceeds max\n",
150 			    nneeded);
151 			return;
152 		}
153 		n = nneeded;
154 		routes = kmem_zalloc(n * sizeof (pci_irq_route_t), KM_SLEEP);
155 		nroutes = pci_bios_get_irq_routing(routes, n, NULL);
156 		if (nroutes == 0) {
157 			cmn_err(CE_CONT,
158 			    "pci: unable to get IRQ routing information, "
159 			    "required buffer space for %d entries\n", n);
160 		}
161 	}
162 
163 	if (nroutes > 0) {
164 		pci_irq_routes = routes;
165 		pci_irq_nroutes = nroutes;
166 	} else {
167 		kmem_free(routes, n * sizeof (pci_irq_route_t));
168 	}
169 }
170 
171 /*
172  * Use the results of the PCI BIOS call that returned the routing tables
173  * to build the 1275 slot-names property for the indicated bus.
174  * Results are returned in buf.  Length is return value, -1 is returned on
175  * overflow and zero is returned if no data exists to build a property.
176  */
177 int
178 pci_slot_names_prop(int bus, char *buf, int len)
179 {
180 	uchar_t		dev;
181 	uchar_t		slot[N_PCI_IRQ_ROUTES_MAX+1];
182 	uint32_t	 mask;
183 	int		i, nnames, plen;
184 
185 	ASSERT(pci_irq_nroutes <= N_PCI_IRQ_ROUTES_MAX);
186 
187 	if (pci_irq_nroutes == 0)
188 		return (0);
189 	nnames = 0;
190 	mask = 0;
191 	for (i = 0; i < pci_irq_nroutes; i++)
192 		slot[i] = 0xff;
193 	for (i = 0; i < pci_irq_nroutes; i++) {
194 		if (pci_irq_routes[i].pir_bus != bus)
195 			continue;
196 		if (pci_irq_routes[i].pir_slot != 0) {
197 			dev = (pci_irq_routes[i].pir_dev & 0xf8) >> 3;
198 			slot[dev] = pci_irq_routes[i].pir_slot;
199 			mask |= (1 << dev);
200 			nnames++;
201 		}
202 	}
203 
204 	if (nnames == 0)
205 		return (0);
206 
207 	if (len < (4 + nnames * 8))
208 		return (-1);
209 	*(uint32_t *)buf = mask;
210 	plen = 4;
211 	for (i = 0; i < pci_irq_nroutes; i++) {
212 		if (slot[i] == 0xff)
213 			continue;
214 		(void) sprintf(buf + plen, "Slot%d", slot[i]);
215 		plen += strlen(buf+plen) + 1;
216 		*(buf + plen) = 0;
217 	}
218 	for (; plen % 4; plen++)
219 		*(buf + plen) = 0;
220 	return (plen);
221 }
222 
223 /*
224  * This is used to discover additional PCI buses that may exist in the system in
225  * addition to the ACPI _BBN method. Historically these were discovered by
226  * asking if there was a valid slot property, e.g. pci_slot_names_prop()
227  * returned valid data. In this case we return any entry that has a bus number
228  * and a non-zero slot value. We rely on the core PCI code to do dedup for us.
229  */
230 void
231 pci_bios_bus_iter(pci_prd_root_complex_f cbfunc, void *arg)
232 {
233 	int i;
234 	for (i = 0; i < pci_irq_nroutes; i++) {
235 		if (pci_irq_routes[i].pir_slot != 0) {
236 			if (!cbfunc(pci_irq_routes[i].pir_bus, arg)) {
237 				return;
238 			}
239 		}
240 	}
241 }
242