1 /* $NetBSD: ttwoga_pci.c,v 1.10 2021/06/25 03:49:47 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>                            /* RCS ID & Copyright macro defns */
33 
34 __KERNEL_RCSID(0, "$NetBSD: ttwoga_pci.c,v 1.10 2021/06/25 03:49:47 thorpej Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/device.h>
40 
41 #include <dev/pci/pcireg.h>
42 #include <dev/pci/pcivar.h>
43 
44 #include <alpha/pci/ttwogareg.h>
45 #include <alpha/pci/ttwogavar.h>
46 
47 static int          ttwoga_bus_maxdevs(void *, int);
48 static pcireg_t     ttwoga_conf_read(void *, pcitag_t, int);
49 static void         ttwoga_conf_write(void *, pcitag_t, int, pcireg_t);
50 
51 static paddr_t      ttwoga_make_type0addr(int, int);
52 
53 /*
54  * The T2 has an annoying bug that can manifest itself while
55  * probing for devices.  If a non-existent CBUS address is
56  * accessed with a read, "a few" subsequent write cycles
57  * will generate spurious memory errors.  We work around this
58  * by tracking which CPU has the PCI configuration mutex and
59  * "expect" machine checks on that CPU for the duraction of
60  * the PCI configuration access routine.
61  */
62 
63 static kmutex_t ttwoga_conf_lock;
64 cpuid_t ttwoga_conf_cpu;                /* XXX core logic bug */
65 
66 #define   TTWOGA_CONF_LOCK()                                                    \
67 do {                                                                                      \
68           mutex_enter(&ttwoga_conf_lock);                                                 \
69           ttwoga_conf_cpu = cpu_number();                                                 \
70 } while (0)
71 
72 #define   TTWOGA_CONF_UNLOCK()                                                            \
73 do {                                                                                      \
74           ttwoga_conf_cpu = (cpuid_t)-1;                                                  \
75           mutex_exit(&ttwoga_conf_lock);                                                  \
76 } while (0)
77 
78 void
ttwoga_pci_init(pci_chipset_tag_t pc,void * v)79 ttwoga_pci_init(pci_chipset_tag_t pc, void *v)
80 {
81 
82           mutex_init(&ttwoga_conf_lock, MUTEX_DEFAULT, IPL_HIGH);
83 
84           pc->pc_conf_v = v;
85           pc->pc_bus_maxdevs = ttwoga_bus_maxdevs;
86           pc->pc_conf_read = ttwoga_conf_read;
87           pc->pc_conf_write = ttwoga_conf_write;
88 }
89 
90 static int
ttwoga_bus_maxdevs(void * cpv,int busno)91 ttwoga_bus_maxdevs(void *cpv, int busno)
92 {
93           /*
94            * We have to drive the IDSEL directly on bus 0, so we are
95            * limited to 9 devices there.
96            */
97           return busno == 0 ? 9 : 32;
98 }
99 
100 static paddr_t
ttwoga_make_type0addr(int d,int f)101 ttwoga_make_type0addr(int d, int f)
102 {
103           KASSERT(d < 9);
104           return PCI_CONF_TYPE0_IDSEL(d) | __SHIFTIN(f, PCI_CONF_TYPE1_FUNCTION);
105 }
106 
107 static pcireg_t
ttwoga_conf_read(void * cpv,pcitag_t tag,int offset)108 ttwoga_conf_read(void *cpv, pcitag_t tag, int offset)
109 {
110           struct ttwoga_config *tcp = cpv;
111           pcireg_t *datap, data;
112           int b, d, f, ba;
113           paddr_t addr;
114           uint64_t old_hae3;
115 
116           if ((unsigned int)offset >= PCI_CONF_SIZE)
117                     return (pcireg_t) -1;
118 
119           pci_decompose_tag(&tcp->tc_pc, tag, &b, &d, &f);
120 
121           addr = b ? tag : ttwoga_make_type0addr(d, f);
122 
123           TTWOGA_CONF_LOCK();
124 
125           alpha_mb();
126           old_hae3 = T2GA(tcp, T2_HAE0_3) & ~HAE0_3_PCA;
127           T2GA(tcp, T2_HAE0_3) =
128               old_hae3 | ((b ? 1UL : 0UL) << HAE0_3_PCA_SHIFT);
129           alpha_mb();
130           alpha_mb();
131 
132           datap =
133               (pcireg_t *)ALPHA_PHYS_TO_K0SEG(tcp->tc_sysmap->tsmap_conf_base |
134               addr << 5UL |             /* address shift */
135               (offset & ~0x03) << 5UL | /* address shift */
136               0x3 << 3UL);              /* 4-byte, size shift */
137           data = (pcireg_t)-1;
138           if (!(ba = badaddr(datap, sizeof *datap)))
139                     data = *datap;
140 
141           alpha_mb();
142           T2GA(tcp, T2_HAE0_3) = old_hae3;
143           alpha_mb();
144           alpha_mb();
145 
146           alpha_pal_draina();
147           alpha_mb();
148           alpha_mb();
149 
150           TTWOGA_CONF_UNLOCK();
151 
152 #if 0
153           printf("ttwoga_conf_read: tag 0x%lx, reg 0x%x -> 0x%x @ %p%s\n",
154               tag, offset, data, datap, ba ? " (badaddr)" : "");
155 #endif
156 
157           return (data);
158 }
159 
160 static void
ttwoga_conf_write(void * cpv,pcitag_t tag,int offset,pcireg_t data)161 ttwoga_conf_write(void *cpv, pcitag_t tag, int offset, pcireg_t data)
162 {
163           struct ttwoga_config *tcp = cpv;
164           pcireg_t *datap;
165           int b, d, f;
166           paddr_t addr;
167           uint64_t old_hae3;
168 
169           if ((unsigned int)offset >= PCI_CONF_SIZE)
170                     return;
171 
172           pci_decompose_tag(&tcp->tc_pc, tag, &b, &d, &f);
173 
174           addr = b ? tag : ttwoga_make_type0addr(d, f);
175 
176           TTWOGA_CONF_LOCK();
177 
178           alpha_mb();
179           old_hae3 = T2GA(tcp, T2_HAE0_3) & ~HAE0_3_PCA;
180           T2GA(tcp, T2_HAE0_3) =
181               old_hae3 | ((b ? 1UL : 0UL) << HAE0_3_PCA_SHIFT);
182           alpha_mb();
183           alpha_mb();
184 
185           datap =
186               (pcireg_t *)ALPHA_PHYS_TO_K0SEG(tcp->tc_sysmap->tsmap_conf_base |
187               addr << 5UL |             /* address shift */
188               (offset & ~0x03) << 5UL | /* address shift */
189               0x3 << 3UL);              /* 4-byte, size shift */
190 
191           alpha_mb();
192           *datap = data;
193           alpha_mb();
194           alpha_mb();
195 
196           alpha_mb();
197           T2GA(tcp, T2_HAE0_3) = old_hae3;
198           alpha_mb();
199           alpha_mb();
200 
201           TTWOGA_CONF_UNLOCK();
202 
203 #if 0
204           printf("ttwoga_conf_write: tag 0x%lx, reg 0x%x -> 0x%x @ %p\n",
205               tag, offset, data, datap);
206 #endif
207 }
208