geode_msr.c revision 621ff18c 
1/*
2 * Copyright (c) 2008 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20 * DEALINGS IN THE SOFTWARE.
21 *
22 * Neither the name of the Advanced Micro Devices, Inc. nor the names of its
23 * contributors may be used to endorse or promote products derived from this
24 * software without specific prior written permission.
25 */
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <stdio.h>
32#include <unistd.h>
33#include <fcntl.h>
34#include <sys/types.h>
35#include <errno.h>
36
37#ifdef __OpenBSD__
38#include <sys/ioctl.h>
39#include <machine/amdmsr.h>
40#endif
41
42#include "os.h"
43#include "geode.h"
44
45#ifdef __OpenBSD__
46#define _PATH_MSRDEV	"/dev/amdmsr"
47#define X_PRIVSEP
48#else
49#define _PATH_MSRDEV	"/dev/cpu/0/msr"
50#endif
51
52static int
53_msr_open(void)
54{
55    static int msrfd = 0;
56
57    if (msrfd == 0) {
58#ifdef X_PRIVSEP
59        msrfd = priv_open_device(_PATH_MSRDEV);
60#else
61        msrfd = open(_PATH_MSRDEV, O_RDWR);
62#endif
63        if (msrfd == -1)
64            FatalError("Unable to open %s: %s\n", _PATH_MSRDEV,
65                strerror(errno));
66    }
67
68    return msrfd;
69}
70
71int
72GeodeReadMSR(unsigned long addr, unsigned long *lo, unsigned long *hi)
73{
74#ifdef __OpenBSD__
75    struct amdmsr_req req;
76    int fd = _msr_open();
77
78    req.addr = addr;
79
80    if (ioctl(fd, RDMSR, &req) == -1)
81	FatalError("Unable to read MSR at address %0x06x: %s\n", addr,
82	    strerror(errno));
83
84    *hi = req.val >> 32;
85    *lo = req.val & 0xffffffff;
86#else
87    unsigned int data[2];
88    int fd = _msr_open();
89    int ret;
90
91    if (fd == -1)
92        return -1;
93
94    ret = lseek(fd, (off_t) addr, SEEK_SET);
95
96    if (ret == -1)
97        return -1;
98
99    ret = read(fd, (void *) data, sizeof(data));
100
101    if (ret != 8)
102        return -1;
103
104    *hi = data[1];
105    *lo = data[0];
106#endif
107    return 0;
108}
109
110int
111GeodeWriteMSR(unsigned long addr, unsigned long lo, unsigned long hi)
112{
113#ifdef __OpenBSD__
114    struct amdmsr_req req;
115    int fd = _msr_open();
116
117    req.addr = addr;
118    req.val = (u_int64_t) hi << 32 | (u_int64_t)lo;
119
120    if (ioctl(fd, WRMSR, &req) == -1)
121        FatalError("Unable to write MSR at address 0x%06x: %s\n", addr,
122            strerror(errno));
123#else
124    unsigned int data[2];
125    int fd = _msr_open();
126
127    if (fd == -1)
128        return -1;
129
130    if (lseek(fd, (off_t) addr, SEEK_SET) == -1)
131        return -1;
132
133    data[0] = lo;
134    data[1] = hi;
135
136    if (write(fd, (void *) data, 8) != 8)
137        return -1;
138#endif
139    return 0;
140}
141