wmlongrun/src/longrun_linux.c

   1 /*
   2  * longrun_linux.c - module to get LongRun(TM) status, for GNU/Linux
   3  *
   4  * Copyright(C) 2001 Transmeta Corporation
   5  * Copyright(C) 2001 Seiichi SATO <ssato@sh.rim.or.jp>
   6  *
   7  * licensed under the GPL
   8  */
   9 #undef USE_PREAD
  10
  11 #ifdef HAVE_CONFIG_H
  12 #include "config.h"
  13 #endif
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <stdint.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <fcntl.h>
  21 #include <errno.h>
  22 #ifdef USE_PREAD
  23 #define __USE_UNIX98         /* for pread/pwrite */
  24 #endif
  25 #define __USE_FILE_OFFSET64 /* msr/cpuid needs 64bit address with newer linuxes */
  26 #include <unistd.h>
  27 #include "common.h"
  28
  29 #define MSR_DEVICE "/dev/cpu/0/msr"
  30 #define MSR_TMx86_LONGRUN       0x80868010
  31 #define MSR_TMx86_LONGRUN_FLAGS 0x80868011
  32
  33 #define LONGRUN_MASK(x)         ((x) & 0x0000007f)
  34 #define LONGRUN_RESERVED(x)     ((x) & 0xffffff80)
  35 #define LONGRUN_WRITE(x, y)     (LONGRUN_RESERVED(x) | LONGRUN_MASK(y))
  36
  37 #define CPUID_DEVICE "/dev/cpu/0/cpuid"
  38 #define CPUID_TMx86_VENDOR_ID           0x80860000
  39 #define CPUID_TMx86_PROCESSOR_INFO      0x80860001
  40 #define CPUID_TMx86_LONGRUN_STATUS      0x80860007
  41 #define CPUID_TMx86_FEATURE_LONGRUN(x)  ((x) & 0x02)
  42
  43 static int  cpuid_fd;                   /* CPUID file descriptor */
  44 static char *cpuid_device;              /* CPUID device name */
  45 static int  msr_fd;                     /* MSR file descriptor */
  46 static char *msr_device;                /* MSR device name */
  47
  48 static void
  49 read_cpuid(loff_t address, int *eax, int *ebx, int *ecx, int *edx)
  50 {
  51     uint32_t data[4];
  52
  53 #ifdef USE_PREAD
  54     if (pread(cpuid_fd, &data, 16, address) != 16) {
  55         perror("pread");
  56 #else
  57     if (lseek(cpuid_fd, address, SEEK_SET) != address) {
  58         perror("lseek");
  59         exit(1);
  60     }
  61     if (read(cpuid_fd, &data, 16) != 16) {
  62         perror("read");
  63 #endif
  64         exit(1);
  65     }
  66
  67     if (eax)
  68         *eax = data[0];
  69     if (ebx)
  70         *ebx = data[1];
  71     if (ecx)
  72         *ecx = data[2];
  73     if (edx)
  74         *edx = data[3];
  75 }
  76
  77 /* note: if an output is NULL, then don't set it */
  78 static void
  79 read_msr(loff_t address, int *lower, int *upper)
  80 {
  81     uint32_t data[2];
  82
  83 #ifdef USE_PREAD
  84     if (pread(msr_fd, &data, 8, address) != 8) {
  85         perror("pread");
  86 #else
  87     if (lseek(msr_fd, address, SEEK_SET) != address) {
  88         perror("lseek");
  89         exit(1);
  90     }
  91     if (read(msr_fd, &data, 8) != 8) {
  92         perror("read");
  93 #endif
  94         exit(1);
  95     }
  96
  97     if (lower)
  98         *lower = data[0];
  99     if (upper)
 100         *upper = data[1];
 101 }
 102
 103 void
 104 longrun_init(char *cpuid_dev, char *msr_dev)
 105 {
 106     int eax, ebx, ecx, edx;
 107
 108     /* set CPUID device */
 109     cpuid_device = CPUID_DEVICE;
 110     if (cpuid_dev)
 111         cpuid_device = cpuid_dev;
 112
 113     /* set MSR device */
 114     msr_device = MSR_DEVICE;
 115     if (msr_dev)
 116         msr_device = msr_dev;
 117
 118     /* open CPUID device */
 119     if ((cpuid_fd = open(cpuid_device, O_RDONLY)) < 0) {
 120         fprintf(stderr, "error opening %s\n", cpuid_device);
 121         if (errno == ENODEV)
 122             fprintf(stderr,
 123                     "make sure your kernel was compiled with CONFIG_X86_CPUID=y\n");
 124         exit(1);
 125     }
 126
 127     /* open MSR device */
 128     if ((msr_fd = open(msr_device, O_RDONLY)) < 0) {
 129         fprintf(stderr, "error opening %s\n", msr_device);
 130         if (errno == ENODEV)
 131             fprintf(stderr,
 132                     "make sure your kernel was compiled with CONFIG_X86_MSR=y\n");
 133         exit(1);
 134     }
 135
 136     /* test for "TransmetaCPU" */
 137     read_cpuid(CPUID_TMx86_VENDOR_ID, &eax, &ebx, &ecx, &edx);
 138     if (ebx != 0x6e617254 || ecx != 0x55504361 || edx != 0x74656d73) {
 139         fprintf(stderr, "not a Transmeta x86 CPU\n");
 140         exit(1);
 141     }
 142
 143     /* test for LongRun feature flag */
 144     read_cpuid(CPUID_TMx86_PROCESSOR_INFO, &eax, &ebx, &ecx, &edx);
 145     if (!CPUID_TMx86_FEATURE_LONGRUN(edx)) {
 146         printf("LongRun: unsupported\n");
 147         exit(0);
 148     }
 149
 150     /* close device */
 151     close(cpuid_fd);
 152     close(msr_fd);
 153 }
 154
 155
 156
 157 /*
 158  * percent:  performance level (0 to 100)
 159  * flags:    performance/economy/unknown
 160  * mhz:      frequency
 161  * volts:    voltage
 162  */
 163 void
 164 longrun_get_stat(int *percent, int *flags, int *mhz, int *voltz)
 165 {
 166     int eax, ebx, ecx;
 167
 168     /* open CPUID device */
 169     if ((cpuid_fd = open(cpuid_device, O_RDWR)) < 0) {
 170         fprintf(stderr, "error opening %s\n", cpuid_device);
 171         if (errno == ENODEV)
 172             fprintf(stderr,
 173                     "make sure your kernel was compiled with CONFIG_X86_CPUID=y\n");
 174         exit(1);
 175     }
 176
 177     /* open MSR device */
 178     if ((msr_fd = open(msr_device, O_RDWR)) < 0) {
 179         fprintf(stderr, "error opening %s\n", msr_device);
 180         if (errno == ENODEV)
 181             fprintf(stderr,
 182                     "make sure your kernel was compiled with CONFIG_X86_MSR=y\n");
 183         exit(1);
 184     }
 185
 186     /* frequency, voltage, performance level, */
 187     read_cpuid(CPUID_TMx86_LONGRUN_STATUS, &eax, &ebx, &ecx, 0);
 188     *mhz = eax;
 189     *voltz = ebx;
 190     *percent = ecx;
 191
 192     /* flags */
 193     read_msr(MSR_TMx86_LONGRUN_FLAGS, flags, NULL);
 194     *flags =
 195         (*flags & 1) ? LONGRUN_FLAGS_PEFORMANCE : LONGRUN_FLAGS_ECONOMY;
 196
 197     /* close device */
 198     close(cpuid_fd);
 199     close(msr_fd);
 200 }