/* * (C) 2004 Bruno Ducrot * * Licensed under the terms of the GNU GPL License version 2. * * Based on code found in * linux/arch/i386/kernel/cpu/cpufreq/powernow-k8.c * and originally developed by Paul Devriendt */ #include #include #include #include #include #include #include #include #define MCPU 32 #define MSR_FIDVID_STATUS 0xc0010042 #define MSR_S_HI_CURRENT_VID 0x0000001f #define MSR_S_LO_CURRENT_FID 0x0000003f static int get_fidvid(uint32_t cpu, uint32_t *fid, uint32_t *vid) { int err = 1; uint64_t msr = 0; int fd; char file[20]; if (cpu > MCPU) goto out; sprintf(file, "/dev/cpu/%d/msr", cpu); fd = open(file, O_RDONLY); if (fd < 0) goto out; lseek(fd, MSR_FIDVID_STATUS, SEEK_CUR); if (read(fd, &msr, 8) != 8) goto err1; *fid = ((uint32_t )(msr & 0xffffffffull)) & MSR_S_LO_CURRENT_FID; *vid = ((uint32_t )(msr>>32 & 0xffffffffull)) & MSR_S_HI_CURRENT_VID; err = 0; err1: close(fd); out: return err; } /* Return a frequency in MHz, given an input fid */ static uint32_t find_freq_from_fid(uint32_t fid) { return 800 + (fid * 100); } /* Return a voltage in miliVolts, given an input vid */ static uint32_t find_millivolts_from_vid(uint32_t vid) { return 1550-vid*25; } int main (int argc, char *argv[]) { int err; int cpu; uint32_t fid, vid; if (argc < 2) cpu = 0; else cpu = strtoul(argv[1], NULL, 0); err = get_fidvid(cpu, &fid, &vid); if (err) { printf("can't get fid, vid from MSR\n"); printf("Possible trouble: you don't run a powernow-k8 capable cpu\n"); printf("or you are not root, or the msr driver is not present\n"); exit(1); } printf("cpu %d currently at %d MHz and %d mV\n", cpu, find_freq_from_fid(fid), find_millivolts_from_vid(vid)); return 0; } le?id=0ca2b46dbb645c1aa23eda6f5ac49a7be31ac87d'>commitdiff
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