osfmk/i386/tsc.c

   1 /*
   2  * Copyright (c) 2005-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31
  32 /*
  33  *      File:           i386/tsc.c
  34  *      Purpose:        Initializes the TSC and the various conversion
  35  *                      factors needed by other parts of the system.
  36  */
  37
  38 #include <platforms.h>
  39
  40 #include <mach/mach_types.h>
  41
  42 #include <kern/cpu_data.h>
  43 #include <kern/cpu_number.h>
  44 #include <kern/clock.h>
  45 #include <kern/host_notify.h>
  46 #include <kern/macro_help.h>
  47 #include <kern/misc_protos.h>
  48 #include <kern/spl.h>
  49 #include <kern/assert.h>
  50 #include <mach/vm_prot.h>
  51 #include <vm/pmap.h>
  52 #include <vm/vm_kern.h>         /* for kernel_map */
  53 #include <architecture/i386/pio.h>
  54 #include <i386/machine_cpu.h>
  55 #include <i386/cpuid.h>
  56 #include <i386/mp.h>
  57 #include <i386/machine_routines.h>
  58 #include <i386/proc_reg.h>
  59 #include <i386/tsc.h>
  60 #include <i386/misc_protos.h>
  61 #include <pexpert/pexpert.h>
  62 #include <machine/limits.h>
  63 #include <machine/commpage.h>
  64 #include <sys/kdebug.h>
  65 #include <pexpert/device_tree.h>
  66
  67 uint64_t        busFCvtt2n = 0;
  68 uint64_t        busFCvtn2t = 0;
  69 uint64_t        tscFreq = 0;
  70 uint64_t        tscFCvtt2n = 0;
  71 uint64_t        tscFCvtn2t = 0;
  72 uint64_t        tscGranularity = 0;
  73 uint64_t        bus2tsc = 0;
  74 uint64_t        busFreq = 0;
  75 uint32_t        flex_ratio = 0;
  76 uint32_t        flex_ratio_min = 0;
  77 uint32_t        flex_ratio_max = 0;
  78
  79
  80 #define bit(n)          (1ULL << (n))
  81 #define bitmask(h,l)    ((bit(h)|(bit(h)-1)) & ~(bit(l)-1))
  82 #define bitfield(x,h,l) (((x) & bitmask(h,l)) >> l)
  83
  84 /* Decimal powers: */
  85 #define kilo (1000ULL)
  86 #define Mega (kilo * kilo)
  87 #define Giga (kilo * Mega)
  88 #define Tera (kilo * Giga)
  89 #define Peta (kilo * Tera)
  90
  91 #define CPU_FAMILY_PENTIUM_M    (0x6)
  92
  93 static const char       FSB_Frequency_prop[] = "FSBFrequency";
  94 /*
  95  * This routine extracts the bus frequency in Hz from the device tree.
  96  */
  97 static uint64_t
  98 EFI_FSB_frequency(void)
  99 {
 100         uint64_t        frequency = 0;
 101         DTEntry         entry;
 102         void            *value;
 103         unsigned int    size;
 104
 105         if (DTLookupEntry(0, "/efi/platform", &entry) != kSuccess) {
 106                 kprintf("EFI_FSB_frequency: didn't find /efi/platform\n");
 107                 return 0;
 108         }
 109         if (DTGetProperty(entry,FSB_Frequency_prop,&value,&size) != kSuccess) {
 110                 kprintf("EFI_FSB_frequency: property %s not found\n",
 111                         FSB_Frequency_prop);
 112                 return 0;
 113         }
 114         if (size == sizeof(uint64_t)) {
 115                 frequency = *(uint64_t *) value;
 116                 kprintf("EFI_FSB_frequency: read %s value: %llu\n",
 117                         FSB_Frequency_prop, frequency);
 118                 if (!(90*Mega < frequency && frequency < 10*Giga)) {
 119                         kprintf("EFI_FSB_frequency: value out of range\n");
 120                         frequency = 0;
 121                 }
 122         } else {
 123                 kprintf("EFI_FSB_frequency: unexpected size %d\n", size);
 124         }
 125         return frequency;
 126 }
 127
 128 /*
 129  * Initialize the various conversion factors needed by code referencing
 130  * the TSC.
 131  */
 132 void
 133 tsc_init(void)
 134 {
 135         boolean_t       N_by_2_bus_ratio = FALSE;
 136
 137         if (cpuid_vmm_present()) {
 138                 kprintf("VMM vendor %u TSC frequency %u KHz bus frequency %u KHz\n",
 139                                 cpuid_vmm_info()->cpuid_vmm_family,
 140                                 cpuid_vmm_info()->cpuid_vmm_tsc_frequency,
 141                                 cpuid_vmm_info()->cpuid_vmm_bus_frequency);
 142
 143                 if (cpuid_vmm_info()->cpuid_vmm_tsc_frequency &&
 144                         cpuid_vmm_info()->cpuid_vmm_bus_frequency) {
 145
 146                         busFreq = (uint64_t)cpuid_vmm_info()->cpuid_vmm_bus_frequency * kilo;
 147                         busFCvtt2n = ((1 * Giga) << 32) / busFreq;
 148                         busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
 149
 150                         tscFreq = (uint64_t)cpuid_vmm_info()->cpuid_vmm_tsc_frequency * kilo;
 151                         tscFCvtt2n = ((1 * Giga) << 32) / tscFreq;
 152                         tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
 153
 154                         tscGranularity = tscFreq / busFreq;
 155
 156                         bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
 157
 158                         return;
 159                 }
 160         }
 161
 162         /*
 163          * Get the FSB frequency and conversion factors from EFI.
 164          */
 165         busFreq = EFI_FSB_frequency();
 166
 167         switch (cpuid_cpufamily()) {
 168         case CPUFAMILY_INTEL_IVYBRIDGE:
 169         case CPUFAMILY_INTEL_SANDYBRIDGE:
 170         case CPUFAMILY_INTEL_WESTMERE:
 171         case CPUFAMILY_INTEL_NEHALEM: {
 172                 uint64_t msr_flex_ratio;
 173                 uint64_t msr_platform_info;
 174
 175                 /* See if FLEX_RATIO is being used */
 176                 msr_flex_ratio = rdmsr64(MSR_FLEX_RATIO);
 177                 msr_platform_info = rdmsr64(MSR_PLATFORM_INFO);
 178                 flex_ratio_min = (uint32_t)bitfield(msr_platform_info, 47, 40);
 179                 flex_ratio_max = (uint32_t)bitfield(msr_platform_info, 15, 8);
 180                 /* No BIOS-programed flex ratio. Use hardware max as default */
 181                 tscGranularity = flex_ratio_max;
 182                 if (msr_flex_ratio & bit(16)) {
 183                         /* Flex Enabled: Use this MSR if less than max */
 184                         flex_ratio = (uint32_t)bitfield(msr_flex_ratio, 15, 8);
 185                         if (flex_ratio < flex_ratio_max)
 186                                 tscGranularity = flex_ratio;
 187                 }
 188
 189                 /* If EFI isn't configured correctly, use a constant
 190                  * value. See 6036811.
 191                  */
 192                 if (busFreq == 0)
 193                     busFreq = BASE_NHM_CLOCK_SOURCE;
 194
 195                 break;
 196             }
 197         default: {
 198                 uint64_t        prfsts;
 199
 200                 prfsts = rdmsr64(IA32_PERF_STS);
 201                 tscGranularity = (uint32_t)bitfield(prfsts, 44, 40);
 202                 N_by_2_bus_ratio = (prfsts & bit(46)) != 0;
 203             }
 204         }
 205
 206         if (busFreq != 0) {
 207                 busFCvtt2n = ((1 * Giga) << 32) / busFreq;
 208                 busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
 209         } else {
 210                 panic("tsc_init: EFI not supported!\n");
 211         }
 212
 213         kprintf(" BUS: Frequency = %6d.%06dMHz, "
 214                 "cvtt2n = %08Xx.%08Xx, cvtn2t = %08Xx.%08Xx\n",
 215                 (uint32_t)(busFreq / Mega),
 216                 (uint32_t)(busFreq % Mega),
 217                 (uint32_t)(busFCvtt2n >> 32), (uint32_t)busFCvtt2n,
 218                 (uint32_t)(busFCvtn2t >> 32), (uint32_t)busFCvtn2t);
 219
 220         /*
 221          * Get the TSC increment.  The TSC is incremented by this
 222          * on every bus tick.  Calculate the TSC conversion factors
 223          * to and from nano-seconds.
 224          * The tsc granularity is also called the "bus ratio". If the N/2 bit
 225          * is set this indicates the bus ration is 0.5 more than this - i.e.
 226          * that the true bus ratio is (2*tscGranularity + 1)/2. If we cannot
 227          * determine the TSC conversion, assume it ticks at the bus frequency.
 228          */
 229         if (tscGranularity == 0)
 230                 tscGranularity = 1;
 231
 232         if (N_by_2_bus_ratio)
 233                 tscFCvtt2n = busFCvtt2n * 2 / (1 + 2*tscGranularity);
 234         else
 235                 tscFCvtt2n = busFCvtt2n / tscGranularity;
 236
 237         tscFreq = ((1 * Giga)  << 32) / tscFCvtt2n;
 238         tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
 239
 240         kprintf(" TSC: Frequency = %6d.%06dMHz, "
 241                 "cvtt2n = %08Xx.%08Xx, cvtn2t = %08Xx.%08Xx, gran = %lld%s\n",
 242                 (uint32_t)(tscFreq / Mega),
 243                 (uint32_t)(tscFreq % Mega),
 244                 (uint32_t)(tscFCvtt2n >> 32), (uint32_t)tscFCvtt2n,
 245                 (uint32_t)(tscFCvtn2t >> 32), (uint32_t)tscFCvtn2t,
 246                 tscGranularity, N_by_2_bus_ratio ? " (N/2)" : "");
 247
 248         /*
 249          * Calculate conversion from BUS to TSC
 250          */
 251         bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
 252 }
 253
 254 void
 255 tsc_get_info(tscInfo_t *info)
 256 {
 257         info->busFCvtt2n     = busFCvtt2n;
 258         info->busFCvtn2t     = busFCvtn2t;
 259         info->tscFreq        = tscFreq;
 260         info->tscFCvtt2n     = tscFCvtt2n;
 261         info->tscFCvtn2t     = tscFCvtn2t;
 262         info->tscGranularity = tscGranularity;
 263         info->bus2tsc        = bus2tsc;
 264         info->busFreq        = busFreq;
 265         info->flex_ratio     = flex_ratio;
 266         info->flex_ratio_min = flex_ratio_min;
 267         info->flex_ratio_max = flex_ratio_max;
 268 }