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
39#include <mach/mach_types.h>
40
41#include <kern/cpu_data.h>
42#include <kern/cpu_number.h>
43#include <kern/clock.h>
44#include <kern/host_notify.h>
45#include <kern/macro_help.h>
46#include <kern/misc_protos.h>
47#include <kern/spl.h>
48#include <kern/assert.h>
49#include <mach/vm_prot.h>
50#include <vm/pmap.h>
51#include <vm/vm_kern.h> /* for kernel_map */
52#include <architecture/i386/pio.h>
53#include <i386/machine_cpu.h>
54#include <i386/cpuid.h>
55#include <i386/mp.h>
56#include <i386/machine_routines.h>
57#include <i386/proc_reg.h>
58#include <i386/tsc.h>
59#include <i386/misc_protos.h>
60#include <pexpert/pexpert.h>
61#include <machine/limits.h>
62#include <machine/commpage.h>
63#include <sys/kdebug.h>
64#include <pexpert/device_tree.h>
65
66uint64_t busFCvtt2n = 0;
67uint64_t busFCvtn2t = 0;
68uint64_t tscFreq = 0;
69uint64_t tscFCvtt2n = 0;
70uint64_t tscFCvtn2t = 0;
71uint64_t tscGranularity = 0;
72uint64_t bus2tsc = 0;
73uint64_t busFreq = 0;
74uint32_t flex_ratio = 0;
75uint32_t flex_ratio_min = 0;
76uint32_t flex_ratio_max = 0;
77
78uint64_t tsc_at_boot = 0;
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/*
94 * This routine extracts a frequency property in Hz from the device tree.
95 * Also reads any initial TSC value at boot from the device tree.
96 */
97static uint64_t
98EFI_get_frequency(const char *prop)
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_get_frequency: didn't find /efi/platform\n");
107 return 0;
108 }
109 if (DTGetProperty(entry,prop,&value,&size) != kSuccess) {
110 kprintf("EFI_get_frequency: property %s not found\n", prop);
111 return 0;
112 }
113 if (size == sizeof(uint64_t)) {
114 frequency = *(uint64_t *) value;
115 kprintf("EFI_get_frequency: read %s value: %llu\n",
116 prop, frequency);
117 }
118
119 /*
120 * While we're here, see if EFI published an initial TSC value.
121 */
122 if (DTGetProperty(entry,"InitialTSC",&value,&size) == kSuccess) {
123 if (size == sizeof(uint64_t)) {
124 tsc_at_boot = *(uint64_t *) value;
125 kprintf("EFI_get_frequency: read InitialTSC: %llu\n",
126 tsc_at_boot);
127 }
128 }
129
130 return frequency;
131}
132
133/*
134 * Initialize the various conversion factors needed by code referencing
135 * the TSC.
136 */
137void
138tsc_init(void)
139{
140 boolean_t N_by_2_bus_ratio = FALSE;
141
142 if (cpuid_vmm_present()) {
143 kprintf("VMM vendor %u TSC frequency %u KHz bus frequency %u KHz\n",
144 cpuid_vmm_info()->cpuid_vmm_family,
145 cpuid_vmm_info()->cpuid_vmm_tsc_frequency,
146 cpuid_vmm_info()->cpuid_vmm_bus_frequency);
147
148 if (cpuid_vmm_info()->cpuid_vmm_tsc_frequency &&
149 cpuid_vmm_info()->cpuid_vmm_bus_frequency) {
150
151 busFreq = (uint64_t)cpuid_vmm_info()->cpuid_vmm_bus_frequency * kilo;
152 busFCvtt2n = ((1 * Giga) << 32) / busFreq;
153 busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
154
155 tscFreq = (uint64_t)cpuid_vmm_info()->cpuid_vmm_tsc_frequency * kilo;
156 tscFCvtt2n = ((1 * Giga) << 32) / tscFreq;
157 tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
158
159 tscGranularity = tscFreq / busFreq;
160
161 bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
162
163 return;
164 }
165 }
166
167 switch (cpuid_cpufamily()) {
168 case CPUFAMILY_INTEL_KABYLAKE:
169 case CPUFAMILY_INTEL_SKYLAKE: {
170 /*
171 * SkyLake and later has an Always Running Timer (ART) providing
172 * the reference frequency. CPUID leaf 0x15 determines the
173 * rationship between this and the TSC frequency expressed as
174 * - multiplier (numerator, N), and
175 * - divisor (denominator, M).
176 * So that TSC = ART * N / M.
177 */
178 cpuid_tsc_leaf_t *tsc_leafp = &cpuid_info()->cpuid_tsc_leaf;
179 uint64_t N = (uint64_t) tsc_leafp->numerator;
180 uint64_t M = (uint64_t) tsc_leafp->denominator;
181 uint64_t refFreq;
182
183 refFreq = EFI_get_frequency("ARTFrequency");
184 if (refFreq == 0)
185 refFreq = BASE_ART_CLOCK_SOURCE;
186
187 assert(N != 0);
188 assert(M != 1);
189 tscFreq = refFreq * N / M;
190 busFreq = tscFreq; /* bus is APIC frequency */
191
192 kprintf(" ART: Frequency = %6d.%06dMHz, N/M = %lld/%llu\n",
193 (uint32_t)(refFreq / Mega),
194 (uint32_t)(refFreq % Mega),
195 N, M);
196
197 break;
198 }
199 default: {
200 uint64_t msr_flex_ratio;
201 uint64_t msr_platform_info;
202
203 /* See if FLEX_RATIO is being used */
204 msr_flex_ratio = rdmsr64(MSR_FLEX_RATIO);
205 msr_platform_info = rdmsr64(MSR_PLATFORM_INFO);
206 flex_ratio_min = (uint32_t)bitfield(msr_platform_info, 47, 40);
207 flex_ratio_max = (uint32_t)bitfield(msr_platform_info, 15, 8);
208 /* No BIOS-programed flex ratio. Use hardware max as default */
209 tscGranularity = flex_ratio_max;
210 if (msr_flex_ratio & bit(16)) {
211 /* Flex Enabled: Use this MSR if less than max */
212 flex_ratio = (uint32_t)bitfield(msr_flex_ratio, 15, 8);
213 if (flex_ratio < flex_ratio_max)
214 tscGranularity = flex_ratio;
215 }
216
217 busFreq = EFI_get_frequency("FSBFrequency");
218 /* If EFI isn't configured correctly, use a constant
219 * value. See 6036811.
220 */
221 if (busFreq == 0)
222 busFreq = BASE_NHM_CLOCK_SOURCE;
223
224 break;
225 }
226 case CPUFAMILY_INTEL_PENRYN: {
227 uint64_t prfsts;
228
229 prfsts = rdmsr64(IA32_PERF_STS);
230 tscGranularity = (uint32_t)bitfield(prfsts, 44, 40);
231 N_by_2_bus_ratio = (prfsts & bit(46)) != 0;
232
233 busFreq = EFI_get_frequency("FSBFrequency");
234 }
235 }
236
237 if (busFreq != 0) {
238 busFCvtt2n = ((1 * Giga) << 32) / busFreq;
239 busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
240 } else {
241 panic("tsc_init: EFI not supported!\n");
242 }
243
244 kprintf(" BUS: Frequency = %6d.%06dMHz, "
245 "cvtt2n = %08X.%08X, cvtn2t = %08X.%08X\n",
246 (uint32_t)(busFreq / Mega),
247 (uint32_t)(busFreq % Mega),
248 (uint32_t)(busFCvtt2n >> 32), (uint32_t)busFCvtt2n,
249 (uint32_t)(busFCvtn2t >> 32), (uint32_t)busFCvtn2t);
250
251 if (tscFreq == busFreq) {
252 bus2tsc = 1;
253 tscGranularity = 1;
254 tscFCvtn2t = busFCvtn2t;
255 tscFCvtt2n = busFCvtt2n;
256 } else {
257 /*
258 * Get the TSC increment. The TSC is incremented by this
259 * on every bus tick. Calculate the TSC conversion factors
260 * to and from nano-seconds.
261 * The tsc granularity is also called the "bus ratio".
262 * If the N/2 bit is set this indicates the bus ration is
263 * 0.5 more than this - i.e. that the true bus ratio
264 * is (2*tscGranularity + 1)/2.
265 */
266 if (N_by_2_bus_ratio)
267 tscFCvtt2n = busFCvtt2n * 2 / (1 + 2*tscGranularity);
268 else
269 tscFCvtt2n = busFCvtt2n / tscGranularity;
270
271 tscFreq = ((1 * Giga) << 32) / tscFCvtt2n;
272 tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
273
274 /*
275 * Calculate conversion from BUS to TSC
276 */
277 bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
278 }
279
280 kprintf(" TSC: Frequency = %6d.%06dMHz, "
281 "cvtt2n = %08X.%08X, cvtn2t = %08X.%08X, gran = %lld%s\n",
282 (uint32_t)(tscFreq / Mega),
283 (uint32_t)(tscFreq % Mega),
284 (uint32_t)(tscFCvtt2n >> 32), (uint32_t)tscFCvtt2n,
285 (uint32_t)(tscFCvtn2t >> 32), (uint32_t)tscFCvtn2t,
286 tscGranularity, N_by_2_bus_ratio ? " (N/2)" : "");
287}
288
289void
290tsc_get_info(tscInfo_t *info)
291{
292 info->busFCvtt2n = busFCvtt2n;
293 info->busFCvtn2t = busFCvtn2t;
294 info->tscFreq = tscFreq;
295 info->tscFCvtt2n = tscFCvtt2n;
296 info->tscFCvtn2t = tscFCvtn2t;
297 info->tscGranularity = tscGranularity;
298 info->bus2tsc = bus2tsc;
299 info->busFreq = busFreq;
300 info->flex_ratio = flex_ratio;
301 info->flex_ratio_min = flex_ratio_min;
302 info->flex_ratio_max = flex_ratio_max;
303}
304