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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 #include <mach_kdb.h>
40
41 #include <mach/mach_types.h>
42
43 #include <kern/cpu_data.h>
44 #include <kern/cpu_number.h>
45 #include <kern/clock.h>
46 #include <kern/host_notify.h>
47 #include <kern/macro_help.h>
48 #include <kern/misc_protos.h>
49 #include <kern/spl.h>
50 #include <kern/assert.h>
51 #include <mach/vm_prot.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_kern.h> /* for kernel_map */
54 #include <i386/ipl.h>
55 #include <architecture/i386/pio.h>
56 #include <i386/misc_protos.h>
57 #include <i386/proc_reg.h>
58 #include <i386/machine_cpu.h>
59 #include <i386/mp.h>
60 #include <i386/cpu_data.h>
61 #include <i386/cpuid.h>
62 #include <i386/machine_routines.h>
63 #include <pexpert/pexpert.h>
64 #include <machine/limits.h>
65 #include <machine/commpage.h>
66 #include <sys/kdebug.h>
67 #include <pexpert/device_tree.h>
68 #include <i386/tsc.h>
69
70 uint64_t busFCvtt2n = 0;
71 uint64_t busFCvtn2t = 0;
72 uint64_t tscFreq = 0;
73 uint64_t tscFCvtt2n = 0;
74 uint64_t tscFCvtn2t = 0;
75 uint64_t tscGranularity = 0;
76 uint64_t bus2tsc = 0;
77 uint64_t busFreq = 0;
78 uint32_t flex_ratio = 0;
79 uint32_t flex_ratio_min = 0;
80 uint32_t flex_ratio_max = 0;
81
82
83 #define bit(n) (1ULL << (n))
84 #define bitmask(h,l) ((bit(h)|(bit(h)-1)) & ~(bit(l)-1))
85 #define bitfield(x,h,l) (((x) & bitmask(h,l)) >> l)
86
87 /* Decimal powers: */
88 #define kilo (1000ULL)
89 #define Mega (kilo * kilo)
90 #define Giga (kilo * Mega)
91 #define Tera (kilo * Giga)
92 #define Peta (kilo * Tera)
93
94 #define CPU_FAMILY_PENTIUM_M (0x6)
95
96 static const char FSB_Frequency_prop[] = "FSBFrequency";
97 /*
98 * This routine extracts the bus frequency in Hz from the device tree.
99 */
100 static uint64_t
101 EFI_FSB_frequency(void)
102 {
103 uint64_t frequency = 0;
104 DTEntry entry;
105 void *value;
106 unsigned int size;
107
108 if (DTLookupEntry(0, "/efi/platform", &entry) != kSuccess) {
109 kprintf("EFI_FSB_frequency: didn't find /efi/platform\n");
110 return 0;
111 }
112 if (DTGetProperty(entry,FSB_Frequency_prop,&value,&size) != kSuccess) {
113 kprintf("EFI_FSB_frequency: property %s not found\n",
114 FSB_Frequency_prop);
115 return 0;
116 }
117 if (size == sizeof(uint64_t)) {
118 frequency = *(uint64_t *) value;
119 kprintf("EFI_FSB_frequency: read %s value: %llu\n",
120 FSB_Frequency_prop, frequency);
121 if (!(90*Mega < frequency && frequency < 10*Giga)) {
122 kprintf("EFI_FSB_frequency: value out of range\n");
123 frequency = 0;
124 }
125 } else {
126 kprintf("EFI_FSB_frequency: unexpected size %d\n", size);
127 }
128 return frequency;
129 }
130
131 /*
132 * Initialize the various conversion factors needed by code referencing
133 * the TSC.
134 */
135 void
136 tsc_init(void)
137 {
138 uint64_t busFCvtInt = 0;
139 boolean_t N_by_2_bus_ratio = FALSE;
140
141 /*
142 * Get the FSB frequency and conversion factors from EFI.
143 */
144 busFreq = EFI_FSB_frequency();
145
146 if (cpuid_info()->cpuid_family != CPU_FAMILY_PENTIUM_M) {
147 panic("tsc_init: unknown CPU family: 0x%X\n",
148 cpuid_info()->cpuid_family);
149 }
150
151 switch (cpuid_info()->cpuid_model) {
152 case CPUID_MODEL_NEHALEM: {
153 uint64_t cpu_mhz;
154 uint64_t msr_flex_ratio;
155 uint64_t msr_platform_info;
156
157 /* See if FLEX_RATIO is being used */
158 msr_flex_ratio = rdmsr64(MSR_FLEX_RATIO);
159 msr_platform_info = rdmsr64(MSR_PLATFORM_INFO);
160 flex_ratio_min = (uint32_t)bitfield(msr_platform_info, 47, 40);
161 flex_ratio_max = (uint32_t)bitfield(msr_platform_info, 15, 8);
162 /* No BIOS-programed flex ratio. Use hardware max as default */
163 tscGranularity = flex_ratio_max;
164 if (msr_flex_ratio & bit(16)) {
165 /* Flex Enabled: Use this MSR if less than max */
166 flex_ratio = (uint32_t)bitfield(msr_flex_ratio, 15, 8);
167 if (flex_ratio < flex_ratio_max)
168 tscGranularity = flex_ratio;
169 }
170
171 /* If EFI isn't configured correctly, use a constant
172 * value. See 6036811.
173 */
174 if (busFreq == 0)
175 busFreq = BASE_NHM_CLOCK_SOURCE;
176
177 cpu_mhz = tscGranularity * BASE_NHM_CLOCK_SOURCE;
178
179 kprintf("[NHM] Maximum Non-Turbo Ratio = [%d]\n",
180 (uint32_t)tscGranularity);
181 kprintf("[NHM] CPU: Frequency = %6d.%04dMhz\n",
182 (uint32_t)(cpu_mhz / Mega), (uint32_t)(cpu_mhz % Mega));
183 break;
184 }
185 default: {
186 uint64_t prfsts;
187
188 prfsts = rdmsr64(IA32_PERF_STS);
189 tscGranularity = (uint32_t)bitfield(prfsts, 44, 40);
190 N_by_2_bus_ratio = (prfsts & bit(46)) != 0;
191 }
192 }
193
194 if (busFreq != 0) {
195 busFCvtt2n = ((1 * Giga) << 32) / busFreq;
196 busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
197 busFCvtInt = tmrCvt(1 * Peta, 0xFFFFFFFFFFFFFFFFULL / busFreq);
198 } else {
199 panic("tsc_init: EFI not supported!\n");
200 }
201
202 kprintf(" BUS: Frequency = %6d.%04dMHz, "
203 "cvtt2n = %08X.%08X, cvtn2t = %08X.%08X, "
204 "cvtInt = %08X.%08X\n",
205 (uint32_t)(busFreq / Mega),
206 (uint32_t)(busFreq % Mega),
207 (uint32_t)(busFCvtt2n >> 32), (uint32_t)busFCvtt2n,
208 (uint32_t)(busFCvtn2t >> 32), (uint32_t)busFCvtn2t,
209 (uint32_t)(busFCvtInt >> 32), (uint32_t)busFCvtInt);
210
211 /*
212 * Get the TSC increment. The TSC is incremented by this
213 * on every bus tick. Calculate the TSC conversion factors
214 * to and from nano-seconds.
215 * The tsc granularity is also called the "bus ratio". If the N/2 bit
216 * is set this indicates the bus ration is 0.5 more than this - i.e.
217 * that the true bus ratio is (2*tscGranularity + 1)/2.
218 */
219 if (N_by_2_bus_ratio)
220 tscFCvtt2n = busFCvtt2n * 2 / (1 + 2*tscGranularity);
221 else
222 tscFCvtt2n = busFCvtt2n / tscGranularity;
223
224 tscFreq = ((1 * Giga) << 32) / tscFCvtt2n;
225 tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
226
227 kprintf(" TSC: Frequency = %6d.%04dMHz, "
228 "cvtt2n = %08X.%08X, cvtn2t = %08X.%08X, gran = %lld%s\n",
229 (uint32_t)(tscFreq / Mega),
230 (uint32_t)(tscFreq % Mega),
231 (uint32_t)(tscFCvtt2n >> 32), (uint32_t)tscFCvtt2n,
232 (uint32_t)(tscFCvtn2t >> 32), (uint32_t)tscFCvtn2t,
233 tscGranularity, N_by_2_bus_ratio ? " (N/2)" : "");
234
235 /*
236 * Calculate conversion from BUS to TSC
237 */
238 bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
239 }
240
241 void
242 tsc_get_info(tscInfo_t *info)
243 {
244 info->busFCvtt2n = busFCvtt2n;
245 info->busFCvtn2t = busFCvtn2t;
246 info->tscFreq = tscFreq;
247 info->tscFCvtt2n = tscFCvtt2n;
248 info->tscFCvtn2t = tscFCvtn2t;
249 info->tscGranularity = tscGranularity;
250 info->bus2tsc = bus2tsc;
251 info->busFreq = busFreq;
252 info->flex_ratio = flex_ratio;
253 info->flex_ratio_min = flex_ratio_min;
254 info->flex_ratio_max = flex_ratio_max;
255 }