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
67uint64_t	busFCvtt2n = 0;
68uint64_t	busFCvtn2t = 0;
69uint64_t	tscFreq = 0;
70uint64_t	tscFCvtt2n = 0;
71uint64_t	tscFCvtn2t = 0;
72uint64_t	tscGranularity = 0;
73uint64_t	bus2tsc = 0;
74uint64_t	busFreq = 0;
75uint32_t	flex_ratio = 0;
76uint32_t	flex_ratio_min = 0;
77uint32_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
93static const char	FSB_Frequency_prop[] = "FSBFrequency";
94/*
95 * This routine extracts the bus frequency in Hz from the device tree.
96 */
97static uint64_t
98EFI_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 */
132void
133tsc_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_HASWELL:
169	case CPUFAMILY_INTEL_IVYBRIDGE:
170	case CPUFAMILY_INTEL_SANDYBRIDGE:
171	case CPUFAMILY_INTEL_WESTMERE:
172	case CPUFAMILY_INTEL_NEHALEM: {
173		uint64_t msr_flex_ratio;
174		uint64_t msr_platform_info;
175
176		/* See if FLEX_RATIO is being used */
177		msr_flex_ratio = rdmsr64(MSR_FLEX_RATIO);
178		msr_platform_info = rdmsr64(MSR_PLATFORM_INFO);
179		flex_ratio_min = (uint32_t)bitfield(msr_platform_info, 47, 40);
180		flex_ratio_max = (uint32_t)bitfield(msr_platform_info, 15, 8);
181		/* No BIOS-programed flex ratio. Use hardware max as default */
182		tscGranularity = flex_ratio_max;
183		if (msr_flex_ratio & bit(16)) {
184		 	/* Flex Enabled: Use this MSR if less than max */
185			flex_ratio = (uint32_t)bitfield(msr_flex_ratio, 15, 8);
186			if (flex_ratio < flex_ratio_max)
187				tscGranularity = flex_ratio;
188		}
189
190		/* If EFI isn't configured correctly, use a constant
191		 * value. See 6036811.
192		 */
193		if (busFreq == 0)
194		    busFreq = BASE_NHM_CLOCK_SOURCE;
195
196		break;
197            }
198	default: {
199		uint64_t	prfsts;
200
201		prfsts = rdmsr64(IA32_PERF_STS);
202		tscGranularity = (uint32_t)bitfield(prfsts, 44, 40);
203		N_by_2_bus_ratio = (prfsts & bit(46)) != 0;
204	    }
205	}
206
207	if (busFreq != 0) {
208		busFCvtt2n = ((1 * Giga) << 32) / busFreq;
209		busFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / busFCvtt2n;
210	} else {
211		panic("tsc_init: EFI not supported!\n");
212	}
213
214	kprintf(" BUS: Frequency = %6d.%06dMHz, "
215		"cvtt2n = %08X.%08X, cvtn2t = %08X.%08X\n",
216		(uint32_t)(busFreq / Mega),
217		(uint32_t)(busFreq % Mega),
218		(uint32_t)(busFCvtt2n >> 32), (uint32_t)busFCvtt2n,
219		(uint32_t)(busFCvtn2t >> 32), (uint32_t)busFCvtn2t);
220
221	/*
222	 * Get the TSC increment.  The TSC is incremented by this
223	 * on every bus tick.  Calculate the TSC conversion factors
224	 * to and from nano-seconds.
225	 * The tsc granularity is also called the "bus ratio". If the N/2 bit
226	 * is set this indicates the bus ration is 0.5 more than this - i.e.
227	 * that the true bus ratio is (2*tscGranularity + 1)/2. If we cannot
228	 * determine the TSC conversion, assume it ticks at the bus frequency.
229	 */
230	if (tscGranularity == 0)
231		tscGranularity = 1;
232
233	if (N_by_2_bus_ratio)
234		tscFCvtt2n = busFCvtt2n * 2 / (1 + 2*tscGranularity);
235	else
236		tscFCvtt2n = busFCvtt2n / tscGranularity;
237
238	tscFreq = ((1 * Giga)  << 32) / tscFCvtt2n;
239	tscFCvtn2t = 0xFFFFFFFFFFFFFFFFULL / tscFCvtt2n;
240
241	kprintf(" TSC: Frequency = %6d.%06dMHz, "
242		"cvtt2n = %08X.%08X, cvtn2t = %08X.%08X, gran = %lld%s\n",
243		(uint32_t)(tscFreq / Mega),
244		(uint32_t)(tscFreq % Mega),
245		(uint32_t)(tscFCvtt2n >> 32), (uint32_t)tscFCvtt2n,
246		(uint32_t)(tscFCvtn2t >> 32), (uint32_t)tscFCvtn2t,
247		tscGranularity, N_by_2_bus_ratio ? " (N/2)" : "");
248
249	/*
250	 * Calculate conversion from BUS to TSC
251	 */
252	bus2tsc = tmrCvt(busFCvtt2n, tscFCvtn2t);
253}
254
255void
256tsc_get_info(tscInfo_t *info)
257{
258	info->busFCvtt2n     = busFCvtt2n;
259	info->busFCvtn2t     = busFCvtn2t;
260	info->tscFreq        = tscFreq;
261	info->tscFCvtt2n     = tscFCvtt2n;
262	info->tscFCvtn2t     = tscFCvtn2t;
263	info->tscGranularity = tscGranularity;
264	info->bus2tsc        = bus2tsc;
265	info->busFreq        = busFreq;
266	info->flex_ratio     = flex_ratio;
267	info->flex_ratio_min = flex_ratio_min;
268	info->flex_ratio_max = flex_ratio_max;
269}
270