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34 * Purpose: Initializes the TSC and the various conversion
35 * factors needed by other parts of the system.
38 #include <platforms.h>
41 #include <mach/mach_types.h>
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>
50 #include <kern/assert.h>
51 #include <mach/vm_prot.h>
53 #include <vm/vm_kern.h> /* for kernel_map */
55 #include <architecture/i386/pio.h>
56 #include <i386/misc_protos.h>
57 #include <i386/proc_reg.h>
58 #include <i386/machine_cpu.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>
70 uint64_t busFCvtt2n
= 0;
71 uint64_t busFCvtn2t
= 0;
73 uint64_t tscFCvtt2n
= 0;
74 uint64_t tscFCvtn2t
= 0;
75 uint64_t tscGranularity
= 0;
78 uint32_t flex_ratio
= 0;
79 uint32_t flex_ratio_min
= 0;
80 uint32_t flex_ratio_max
= 0;
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)
88 #define kilo (1000ULL)
89 #define Mega (kilo * kilo)
90 #define Giga (kilo * Mega)
91 #define Tera (kilo * Giga)
92 #define Peta (kilo * Tera)
94 #define CPU_FAMILY_PENTIUM_M (0x6)
96 static const char FSB_Frequency_prop
[] = "FSBFrequency";
98 * This routine extracts the bus frequency in Hz from the device tree.
101 EFI_FSB_frequency(void)
103 uint64_t frequency
= 0;
108 if (DTLookupEntry(0, "/efi/platform", &entry
) != kSuccess
) {
109 kprintf("EFI_FSB_frequency: didn't find /efi/platform\n");
112 if (DTGetProperty(entry
,FSB_Frequency_prop
,&value
,&size
) != kSuccess
) {
113 kprintf("EFI_FSB_frequency: property %s not found\n",
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");
126 kprintf("EFI_FSB_frequency: unexpected size %d\n", size
);
132 * Initialize the various conversion factors needed by code referencing
138 uint64_t busFCvtInt
= 0;
139 boolean_t N_by_2_bus_ratio
= FALSE
;
142 * Get the FSB frequency and conversion factors from EFI.
144 busFreq
= EFI_FSB_frequency();
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
);
151 switch (cpuid_info()->cpuid_model
) {
152 case CPUID_MODEL_NEHALEM
: {
154 uint64_t msr_flex_ratio
;
155 uint64_t msr_platform_info
;
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
;
171 /* If EFI isn't configured correctly, use a constant
172 * value. See 6036811.
175 busFreq
= BASE_NHM_CLOCK_SOURCE
;
177 cpu_mhz
= tscGranularity
* BASE_NHM_CLOCK_SOURCE
;
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
));
188 prfsts
= rdmsr64(IA32_PERF_STS
);
189 tscGranularity
= (uint32_t)bitfield(prfsts
, 44, 40);
190 N_by_2_bus_ratio
= (prfsts
& bit(46)) != 0;
195 busFCvtt2n
= ((1 * Giga
) << 32) / busFreq
;
196 busFCvtn2t
= 0xFFFFFFFFFFFFFFFFULL
/ busFCvtt2n
;
197 busFCvtInt
= tmrCvt(1 * Peta
, 0xFFFFFFFFFFFFFFFFULL
/ busFreq
);
199 panic("tsc_init: EFI not supported!\n");
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
);
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.
219 if (N_by_2_bus_ratio
)
220 tscFCvtt2n
= busFCvtt2n
* 2 / (1 + 2*tscGranularity
);
222 tscFCvtt2n
= busFCvtt2n
/ tscGranularity
;
224 tscFreq
= ((1 * Giga
) << 32) / tscFCvtt2n
;
225 tscFCvtn2t
= 0xFFFFFFFFFFFFFFFFULL
/ tscFCvtt2n
;
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)" : "");
236 * Calculate conversion from BUS to TSC
238 bus2tsc
= tmrCvt(busFCvtt2n
, tscFCvtn2t
);
242 tsc_get_info(tscInfo_t
*info
)
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
;