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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 582 | mauro | 1 | /* |
| 2 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> |
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| 3 | * |
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| 4 | * Licensed under the terms of the GNU GPL License version 2. |
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| 5 | * |
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| 6 | * Library for common functions for Intel SpeedStep v.1 and v.2 support |
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| 7 | * |
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| 8 | * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* |
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| 9 | */ |
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| 10 | |||
| 11 | #include <linuxcomp.h> |
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| 12 | |||
| 13 | #include <linux/kernel.h> |
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| 14 | #include <linux/module.h> |
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| 15 | #include <linux/init.h> |
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| 16 | #include <linux/cpufreq.h> |
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| 17 | #include <linux/pci.h> |
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| 18 | #include <linux/slab.h> |
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| 19 | |||
| 20 | #include <asm/msr.h> |
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| 21 | #include "speedstep-lib.h" |
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| 22 | |||
| 23 | |||
| 24 | /* DEBUG |
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| 25 | * Define it if you want verbose debug output, e.g. for bug reporting |
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| 26 | */ |
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| 775 | mauro | 27 | //#define SPEEDSTEP_DEBUG |
| 582 | mauro | 28 | |
| 29 | #ifdef SPEEDSTEP_DEBUG |
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| 30 | #define dprintk(msg...) printk(msg) |
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| 31 | #else |
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| 32 | #define dprintk(msg...) do { } while(0) |
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| 33 | #endif |
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| 34 | |||
| 35 | /********************************************************************* |
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| 36 | * GET PROCESSOR CORE SPEED IN KHZ * |
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| 37 | *********************************************************************/ |
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| 38 | |||
| 39 | static unsigned int pentium3_get_frequency (unsigned int processor) |
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| 40 | { |
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| 41 | /* See table 14 of p3_ds.pdf and table 22 of 29834003.pdf */ |
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| 42 | struct { |
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| 43 | unsigned int ratio; /* Frequency Multiplier (x10) */ |
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| 44 | u8 bitmap; /* power on configuration bits |
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| 45 | [27, 25:22] (in MSR 0x2a) */ |
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| 46 | } msr_decode_mult [] = { |
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| 47 | { 30, 0x01 }, |
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| 48 | { 35, 0x05 }, |
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| 49 | { 40, 0x02 }, |
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| 50 | { 45, 0x06 }, |
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| 51 | { 50, 0x00 }, |
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| 52 | { 55, 0x04 }, |
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| 53 | { 60, 0x0b }, |
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| 54 | { 65, 0x0f }, |
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| 55 | { 70, 0x09 }, |
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| 56 | { 75, 0x0d }, |
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| 57 | { 80, 0x0a }, |
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| 58 | { 85, 0x26 }, |
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| 59 | { 90, 0x20 }, |
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| 60 | { 100, 0x2b }, |
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| 61 | { 0, 0xff } /* error or unknown value */ |
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| 62 | }; |
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| 63 | |||
| 64 | /* PIII(-M) FSB settings: see table b1-b of 24547206.pdf */ |
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| 65 | struct { |
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| 66 | unsigned int value; /* Front Side Bus speed in MHz */ |
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| 67 | u8 bitmap; /* power on configuration bits [18: 19] |
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| 68 | (in MSR 0x2a) */ |
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| 69 | } msr_decode_fsb [] = { |
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| 70 | { 66, 0x0 }, |
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| 71 | { 100, 0x2 }, |
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| 72 | { 133, 0x1 }, |
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| 73 | { 0, 0xff} |
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| 74 | }; |
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| 75 | |||
| 76 | u32 msr_lo, msr_tmp; |
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| 77 | int i = 0, j = 0; |
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| 78 | |||
| 79 | /* read MSR 0x2a - we only need the low 32 bits */ |
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| 80 | rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_tmp); |
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| 81 | dprintk(KERN_DEBUG "speedstep-lib: P3 - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp); |
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| 82 | msr_tmp = msr_lo; |
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| 83 | |||
| 84 | /* decode the FSB */ |
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| 85 | msr_tmp &= 0x00c0000; |
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| 86 | msr_tmp >>= 18; |
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| 87 | while (msr_tmp != msr_decode_fsb[i].bitmap) { |
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| 88 | if (msr_decode_fsb[i].bitmap == 0xff) |
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| 89 | return 0; |
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| 90 | i++; |
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| 91 | } |
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| 92 | |||
| 93 | /* decode the multiplier */ |
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| 94 | if (processor == SPEEDSTEP_PROCESSOR_PIII_C_EARLY) |
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| 95 | msr_lo &= 0x03c00000; |
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| 96 | else |
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| 97 | msr_lo &= 0x0bc00000; |
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| 98 | msr_lo >>= 22; |
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| 99 | while (msr_lo != msr_decode_mult[j].bitmap) { |
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| 100 | if (msr_decode_mult[j].bitmap == 0xff) |
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| 101 | return 0; |
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| 102 | j++; |
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| 103 | } |
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| 104 | |||
| 105 | return (msr_decode_mult[j].ratio * msr_decode_fsb[i].value * 100); |
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| 106 | } |
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| 107 | |||
| 108 | |||
| 109 | static unsigned int pentium4_get_frequency(void) |
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| 110 | { |
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| 111 | u32 msr_lo, msr_hi; |
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| 112 | |||
| 113 | rdmsr(0x2c, msr_lo, msr_hi); |
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| 114 | |||
| 115 | dprintk(KERN_DEBUG "speedstep-lib: P4 - MSR_EBC_FREQUENCY_ID: 0x%x 0x%x\n", msr_lo, msr_hi); |
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| 116 | |||
| 117 | msr_lo >>= 24; |
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| 118 | return (msr_lo * 100000); |
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| 119 | } |
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| 120 | |||
| 121 | |||
| 122 | unsigned int speedstep_get_processor_frequency(unsigned int processor) |
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| 123 | { |
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| 124 | switch (processor) { |
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| 125 | case SPEEDSTEP_PROCESSOR_P4M: |
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| 126 | return pentium4_get_frequency(); |
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| 127 | case SPEEDSTEP_PROCESSOR_PIII_T: |
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| 128 | case SPEEDSTEP_PROCESSOR_PIII_C: |
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| 129 | case SPEEDSTEP_PROCESSOR_PIII_C_EARLY: |
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| 130 | return pentium3_get_frequency(processor); |
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| 131 | default: |
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| 132 | return 0; |
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| 133 | }; |
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| 134 | return 0; |
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| 135 | } |
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| 136 | EXPORT_SYMBOL_GPL(speedstep_get_processor_frequency); |
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| 137 | |||
| 138 | |||
| 139 | /********************************************************************* |
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| 140 | * DETECT SPEEDSTEP-CAPABLE PROCESSOR * |
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| 141 | *********************************************************************/ |
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| 142 | |||
| 143 | unsigned int speedstep_detect_processor (void) |
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| 144 | { |
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| 145 | struct cpuinfo_x86 *c = cpu_data; |
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| 146 | u32 ebx, msr_lo, msr_hi; |
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| 147 | |||
| 148 | if ((c->x86_vendor != X86_VENDOR_INTEL) || |
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| 149 | ((c->x86 != 6) && (c->x86 != 0xF))) |
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| 150 | return 0; |
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| 151 | |||
| 152 | if (c->x86 == 0xF) { |
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| 153 | /* Intel Mobile Pentium 4-M |
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| 154 | * or Intel Mobile Pentium 4 with 533 MHz FSB */ |
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| 155 | if (c->x86_model != 2) |
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| 156 | return 0; |
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| 157 | |||
| 158 | if ((c->x86_mask != 4) && /* B-stepping [M-P4-M] */ |
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| 159 | (c->x86_mask != 7) && /* C-stepping [M-P4-M] */ |
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| 160 | (c->x86_mask != 9)) /* D-stepping [M-P4-M or M-P4/533] */ |
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| 161 | return 0; |
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| 162 | |||
| 163 | ebx = cpuid_ebx(0x00000001); |
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| 164 | ebx &= 0x000000FF; |
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| 165 | if ((ebx != 0x0e) && (ebx != 0x0f)) |
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| 166 | return 0; |
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| 167 | |||
| 168 | return SPEEDSTEP_PROCESSOR_P4M; |
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| 169 | } |
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| 170 | |||
| 171 | switch (c->x86_model) { |
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| 172 | case 0x0B: /* Intel PIII [Tualatin] */ |
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| 173 | /* cpuid_ebx(1) is 0x04 for desktop PIII, |
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| 174 | 0x06 for mobile PIII-M */ |
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| 175 | ebx = cpuid_ebx(0x00000001); |
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| 176 | |||
| 177 | ebx &= 0x000000FF; |
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| 178 | if (ebx != 0x06) |
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| 179 | return 0; |
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| 180 | |||
| 181 | /* So far all PIII-M processors support SpeedStep. See |
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| 182 | * Intel's 24540640.pdf of June 2003 |
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| 183 | */ |
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| 184 | |||
| 185 | return SPEEDSTEP_PROCESSOR_PIII_T; |
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| 186 | |||
| 187 | case 0x08: /* Intel PIII [Coppermine] */ |
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| 188 | |||
| 189 | /* all mobile PIII Coppermines have FSB 100 MHz |
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| 190 | * ==> sort out a few desktop PIIIs. */ |
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| 191 | rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_hi); |
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| 192 | dprintk(KERN_DEBUG "cpufreq: Coppermine: MSR_IA32_EBL_CR_POWERON is 0x%x, 0x%x\n", msr_lo, msr_hi); |
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| 193 | msr_lo &= 0x00c0000; |
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| 194 | if (msr_lo != 0x0080000) |
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| 195 | return 0; |
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| 196 | |||
| 197 | /* |
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| 198 | * If the processor is a mobile version, |
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| 199 | * platform ID has bit 50 set |
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| 200 | * it has SpeedStep technology if either |
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| 201 | * bit 56 or 57 is set |
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| 202 | */ |
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| 203 | rdmsr(MSR_IA32_PLATFORM_ID, msr_lo, msr_hi); |
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| 204 | dprintk(KERN_DEBUG "cpufreq: Coppermine: MSR_IA32_PLATFORM ID is 0x%x, 0x%x\n", msr_lo, msr_hi); |
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| 205 | if ((msr_hi & (1<<18)) && (msr_hi & (3<<24))) { |
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| 206 | if (c->x86_mask == 0x01) |
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| 207 | return SPEEDSTEP_PROCESSOR_PIII_C_EARLY; |
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| 208 | else |
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| 209 | return SPEEDSTEP_PROCESSOR_PIII_C; |
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| 210 | } |
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| 211 | |||
| 212 | default: |
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| 213 | return 0; |
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| 214 | } |
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| 215 | } |
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| 216 | EXPORT_SYMBOL_GPL(speedstep_detect_processor); |
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| 217 | |||
| 218 | |||
| 219 | /********************************************************************* |
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| 220 | * DETECT SPEEDSTEP SPEEDS * |
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| 221 | *********************************************************************/ |
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| 222 | |||
| 223 | unsigned int speedstep_get_freqs(unsigned int processor, |
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| 224 | unsigned int *low_speed, |
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| 225 | unsigned int *high_speed, |
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| 226 | void (*set_state) (unsigned int state, |
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| 227 | unsigned int notify) |
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| 228 | ) |
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| 229 | { |
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| 230 | unsigned int prev_speed; |
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| 231 | unsigned int ret = 0; |
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| 232 | unsigned long flags; |
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| 233 | |||
| 234 | if ((!processor) || (!low_speed) || (!high_speed) || (!set_state)) |
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| 235 | return -EINVAL; |
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| 236 | |||
| 237 | /* get current speed */ |
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| 238 | prev_speed = speedstep_get_processor_frequency(processor); |
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| 239 | if (!prev_speed) |
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| 240 | return -EIO; |
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| 241 | |||
| 242 | local_irq_save(flags); |
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| 243 | |||
| 244 | /* switch to low state */ |
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| 245 | set_state(SPEEDSTEP_LOW, 0); |
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| 246 | *low_speed = speedstep_get_processor_frequency(processor); |
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| 247 | if (!*low_speed) { |
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| 248 | ret = -EIO; |
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| 249 | goto out; |
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| 250 | } |
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| 251 | |||
| 252 | /* switch to high state */ |
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| 253 | set_state(SPEEDSTEP_HIGH, 0); |
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| 254 | *high_speed = speedstep_get_processor_frequency(processor); |
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| 255 | if (!*high_speed) { |
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| 256 | ret = -EIO; |
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| 257 | goto out; |
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| 258 | } |
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| 259 | |||
| 260 | if (*low_speed == *high_speed) { |
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| 261 | ret = -ENODEV; |
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| 262 | goto out; |
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| 263 | } |
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| 264 | |||
| 265 | /* switch to previous state, if necessary */ |
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| 266 | if (*high_speed != prev_speed) |
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| 267 | set_state(SPEEDSTEP_LOW, 0); |
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| 268 | |||
| 269 | out: |
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| 270 | local_irq_restore(flags); |
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| 271 | return (ret); |
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| 272 | } |
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| 273 | EXPORT_SYMBOL_GPL(speedstep_get_freqs); |
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| 274 | |||
| 275 | MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>"); |
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| 276 | MODULE_DESCRIPTION ("Library for Intel SpeedStep 1 or 2 cpufreq drivers."); |
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| 277 | MODULE_LICENSE ("GPL"); |