+++ /dev/null
-/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the License
- * may not be used to create, or enable the creation or redistribution of,
- * unlawful or unlicensed copies of an Apple operating system, or to
- * circumvent, violate, or enable the circumvention or violation of, any
- * terms of an Apple operating system software license agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
- */
-/*
- * pe_clock_speed.c - Determine the best guess for the processor and bus
- * speed buy using the values returned by run_clock_test.
- *
- * (c) Apple Computer, Inc. 1998-2002
- *
- * Writen by: Josh de Cesare
- *
- */
-
-#include <pexpert/pexpert.h>
-
-#include <ppc/machine_routines.h>
-
-// prototypes
-extern void pe_run_clock_test(void *tmp);
-void pe_do_clock_test(unsigned int via_addr,
- int num_speeds, unsigned long *speed_list);
-void PE_Determine_Clock_Speeds(unsigned int via_addr, int num_speeds, unsigned long *speed_list);
-
-// Threshold for bus speed matches.
-#define kMaxFreqDiff (30000)
-
-// This is the structure for the data that get passed to pe_run_clock_test.
-struct clock_test_data {
- unsigned int via_addr;
- unsigned int via_ticks;
- unsigned int dec_ticks;
-};
-
-// glocal variables to simplify some stuff.
-static long bus_freq_num, bus_freq_den, cpu_pll;
-
-// PE_Determine_Clock_Speeds is called by the via driver in IOKit
-// It uses the numbers generated by pe_do_clock_test and reports
-// the cleaned up values to the rest of the OS.
-void PE_Determine_Clock_Speeds(unsigned int via_addr, int num_speeds,
- unsigned long *speed_list)
-{
- boolean_t oldLevel;
- unsigned long tmp_bus_speed, tmp_cpu_speed;
- unsigned long long tmp;
-
- oldLevel = ml_set_interrupts_enabled(FALSE);
- pe_do_clock_test(via_addr, num_speeds, speed_list);
- ml_set_interrupts_enabled(oldLevel);
-
- tmp_bus_speed = bus_freq_num / bus_freq_den;
- tmp = ((unsigned long long)bus_freq_num * cpu_pll) / (bus_freq_den * 2);
- tmp_cpu_speed = (unsigned long)tmp;
-
- // Report the bus clock rate as is.
- gPEClockFrequencyInfo.bus_clock_rate_num = bus_freq_num;
- gPEClockFrequencyInfo.bus_clock_rate_den = bus_freq_den;
-
- // pll multipliers are in halfs so set the denominator to 2.
- gPEClockFrequencyInfo.bus_to_cpu_rate_num = cpu_pll;
- gPEClockFrequencyInfo.bus_to_cpu_rate_den = 2;
-
- // The decrementer rate is one fourth the bus rate.
- gPEClockFrequencyInfo.bus_to_dec_rate_num = 1;
- gPEClockFrequencyInfo.bus_to_dec_rate_den = 4;
-
- // Assume that the timebase frequency is derived from the bus clock.
- gPEClockFrequencyInfo.timebase_frequency_num = bus_freq_num;
- gPEClockFrequencyInfo.timebase_frequency_den = bus_freq_den * 4;
-
- // Set the truncated numbers in gPEClockFrequencyInfo.
- gPEClockFrequencyInfo.bus_clock_rate_hz = tmp_bus_speed;
- gPEClockFrequencyInfo.cpu_clock_rate_hz = tmp_cpu_speed;
- gPEClockFrequencyInfo.dec_clock_rate_hz = tmp_bus_speed / 4;
- gPEClockFrequencyInfo.timebase_frequency_hz = tmp_bus_speed / 4;
-
- gPEClockFrequencyInfo.bus_frequency_hz = tmp_bus_speed;
- gPEClockFrequencyInfo.bus_frequency_min_hz = tmp_bus_speed;
- gPEClockFrequencyInfo.bus_frequency_max_hz = tmp_bus_speed;
- gPEClockFrequencyInfo.cpu_frequency_hz = tmp_cpu_speed;
- gPEClockFrequencyInfo.cpu_frequency_min_hz = tmp_cpu_speed;
- gPEClockFrequencyInfo.cpu_frequency_max_hz = tmp_cpu_speed;
-
- PE_call_timebase_callback();
-}
-
-// pe_do_clock_test uses the number from pe_run_clock_test to
-// find a best fit guess for the bus speed.
-void pe_do_clock_test(unsigned int via_addr,
- int num_speeds, unsigned long *speed_list)
-{
- struct clock_test_data clock_test_data;
- long cnt, diff, raw_cpu_freq, raw_bus_freq, tmp_bus_freq,
- last_bus_freq, tries = 10;
-
- // Save the via addr so the asm part can use it.
- clock_test_data.via_addr = via_addr;
-
- // Keep looping until it matches the last try.
- bus_freq_num = 0;
- do {
- last_bus_freq = bus_freq_num;
-
- // The the asm part to do the real work.
- pe_run_clock_test((void *)&clock_test_data);
-
- // First find the pll mode. Allow any integer times two.
- cpu_pll = 10000000 / clock_test_data.dec_ticks;
- cpu_pll = (cpu_pll / 2) + (cpu_pll & 1);
-
- // Using 64 bit math figure out the raw bus speed.
- // 0xBF401675E5DULL is 1 / 1.27655us times 2 ^ 24.
- raw_bus_freq = ((0xBF401675E5DULL * clock_test_data.dec_ticks) /
- clock_test_data.via_ticks) >> 22;
-
- // use the pll mode and the raw bus speed to find the raw cpu speed.
- raw_cpu_freq = raw_bus_freq * cpu_pll / 2;
-
- // Look to see if the bus speed is close to one of the
- // speeds in the table.
- for (cnt = 0; cnt < num_speeds; cnt++) {
- bus_freq_num = speed_list[cnt * 2];
- bus_freq_den = speed_list[cnt * 2 + 1];
- diff = bus_freq_num - raw_bus_freq * bus_freq_den;
- if (diff < 0) diff = -diff;
-
- if (diff < kMaxFreqDiff * bus_freq_den) break;
- }
- if (cnt != num_speeds) continue;
-
- // Look to see if the bus speed is close to n * 0.5 MHz
- tmp_bus_freq = ((raw_bus_freq + 250000) / 500000) * 500000;
-
- diff = tmp_bus_freq - raw_bus_freq;
- if (diff < 0) diff = -diff;
-
- if (diff < kMaxFreqDiff) {
- bus_freq_num = tmp_bus_freq;
- bus_freq_den = 1;
- continue;
- }
-
- // Look to see if the bus speed is close to n * 50/3 MHz
- tmp_bus_freq = ((raw_bus_freq * 3 + 25000000) / 50000000) * 50000000;
-
- diff = tmp_bus_freq - raw_bus_freq * 3;
- if (diff < 0) diff = -diff;
-
- if (diff < kMaxFreqDiff * 3) {
- bus_freq_num = tmp_bus_freq;
- bus_freq_den = 3;
- continue;
- }
-
- // Since all else failed return the raw bus speed
- bus_freq_num = raw_bus_freq;
- bus_freq_den = 1;
- } while ((bus_freq_num != last_bus_freq) && tries--);
-}
projects / apple / xnu.git / blobdiff