1 // SPDX-License-Identifier: GPL-2.0-only
3  * (C) 2002 - 2003 Dominik Brodowski <[email protected]>
20 #include "speedstep-lib.h"
22 #define PFX "speedstep-lib: "
31  *                   GET PROCESSOR CORE SPEED IN KHZ                 *
34 static unsigned int pentium3_get_frequency(enum speedstep_processor processor)  in pentium3_get_frequency()  argument
59 	/* PIII(-M) FSB settings: see table b1-b of 24547206.pdf */  in pentium3_get_frequency()
61 		unsigned int value;	/* Front Side Bus speed in MHz */  in pentium3_get_frequency()
74 	/* read MSR 0x2a - we only need the low 32 bits */  in pentium3_get_frequency()
76 	pr_debug("P3 - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp);  in pentium3_get_frequency()
89 	if (processor == SPEEDSTEP_CPU_PIII_C_EARLY) {  in pentium3_get_frequency()
113 	pr_debug("PM - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp);  in pentiumM_get_frequency()
115 	/* see table B-2 of 24547212.pdf */  in pentiumM_get_frequency()
117 		printk(KERN_DEBUG PFX "PM - invalid FSB: 0x%x 0x%x\n",  in pentiumM_get_frequency()
123 	pr_debug("bits 22-26 are 0x%x, speed is %u\n",  in pentiumM_get_frequency()
136 	/* see table B-2 of 25366920.pdf */  in pentium_core_get_frequency()
157 		pr_err("PCORE - MSR_FSB_FREQ undefined value\n");  in pentium_core_get_frequency()
161 	pr_debug("PCORE - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n",  in pentium_core_get_frequency()
165 	pr_debug("bits 22-26 are 0x%x, speed is %u\n",  in pentium_core_get_frequency()
182 	 * to System Bus Frequency Ratio Field in the Processor Frequency  in pentium4_get_frequency()
186 	if (c->x86_model < 2)  in pentium4_get_frequency()
191 	pr_debug("P4 - MSR_EBC_FREQUENCY_ID: 0x%x 0x%x\n", msr_lo, msr_hi);  in pentium4_get_frequency()
193 	/* decode the FSB: see IA-32 Intel (C) Architecture Software  in pentium4_get_frequency()
195 	 * revision #12 in Table B-1: MSRs in the Pentium 4 and  in pentium4_get_frequency()
196 	 * Intel Xeon Processors, on page B-4 and B-5.  in pentium4_get_frequency()
213 				"Please send an e-mail to <[email protected]>\n");  in pentium4_get_frequency()
218 	pr_debug("P4 - FSB %u kHz; Multiplier %u; Speed %u kHz\n",  in pentium4_get_frequency()
227 unsigned int speedstep_get_frequency(enum speedstep_processor processor)  in speedstep_get_frequency()  argument
229 	switch (processor) {  in speedstep_get_frequency()
240 		return pentium3_get_frequency(processor);  in speedstep_get_frequency()
250  *                 DETECT SPEEDSTEP-CAPABLE PROCESSOR                *
259 	pr_debug("x86: %x, model: %x\n", c->x86, c->x86_model);  in speedstep_detect_processor()
261 	if ((c->x86_vendor != X86_VENDOR_INTEL) ||  in speedstep_detect_processor()
262 	    ((c->x86 != 6) && (c->x86 != 0xF)))  in speedstep_detect_processor()
265 	if (c->x86 == 0xF) {  in speedstep_detect_processor()
266 		/* Intel Mobile Pentium 4-M  in speedstep_detect_processor()
268 		if (c->x86_model != 2)  in speedstep_detect_processor()
274 		pr_debug("ebx value is %x, x86_stepping is %x\n", ebx, c->x86_stepping);  in speedstep_detect_processor()
276 		switch (c->x86_stepping) {  in speedstep_detect_processor()
279 			 * B-stepping [M-P4-M]  in speedstep_detect_processor()
287 			 * C-stepping [M-P4-M]  in speedstep_detect_processor()
291 			 * samples are only of B-stepping...  in speedstep_detect_processor()
298 			 * D-stepping [M-P4-M or M-P4/533]  in speedstep_detect_processor()
301 			 * used by M-P4-M, M-P4/533 and(!) Celeron CPUs.  in speedstep_detect_processor()
305 			 * ebx=0x8 or 0xf -- 25130917.pdf doesn't say anything  in speedstep_detect_processor()
307 			 * M-P4-Ms may have either ebx=0xe or 0xf [see above]  in speedstep_detect_processor()
308 			 * M-P4/533 have either ebx=0xe or 0xf. [25317607.pdf]  in speedstep_detect_processor()
309 			 * also, M-P4M HTs have ebx=0x8, too  in speedstep_detect_processor()
314 				(strstr(c->x86_model_id,  in speedstep_detect_processor()
324 	switch (c->x86_model) {  in speedstep_detect_processor()
327 		 * 0x06 for mobile PIII-M */  in speedstep_detect_processor()
336 		/* So far all PIII-M processors support SpeedStep. See  in speedstep_detect_processor()
353 		 * If the processor is a mobile version,  in speedstep_detect_processor()
363 			if (c->x86_stepping == 0x01) {  in speedstep_detect_processor()
381 unsigned int speedstep_get_freqs(enum speedstep_processor processor,  in speedstep_get_freqs()  argument
392 	if ((!processor) || (!low_speed) || (!high_speed) || (!set_state))  in speedstep_get_freqs()
393 		return -EINVAL;  in speedstep_get_freqs()
398 	prev_speed = speedstep_get_frequency(processor);  in speedstep_get_freqs()
400 		return -EIO;  in speedstep_get_freqs()
409 	*low_speed = speedstep_get_frequency(processor);  in speedstep_get_freqs()
411 		ret = -EIO;  in speedstep_get_freqs()
428 	*high_speed = speedstep_get_frequency(processor);  in speedstep_get_freqs()
430 		ret = -EIO;  in speedstep_get_freqs()
437 		ret = -ENODEV;  in speedstep_get_freqs()