[CPUFREQ] Merge speedstep-smi driver.

From: Hiroshi Miura <miura@da-cha.org>

Intel SpeedStep driver using a BIOS SMI call.

Quoting his original announcement:

"This driver is based on the information from

1. Microsoft Windows XP Document.
we can get the SMI interface values from ax=E980/int15 BIOS call.

2. Intel SpeedStep Applet Document.(from HP.com)
http://h18007.www1.hp.com/support/files/evonotebook/us/download/10631.html
" Adds code to request transition ownership when processing
the system critical resume message. When a critical hibernate occurs,
the Applet does not receive any system level notification. The change forces
the Applet to re-acquire transition ownership upon resume from a critical hibernate. "

This is informative. This saied that  something 'ownership' call is needed on SMI
interface first.

3. Grover, Andrew's int 15h patch posted to cpufreq ml
Message-ID: <F760B14C9561B941B89469F59BA3A847E96E28@orsmsx401.jf.intel.com>
code which call BIOS to get SMI values. I included it.

4. Malik Martin's rev engineering results.
call is made with BX, CX, EDI register values.
and need signature 'ISG' when call.
find function values. bx=1(get) and bx=2(set)

5. Marc Lehmann's 'speedstep' utility,
sample of assembler code to call SMI.

6. My work.
find function to return max/min freq which system supportd. (bx=4)
more values are gotten, but I cannot understand...
find 'ownership' function value(bx=0, which is other than 1 2 4..).

ToDo(in pregress)
support governor "auto" and using smi_event call, imprement auto freqchange
feature.
test on 440BX/ZX platform.

Memo
 module parameters are override result of an int 15h/eax=E890h call.
 these parameter value are gotten from Windows XP registory."

Also includes some bugfixes, updates and workarounds from me.

NB: A lot of BIOS out there are buggy. You might want to try this driver
also with Intel's default values -- smi_cmd = 0x82 and smi_port = 0xb2

arch/i386/boot/setup.S

@@ -506,6 +506,17 @@ no_voyager:
 	movw	$0xAA, (0x1ff)			# device present
 no_psmouse:
 
+#if defined(CONFIG_X86_SPEEDSTEP_SMI) || defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
+	movl	$0x0000E980, %eax		# IST Support 
+	movl	$0x47534943, %edx		# Request value
+	int	$0x15
+
+	movl	%eax, (96)
+	movl	%ebx, (100)
+	movl	%ecx, (104)
+	movl	%edx, (108)
+#endif
+
 #if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
 # Then check for an APM BIOS...
 						# %ds points to the bootsector

arch/i386/kernel/cpu/cpufreq/Kconfig

@@ -99,34 +99,46 @@ config X86_GX_SUSPMOD
 
 	 If in doubt, say N.
 
+config X86_SPEEDSTEP_CENTRINO
+	tristate "Intel Enhanced SpeedStep"
+	depends on CPU_FREQ_TABLE
+	help
+	  This adds the CPUFreq driver for Enhanced SpeedStep enabled
+	  mobile CPUs.  This means Intel Pentium M (Centrino) CPUs.
+	  
+	  For details, take a look at linux/Documentation/cpu-freq. 
+	  
+	  If in doubt, say N.
+
 config X86_SPEEDSTEP_ICH
-	tristate "Intel Speedstep"
+	tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
 	depends on CPU_FREQ_TABLE
 	help
 	  This adds the CPUFreq driver for certain mobile Intel Pentium III
 	  (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
-	  mobile Intel Pentium 4 P4-Ms, with an Intel ICH2, ICH3,
-	  or ICH4 southbridge.
+	  mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2, 
+	  ICH3 or ICH4 southbridge.
 
 	  For details, take a look at linux/Documentation/cpu-freq. 
 
 	  If in doubt, say N.
 
-config X86_SPEEDSTEP_CENTRINO
-	tristate "Intel Enhanced SpeedStep"
-	depends on CPU_FREQ_TABLE
+config X86_SPEEDSTEP_SMI
+	tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
+	depends on CPU_FREQ_TABLE && EXPERIMENTAL
 	help
-	  This adds the CPUFreq driver for Enhanced SpeedStep enabled
-	  mobile CPUs.  This means Intel Pentium M (Centrino) CPUs.
-	  
-	  For details, take a look at linux/Documentation/cpu-freq. 
-	  
+	  This adds the CPUFreq driver for certain mobile Intel Pentium III
+	  (Coppermine), all mobile Intel Pentium III-M (Tualatin)  
+	  on systems which have an Intel 440BX/ZX/MX southbridge.
+
+	  For details, take a look at linux/Documentation/cpu-freq.
+
 	  If in doubt, say N.
 
 config X86_SPEEDSTEP_LIB
-       tristate
-       depends on X86_SPEEDSTEP_ICH
-       default X86_SPEEDSTEP_ICH
+	tristate
+	depends on (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI)
+	default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI)
 
 config X86_P4_CLOCKMOD
 	tristate "Intel Pentium 4 clock modulation"

arch/i386/kernel/cpu/cpufreq/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_X86_ACPI_CPUFREQ)	+= acpi.o
 obj-$(CONFIG_X86_SPEEDSTEP_ICH)	+= speedstep-ich.o
 obj-$(CONFIG_X86_SPEEDSTEP_CENTRINO) += speedstep-centrino.o
 obj-$(CONFIG_X86_SPEEDSTEP_LIB) += speedstep-lib.o
+obj-$(CONFIG_X86_SPEEDSTEP_SMI) += speedstep-smi.o
 
 ifdef CONFIG_X86_ACPI_CPUFREQ
   ifdef CONFIG_ACPI_DEBUG

arch/i386/kernel/cpu/cpufreq/speedstep-smi.c

+/*
+ * Intel SpeedStep SMI driver.
+ *
+ * (C) 2003  Hiroshi Miura <miura@da-cha.org>
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ *
+ */
+
+
+/*********************************************************************
+ *                        SPEEDSTEP - DEFINITIONS                    *
+ *********************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h> 
+#include <linux/moduleparam.h> 
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <asm/ist.h>
+
+#include "speedstep-lib.h"
+
+/* speedstep system management interface port/command.
+ *
+ * These parameters are got from IST-SMI BIOS call.
+ * If user gives it, these are used.
+ * 
+ */
+static int		smi_port	= 0;
+static int		smi_cmd		= 0;
+static unsigned int	smi_sig		= 0;
+
+
+/* 
+ *   There are only two frequency states for each processor. Values
+ * are in kHz for the time being.
+ */
+static struct cpufreq_frequency_table speedstep_freqs[] = {
+	{SPEEDSTEP_HIGH, 	0},
+	{SPEEDSTEP_LOW,		0},
+	{0,			CPUFREQ_TABLE_END},
+};
+
+#define GET_SPEEDSTEP_OWNER 0
+#define GET_SPEEDSTEP_STATE 1
+#define SET_SPEEDSTEP_STATE 2
+#define GET_SPEEDSTEP_FREQS 4
+
+/* DEBUG
+ *   Define it if you want verbose debug output, e.g. for bug reporting
+ */
+#define SPEEDSTEP_DEBUG
+
+#ifdef SPEEDSTEP_DEBUG
+#define dprintk(msg...) printk(msg)
+#else
+#define dprintk(msg...) do { } while(0)
+#endif
+
+/**
+ * speedstep_smi_ownership
+ */
+static int speedstep_smi_ownership (void)
+{
+        u32     command, result, magic;
+        u32     function = GET_SPEEDSTEP_OWNER;
+	unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
+
+        command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+	magic = virt_to_phys(magic_data);
+
+        __asm__ __volatile__(
+            "out %%al, (%%dx)\n"
+            : "=D" (result)
+            : "a" (command), "b" (function), "c" (0), "d" (smi_port), "D" (0), "S" (magic)
+        );
+
+        return result;
+}
+/**
+ * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
+ *
+ */
+static int speedstep_smi_get_freqs (unsigned int *low, unsigned int *high)
+{
+        u32     command, result, edi, high_mhz, low_mhz;
+        u32     state=0;
+        u32	function = GET_SPEEDSTEP_FREQS;
+
+        command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+
+        __asm__ __volatile__("movl $0, %%edi\n"
+            "out %%al, (%%dx)\n"
+            : "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
+            : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
+        );
+	*high = high_mhz * 1000;
+	*low  = low_mhz  * 1000;
+
+	return result;
+} 
+/**
+ * speedstep_get_state - set the SpeedStep state
+ * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
+ *
+ */
+static int speedstep_get_state (void)
+{
+	u32		function=GET_SPEEDSTEP_STATE;
+	u32		result, state, edi, command;
+
+        command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+
+        __asm__ __volatile__("movl $0, %%edi\n"
+            "out %%al, (%%dx)\n"
+            : "=a" (result), "=b" (state), "=D" (edi)
+            : "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
+        );
+	
+	return state;
+}
+
+/**
+ * speedstep_set_state - set the SpeedStep state
+ * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
+ *
+ */
+static void speedstep_set_state (unsigned int state, unsigned int notify)
+{
+	unsigned int		old_state, result, command, new_state;
+	unsigned long		flags;
+	struct cpufreq_freqs	freqs;
+	unsigned int		function=SET_SPEEDSTEP_STATE;
+
+	if (state > 0x1)
+		return;
+
+	old_state = speedstep_get_state();
+	freqs.old = speedstep_freqs[old_state].frequency;
+	freqs.new = speedstep_freqs[state].frequency;
+	freqs.cpu = 0; /* speedstep.c is UP only driver */
+	
+	if (old_state == state)
+		return;
+
+	if (notify)
+		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+	/* Disable IRQs */
+	local_irq_save(flags);
+
+        command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+        __asm__ __volatile__(
+	    "movl $0, %%edi\n"
+            "out %%al, (%%dx)\n"
+            : "=b" (new_state), "=D" (result)
+            : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
+        );
+
+	/* enable IRQs */
+	local_irq_restore(flags);
+
+	if (new_state == state) {
+		dprintk(KERN_INFO "cpufreq: change to %u MHz succeded\n", (freqs.new / 1000));
+	} else {
+		printk(KERN_ERR "cpufreq: change failed\n");
+	}
+
+	if (notify)
+		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+	return;
+}
+
+
+/**
+ * speedstep_target - set a new CPUFreq policy
+ * @policy: new policy
+ * @target_freq: new freq
+ * @relation: 
+ *
+ * Sets a new CPUFreq policy/freq.
+ */
+static int speedstep_target (struct cpufreq_policy *policy,
+			     unsigned int target_freq,
+			     unsigned int relation)
+{
+	unsigned int	newstate = 0;
+
+	if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
+		return -EINVAL;
+
+	speedstep_set_state(newstate, 1);
+
+	return 0;
+}
+
+
+/**
+ * speedstep_verify - verifies a new CPUFreq policy
+ * @freq: new policy
+ *
+ * Limit must be within speedstep_low_freq and speedstep_high_freq, with
+ * at least one border included.
+ */
+static int speedstep_verify (struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
+}
+
+
+static int speedstep_cpu_init(struct cpufreq_policy *policy)
+{
+	int		result;
+	unsigned int	speed,state;
+
+	/* capability check */
+	if (policy->cpu != 0)
+		return -ENODEV;
+
+	result = speedstep_smi_ownership();
+
+	if (result)
+		dprintk(KERN_INFO "cpufreq: fails an aquiring ownership of a SMI interface.\n");
+
+	/* detect low and high frequency */
+	result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
+				         &speedstep_freqs[SPEEDSTEP_HIGH].frequency);
+	if (result) {
+		/* fall back to speedstep_lib.c dection mechanism: try both states out */
+		unsigned int speedstep_processor = speedstep_detect_processor();
+
+		dprintk(KERN_INFO "speedstep-smi: could not detect low and high frequencies by SMI call.\n");
+		if (!speedstep_processor)
+			return -ENODEV;
+
+		result = speedstep_get_freqs(speedstep_processor,
+					     &speedstep_freqs[SPEEDSTEP_LOW].frequency,
+					     &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
+					     &speedstep_set_state);
+
+		if (result) {
+			dprintk(KERN_INFO "speedstep-smi: could not detect two different speeds -- aborting.\n");
+			return result;
+		} else
+			dprintk(KERN_INFO "speedstep-smi: workaround worked.\n");
+	}
+
+	/* get current speed setting */
+	state = speedstep_get_state();
+	speed = speedstep_freqs[state].frequency;
+
+	dprintk(KERN_INFO "cpufreq: currently at %s speed setting - %i MHz\n", 
+		(speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
+		(speed / 1000));
+
+	/* cpuinfo and default policy values */
+	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	policy->cur = speed;
+
+	return cpufreq_frequency_table_cpuinfo(policy, &speedstep_freqs[0]);
+}
+
+
+static int speedstep_resume(struct cpufreq_policy *policy)
+{
+	int result = speedstep_smi_ownership();
+
+	if (result)
+		dprintk(KERN_INFO "cpufreq: fails an aquiring ownership of a SMI interface.\n");
+
+	return result;
+}
+
+
+static struct cpufreq_driver speedstep_driver = {
+	.name		= "speedstep-smi",
+	.verify 	= speedstep_verify,
+	.target 	= speedstep_target,
+	.init		= speedstep_cpu_init,
+	.resume		= speedstep_resume,
+};
+
+/**
+ * speedstep_init - initializes the SpeedStep CPUFreq driver
+ *
+ *   Initializes the SpeedStep support. Returns -ENODEV on unsupported
+ * BIOS, -EINVAL on problems during initiatization, and zero on
+ * success.
+ */
+static int __init speedstep_init(void)
+{
+
+	dprintk("speedstep-smi: signature:0%.8lx, command:0lx%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n", 
+		ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);
+
+
+	/* Error if no IST-SMI BIOS or no PARM 
+		 sig= 'ISGE' aka 'Intel Speedstep Gate E' */
+	if ((ist_info.signature !=  0x47534943) && ( 
+	    (smi_port == 0) || (smi_cmd == 0)))
+		return -ENODEV;
+
+	if (smi_sig == 1)
+		smi_sig = 0x47534943;
+	else
+		smi_sig = ist_info.signature;
+
+	/* setup smi_port from MODLULE_PARM or BIOS */
+	if ((smi_port > 0xff) || (smi_port < 0)) {
+		return -EINVAL;
+	} else if (smi_port == 0) {
+		smi_port = ist_info.command & 0xff;
+	}
+
+	if ((smi_cmd > 0xff) || (smi_cmd < 0)) {
+		return -EINVAL;
+	} else if (smi_cmd == 0) {
+		smi_cmd = (ist_info.command >> 16) & 0xff;
+	}
+
+	return cpufreq_register_driver(&speedstep_driver);
+}
+
+
+/**
+ * speedstep_exit - unregisters SpeedStep support
+ *
+ *   Unregisters SpeedStep support.
+ */
+static void __exit speedstep_exit(void)
+{
+	cpufreq_unregister_driver(&speedstep_driver);
+}
+
+module_param(smi_port,  int, 0444);
+module_param(smi_cmd,   int, 0444);
+module_param(smi_sig,  uint, 0444);
+
+MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
+MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
+MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");
+
+MODULE_AUTHOR ("Hiroshi Miura");
+MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
+MODULE_LICENSE ("GPL");
+
+module_init(speedstep_init);
+module_exit(speedstep_exit);

arch/i386/kernel/i386_ksyms.c

@@ -33,6 +33,7 @@
 #include <asm/tlbflush.h>
 #include <asm/nmi.h>
 #include <asm/edd.h>
+#include <asm/ist.h>
 
 extern void dump_thread(struct pt_regs *, struct user *);
 extern spinlock_t rtc_lock;
@@ -209,3 +210,7 @@ EXPORT_SYMBOL(kmap_atomic_to_page);
 EXPORT_SYMBOL(edd);
 EXPORT_SYMBOL(eddnr);
 #endif
+
+#if defined(CONFIG_X86_SPEEDSTEP_SMI) || defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
+EXPORT_SYMBOL(ist_info);
+#endif

arch/i386/kernel/setup.c

@@ -44,6 +44,7 @@
 #include <asm/arch_hooks.h>
 #include <asm/sections.h>
 #include <asm/io_apic.h>
+#include <asm/ist.h>
 #include "setup_arch_pre.h"
 #include "mach_resources.h"
 
@@ -102,6 +103,7 @@ struct sys_desc_table_struct {
 	unsigned char table[0];
 };
 struct edid_info edid_info;
+struct ist_info ist_info;
 struct e820map e820;
 
 unsigned char aux_device_present;
@@ -960,6 +962,7 @@ void __init setup_arch(char **cmdline_p)
  	screen_info = SCREEN_INFO;
 	edid_info = EDID_INFO;
 	apm_info.bios = APM_BIOS_INFO;
+	ist_info = IST_INFO;
 	saved_videomode = VIDEO_MODE;
 	printk("Video mode to be used for restore is %lx\n", saved_videomode);
 	if( SYS_DESC_TABLE.length != 0 ) {

include/asm-i386/ist.h

+#ifndef _ASM_IST_H
+#define _ASM_IST_H
+
+/*
+ * Include file for the interface to IST BIOS
+ * Copyright 2002 Andy Grover <andrew.grover@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+
+#ifdef __KERNEL__
+
+struct ist_info {
+	unsigned long	signature;
+	unsigned long	command;
+	unsigned long	event;
+	unsigned long	perf_level;
+};
+
+extern struct ist_info ist_info;
+
+#endif	/* __KERNEL__ */
+#endif	/* _ASM_IST_H */

include/asm-i386/setup.h

@@ -26,6 +26,7 @@
 #define E820_MAP_NR (*(char*) (PARAM+E820NR))
 #define E820_MAP    ((struct e820entry *) (PARAM+E820MAP))
 #define APM_BIOS_INFO (*(struct apm_bios_info *) (PARAM+0x40))
+#define IST_INFO   (*(struct ist_info *) (PARAM+0x60))
 #define DRIVE_INFO (*(struct drive_info_struct *) (PARAM+0x80))
 #define SYS_DESC_TABLE (*(struct sys_desc_table_struct*)(PARAM+0xa0))
 #define MOUNT_ROOT_RDONLY (*(unsigned short *) (PARAM+0x1F2))