amd76x_pm: C2 powersaving for AMD K7

diff -Nru linux-2.6.12/Documentation/amd76x_pm.txt linux-2.6.12-jo1/Documentation/amd76x_pm.txt
@@ -0,0 +1,97 @@
+	ACPI style power management for SMP AMD-760MP(X) based systems
+	==============================================================
+
+For use until the ACPI project catches up. :-)
+
+Using this module saves about 70 - 90W of energy in the idle mode compared
+to the default idle mode. Waking up from the idle mode is fast to keep the
+system response time good. Currently no CPU load calculation is done, the
+system exits the idle mode if there is a CPU that isn't idle.
+
+NOTE: Currently there's a bug somewhere where the reading the
+      P_LVL2 for the first time causes the system to sleep instead of 
+      idling. This means that you need to hit the power button once to
+      wake the system after loading the module for the first time after
+      reboot. After that the system idles as supposed.
+      (Only observed on Tony's system.)
+
+
+Influenced by Vcool, and LVCool. Rewrote everything from scratch to
+use the PCI features in Linux, and to support SMP systems.
+
+Currently tested amongst others on a TYAN S2460 (760MP) system (Tony), an
+ASUS A7M266-D (760MPX) system (Johnathan) and a TYAN S2466 (760MPX)
+system (Jo). Adding support for other Athlon SMP or single processor
+systems should be easy if desired.  
+
+You'll find some files in /sys/devices/pci0000:00/0000:00:00.0/
+lazy_idle (rw)	see below
+C2_cnt    (ro)	the number of C2 calls
+
+There is a tunable lazy_idle parameter that defines the number of idle
+calls before C2 mode is entered.  Higher values give better system
+response and lower values give better cooling.  This value has an
+influence on the system clock stability too: If the system clock is
+synchronized via ntpd you may watch lower values for the frequency if
+the module is loaded.  If this happens then the system clock speed
+depends on the system load: higher load, less idle calls, higher
+frequency.  Play around with this parameter and try to find a value that
+gives acceptable cooling and clock stability.  This parameter can be set
+as a module parameter to amd76x_pm or via the writable sysfs file
+lazy_idle (see above).  Feel free to play around with this parameter to
+find out which fits best for you.  The default value of 512 might be not
+suitable for your needs but is a good starting point.  
+
+This software is licensed under GNU General Public License Version 2 
+as specified in file COPYING in the Linux kernel source tree main 
+directory.
+
+Copyright (C) 2002 - 2005	Johnathan Hicks <[email protected]>
+				Tony Lindgren <[email protected]>
+				Joerg Sommrey <[email protected]>
+
+History:
+
+  20020702 - amd-smp-idle: Tony Lindgren <[email protected]>
+Influenced by Vcool, and LVCool. Rewrote everything from scratch to
+use the PCI features in Linux, and to support SMP systems. Provides
+C2 idling on SMP AMD-760MP systems.
+
+  20020722: JH
+  	I adapted Tony's code for the AMD-765/766 southbridge and adapted it
+  	according to the AMD-768 data sheet to provide the same capability for
+  	SMP AMD-760MPX systems. Posted to acpi-devel list.
+  	
+  20020722: Alan Cox
+  	Replaces non-functional amd76x_pm code in -ac tree.
+  	
+  20020730: JH
+  	Added ability to do normal throttling (the non-thermal kind), C3 idling
+  	and Power On Suspend (S1 sleep). It would be very easy to tie swsusp
+  	into activate_amd76x_SLP(). C3 idling doesn't happen yet; see my note
+  	in amd76x_smp_idle(). I've noticed that when NTH and idling are both
+  	enabled, my hardware locks and requires a hard reset, so I have
+  	#ifndefed around the idle loop setting to prevent this. POS locks it up
+  	too, both ought to be fixable. I've also noticed that idling and NTH
+  	make some interference that is picked up by the onboard sound chip on
+  	my ASUS A7M266-D motherboard.
+
+  20030601: Pasi Savolainen
+     Simple port to 2.5
+     Added sysfs interface for making nice graphs with mrtg.
+     Look for /sys/devices/pci0/00:00.0/C2_cnt & lazy_idle (latter writable)
+
+  20050601: Joerg Sommrey (jo)
+     2.6 stuff
+     redesigned amd76x_smp_idle.  The algorithm is basically the same
+        but the implementation has changed.  This part is now independent
+        from the number of CPUs and data is locked against concurrent
+        updates from different CPUs.
+     use _smp_processor_id()
+     use cpu_idle_wait()
+     NTH and POS code not touched and not tested.
+
+TODO: Thermal throttling (TTH).
+	 /proc interface for normal throttling level.
+	 /proc interface for POS.
+

diff -Nru linux-2.6.12/drivers/acpi/Kconfig linux-2.6.12-jo1/drivers/acpi/Kconfig
@@ -352,4 +352,18 @@
 		$>modprobe acpi_memhotplug 
 endif	# ACPI
 
+config AMD76X_PM
+        tristate "AMD76x Native Power Management support"
+        default n
+        depends on X86 && PCI
+        ---help---
+          This driver enables Power Management on AMD760MP & AMD760MPX chipsets.          This is about same as ACPI C2, except that ACPI folks don't do SMP ATM.
+          See Documentation/amd76x_pm.txt for further details.
+
+          To compile this driver as a module ( = code which can be inserted in
+          and removed from the running kernel whenever you want), say M
+          here.  The module will be called amd76x_pm.
+
+          If unsure, say N.
+
 endmenu

diff -Nru linux-2.6.12/drivers/acpi/Makefile linux-2.6.12-jo1/drivers/acpi/Makefile
@@ -56,3 +56,8 @@
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o
 obj-$(CONFIG_ACPI_BUS)		+= scan.o motherboard.o
 obj-$(CONFIG_ACPI_HOTPLUG_MEMORY)	+= acpi_memhotplug.o
+
+#
+# not really ACPI thing, until they handle SMP.
+#
+obj-$(CONFIG_AMD76X_PM)               += amd76x_pm.o