High-res-timers part 2 (x86 platform code) take 8

diff -urP -I \$Id:.*Exp \$ -X /usr/src/patch.exclude linux-2.5.44-bk1-core/arch/i386/Config.help linux/arch/i386/Config.help
@@ -52,6 +52,75 @@
   Say Y here if you are building a kernel for a desktop, embedded
   or real-time system.  Say N if you are unsure.
 
+High-res-timers
+CONFIG_HIGH_RES_TIMERS
+  POSIX timers are available by default.  This option enables high
+  resolution POSIX timers.  With this option the resolution is at
+  least 1 micro second.  High resolution is not free.  If enabled this
+  option will add a small overhead each time a timer expires that is
+  not on a 1/HZ tick boundry.  If no such timers are used the overhead
+  is nil.
+
+  This option enables two additional POSIX CLOCKS, CLOCK_REALTIME_HR
+  and CLOCK_MONOTONIC_HR.  Note that this option does not change the
+  resolution of CLOCK_REALTIME or CLOCK_MONOTONIC which remain at 1/HZ
+  resolution.
+
+High-res-timers clock
+CONFIG_HIGH_RES_TIMER_ACPI_PM 
+  This option allows you to choose the wall clock timer for your system.
+  With high resolution timers on the x86 platforms it is best to keep
+  the interrupt generating timer separate from the time keeping timer.
+  On x86 platforms there are three possible sources implemented for the
+  wall clock.  These are:
+ 
+  <timer>				<resolution>
+  ACPI power management (pm) timer	~280 nano seconds
+  TSC (Time Stamp Counter)		1/CPU clock
+  PIT (Programmable Interrupt Timer)	~838 nano seconds
+
+  The PIT is used to generate interrupts and at any given time will be
+  programmed to interrupt when the next timer is to expire or on the
+  next 1/HZ tick.  For this reason it is best to not use this timer as
+  the wall clock timer.  This timer has a resolution of 838 nano
+  seconds.  THIS OPTION SHOULD ONLY BE USED IF BOTH ACPI AND TSC ARE
+  NOT AVAILABLE.
+
+  The TSC runs at the cpu clock rate (i.e. its resolution is 1/CPU
+  clock) and it has a very low access time.  However, it is subject,
+  in some (incorrect) processors, to throttling to cool the cpu, and
+  to other slow downs during power management.  If your cpu is correct
+  and does not change the TSC frequency for throttling or power
+  management this is the best clock timer.
+
+  The ACPI pm timer is available on systems with Advanced Configuration
+  and Power Interface support.  The pm timer is available on these
+  systems even if you don't use or enable ACPI in the software or the
+  BIOS (but see Default ACPI pm timer address).  The timer has a
+  resolution of about 280 nanoseconds, however, the access time is a bit
+  higher that that of the TSC.  Since it is part of ACPI it is intended
+  to keep track of time while the system is under power management, thus
+  it is not subject to the problems of the TSC.
+
+  If you enable the ACPI pm timer and it can not be found, it is
+  possible that your BIOS is not producing the ACPI table or that your
+  machine does not support ACPI.  In the former case, see "Default ACPI
+  pm timer address".  If the timer is not found the boot will fail when
+  trying to calibrate the delay timer.
+
+Default ACPI pm timer address
+CONFIG_HIGH_RES_TIMER_ACPI_PM_ADD
+  This option is available for use on systems where the BIOS does not
+  generate the ACPI tables if ACPI is not enabled.  For example some
+  BIOSes will not generate the ACPI tables if APM is enabled.  The ACPI
+  pm timer is still available but can not be found by the software.
+  This option allows you to supply the needed address.  When the high
+  resolution timers code finds a valid ACPI pm timer address it reports
+  it in the boot messages log (look for lines that begin with
+  "High-res-timers:").  You can turn on the ACPI support in the BIOS,
+  boot the system and find this value.  You can then enter it at
+  configure time.  Both the report and the entry are in decimal.
+
 CONFIG_X86
   This is Linux's home port.  Linux was originally native to the Intel
   386, and runs on all the later x86 processors including the Intel

diff -urP -I \$Id:.*Exp \$ -X /usr/src/patch.exclude linux-2.5.44-bk1-core/arch/i386/config.in linux/arch/i386/config.in
@@ -156,6 +156,23 @@
 bool 'Huge TLB Page Support' CONFIG_HUGETLB_PAGE
 
 bool 'Symmetric multi-processing support' CONFIG_SMP
+bool 'Configure High-Resolution-Timers' CONFIG_HIGH_RES_TIMERS
+#
+# We assume that if the box doesn't have a TSC it doesn't have ACPI either.
+#
+if [ "$CONFIG_HIGH_RES_TIMERS" = "y" -a "$CONFIG_X86_TSC" = "y" ]; then
+	choice 'Clock source?' \
+		"ACPI-pm-timer  CONFIG_HIGH_RES_TIMER_ACPI_PM  \
+		Time-stamp-counter/TSC  CONFIG_HIGH_RES_TIMER_TSC \
+		Programable-interrupt-timer/PIT CONFIG_HIGH_RES_TIMER_PIT" Time-stamp-counter/TSC
+else
+	if [ "$CONFIG_HIGH_RES_TIMERS" = "y" ]; then
+		define_bool CONFIG_HIGH_RES_TIMER_PIT y
+        fi
+fi
+if [ "$CONFIG_HIGH_RES_TIMER_ACPI_PM" = "y" ]; then
+	int 'Default ACPI pm timer address' CONFIG_HIGH_RES_TIMER_ACPI_PM_ADD 0
+fi 
 bool 'Preemptible Kernel' CONFIG_PREEMPT
 if [ "$CONFIG_SMP" != "y" ]; then
    bool 'Local APIC support on uniprocessors' CONFIG_X86_UP_APIC

@@ -355,6 +372,7 @@
 else
    define_bool CONFIG_BLK_DEV_HD n
 fi
+
 endmenu
 
 mainmenu_option next_comment

diff -urP -I \$Id:.*Exp \$ -X /usr/src/patch.exclude linux-2.5.44-bk1-core/arch/i386/kernel/timers/Makefile linux/arch/i386/kernel/timers/Makefile
@@ -6,6 +6,12 @@
 
 obj-y += timer_tsc.o
 obj-y += timer_pit.o
+obj-$(CONFIG_X86_TSC) -= timer_pit.o
+obj-$(CONFIG_HIGH_RES_TIMERS) -= timer_tsc.o
 obj-$(CONFIG_X86_CYCLONE)   += timer_cyclone.o
+obj-$(CONFIG_HIGH_RES_TIMER_ACPI_PM) += hrtimer_pm.o
+obj-$(CONFIG_HIGH_RES_TIMER_ACPI_PM) += high-res-tbxfroot.o
+obj-$(CONFIG_HIGH_RES_TIMER_TSC) += hrtimer_tsc.o
+obj-$(CONFIG_HIGH_RES_TIMER_PIT) += hrtimer_pit.o
 
 include $(TOPDIR)/Rules.make