Linux headers: Remove ACPI_PREEMPTION_POINT() due to no usages.

This patch deletes deprecated ACPI_PREEMPTION_POINT(), there is no user for
it in Linux kernel now. Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Linux headers: Add <acpi/platform/aclinuxex.h> to remove mis-ordered inclusion of <acpi/actypes.h> from <acpi/platform/aclinux.h>.

From ACPICA's perspective, <acpi/actypes.h> should be included after
inclusion of <acpi/platform/acenv.h>.  But currently in Linux,
<acpi/platform/aclinux.h> included by <acpi/platform/acenv.h> has
included <acpi/actypes.h> to find ACPICA types for inline functions.

This causes the following problem:
1. Redundant code in <asm/acpi.h> and <acpi/platform/aclinux.h>:
   Linux must be careful to keep conditions for <acpi/actypes.h> inclusion
   consistent with the conditions for <acpi/platform/aclinux.h> inclusion.
   Which finally leads to the issue that we have to keep many useless macro
   definitions in <acpi/platform/aclinux.h> or <asm/acpi.h>.
   Such conditions include:
     COMPILER_DEPENDENT_UINT64
     COMPILER_DEPENDENT_INT64
     ACPI_INLINE
     ACPI_SYSTEM_XFACE
     ACPI_EXTERNAL_XFACE
     ACPI_INTERNAL_XFACE
     ACPI_INTERNAL_VAR_XFACE
     ACPI_MUTEX_TYPE
     DEBUGGER_THREADING
     ACPI_ACQUIRE_GLOBAL_LOCK
     ACPI_RELEASE_GLOBAL_LOCK
     ACPI_FLUSH_CPU_CACHE
   They have default implementations in <include/acpi/platform/acenv.h>
   while Linux need to keep a copy in <asm/acpi.h> to avoid build errors.
   Typical Linux build error if we deletes COMPILER_DEPENDENT_x and
   ACPI_x_XFACE definitions from asm/acpi.h:
      CC      init/main.o
    In file included from include/acpi/platform/aclinux.h:293:0,
                     from include/acpi/platform/acenv.h:149,
                     from include/acpi/acpi.h:56,
                     from include/linux/acpi.h:41,
                     from init/main.c:27:
    include/acpi/actypes.h:129:1: error: unknown type name 'COMPILER_DEPENDENT_UINT64'
    include/acpi/actypes.h:130:1: error: unknown type name 'COMPILER_DEPENDENT_INT64'
    In file included from include/acpi/platform/aclinux.h:293:0,
                     from include/acpi/platform/acenv.h:149,
                     from include/acpi/acpi.h:56,
                     from include/linux/acpi.h:41,
                     from init/main.c:27:
    include/acpi/actypes.h:1025:21: error: expected ')' before '*' token
    include/acpi/actypes.h:1028:21: error: expected ')' before '*' token
    In file included from include/acpi/acpi.h:63:0,
                     from include/linux/acpi.h:41,
                     from init/main.c:27:
    include/acpi/acpiosxf.h:240:7: error: unknown type name 'acpi_osd_handler'
    include/acpi/acpiosxf.h:247:6: error: unknown type name 'acpi_osd_handler'
    include/acpi/acpiosxf.h:260:3: error: unknown type name 'acpi_osd_exec_callback'

This patch introduces <acpi/platform/aclinuxex.h> to fix this issue by
splitting conditions and declarations (most of them are inline functions)
into 2 header files so that the wrong inclusion of <acpi/actypes.h> can be
removed from <acpi/platform/aclinux.h>.

This patch also removes old ACPI_NATIVE_INTERFACE_HEADER mechanism which is
not preferred by Linux and adds the platform/acenvex.h to be the solution
to solve this issue. Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Linux headers: Add <asm/acenv.h> to remove mis-ordered inclusion of <asm/acpi.h> from <acpi/platform/aclinux.h>.

There is a mis-order inclusion for <asm/acpi.h>.

As we will enforce including <linux/acpi.h> for all Linux ACPI users, we
can find the inclusion order is as follows:

<linux/acpi.h>
  <acpi/acpi.h>
   <acpi/platform/acenv.h>
    (acenv.h before including aclinux.h)
    <acpi/platform/aclinux.h>
...........................................................................
     (aclinux.h before including asm/acpi.h)
     <asm/acpi.h>                             @Redundant@
      (ACPICA specific stuff)
...........................................................................
...........................................................................
      (Linux ACPI specific stuff) ? - - - - - - - - - - - - +
     (aclinux.h after including asm/acpi.h)   @Invisible@   |
    (acenv.h after including aclinux.h)       @Invisible@   |
   other ACPICA headers                       @Invisible@   |
............................................................|..............
  <acpi/acpi_bus.h>                                         |
  <acpi/acpi_drivers.h>                                     |
  <asm/acpi.h> (Excluded)                                   |
   (Linux ACPI specific stuff) ! <- - - - - - - - - - - - - +

NOTE that, in ACPICA, <acpi/platform/acenv.h> is more like Kconfig
generated <generated/autoconf.h> for Linux, it is meant to be included
before including any ACPICA code.

In the above figure, there is a question mark for "Linux ACPI specific
stuff" in <asm/acpi.h> which should be included after including all other
ACPICA header files.  Thus they really need to be moved to the position
marked with exclaimation mark or the definitions in the blocks marked with
"@Invisible@" will be invisible to such architecture specific "Linux ACPI
specific stuff" header blocks.  This leaves 2 issues:
1. All environmental definitions in these blocks should have a copy in the
   area marked with "@Redundant@" if they are required by the "Linux ACPI
   specific stuff".
2. We cannot use any ACPICA defined types in <asm/acpi.h>.

This patch splits architecture specific ACPICA stuff from <asm/acpi.h> to
fix this issue. Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Linux headers: Cleanup redudant definitions that already have defaults in <acpi/platform/acenv.h>.

Since mis-order issues have been solved, we can cleanup redundant
definitions that already have defaults in <acpi/platform/acenv.h>.

This patch removes redudant environments for __KERNEL__ surrounded code.
Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
ACPI: introduce CONFIG_ACPI_REDUCED_HARDWARE_ONLY

ACPI hardware reduced mode exists to allow newer platforms to use a
simpler form of ACPI that does not require supporting legacy versions
of the specification and their associated hardware.  This mode was
introduced in the ACPI 5.0 specification.

The ACPI hardware reduced mode is supposed to be used on systems
having the HW_REDUCED_ACPI flag set in the FADT.  ACPICA checks
that flag to determine whether or not it should work in the HW
reduced mode and there are pieces of code in it that will never
be used in that case.

Since some architecutres will always use the ACPI HW reduced mode,
it doesn't make sense for them to ever compile support for anything
else.  Thus, they should set the flag ACPI_REDUCED_HARDWARE to TRUE
in the ACPICA source.  To enable them to do that, introduce a new
kernel configuration option, CONFIG_ACPI_REDUCED_HARDWARE_ONLY, that
will cause the ACPICA's ACPI_REDUCED_HARDWARE flag to be TRUE when
set.

Introducing this configuration item is based on suggestions from Lv
Zheng saying that this does not belong in ACPICA, but rather to the
Linux kernel itself.  Al Stone.

References: http://www.spinics.net/lists/linux-acpi/msg46369.html
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Al Stone <al.stone@linaro.org>
[rjw: Subject and changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge pull request #33 from zetalog/acpica-linux