The acpi_os_ioremap() function may be used to map normal RAM or IO
regions. The current implementation simply uses ioremap_cache(). This
will work for some architectures, but arm64 ioremap_cache() cannot be
used to map IO regions which don't support caching. So for arm64, use
ioremap() for non-RAM regions.

CC: Rafael J Wysocki <rjw@rjwysocki.net>
CC: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: NRobert Richter <rrichter@cavium.com>
Tested-by: NTimur Tabi <timur@codeaurora.org>
Acked-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ACPICA doesn't include protections around address space checking, Linux
build tests always complain increased sparse warnings around ACPICA
internal acpi_os_map/unmap_memory() invocations.  This patch tries to fix
this issue permanently.

There are 2 choices left for us to solve this issue:
 1. Add __iomem address space awareness into ACPICA.
 2. Remove sparse checker of __iomem from ACPICA source code.

This patch chooses solution 2, because:
 1.  Most of the acpi_os_map/unmap_memory() invocations are used for ACPICA.
     table mappings, which in fact are not IO addresses.
 2.  The only IO addresses usage is for "system memory space" mapping code in:
      drivers/acpi/acpica/exregion.c
      drivers/acpi/acpica/evrgnini.c
      drivers/acpi/acpica/exregion.c
    The mapped address is accessed in the handler of "system memory space"
    - acpi_ex_system_memory_space_handler().  This function in fact can be
    changed to invoke acpi_os_read/write_memory() so that __iomem can
    always be type-casted in the OSL layer.

According to the above investigation, we drew the following conclusion:
It is not a good idea to introduce __iomem address space awareness into
ACPICA mostly in order to protect non-IO addresses.

We can simply remove __iomem for acpi_os_map/unmap_memory() to remove
__iomem checker for ACPICA code. Then we need to enforce external usages
to invoke other APIs that are aware of __iomem address space.
The external usages are:
 drivers/acpi/apei/einj.c
 drivers/acpi/acpi_extlog.c
 drivers/char/tpm/tpm_acpi.c
 drivers/acpi/nvs.c

This patch thus performs cleanups in this way:
 1. Add acpi_os_map/unmap_iomem() to be invoked by non-ACPICA code.
 2. Remove __iomem from acpi_os_map/unmap_memory().
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To avoid build problems and breaking dependencies between ACPI header
files, <acpi/acpi.h> should not be included directly by code outside
of the ACPI core subsystem.  However, that is possible if
<linux/acpi_io.h> is included, because that file contains
a direct inclusion of <acpi/acpi.h>.

For this reason, remove the direct <acpi/acpi.h> inclusion from
<linux/acpi_io.h>, move that file from include/linux/ to include/acpi/
and make <linux/acpi.h> include it for CONFIG_ACPI set along with the
other ACPI header files.  Accordingly, Remove the inclusions of
<linux/acpi_io.h> from everywhere.

Of course, that causes the contents of the new <acpi/acpi_io.h> file
to be available for CONFIG_ACPI set only, so intel_opregion.o that
depends on it should also depend on CONFIG_ACPI (and it really should
not be compiled for CONFIG_ACPI unset anyway).

References: https://01.org/linuxgraphics/sites/default/files/documentation/acpi_igd_opregion_spec.pdf
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[rjw: Subject and changelog]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there.  And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
<linux/acpi.h> as appropriate.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Export remapping and unmapping interfaces - acpi_os_map_generic_address()
and acpi_os_unmap_generic_address() - for ACPI generic registers that are
backed by memory mapped I/O (MMIO).

The acpi_os_map_generic_address() and acpi_os_unmap_generic_address()
declarations may more properly belong in include/acpi/acpiosxf.h next to
acpi_os_read_memory() but I believe that would require the ACPI CA making
them an official part of the ACPI CA - OS interface.

ACPI Generic Address Structure (GAS) reference (ACPI's fixed/generic
hardware registers use the GAS format):
  ACPI Specification, Revision 4.0, Section 5.2.3.1, "Generic Address
  Structure"
Signed-off-by: NMyron Stowe <myron.stowe@redhat.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

Introduce function acpi_os_get_iomem() that may be used by its callers
to get a reference to an ACPI iomap.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The functions acpi_os_map_generic_address() and
acpi_os_unmap_generic_address() are only used in drivers/acpi/osl.c,
so make them static and remove the extern definitions of them from
include/linux/acpi_io.h.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Commit ca9b600b ("ACPI / PM: Make suspend_nvs_save() use
acpi_os_map_memory()") attempted to prevent the code in osl.c and nvs.c
from using different ioremap() variants by making the latter use
acpi_os_map_memory() for mapping the NVS pages.  However, that also
requires acpi_os_unmap_memory() to be used for unmapping them, which
causes synchronize_rcu() to be executed many times in a row
unnecessarily and introduces substantial delays during resume on some
systems.

Instead of using acpi_os_map_memory() for mapping the NVS pages in nvs.c
introduce acpi_os_ioremap() calling ioremap_cache() and make the code in
both osl.c and nvs.c use it.
Reported-by: NJeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>