Commit Graph

4 Commits

Author SHA1 Message Date
Myron Stowe
6f68c91c55 ACPI: Export interfaces for ioremapping/iounmapping ACPI registers
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: Myron Stowe <myron.stowe@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-01-17 04:35:20 -05:00
Rafael J. Wysocki
13606a2de1 ACPI: Introduce acpi_os_get_iomem()
Introduce function acpi_os_get_iomem() that may be used by its callers
to get a reference to an ACPI iomap.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-02-24 19:58:42 +01:00
Rafael J. Wysocki
073b4964b3 ACPI: Do not export functions that are only used in osl.c
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: Rafael J. Wysocki <rjw@sisk.pl>
2011-02-24 19:58:41 +01:00
Rafael J. Wysocki
2d6d9fd3a5 ACPI: Introduce acpi_os_ioremap()
Commit ca9b600be3 ("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: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-20 18:30:17 -08:00