linux/drivers/acpi/apei
Lv Zheng a238317ce8 ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem.
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: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-27 18:13:08 +02:00
..
apei-base.c ACPI and power management updates for 3.14-rc1 2014-01-24 15:51:02 -08:00
apei-internal.h ACPI / i915: Fix incorrect <acpi/acpi.h> inclusions via <linux/acpi_io.h> 2013-12-07 01:24:33 +01:00
einj.c ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem. 2014-05-27 18:13:08 +02:00
erst-dbg.c ACPI / APEI: Fix the returned value in erst_dbg_read 2013-01-03 13:10:20 +01:00
erst.c SCI reporting for other error types not only correctable ones 2014-01-12 17:56:54 +01:00
ghes.c ACPI and power management updates for 3.14-rc1 2014-01-24 15:51:02 -08:00
hest.c x86/mce, acpi/apei: Only disable banks listed in HEST if mce is configured 2013-08-12 17:55:12 +02:00
Kconfig ACPI / APEI: Remove X86 redundant dependency for APEI GHES. 2014-02-18 01:29:45 +01:00
Makefile Move cper.c from drivers/acpi/apei to drivers/firmware/efi 2013-10-31 11:27:04 -07:00