2 Commits

Author SHA1 Message Date
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
Lv Zheng
d13bd5a602 ACPICA: Linux headers: Add <acpi/platform/aclinuxex.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.

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.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-27 18:13:07 +02:00