mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 21:02:19 +00:00
a238317ce8
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>
21 lines
593 B
C
21 lines
593 B
C
#ifndef _ACPI_IO_H_
|
|
#define _ACPI_IO_H_
|
|
|
|
#include <linux/io.h>
|
|
|
|
static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
|
|
acpi_size size)
|
|
{
|
|
return ioremap_cache(phys, size);
|
|
}
|
|
|
|
void __iomem *__init_refok
|
|
acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
|
|
void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
|
|
void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
|
|
|
|
int acpi_os_map_generic_address(struct acpi_generic_address *addr);
|
|
void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
|
|
|
|
#endif
|