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>
20 lines
593 B
C
20 lines
593 B
C
#ifndef _ACPI_IO_H_
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#define _ACPI_IO_H_
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#include <linux/io.h>
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static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
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acpi_size size)
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{
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return ioremap_cache(phys, size);
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}
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void __iomem *__init_refok
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acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
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void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
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void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
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int acpi_os_map_generic_address(struct acpi_generic_address *addr);
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void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
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#endif
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