![Lv Zheng](/assets/img/avatar_default.png)
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_
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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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