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author | Lv Zheng <lv.zheng@intel.com> | 2014-05-20 07:39:41 (GMT) |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-05-27 16:13:08 (GMT) |
commit | a238317ce8185519ed083e81e84260907fbbcf7f (patch) | |
tree | f5b228ac40941946db2e7427b1085a90c78c85b5 /drivers/acpi/osl.c | |
parent | 92985ef1db428cc6129a1d375a68c277aa05820b (diff) | |
download | linux-a238317ce8185519ed083e81e84260907fbbcf7f.tar.xz |
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>
Diffstat (limited to 'drivers/acpi/osl.c')
-rw-r--r-- | drivers/acpi/osl.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 9aeae41..147bc1b 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -355,7 +355,7 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr) } void __iomem *__init_refok -acpi_os_map_memory(acpi_physical_address phys, acpi_size size) +acpi_os_map_iomem(acpi_physical_address phys, acpi_size size) { struct acpi_ioremap *map; void __iomem *virt; @@ -401,10 +401,17 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size) list_add_tail_rcu(&map->list, &acpi_ioremaps); - out: +out: mutex_unlock(&acpi_ioremap_lock); return map->virt + (phys - map->phys); } +EXPORT_SYMBOL_GPL(acpi_os_map_iomem); + +void *__init_refok +acpi_os_map_memory(acpi_physical_address phys, acpi_size size) +{ + return (void *)acpi_os_map_iomem(phys, size); +} EXPORT_SYMBOL_GPL(acpi_os_map_memory); static void acpi_os_drop_map_ref(struct acpi_ioremap *map) @@ -422,7 +429,7 @@ static void acpi_os_map_cleanup(struct acpi_ioremap *map) } } -void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) +void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size) { struct acpi_ioremap *map; @@ -443,6 +450,12 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) acpi_os_map_cleanup(map); } +EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem); + +void __ref acpi_os_unmap_memory(void *virt, acpi_size size) +{ + return acpi_os_unmap_iomem((void __iomem *)virt, size); +} EXPORT_SYMBOL_GPL(acpi_os_unmap_memory); void __init early_acpi_os_unmap_memory(void __iomem *virt, acpi_size size) @@ -464,7 +477,7 @@ int acpi_os_map_generic_address(struct acpi_generic_address *gas) if (!addr || !gas->bit_width) return -EINVAL; - virt = acpi_os_map_memory(addr, gas->bit_width / 8); + virt = acpi_os_map_iomem(addr, gas->bit_width / 8); if (!virt) return -EIO; |