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authorLv Zheng <lv.zheng@intel.com>2014-05-20 11:39:41 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-27 20:13:08 +0400
commita238317ce8185519ed083e81e84260907fbbcf7f (patch)
treef5b228ac40941946db2e7427b1085a90c78c85b5 /drivers/acpi/osl.c
parent92985ef1db428cc6129a1d375a68c277aa05820b (diff)
downloadlinux-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.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 9aeae41e22fb..147bc1b91b42 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;