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ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem.

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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>
This commit is contained in:
Lv Zheng
2014-05-20 15:39:41 +08:00
committed by Rafael J. Wysocki
parent 92985ef1db
commit a238317ce8
8 changed files with 39 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/acpi/apei/einj.c
View File

@@ -202,7 +202,7 @@ static void check_vendor_extension(u64 paddr,
if (!offset)
return;
v = acpi_os_map_memory(paddr + offset, sizeof(*v));
v = acpi_os_map_iomem(paddr + offset, sizeof(*v));
if (!v)
return;
sbdf = v->pcie_sbdf;
@@ -210,7 +210,7 @@ static void check_vendor_extension(u64 paddr,
sbdf >> 24, (sbdf >> 16) & 0xff,
(sbdf >> 11) & 0x1f, (sbdf >> 8) & 0x7,
v->vendor_id, v->device_id, v->rev_id);
acpi_os_unmap_memory(v, sizeof(*v));
acpi_os_unmap_iomem(v, sizeof(*v));
}
static void *einj_get_parameter_address(void)
@@ -236,7 +236,7 @@ static void *einj_get_parameter_address(void)
if (pa_v5) {
struct set_error_type_with_address *v5param;
v5param = acpi_os_map_memory(pa_v5, sizeof(*v5param));
v5param = acpi_os_map_iomem(pa_v5, sizeof(*v5param));
if (v5param) {
acpi5 = 1;
check_vendor_extension(pa_v5, v5param);
@@ -246,11 +246,11 @@ static void *einj_get_parameter_address(void)
if (param_extension && pa_v4) {
struct einj_parameter *v4param;
v4param = acpi_os_map_memory(pa_v4, sizeof(*v4param));
v4param = acpi_os_map_iomem(pa_v4, sizeof(*v4param));
if (!v4param)
return NULL;
if (v4param->reserved1 || v4param->reserved2) {
acpi_os_unmap_memory(v4param, sizeof(*v4param));
acpi_os_unmap_iomem(v4param, sizeof(*v4param));
return NULL;
}
return v4param;
@@ -794,7 +794,7 @@ err_unmap:
sizeof(struct set_error_type_with_address) :
sizeof(struct einj_parameter);
acpi_os_unmap_memory(einj_param, size);
acpi_os_unmap_iomem(einj_param, size);
}
apei_exec_post_unmap_gars(&ctx);
err_release:
@@ -816,7 +816,7 @@ static void __exit einj_exit(void)
sizeof(struct set_error_type_with_address) :
sizeof(struct einj_parameter);
acpi_os_unmap_memory(einj_param, size);
acpi_os_unmap_iomem(einj_param, size);
}
einj_exec_ctx_init(&ctx);
apei_exec_post_unmap_gars(&ctx);