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>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index 1be6f5564485..a095d4f858da 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -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);