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, 8 insertions, 8 deletions

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index c4a5d87ede7e..185334114d71 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -220,13 +220,13 @@ static int __init extlog_init(void)
 		goto err;
 	}
 
-	extlog_l1_hdr = acpi_os_map_memory(l1_dirbase, l1_hdr_size);
+	extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
 	l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
 	l1_size = l1_head->total_len;
 	l1_percpu_entry = l1_head->entries;
 	elog_base = l1_head->elog_base;
 	elog_size = l1_head->elog_len;
-	acpi_os_unmap_memory(extlog_l1_hdr, l1_hdr_size);
+	acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
 	release_mem_region(l1_dirbase, l1_hdr_size);
 
 	/* remap L1 header again based on completed information */
@@ -237,7 +237,7 @@ static int __init extlog_init(void)
 			(unsigned long long)l1_dirbase + l1_size);
 		goto err;
 	}
-	extlog_l1_addr = acpi_os_map_memory(l1_dirbase, l1_size);
+	extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
 	l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
 
 	/* remap elog table */
@@ -248,7 +248,7 @@ static int __init extlog_init(void)
 			(unsigned long long)elog_base + elog_size);
 		goto err_release_l1_dir;
 	}
-	elog_addr = acpi_os_map_memory(elog_base, elog_size);
+	elog_addr = acpi_os_map_iomem(elog_base, elog_size);
 
 	rc = -ENOMEM;
 	/* allocate buffer to save elog record */
@@ -270,11 +270,11 @@ static int __init extlog_init(void)
 
 err_release_elog:
 	if (elog_addr)
-		acpi_os_unmap_memory(elog_addr, elog_size);
+		acpi_os_unmap_iomem(elog_addr, elog_size);
 	release_mem_region(elog_base, elog_size);
 err_release_l1_dir:
 	if (extlog_l1_addr)
-		acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 	release_mem_region(l1_dirbase, l1_size);
 err:
 	pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
@@ -287,9 +287,9 @@ static void __exit extlog_exit(void)
 	mce_unregister_decode_chain(&extlog_mce_dec);
 	((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
 	if (extlog_l1_addr)
-		acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
 	if (elog_addr)
-		acpi_os_unmap_memory(elog_addr, elog_size);
+		acpi_os_unmap_iomem(elog_addr, elog_size);
 	release_mem_region(elog_base, elog_size);
 	release_mem_region(l1_dirbase, l1_size);
 	kfree(elog_buf);