[BUGFIX] ACPI, APEI, Avoid too much error reporting in runtime

[Huang Ying <ying.huang@intel.com>]

This patch fixed the following bug.

https://bugzilla.kernel.org/show_bug.cgi?id=43282

This is caused by a firmware bug checking (checking generic address
register provided by firmware) in runtime.  The checking should be
done in address mapping time instead of runtime to avoid too much
error reporting in runtime.

Reported-by: Pawel Sikora <pluto@agmk.net>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Tested-by: Jean Delvare <khali@linux-fr.org>
---
 drivers/acpi/apei/apei-base.c     |   17 +++++++++++++++--
 drivers/acpi/apei/apei-internal.h |    9 +++++++++
 drivers/acpi/apei/ghes.c          |    6 +++---
 3 files changed, 27 insertions(+), 5 deletions(-)

--- a/drivers/acpi/apei/apei-base.c
+++ b/drivers/acpi/apei/apei-base.c
@@ -243,7 +243,7 @@ static int pre_map_gar_callback(struct a
 	u8 ins = entry->instruction;
 
 	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
-		return acpi_os_map_generic_address(&entry->register_region);
+		return apei_map_generic_address(&entry->register_region);
 
 	return 0;
 }
@@ -276,7 +276,7 @@ static int post_unmap_gar_callback(struc
 	u8 ins = entry->instruction;
 
 	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
-		acpi_os_unmap_generic_address(&entry->register_region);
+		apei_unmap_generic_address(&entry->register_region);
 
 	return 0;
 }
@@ -606,6 +606,19 @@ static int apei_check_gar(struct acpi_ge
 	return 0;
 }
 
+int apei_map_generic_address(struct acpi_generic_address *reg)
+{
+	int rc;
+	u32 access_bit_width;
+	u64 address;
+
+	rc = apei_check_gar(reg, &address, &access_bit_width);
+	if (rc)
+		return rc;
+	return acpi_os_map_generic_address(reg);
+}
+EXPORT_SYMBOL_GPL(apei_map_generic_address);
+
 /* read GAR in interrupt (including NMI) or process context */
 int apei_read(u64 *val, struct acpi_generic_address *reg)
 {
--- a/drivers/acpi/apei/apei-internal.h
+++ b/drivers/acpi/apei/apei-internal.h
@@ -7,6 +7,8 @@
 #define APEI_INTERNAL_H
 
 #include <linux/cper.h>
+#include <linux/acpi.h>
+#include <linux/acpi_io.h>
 
 struct apei_exec_context;
 
@@ -68,6 +70,13 @@ static inline int apei_exec_run_optional
 /* IP has been set in instruction function */
 #define APEI_EXEC_SET_IP	1
 
+int apei_map_generic_address(struct acpi_generic_address *reg);
+
+static inline void apei_unmap_generic_address(struct acpi_generic_address *reg)
+{
+	acpi_os_unmap_generic_address(reg);
+}
+
 int apei_read(u64 *val, struct acpi_generic_address *reg);
 int apei_write(u64 val, struct acpi_generic_address *reg);
 
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -301,7 +301,7 @@ static struct ghes *ghes_new(struct acpi
 	if (!ghes)
 		return ERR_PTR(-ENOMEM);
 	ghes->generic = generic;
-	rc = acpi_os_map_generic_address(&generic->error_status_address);
+	rc = apei_map_generic_address(&generic->error_status_address);
 	if (rc)
 		goto err_free;
 	error_block_length = generic->error_block_length;
@@ -321,7 +321,7 @@ static struct ghes *ghes_new(struct acpi
 	return ghes;
 
 err_unmap:
-	acpi_os_unmap_generic_address(&generic->error_status_address);
+	apei_unmap_generic_address(&generic->error_status_address);
 err_free:
 	kfree(ghes);
 	return ERR_PTR(rc);
@@ -330,7 +330,7 @@ err_free:
 static void ghes_fini(struct ghes *ghes)
 {
 	kfree(ghes->estatus);
-	acpi_os_unmap_generic_address(&ghes->generic->error_status_address);
+	apei_unmap_generic_address(&ghes->generic->error_status_address);
 }
 
 enum {