ACPI, APEI, Avoid too much error reporting in runtime

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>
Cc: stable@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c
index 5577762..6686b1e 100644
--- a/drivers/acpi/apei/apei-base.c
+++ b/drivers/acpi/apei/apei-base.c
@@ -243,7 +243,7 @@
 	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 @@
 	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 @@
 	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)
 {