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 <[e-mail]>
Signed-off-by: Huang Ying <[e-mail]>
Tested-by: Jean Delvare <[e-mail]>
Cc: [e-mail]
Signed-off-by: Len Brown <[e-mail]>

drivers/acpi/apei/apei-base.c

···
 	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;
 }
···
 	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;
 }
···
 
 	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)

drivers/acpi/apei/apei-internal.h

···
 #define APEI_INTERNAL_H
 
 #include <linux/cper.h>
+#include <linux/acpi.h>
+#include <linux/acpi_io.h>
 
 struct apei_exec_context;
 
···
 
 /* 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);

drivers/acpi/apei/ghes.c

···
 	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;
···
 	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);
···
 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 {