3 files changed, 24 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 255ec535bba8..54983246930d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1370,6 +1370,9 @@ running once the system is up.
                         Reserves a hole at the top of the kernel virtual
                         address space.
 
+        reset_devices   [KNL] Force drivers to reset the underlying device
+                        during initialization.
+
         resume=         [SWSUSP]
                         Specify the partition device for software suspend
 
diff --git a/include/linux/init.h b/include/linux/init.h
index 6667785dd1ff..e92b1455d7af 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -68,6 +68,7 @@ extern initcall_t __security_initcall_start[], __security_initcall_end[];
 
 /* Defined in init/main.c */
 extern char saved_command_line[];
+extern unsigned int reset_devices;
 
 /* used by init/main.c */
 extern void setup_arch(char **);
diff --git a/init/main.c b/init/main.c
index 913e48d658ee..0766e69712b2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -128,6 +128,18 @@ static char *ramdisk_execute_command;
 static unsigned int max_cpus = NR_CPUS;
 
 /*
+ * If set, this is an indication to the drivers that reset the underlying
+ * device before going ahead with the initialization otherwise driver might
+ * rely on the BIOS and skip the reset operation.
+ *
+ * This is useful if kernel is booting in an unreliable environment.
+ * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
+ * skipped and devices will be in unknown state.
+ */
+unsigned int reset_devices;
+EXPORT_SYMBOL(reset_devices);
+
+/*
  * Setup routine for controlling SMP activation
  *
  * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
@@ -153,6 +165,14 @@ static int __init maxcpus(char *str)
 
 __setup("maxcpus=", maxcpus);
 
+static int __init set_reset_devices(char *str)
+{
+        reset_devices = 1;
+        return 1;
+}
+
+__setup("reset_devices", set_reset_devices);
+
 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 static const char *panic_later, *panic_param;