1 files changed, 36 insertions, 2 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 050963f15802..61eb7caa1567 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -16,11 +16,10 @@
 #include <linux/device.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
-
 #include <asm/cio.h>
 #include <asm/delay.h>
 #include <asm/irq.h>
-
+#include <asm/setup.h>
 #include "airq.h"
 #include "cio.h"
 #include "css.h"
@@ -909,3 +908,38 @@ void reipl_ccw_dev(struct ccw_dev_id *devid)
         cio_reset_channel_paths();
         do_reipl_asm(*((__u32*)&schid));
 }
+
+extern struct schib ipl_schib;
+
+/*
+ * ipl_save_parameters gets called very early. It is not allowed to access
+ * anything in the bss section at all. The bss section is not cleared yet,
+ * but may contain some ipl parameters written by the firmware.
+ * These parameters (if present) are copied to 0x2000.
+ * To avoid corruption of the ipl parameters, all variables used by this
+ * function must reside on the stack or in the data section.
+ */
+void ipl_save_parameters(void)
+{
+        struct subchannel_id schid;
+        unsigned int *ipl_ptr;
+        void *src, *dst;
+
+        schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
+        if (!schid.one)
+                return;
+        if (stsch(schid, &ipl_schib))
+                return;
+        if (!ipl_schib.pmcw.dnv)
+                return;
+        ipl_devno = ipl_schib.pmcw.dev;
+        ipl_flags |= IPL_DEVNO_VALID;
+        if (!ipl_schib.pmcw.qf)
+                return;
+        ipl_flags |= IPL_PARMBLOCK_VALID;
+        ipl_ptr = (unsigned int *)__LC_IPL_PARMBLOCK_PTR;
+        src = (void *)(unsigned long)*ipl_ptr;
+        dst = (void *)IPL_PARMBLOCK_ORIGIN;
+        memmove(dst, src, PAGE_SIZE);
+        *ipl_ptr = IPL_PARMBLOCK_ORIGIN;
+}