[S390] Extra Kernel Parameters via VMPARM

Now it is possible to specify additional kernel parameters on the IPL
command line using the IPL PARM option.
If the Linux system is already running, the new reipl sysfs attribute
'parm' can be used to change kernel parameters for the next reboot.
Examples:
  IPL    C PARM dasd=1234 root=/dev/dasda1
  IPL 1234 PARM savesys=mylnxnss
  echo "init=/bin/bash" > /sys/firmware/reipl/ccw/parm

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 14 insertions, 3 deletions

diff --git a/include/asm-s390/ipl.h b/include/asm-s390/ipl.h
index c1b2e50392bb..eaca6dff5405 100644
--- a/include/asm-s390/ipl.h
+++ b/include/asm-s390/ipl.h
@@ -56,15 +56,19 @@ struct ipl_block_fcp {
         u8  scp_data[];
 } __attribute__((packed));
 
+#define DIAG308_VMPARM_SIZE     64
+
 struct ipl_block_ccw {
-        u8  load_param[8];
+        u8  load_parm[8];
         u8  reserved1[84];
         u8  reserved2[2];
         u16 devno;
         u8  vm_flags;
         u8  reserved3[3];
         u32 vm_parm_len;
-        u8  reserved4[80];
+        u8  nss_name[8];
+        u8  vm_parm[DIAG308_VMPARM_SIZE];
+        u8  reserved4[8];
 } __attribute__((packed));
 
 struct ipl_parameter_block {
@@ -73,7 +77,7 @@ struct ipl_parameter_block {
                 struct ipl_block_fcp fcp;
                 struct ipl_block_ccw ccw;
         } ipl_info;
-} __attribute__((packed));
+} __attribute__((packed,aligned(4096)));
 
 /*
  * IPL validity flags
@@ -86,6 +90,8 @@ extern void do_reipl(void);
 extern void do_halt(void);
 extern void do_poff(void);
 extern void ipl_save_parameters(void);
+extern void ipl_update_parameters(void);
+extern void get_ipl_vmparm(char *);
 
 enum {
         IPL_DEVNO_VALID         = 1,
@@ -147,6 +153,11 @@ enum diag308_flags {
         DIAG308_FLAGS_LP_VALID  = 0x80,
 };
 
+enum diag308_vm_flags {
+        DIAG308_VM_FLAGS_NSS_VALID      = 0x80,
+        DIAG308_VM_FLAGS_VP_VALID       = 0x40,
+};
+
 enum diag308_rc {
         DIAG308_RC_OK   = 1,
 };