[S390] Add PSW restart shutdown trigger
With this patch a new S390 shutdown trigger "restart" is added. If under
z/VM "systerm restart" is entered or under the HMC the "PSW restart" button
is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded.
Now we execute do_restart() that processes the restart action that is
defined under /sys/firmware/shutdown_actions/on_restart. Currently the
following actions are possible: reipl (default), stop, vmcmd, dump, and
dump_reipl.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 3eab7cf..02ec8fe 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -849,6 +849,34 @@
restart_go:
#endif
+#
+# PSW restart interrupt handler
+#
+ENTRY(psw_restart_int_handler)
+ st %r15,__LC_SAVE_AREA_64(%r0) # save r15
+ basr %r15,0
+0: l %r15,.Lrestart_stack-0b(%r15) # load restart stack
+ l %r15,0(%r15)
+ ahi %r15,-SP_SIZE # make room for pt_regs
+ stm %r0,%r14,SP_R0(%r15) # store gprs %r0-%r14 to stack
+ mvc SP_R15(4,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack
+ mvc SP_PSW(8,%r15),__LC_RST_OLD_PSW(%r0) # store restart old psw
+ xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0
+ basr %r14,0
+1: l %r14,.Ldo_restart-1b(%r14)
+ basr %r14,%r14
+
+ basr %r14,0 # load disabled wait PSW if
+2: lpsw restart_psw_crash-2b(%r14) # do_restart returns
+ .align 4
+.Ldo_restart:
+ .long do_restart
+.Lrestart_stack:
+ .long restart_stack
+ .align 8
+restart_psw_crash:
+ .long 0x000a0000,0x00000000 + restart_psw_crash
+
.section .kprobes.text, "ax"
#ifdef CONFIG_CHECK_STACK