[PATCH] s390: kexec fixes and improvements.

Disable pseudo page fault handling before starting the new kernel and try
to use diag308 to reset the machine.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 109 insertions, 5 deletions

diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 2721c3a32b84..5aa71b05b8ae 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -70,6 +70,8 @@ machine_kexec(struct kimage *image)
         for (;;);
 }
 
+extern void pfault_fini(void);
+
 static void
 kexec_halt_all_cpus(void *kernel_image)
 {
@@ -78,6 +80,11 @@ kexec_halt_all_cpus(void *kernel_image)
         struct kimage *image;
         relocate_kernel_t data_mover;
 
+#ifdef CONFIG_PFAULT
+        if (MACHINE_IS_VM)
+                pfault_fini();
+#endif
+
         if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid))
                 signal_processor(smp_processor_id(), sigp_stop);
 
diff --git a/arch/s390/kernel/relocate_kernel.S b/arch/s390/kernel/relocate_kernel.S
index d5e4a62fbb79..2a25ec7147ff 100644
--- a/arch/s390/kernel/relocate_kernel.S
+++ b/arch/s390/kernel/relocate_kernel.S
@@ -4,6 +4,7 @@
  * (C) Copyright IBM Corp. 2005
  *
  * Author(s): Rolf Adelsberger <adelsberger@de.ibm.com>
+ *            Heiko Carstens <heiko.carstens@de.ibm.com>
  *
  */
 
@@ -25,8 +26,31 @@
         relocate_kernel:
                 basr    %r13,0          #base address
         .base:
-                spx     zero64-.base(%r13)      #absolute addressing mode
                 stnsm   sys_msk-.base(%r13),0xf8        #disable DAT and IRQ (external)
+                spx     zero64-.base(%r13)      #absolute addressing mode
+                stctl   %c0,%c15,ctlregs-.base(%r13)
+                stm     %r0,%r15,gprregs-.base(%r13)
+                la      %r1,load_psw-.base(%r13)
+                mvc     0(8,%r0),0(%r1)
+                la      %r0,.back-.base(%r13)
+                st      %r0,4(%r0)
+                oi      4(%r0),0x80
+                mvc     0x68(8,%r0),0(%r1)
+                la      %r0,.back_pgm-.base(%r13)
+                st      %r0,0x6c(%r0)
+                oi      0x6c(%r0),0x80
+                lhi     %r0,0
+                diag    %r0,%r0,0x308
+        .back:
+                basr    %r13,0
+        .back_base:
+                oi      have_diag308-.back_base(%r13),0x01
+                lctl    %c0,%c15,ctlregs-.back_base(%r13)
+                lm      %r0,%r15,gprregs-.back_base(%r13)
+                j       .start_reloc
+        .back_pgm:
+                lm      %r0,%r15,gprregs-.base(%r13)
+        .start_reloc:
                 lhi     %r10,-1         #preparing the mask
                 sll     %r10,12         #shift it such that it becomes 0xf000
         .top:
@@ -63,6 +87,10 @@
                 o       %r3,4(%r4)      #or load address into psw
                 st      %r3,4(%r4)
                 mvc     0(8,%r0),0(%r4) #copy psw to absolute address 0
+                tm      have_diag308-.base(%r13),0x01
+                jno     .no_diag308
+                diag    %r0,%r0,0x308
+        .no_diag308:
                 sr      %r1,%r1         #clear %r1
                 sr      %r2,%r2         #clear %r2
                 sigp    %r1,%r2,0x12    #set cpuid to zero
@@ -75,6 +103,17 @@
                 .long   0x00080000,0x80000000
         sys_msk:
                 .quad   0
+        ctlregs:
+                .rept   16
+                .long   0
+                .endr
+        gprregs:
+                .rept   16
+                .long   0
+                .endr
+        have_diag308:
+                .byte   0
+                .align  8
         relocate_kernel_end:
         .globl  relocate_kernel_len
         relocate_kernel_len:
diff --git a/arch/s390/kernel/relocate_kernel64.S b/arch/s390/kernel/relocate_kernel64.S
index 96290cc4eb3c..8cdb86e8911f 100644
--- a/arch/s390/kernel/relocate_kernel64.S
+++ b/arch/s390/kernel/relocate_kernel64.S
@@ -4,6 +4,7 @@
  * (C) Copyright IBM Corp. 2005
  *
  * Author(s): Rolf Adelsberger <adelsberger@de.ibm.com>
+ *            Heiko Carstens <heiko.carstens@de.ibm.com>
  *
  */
 
@@ -26,8 +27,34 @@
         relocate_kernel:
                 basr    %r13,0          #base address
         .base:
+                stnsm   sys_msk-.base(%r13),0xf8        #disable DAT and IRQs
                 spx     zero64-.base(%r13)      #absolute addressing mode
-                stnsm   sys_msk-.base(%r13),0xf8        #disable DAT and IRQ (external)
+                stctg   %c0,%c15,ctlregs-.base(%r13)
+                stmg    %r0,%r15,gprregs-.base(%r13)
+                lghi    %r0,3
+                sllg    %r0,%r0,31
+                stg     %r0,0x1d0(%r0)
+                la      %r0,.back_pgm-.base(%r13)
+                stg     %r0,0x1d8(%r0)
+                la      %r1,load_psw-.base(%r13)
+                mvc     0(8,%r0),0(%r1)
+                la      %r0,.back-.base(%r13)
+                st      %r0,4(%r0)
+                oi      4(%r0),0x80
+                lghi    %r0,0
+                diag    %r0,%r0,0x308
+        .back:
+                lhi     %r1,1           #mode 1 = esame
+                sigp    %r1,%r0,0x12    #switch to esame mode
+                sam64                   #switch to 64 bit addressing mode
+                basr    %r13,0
+        .back_base:
+                oi      have_diag308-.back_base(%r13),0x01
+                lctlg   %c0,%c15,ctlregs-.back_base(%r13)
+                lmg     %r0,%r15,gprregs-.back_base(%r13)
+                j       .top
+        .back_pgm:
+                lmg     %r0,%r15,gprregs-.base(%r13)
         .top:
                 lghi    %r7,4096        #load PAGE_SIZE in r7
                 lghi    %r9,4096        #load PAGE_SIZE in r9
@@ -62,6 +89,10 @@
                 o       %r3,4(%r4)      #or load address into psw
                 st      %r3,4(%r4)
                 mvc     0(8,%r0),0(%r4) #copy psw to absolute address 0
+                tm      have_diag308-.base(%r13),0x01
+                jno     .no_diag308
+                diag    %r0,%r0,0x308
+        .no_diag308:
                 sam31                   #31 bit mode
                 sr      %r1,%r1         #erase register r1
                 sr      %r2,%r2         #erase register r2
@@ -75,8 +106,18 @@
                 .long   0x00080000,0x80000000
         sys_msk:
                 .quad   0
+        ctlregs:
+                .rept   16
+                .quad   0
+                .endr
+        gprregs:
+                .rept   16
+                .quad   0
+                .endr
+        have_diag308:
+                .byte   0
+                .align  8
         relocate_kernel_end:
         .globl  relocate_kernel_len
         relocate_kernel_len:
                 .quad   relocate_kernel_end - relocate_kernel
-
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index da77f001af8d..85222fee4361 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -537,7 +537,8 @@ int __devinit start_secondary(void *cpuvoid)
 #endif
 #ifdef CONFIG_PFAULT
         /* Enable pfault pseudo page faults on this cpu. */
-        pfault_init();
+        if (MACHINE_IS_VM)
+                pfault_init();
 #endif
         /* Mark this cpu as online */
         cpu_set(smp_processor_id(), cpu_online_map);
@@ -690,7 +691,8 @@ __cpu_disable(void)
 
 #ifdef CONFIG_PFAULT
         /* Disable pfault pseudo page faults on this cpu. */
-        pfault_fini();
+        if (MACHINE_IS_VM)
+                pfault_fini();
 #endif
 
         /* disable all external interrupts */
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index bc7b7be7acbe..6b8703ec2ae6 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -29,6 +29,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
+#include <linux/reboot.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -675,6 +676,19 @@ asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
         panic("Corrupt kernel stack, can't continue.");
 }
 
+#ifndef CONFIG_ARCH_S390X
+static int
+pagex_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+        if (MACHINE_IS_VM)
+                cpcmd("SET PAGEX OFF", NULL, 0, NULL);
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block pagex_reboot_notifier = {
+        .notifier_call = &pagex_reboot_event,
+};
+#endif
 
 /* init is done in lowcore.S and head.S */
 
@@ -735,6 +749,7 @@ void __init trap_init(void)
                                                     &ext_int_pfault);
 #endif
 #ifndef CONFIG_ARCH_S390X
+                register_reboot_notifier(&pagex_reboot_notifier);
                 cpcmd("SET PAGEX ON", NULL, 0, NULL);
 #endif
         }