[PATCH] s390: improved machine check handling

Improved machine check handling.  Kernel is now able to receive machine checks
while in kernel mode (system call, interrupt and program check handling).
Also register validation is now performed.

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>

1 files changed, 10 insertions, 3 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index df83215beac3..eb7be0ad7175 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -414,7 +414,8 @@ setup_lowcore(void)
         lc->program_new_psw.mask = PSW_KERNEL_BITS;
         lc->program_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
-        lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
+        lc->mcck_new_psw.mask =
+                PSW_KERNEL_BITS & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
         lc->mcck_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
         lc->io_new_psw.mask = PSW_KERNEL_BITS;
@@ -424,12 +425,18 @@ setup_lowcore(void)
         lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
         lc->async_stack = (unsigned long)
                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
-#ifdef CONFIG_CHECK_STACK
         lc->panic_stack = (unsigned long)
                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
-#endif
         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
         lc->thread_info = (unsigned long) &init_thread_union;
+#ifndef CONFIG_ARCH_S390X
+        if (MACHINE_HAS_IEEE) {
+                lc->extended_save_area_addr = (__u32)
+                        __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
+                /* enable extended save area */
+                ctl_set_bit(14, 29);
+        }
+#endif
 #ifdef CONFIG_ARCH_S390X
         if (MACHINE_HAS_DIAG44)
                 lc->diag44_opcode = 0x83000044;