[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, 20 insertions, 32 deletions

diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index fb46e9090b50..8bd14de69e35 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -207,6 +207,18 @@ unsigned long get_wchan(struct task_struct *p);
 #endif /* __s390x__ */
 
 /*
+ * Set PSW to specified value.
+ */
+static inline void __load_psw(psw_t psw)
+{
+#ifndef __s390x__
+        asm volatile ("lpsw  0(%0)" : : "a" (&psw), "m" (psw) : "cc" );
+#else
+        asm volatile ("lpswe 0(%0)" : : "a" (&psw), "m" (psw) : "cc" );
+#endif
+}
+
+/*
  * Set PSW mask to specified value, while leaving the
  * PSW addr pointing to the next instruction.
  */
@@ -214,8 +226,8 @@ unsigned long get_wchan(struct task_struct *p);
 static inline void __load_psw_mask (unsigned long mask)
 {
         unsigned long addr;
-
         psw_t psw;
+
         psw.mask = mask;
 
 #ifndef __s390x__
@@ -241,30 +253,8 @@ static inline void __load_psw_mask (unsigned long mask)
  */
 static inline void enabled_wait(void)
 {
-        unsigned long reg;
-        psw_t wait_psw;
-
-        wait_psw.mask = PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
-                PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY;
-#ifndef __s390x__
-        asm volatile (
-                "    basr %0,0\n"
-                "0:  la   %0,1f-0b(%0)\n"
-                "    st   %0,4(%1)\n"
-                "    oi   4(%1),0x80\n"
-                "    lpsw 0(%1)\n"
-                "1:"
-                : "=&a" (reg) : "a" (&wait_psw), "m" (wait_psw)
-                : "memory", "cc" );
-#else /* __s390x__ */
-        asm volatile (
-                "    larl  %0,0f\n"
-                "    stg   %0,8(%1)\n"
-                "    lpswe 0(%1)\n"
-                "0:"
-                : "=&a" (reg) : "a" (&wait_psw), "m" (wait_psw)
-                : "memory", "cc" );
-#endif /* __s390x__ */
+        __load_psw_mask(PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
+                        PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY);
 }
 
 /*
@@ -273,13 +263,11 @@ static inline void enabled_wait(void)
 
 static inline void disabled_wait(unsigned long code)
 {
-        char psw_buffer[2*sizeof(psw_t)];
         unsigned long ctl_buf;
-        psw_t *dw_psw = (psw_t *)(((unsigned long) &psw_buffer+sizeof(psw_t)-1)
-                                  & -sizeof(psw_t));
+        psw_t dw_psw;
 
-        dw_psw->mask = PSW_BASE_BITS | PSW_MASK_WAIT;
-        dw_psw->addr = code;
+        dw_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
+        dw_psw.addr = code;
         /* 
          * Store status and then load disabled wait psw,
          * the processor is dead afterwards
@@ -301,7 +289,7 @@ static inline void disabled_wait(unsigned long code)
                       "    oi    0x1c0,0x10\n" /* fake protection bit */
                       "    lpsw 0(%1)"
                       : "=m" (ctl_buf)
-                      : "a" (dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc" );
+                      : "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc" );
 #else /* __s390x__ */
         asm volatile ("    stctg 0,0,0(%2)\n"
                       "    ni    4(%2),0xef\n" /* switch off protection */
@@ -333,7 +321,7 @@ static inline void disabled_wait(unsigned long code)
                       "    oi    0x384(1),0x10\n" /* fake protection bit */
                       "    lpswe 0(%1)"
                       : "=m" (ctl_buf)
-                      : "a" (dw_psw), "a" (&ctl_buf),
+                      : "a" (&dw_psw), "a" (&ctl_buf),
                         "m" (dw_psw) : "cc", "0", "1");
 #endif /* __s390x__ */
 }