[PATCH] s390: default storage key

Provide an easy way to define a non-zero storage key at compile time.  This is
useful for debugging purposes.

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>

3 files changed, 16 insertions, 4 deletions

diff --git a/include/asm-s390/page.h b/include/asm-s390/page.h
index 614e2a93c703..2be287b9df88 100644
--- a/include/asm-s390/page.h
+++ b/include/asm-s390/page.h
@@ -16,6 +16,8 @@
 #define PAGE_SHIFT      12
 #define PAGE_SIZE       (1UL << PAGE_SHIFT)
 #define PAGE_MASK       (~(PAGE_SIZE-1))
+#define PAGE_DEFAULT_ACC        0
+#define PAGE_DEFAULT_KEY        (PAGE_DEFAULT_ACC << 4)
 
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 88c272ca48bf..fb46e9090b50 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -245,7 +245,7 @@ static inline void enabled_wait(void)
         psw_t wait_psw;
 
         wait_psw.mask = PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
-                PSW_MASK_MCHECK | PSW_MASK_WAIT;
+                PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY;
 #ifndef __s390x__
         asm volatile (
                 "    basr %0,0\n"
diff --git a/include/asm-s390/ptrace.h b/include/asm-s390/ptrace.h
index 1dc80666e97e..4eff8f2e3bf1 100644
--- a/include/asm-s390/ptrace.h
+++ b/include/asm-s390/ptrace.h
@@ -185,6 +185,7 @@
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <asm/setup.h>
+#include <asm/page.h>
 
 typedef union
 {
@@ -235,6 +236,7 @@ typedef struct
 #define PSW_ADDR_INSN           0x7FFFFFFFUL
 
 #define PSW_BASE_BITS           0x00080000UL
+#define PSW_DEFAULT_KEY         (((unsigned long) PAGE_DEFAULT_ACC) << 20)
 
 #define PSW_ASC_PRIMARY         0x00000000UL
 #define PSW_ASC_ACCREG          0x00004000UL
@@ -260,6 +262,7 @@ typedef struct
 
 #define PSW_BASE_BITS           0x0000000180000000UL
 #define PSW_BASE32_BITS         0x0000000080000000UL
+#define PSW_DEFAULT_KEY         (((unsigned long) PAGE_DEFAULT_ACC) << 52)
 
 #define PSW_ASC_PRIMARY         0x0000000000000000UL
 #define PSW_ASC_ACCREG          0x0000400000000000UL
@@ -268,14 +271,15 @@ typedef struct
 
 #define PSW_USER32_BITS (PSW_BASE32_BITS | PSW_MASK_DAT | PSW_ASC_HOME | \
                          PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK | \
-                         PSW_MASK_PSTATE)
+                         PSW_MASK_PSTATE | PSW_DEFAULT_KEY)
 
 #endif /* __s390x__ */
 
-#define PSW_KERNEL_BITS (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY)
+#define PSW_KERNEL_BITS (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY | \
+                         PSW_DEFAULT_KEY)
 #define PSW_USER_BITS   (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME | \
                          PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK | \
-                         PSW_MASK_PSTATE)
+                         PSW_MASK_PSTATE | PSW_DEFAULT_KEY)
 
 /* This macro merges a NEW PSW mask specified by the user into
    the currently active PSW mask CURRENT, modifying only those
@@ -470,6 +474,12 @@ struct user_regs_struct
 extern void show_regs(struct pt_regs * regs);
 #endif
 
+static inline void
+psw_set_key(unsigned int key)
+{
+        asm volatile ( "spka 0(%0)" : : "d" (key) );
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _S390_PTRACE_H */