[S390] cleanup psw related bits and pieces

Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS
to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function
enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros.
Change psw_kernel_bits / psw_user_bits to contain only the bits that
are always set in the respective mode.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

18 files changed, 105 insertions, 122 deletions

diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index cdb9b78f6c08..2e49748b27da 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -12,6 +12,7 @@
 #define PSW32_MASK_IO           0x02000000UL
 #define PSW32_MASK_EXT          0x01000000UL
 #define PSW32_MASK_KEY          0x00F00000UL
+#define PSW32_MASK_BASE         0x00080000UL    /* Always one */
 #define PSW32_MASK_MCHECK       0x00040000UL
 #define PSW32_MASK_WAIT         0x00020000UL
 #define PSW32_MASK_PSTATE       0x00010000UL
@@ -19,21 +20,19 @@
 #define PSW32_MASK_CC           0x00003000UL
 #define PSW32_MASK_PM           0x00000f00UL
 
-#define PSW32_ADDR_AMODE31      0x80000000UL
+#define PSW32_MASK_USER         0x00003F00UL
+
+#define PSW32_ADDR_AMODE        0x80000000UL
 #define PSW32_ADDR_INSN         0x7FFFFFFFUL
 
-#define PSW32_BASE_BITS         0x00080000UL
+#define PSW32_DEFAULT_KEY       (((u32) PAGE_DEFAULT_ACC) << 20)
 
 #define PSW32_ASC_PRIMARY       0x00000000UL
 #define PSW32_ASC_ACCREG        0x00004000UL
 #define PSW32_ASC_SECONDARY     0x00008000UL
 #define PSW32_ASC_HOME          0x0000C000UL
 
-#define PSW32_MASK_MERGE(CURRENT,NEW) \
-        (((CURRENT) & ~(PSW32_MASK_CC|PSW32_MASK_PM)) | \
-         ((NEW) & (PSW32_MASK_CC|PSW32_MASK_PM)))
-
-extern long psw32_user_bits;
+extern u32 psw32_user_bits;
 
 #define COMPAT_USER_HZ          100
 #define COMPAT_UTS_MACHINE      "s390\0\0\0\0"
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 306c93c1b184..20ffb12d4ae9 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -118,17 +118,17 @@ struct stack_frame {
 /*
  * Do necessary setup to start up a new thread.
  */
-#define start_thread(regs, new_psw, new_stackp) do {            \
-        regs->psw.mask  = psw_user_bits;                        \
-        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
-        regs->gprs[15]  = new_stackp;                           \
+#define start_thread(regs, new_psw, new_stackp) do {                    \
+        regs->psw.mask  = psw_user_bits | PSW_MASK_EA | PSW_MASK_BA;    \
+        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;                     \
+        regs->gprs[15]  = new_stackp;                                   \
 } while (0)
 
-#define start_thread31(regs, new_psw, new_stackp) do {          \
-        regs->psw.mask  = psw_user32_bits;                      \
-        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
-        regs->gprs[15]  = new_stackp;                           \
-        crst_table_downgrade(current->mm, 1UL << 31);           \
+#define start_thread31(regs, new_psw, new_stackp) do {                  \
+        regs->psw.mask  = psw_user_bits | PSW_MASK_BA;                  \
+        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;                     \
+        regs->gprs[15]  = new_stackp;                                   \
+        crst_table_downgrade(current->mm, 1UL << 31);                   \
 } while (0)
 
 /* Forward declaration, a strange C thing */
@@ -234,24 +234,14 @@ static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
 }
  
 /*
- * Function to stop a processor until an interruption occurred
- */
-static inline void enabled_wait(void)
-{
-        __load_psw_mask(PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
-                        PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY);
-}
-
-/*
  * Function to drop a processor into disabled wait state
  */
-
 static inline void ATTRIB_NORET disabled_wait(unsigned long code)
 {
         unsigned long ctl_buf;
         psw_t dw_psw;
 
-        dw_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
+        dw_psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
         dw_psw.addr = code;
         /* 
          * Store status and then load disabled wait psw,
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 2904cc66967a..6fc00d268143 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -230,6 +230,7 @@ typedef struct
 #define PSW_MASK_IO             0x02000000UL
 #define PSW_MASK_EXT            0x01000000UL
 #define PSW_MASK_KEY            0x00F00000UL
+#define PSW_MASK_BASE           0x00080000UL    /* always one */
 #define PSW_MASK_MCHECK         0x00040000UL
 #define PSW_MASK_WAIT           0x00020000UL
 #define PSW_MASK_PSTATE         0x00010000UL
@@ -239,10 +240,11 @@ typedef struct
 #define PSW_MASK_EA             0x00000000UL
 #define PSW_MASK_BA             0x00000000UL
 
+#define PSW_MASK_USER           0x00003F00UL
+
 #define PSW_ADDR_AMODE          0x80000000UL
 #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
@@ -256,6 +258,7 @@ typedef struct
 #define PSW_MASK_DAT            0x0400000000000000UL
 #define PSW_MASK_IO             0x0200000000000000UL
 #define PSW_MASK_EXT            0x0100000000000000UL
+#define PSW_MASK_BASE           0x0000000000000000UL
 #define PSW_MASK_KEY            0x00F0000000000000UL
 #define PSW_MASK_MCHECK         0x0004000000000000UL
 #define PSW_MASK_WAIT           0x0002000000000000UL
@@ -266,11 +269,11 @@ typedef struct
 #define PSW_MASK_EA             0x0000000100000000UL
 #define PSW_MASK_BA             0x0000000080000000UL
 
+#define PSW_MASK_USER           0x00003F0000000000UL
+
 #define PSW_ADDR_AMODE          0x0000000000000000UL
 #define PSW_ADDR_INSN           0xFFFFFFFFFFFFFFFFUL
 
-#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
@@ -283,18 +286,7 @@ typedef struct
 #ifdef __KERNEL__
 extern long psw_kernel_bits;
 extern long psw_user_bits;
-#ifdef CONFIG_64BIT
-extern long psw_user32_bits;
 #endif
-#endif
-
-/* This macro merges a NEW PSW mask specified by the user into
-   the currently active PSW mask CURRENT, modifying only those
-   bits in CURRENT that the user may be allowed to change: this
-   is the condition code and the program mask bits.  */
-#define PSW_MASK_MERGE(CURRENT,NEW) \
-        (((CURRENT) & ~(PSW_MASK_CC|PSW_MASK_PM)) | \
-         ((NEW) & (PSW_MASK_CC|PSW_MASK_PM)))
 
 /*
  * The s390_regs structure is used to define the elf_gregset_t.
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index afb849e4bf4b..d73cc6b60000 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -212,8 +212,10 @@ __set_psw_mask(unsigned long mask)
         __load_psw_mask(mask | (arch_local_save_flags() & ~(-1UL >> 8)));
 }
 
-#define local_mcck_enable()  __set_psw_mask(psw_kernel_bits)
-#define local_mcck_disable() __set_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK)
+#define local_mcck_enable() \
+        __set_psw_mask(psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK)
+#define local_mcck_disable() \
+        __set_psw_mask(psw_kernel_bits | PSW_MASK_DAT)
 
 #ifdef CONFIG_SMP
 
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 53acaa86dd94..24b218737b9b 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -60,12 +60,9 @@
 
 #include "compat_linux.h"
 
-long 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_DEFAULT_KEY);
-long psw32_user_bits    = (PSW32_BASE_BITS | PSW32_MASK_DAT | PSW32_ASC_HOME |
-                           PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
-                           PSW32_MASK_PSTATE);
+u32 psw32_user_bits = PSW32_MASK_DAT | PSW32_MASK_IO | PSW32_MASK_EXT |
+                      PSW32_DEFAULT_KEY | PSW32_MASK_BASE | PSW32_MASK_MCHECK |
+                      PSW32_MASK_PSTATE | PSW32_ASC_HOME;
  
 /* For this source file, we want overflow handling. */
 
diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 72a1c8d8d212..fd83b69207f5 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -300,9 +300,9 @@ static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
         _s390_regs_common32 regs32;
         int err, i;
 
-        regs32.psw.mask = PSW32_MASK_MERGE(psw32_user_bits,
-                                           (__u32)(regs->psw.mask >> 32));
-        regs32.psw.addr = PSW32_ADDR_AMODE31 | (__u32) regs->psw.addr;
+        regs32.psw.mask = psw32_user_bits |
+                ((__u32)(regs->psw.mask >> 32) & PSW32_MASK_USER);
+        regs32.psw.addr = PSW32_ADDR_AMODE | (__u32) regs->psw.addr;
         for (i = 0; i < NUM_GPRS; i++)
                 regs32.gprs[i] = (__u32) regs->gprs[i];
         save_access_regs(current->thread.acrs);
@@ -327,8 +327,8 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
         err = __copy_from_user(&regs32, &sregs->regs, sizeof(regs32));
         if (err)
                 return err;
-        regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
-                                        (__u64)regs32.psw.mask << 32);
+        regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+                (__u64)(regs32.psw.mask & PSW32_MASK_USER) << 32;
         regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
         for (i = 0; i < NUM_GPRS; i++)
                 regs->gprs[i] = (__u64) regs32.gprs[i];
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index f297456dba7a..37394b3413e2 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -252,7 +252,7 @@ static noinline __init void setup_lowcore_early(void)
 {
         psw_t psw;
 
-        psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
         S390_lowcore.external_new_psw = psw;
         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index ca0520c52547..296458360a32 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -2033,12 +2033,12 @@ void s390_reset_system(void (*func)(void *), void *data)
         __ctl_clear_bit(0,28);
 
         /* Set new machine check handler */
-        S390_lowcore.mcck_new_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
+        S390_lowcore.mcck_new_psw.mask = psw_kernel_bits | PSW_MASK_DAT;
         S390_lowcore.mcck_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) s390_base_mcck_handler;
 
         /* Set new program check handler */
-        S390_lowcore.program_new_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
+        S390_lowcore.program_new_psw.mask = psw_kernel_bits | PSW_MASK_DAT;
         S390_lowcore.program_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 13a0b528c70b..3cd0f25ab015 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -108,7 +108,7 @@ static void __do_machine_kdump(void *image)
 #ifdef CONFIG_CRASH_DUMP
         int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
 
-        __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
+        __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
         setup_regs();
         start_kdump(1);
 #endif
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 541a7509faeb..5e64a9a29ea4 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -117,7 +117,8 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
         struct pt_regs regs;
 
         memset(&regs, 0, sizeof(regs));
-        regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
+        regs.psw.mask = psw_kernel_bits |
+                PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
         regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
         regs.gprs[9] = (unsigned long) fn;
         regs.gprs[10] = (unsigned long) arg;
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 3519c99ae0c0..41e20763886e 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -169,8 +169,9 @@ static unsigned long __peek_user(struct task_struct *child, addr_t addr)
                  */
                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
                 if (addr == (addr_t) &dummy->regs.psw.mask)
-                        /* Remove per bit from user psw. */
-                        tmp &= ~PSW_MASK_PER;
+                        /* Return a clean psw mask. */
+                        tmp = psw_user_bits | (tmp & PSW_MASK_USER) |
+                                PSW_MASK_EA | PSW_MASK_BA;
 
         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
                 /*
@@ -285,17 +286,18 @@ static inline void __poke_user_per(struct task_struct *child,
 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 {
         struct user *dummy = NULL;
-        addr_t offset;
+        addr_t offset, tmp;
 
         if (addr < (addr_t) &dummy->regs.acrs) {
                 /*
                  * psw and gprs are stored on the stack
                  */
+                tmp = (data & ~PSW_MASK_USER) ^ psw_user_bits;
                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 #ifdef CONFIG_COMPAT
-                    data != PSW_MASK_MERGE(psw_user32_bits, data) &&
+                    tmp != PSW_MASK_BA &&
 #endif
-                    data != PSW_MASK_MERGE(psw_user_bits, data))
+                    tmp != (PSW_MASK_EA | PSW_MASK_BA))
                         /* Invalid psw mask. */
                         return -EINVAL;
 #ifndef CONFIG_64BIT
@@ -505,21 +507,20 @@ static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
         __u32 tmp;
 
         if (addr < (addr_t) &dummy32->regs.acrs) {
+                struct pt_regs *regs = task_pt_regs(child);
                 /*
                  * psw and gprs are stored on the stack
                  */
                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
                         /* Fake a 31 bit psw mask. */
-                        tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
-                        tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
+                        tmp = (__u32)(regs->psw.mask >> 32);
+                        tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
                         /* Fake a 31 bit psw address. */
-                        tmp = (__u32) task_pt_regs(child)->psw.addr |
-                                PSW32_ADDR_AMODE31;
+                        tmp = (__u32) regs->psw.addr | PSW32_ADDR_AMODE;
                 } else {
                         /* gpr 0-15 */
-                        tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
-                                         addr*2 + 4);
+                        tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
                 }
         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
                 /*
@@ -604,20 +605,20 @@ static int __poke_user_compat(struct task_struct *child,
         addr_t offset;
 
         if (addr < (addr_t) &dummy32->regs.acrs) {
+                struct pt_regs *regs = task_pt_regs(child);
                 /*
                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
                  */
                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
                         /* Build a 64 bit psw mask from 31 bit mask. */
-                        if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
+                        if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
                                 /* Invalid psw mask. */
                                 return -EINVAL;
-                        task_pt_regs(child)->psw.mask =
-                                PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
+                        regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+                                (__u64)(tmp & PSW32_MASK_USER) << 32;
                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
                         /* Build a 64 bit psw address from 31 bit address. */
-                        task_pt_regs(child)->psw.addr =
-                                (__u64) tmp & PSW32_ADDR_INSN;
+                        regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
                         /*
                          * The debugger changed the instruction address,
                          * reset system call restart, see signal.c:do_signal
@@ -625,8 +626,7 @@ static int __poke_user_compat(struct task_struct *child,
                         task_thread_info(child)->system_call = 0;
                 } else {
                         /* gpr 0-15 */
-                        *(__u32*)((addr_t) &task_pt_regs(child)->psw
-                                  + addr*2 + 4) = tmp;
+                        *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
                 }
         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
                 /*
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 6f8e3777a0c8..8ac6bfa2786c 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -62,11 +62,11 @@
 #include <asm/kvm_virtio.h>
 #include <asm/diag.h>
 
-long psw_kernel_bits    = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
-                           PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
-long 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_DEFAULT_KEY);
+long psw_kernel_bits    = PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_PRIMARY |
+                          PSW_MASK_EA | PSW_MASK_BA;
+long psw_user_bits      = PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT |
+                          PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK |
+                          PSW_MASK_PSTATE | PSW_ASC_HOME;
 
 /*
  * User copy operations.
@@ -278,22 +278,14 @@ early_param("mem", early_parse_mem);
 unsigned int user_mode = HOME_SPACE_MODE;
 EXPORT_SYMBOL_GPL(user_mode);
 
-static int set_amode_and_uaccess(unsigned long user_amode,
-                                 unsigned long user32_amode)
+static int set_amode_primary(void)
 {
-        psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
-                        PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
-                        PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
+        psw_kernel_bits = (psw_kernel_bits & ~PSW_MASK_ASC) | PSW_ASC_HOME;
+        psw_user_bits = (psw_user_bits & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY;
 #ifdef CONFIG_COMPAT
-        psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
-                          PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
-                          PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
-        psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
-                          PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
-                          PSW32_MASK_PSTATE;
+        psw32_user_bits =
+                (psw32_user_bits & ~PSW32_MASK_ASC) | PSW32_ASC_PRIMARY;
 #endif
-        psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
-                          PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
 
         if (MACHINE_HAS_MVCOS) {
                 memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
@@ -329,7 +321,7 @@ early_param("user_mode", early_parse_user_mode);
 static void setup_addressing_mode(void)
 {
         if (user_mode == PRIMARY_SPACE_MODE) {
-                if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
+                if (set_amode_primary())
                         pr_info("Address spaces switched, "
                                 "mvcos available\n");
                 else
@@ -348,24 +340,25 @@ setup_lowcore(void)
          */
         BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
         lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
-        lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        lc->restart_psw.mask = psw_kernel_bits;
         lc->restart_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
-        if (user_mode != HOME_SPACE_MODE)
-                lc->restart_psw.mask |= PSW_ASC_HOME;
-        lc->external_new_psw.mask = psw_kernel_bits;
+        lc->external_new_psw.mask = psw_kernel_bits |
+                PSW_MASK_DAT | PSW_MASK_MCHECK;
         lc->external_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
-        lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
+        lc->svc_new_psw.mask = psw_kernel_bits |
+                PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
         lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
-        lc->program_new_psw.mask = psw_kernel_bits;
+        lc->program_new_psw.mask = psw_kernel_bits |
+                PSW_MASK_DAT | PSW_MASK_MCHECK;
         lc->program_new_psw.addr =
-                PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
-        lc->mcck_new_psw.mask =
-                psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
+                PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
+        lc->mcck_new_psw.mask = psw_kernel_bits;
         lc->mcck_new_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
-        lc->io_new_psw.mask = psw_kernel_bits;
+        lc->io_new_psw.mask = psw_kernel_bits |
+                PSW_MASK_DAT | PSW_MASK_MCHECK;
         lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
         lc->clock_comparator = -1ULL;
         lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
@@ -554,7 +547,7 @@ static void __init setup_restart_psw(void)
          * Setup restart PSW for absolute zero lowcore. This is necesary
          * if PSW restart is done on an offline CPU that has lowcore zero
          */
-        psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        psw.mask = PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
         psw.addr = PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
         copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw));
 }
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 0e905cb7604a..c19755815e53 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -117,7 +117,8 @@ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
 
         /* Copy a 'clean' PSW mask to the user to avoid leaking
            information about whether PER is currently on.  */
-        user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
+        user_sregs.regs.psw.mask = psw_user_bits | PSW_MASK_EA | PSW_MASK_BA |
+                                   (regs->psw.mask & PSW_MASK_USER);
         user_sregs.regs.psw.addr = regs->psw.addr;
         memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
         memcpy(&user_sregs.regs.acrs, current->thread.acrs,
@@ -144,8 +145,8 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
         err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
         if (err)
                 return err;
-        regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
-                                        user_sregs.regs.psw.mask);
+        regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+                         (user_sregs.regs.psw.mask & PSW_MASK_USER);
         regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
         memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
         memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index e3f51dfa5cad..6c8a977af595 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -108,7 +108,7 @@ void smp_restart_with_online_cpu(void)
         for_each_online_cpu(cpu) {
                 if (stap() == __cpu_logical_map[cpu]) {
                         /* We are online: Enable DAT again and return */
-                        __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
+                        __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
                         return;
                 }
         }
@@ -130,14 +130,16 @@ void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
 
         if (smp_processor_id() == 0)
                 func(data);
-        __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
+        __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE |
+                        PSW_MASK_EA | PSW_MASK_BA);
         /* Disable lowcore protection */
         __ctl_clear_bit(0, 28);
         current_lc = lowcore_ptr[smp_processor_id()];
         lc = lowcore_ptr[0];
         if (!lc)
                 lc = current_lc;
-        lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        lc->restart_psw.mask =
+                PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
         lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
         if (!cpu_online(0))
                 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
@@ -159,7 +161,7 @@ void smp_send_stop(void)
         int cpu, rc;
 
         /* Disable all interrupts/machine checks */
-        __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
+        __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
         trace_hardirqs_off();
 
         /* stop all processors */
@@ -501,7 +503,8 @@ int __cpuinit start_secondary(void *cpuvoid)
         set_cpu_online(smp_processor_id(), true);
         ipi_call_unlock();
         __ctl_clear_bit(0, 28); /* Disable lowcore protection */
-        S390_lowcore.restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        S390_lowcore.restart_psw.mask =
+                PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
         S390_lowcore.restart_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
         __ctl_set_bit(0, 28); /* Enable lowcore protection */
@@ -549,7 +552,8 @@ static int __cpuinit smp_alloc_lowcore(int cpu)
         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
         lowcore->async_stack = async_stack + ASYNC_SIZE;
         lowcore->panic_stack = panic_stack + PAGE_SIZE;
-        lowcore->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        lowcore->restart_psw.mask =
+                PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
         lowcore->restart_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
         if (user_mode != HOME_SPACE_MODE)
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index ffabcd9d3363..79eee3f27afb 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -200,7 +200,7 @@ void show_registers(struct pt_regs *regs)
                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 #ifdef CONFIG_64BIT
-        printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
+        printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
 #endif
         printk("\n%s GPRS: " FOURLONG, mode,
                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 2d6228f60cd6..4f3de980b0e5 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -170,7 +170,8 @@ void __kprobes vtime_stop_cpu(void)
         psw_t psw;
 
         /* Wait for external, I/O or machine check interrupt. */
-        psw.mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_IO | PSW_MASK_EXT;
+        psw.mask = psw_kernel_bits | PSW_MASK_WAIT |
+                PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 
         idle->nohz_delay = 0;
 
@@ -183,7 +184,8 @@ void __kprobes vtime_stop_cpu(void)
                  *      set_cpu_timer(VTIMER_MAX_SLICE);
                  *      idle->idle_enter = get_clock();
                  *      __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
-                 *                         PSW_MASK_IO | PSW_MASK_EXT);
+                 *                         PSW_MASK_DAT | PSW_MASK_IO |
+                 *                         PSW_MASK_EXT | PSW_MASK_MCHECK);
                  * The difference is that the inline assembly makes sure that
                  * the last three instruction are stpt, stck and lpsw in that
                  * order. This is done to increase the precision.
@@ -216,7 +218,8 @@ void __kprobes vtime_stop_cpu(void)
                  *      vq->idle = get_cpu_timer();
                  *      idle->idle_enter = get_clock();
                  *      __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
-                 *                         PSW_MASK_IO | PSW_MASK_EXT);
+                 *                         PSW_MASK_DAT | PSW_MASK_IO |
+                 *                         PSW_MASK_EXT | PSW_MASK_MCHECK);
                  * The difference is that the inline assembly makes sure that
                  * the last three instruction are stpt, stck and lpsw in that
                  * order. This is done to increase the precision.
diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
index a65229d91c92..db92f044024c 100644
--- a/arch/s390/lib/delay.c
+++ b/arch/s390/lib/delay.c
@@ -32,7 +32,8 @@ static void __udelay_disabled(unsigned long long usecs)
         u64 clock_saved;
         u64 end;
 
-        mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_EXT;
+        mask = psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_WAIT |
+                PSW_MASK_EXT | PSW_MASK_MCHECK;
         end = get_clock() + (usecs << 12);
         clock_saved = local_tick_disable();
         __ctl_store(cr0_saved, 0, 0);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index a90fd91a9c72..de3af0c053c0 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -454,7 +454,7 @@ int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
         struct pt_regs regs;
         int access, fault;
 
-        regs.psw.mask = psw_kernel_bits;
+        regs.psw.mask = psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK;
         if (!irqs_disabled())
                 regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT;
         regs.psw.addr = (unsigned long) __builtin_return_address(0);