[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>

arch/s390/include/asm/compat.h

@@ -12,28 +12,27 @@
 #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
 #define PSW32_MASK_ASC		0x0000C000UL
 #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"

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 */
@@ -233,25 +233,15 @@ static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
 #endif
 }
 
-/*
- * 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,

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.

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
 

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. */
 

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];

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;

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;
 

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

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;

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)) {
 		/*
@@ -604,29 +605,28 @@ 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
 			 */
 			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)) {
 		/*