s390/uaccess: always run the kernel in home space

Simplify the uaccess code by removing the user_mode=home option.
The kernel will now always run in the home space mode.

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

21 files changed, 51 insertions, 459 deletions

diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index 9f973d8..5d1f950 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -40,14 +40,8 @@ static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
 	pgd_t *pgd = mm->pgd;
 
 	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
-	if (s390_user_mode != HOME_SPACE_MODE) {
-		/* Load primary space page table origin. */
-		asm volatile(LCTL_OPCODE" 1,1,%0\n"
-			     : : "m" (S390_lowcore.user_asce) );
-	} else
-		/* Load home space page table origin. */
-		asm volatile(LCTL_OPCODE" 13,13,%0"
-			     : : "m" (S390_lowcore.user_asce) );
+	/* Load primary space page table origin. */
+	asm volatile(LCTL_OPCODE" 1,1,%0\n" : : "m" (S390_lowcore.user_asce));
 	set_fs(current->thread.mm_segment);
 }
 
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 50256f0..3caaf65 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -134,14 +134,14 @@ 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 | PSW_MASK_EA | PSW_MASK_BA;	\
+	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;					\
 	execve_tail();							\
 } while (0)
 
 #define start_thread31(regs, new_psw, new_stackp) do {			\
-	regs->psw.mask	= psw_user_bits | PSW_MASK_BA;			\
+	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
 	regs->psw.addr	= new_psw | PSW_ADDR_AMODE;			\
 	regs->gprs[15]	= new_stackp;					\
 	__tlb_flush_mm(current->mm);					\
@@ -343,9 +343,9 @@ __set_psw_mask(unsigned long mask)
 }
 
 #define local_mcck_enable() \
-	__set_psw_mask(psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK)
+	__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)
+	__set_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT)
 
 /*
  * Basic Machine Check/Program Check Handler.
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 52b5653..9c82ceb 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -10,8 +10,11 @@
 
 #ifndef __ASSEMBLY__
 
-extern long psw_kernel_bits;
-extern long psw_user_bits;
+#define PSW_KERNEL_BITS	(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_HOME | \
+			 PSW_MASK_EA | PSW_MASK_BA)
+#define 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_PRIMARY)
 
 /*
  * The pt_regs struct defines the way the registers are stored on
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index 59880dba..df802ee 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -48,13 +48,6 @@ void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize);
 void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
 		     unsigned long size);
 
-#define PRIMARY_SPACE_MODE	0
-#define ACCESS_REGISTER_MODE	1
-#define SECONDARY_SPACE_MODE	2
-#define HOME_SPACE_MODE		3
-
-extern unsigned int s390_user_mode;
-
 /*
  * Machine features detected in head.S
  */
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 9c33ed4..79330af 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -94,9 +94,7 @@ static inline unsigned long extable_fixup(const struct exception_table_entry *x)
 
 struct uaccess_ops {
 	size_t (*copy_from_user)(size_t, const void __user *, void *);
-	size_t (*copy_from_user_small)(size_t, const void __user *, void *);
 	size_t (*copy_to_user)(size_t, void __user *, const void *);
-	size_t (*copy_to_user_small)(size_t, void __user *, const void *);
 	size_t (*copy_in_user)(size_t, void __user *, const void __user *);
 	size_t (*clear_user)(size_t, void __user *);
 	size_t (*strnlen_user)(size_t, const char __user *);
@@ -106,22 +104,20 @@ struct uaccess_ops {
 };
 
 extern struct uaccess_ops uaccess;
-extern struct uaccess_ops uaccess_std;
 extern struct uaccess_ops uaccess_mvcos;
-extern struct uaccess_ops uaccess_mvcos_switch;
 extern struct uaccess_ops uaccess_pt;
 
 extern int __handle_fault(unsigned long, unsigned long, int);
 
 static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
 {
-	size = uaccess.copy_to_user_small(size, ptr, x);
+	size = uaccess.copy_to_user(size, ptr, x);
 	return size ? -EFAULT : size;
 }
 
 static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
 {
-	size = uaccess.copy_from_user_small(size, ptr, x);
+	size = uaccess.copy_from_user(size, ptr, x);
 	return size ? -EFAULT : size;
 }
 
@@ -226,10 +222,7 @@ extern int __get_user_bad(void) __attribute__((noreturn));
 static inline unsigned long __must_check
 __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	if (__builtin_constant_p(n) && (n <= 256))
-		return uaccess.copy_to_user_small(n, to, from);
-	else
-		return uaccess.copy_to_user(n, to, from);
+	return uaccess.copy_to_user(n, to, from);
 }
 
 #define __copy_to_user_inatomic __copy_to_user
@@ -275,10 +268,7 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
 static inline unsigned long __must_check
 __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (__builtin_constant_p(n) && (n <= 256))
-		return uaccess.copy_from_user_small(n, from, to);
-	else
-		return uaccess.copy_from_user(n, from, to);
+	return uaccess.copy_from_user(n, from, to);
 }
 
 extern void copy_from_user_overflow(void)
diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index adaa9e9..ee82007 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -188,8 +188,8 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
 		(__u64)(regs32.psw.mask & PSW32_MASK_USER) << 32 |
 		(__u64)(regs32.psw.addr & PSW32_ADDR_AMODE);
 	/* Check for invalid user address space control. */
-	if ((regs->psw.mask & PSW_MASK_ASC) >= (psw_kernel_bits & PSW_MASK_ASC))
-		regs->psw.mask = (psw_user_bits & PSW_MASK_ASC) |
+	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
+		regs->psw.mask = PSW_ASC_PRIMARY |
 			(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
 	for (i = 0; i < NUM_GPRS; i++)
@@ -348,7 +348,7 @@ static int setup_frame32(int sig, struct k_sigaction *ka,
 	regs->gprs[15] = (__force __u64) frame;
 	/* Force 31 bit amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_BA |
-		(psw_user_bits & PSW_MASK_ASC) |
+		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__force __u64) ka->sa.sa_handler;
 
@@ -415,7 +415,7 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->gprs[15] = (__force __u64) frame;
 	/* Force 31 bit amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_BA |
-		(psw_user_bits & PSW_MASK_ASC) |
+		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__u64 __force) ka->sa.sa_handler;
 
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index feb719d..633ca75 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -2051,12 +2051,12 @@ 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_DAT;
+	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_DAT;
+	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/process.c b/arch/s390/kernel/process.c
index c5dbb33..e1cdd31 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -139,7 +139,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
 		memset(&frame->childregs, 0, sizeof(struct pt_regs));
-		frame->childregs.psw.mask = psw_kernel_bits | PSW_MASK_DAT |
+		frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
 				PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 		frame->childregs.psw.addr = PSW_ADDR_AMODE |
 				(unsigned long) kernel_thread_starter;
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 9556905..e6abd5b 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -200,7 +200,7 @@ 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)
 			/* Return a clean psw mask. */
-			tmp = psw_user_bits | (tmp & PSW_MASK_USER);
+			tmp = PSW_USER_BITS | (tmp & PSW_MASK_USER);
 
 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 		/*
@@ -322,7 +322,7 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 		 * psw and gprs are stored on the stack
 		 */
 		if (addr == (addr_t) &dummy->regs.psw.mask &&
-		    ((data & ~PSW_MASK_USER) != psw_user_bits ||
+		    ((data & ~PSW_MASK_USER) != PSW_USER_BITS ||
 		     ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))
 			/* Invalid psw mask. */
 			return -EINVAL;
diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
index e1c9d1c..d817cce 100644
--- a/arch/s390/kernel/runtime_instr.c
+++ b/arch/s390/kernel/runtime_instr.c
@@ -40,8 +40,6 @@ static void disable_runtime_instr(void)
 static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
 {
 	cb->buf_limit = 0xfff;
-	if (s390_user_mode == HOME_SPACE_MODE)
-		cb->home_space = 1;
 	cb->int_requested = 1;
 	cb->pstate = 1;
 	cb->pstate_set_buf = 1;
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index aeed8a6..ffe1c53 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -64,12 +64,6 @@
 #include <asm/sclp.h>
 #include "entry.h"
 
-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.
  */
@@ -300,43 +294,14 @@ static int __init parse_vmalloc(char *arg)
 }
 early_param("vmalloc", parse_vmalloc);
 
-unsigned int s390_user_mode = PRIMARY_SPACE_MODE;
-EXPORT_SYMBOL_GPL(s390_user_mode);
-
-static void __init set_user_mode_primary(void)
-{
-	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
-	psw32_user_bits =
-		(psw32_user_bits & ~PSW32_MASK_ASC) | PSW32_ASC_PRIMARY;
-#endif
-	uaccess = MACHINE_HAS_MVCOS ? uaccess_mvcos_switch : uaccess_pt;
-}
-
 static int __init early_parse_user_mode(char *p)
 {
-	if (p && strcmp(p, "primary") == 0)
-		s390_user_mode = PRIMARY_SPACE_MODE;
-	else if (!p || strcmp(p, "home") == 0)
-		s390_user_mode = HOME_SPACE_MODE;
-	else
-		return 1;
-	return 0;
+	if (!p || strcmp(p, "primary") == 0)
+		return 0;
+	return 1;
 }
 early_param("user_mode", early_parse_user_mode);
 
-static void __init setup_addressing_mode(void)
-{
-	if (s390_user_mode != PRIMARY_SPACE_MODE)
-		return;
-	set_user_mode_primary();
-	if (MACHINE_HAS_MVCOS)
-		pr_info("Address spaces switched, mvcos available\n");
-	else
-		pr_info("Address spaces switched, mvcos not available\n");
-}
-
 void *restart_stack __attribute__((__section__(".data")));
 
 static void __init setup_lowcore(void)
@@ -348,24 +313,24 @@ static void __init 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_kernel_bits;
+	lc->restart_psw.mask = PSW_KERNEL_BITS;
 	lc->restart_psw.addr =
 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
-	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 |
+	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;
+	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;
@@ -1043,10 +1008,7 @@ void __init setup_arch(char **cmdline_p)
 	init_mm.end_data = (unsigned long) &_edata;
 	init_mm.brk = (unsigned long) &_end;
 
-	if (MACHINE_HAS_MVCOS)
-		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
-	else
-		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
+	uaccess = MACHINE_HAS_MVCOS ? uaccess_mvcos : uaccess_pt;
 
 	parse_early_param();
 	detect_memory_layout(memory_chunk, memory_end);
@@ -1054,7 +1016,6 @@ void __init setup_arch(char **cmdline_p)
 	setup_ipl();
 	reserve_oldmem();
 	setup_memory_end();
-	setup_addressing_mode();
 	reserve_crashkernel();
 	setup_memory();
 	setup_resources();
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index c45becf..b4fa7c0 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -57,7 +57,7 @@ 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_user_bits |
+	user_sregs.regs.psw.mask = PSW_USER_BITS |
 		(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));
@@ -85,12 +85,12 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
 	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
 	if (err)
 		return err;
-	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
+	/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
 	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 		(user_sregs.regs.psw.mask & PSW_MASK_USER);
 	/* Check for invalid user address space control. */
-	if ((regs->psw.mask & PSW_MASK_ASC) >= (psw_kernel_bits & PSW_MASK_ASC))
-		regs->psw.mask = (psw_user_bits & PSW_MASK_ASC) |
+	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
+		regs->psw.mask = PSW_ASC_PRIMARY |
 			(regs->psw.mask & ~PSW_MASK_ASC);
 	/* Check for invalid amode */
 	if (regs->psw.mask & PSW_MASK_EA)
@@ -224,7 +224,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 	regs->gprs[15] = (unsigned long) frame;
 	/* Force default amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
-		(psw_user_bits & PSW_MASK_ASC) |
+		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
@@ -295,7 +295,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->gprs[15] = (unsigned long) frame;
 	/* Force default amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
-		(psw_user_bits & PSW_MASK_ASC) |
+		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 1a4313a..cca6cf6 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -283,7 +283,7 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
 	struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
 	unsigned long source_cpu = stap();
 
-	__load_psw_mask(psw_kernel_bits);
+	__load_psw_mask(PSW_KERNEL_BITS);
 	if (pcpu->address == source_cpu)
 		func(data);	/* should not return */
 	/* Stop target cpu (if func returns this stops the current cpu). */
@@ -395,7 +395,7 @@ void smp_send_stop(void)
 	int cpu;
 
 	/* Disable all interrupts/machine checks */
-	__load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
+	__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 	trace_hardirqs_off();
 
 	debug_set_critical();
@@ -693,7 +693,7 @@ static void smp_start_secondary(void *cpuvoid)
 	S390_lowcore.restart_source = -1UL;
 	restore_access_regs(S390_lowcore.access_regs_save_area);
 	__ctl_load(S390_lowcore.cregs_save_area, 0, 15);
-	__load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
+	__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 	cpu_init();
 	preempt_disable();
 	init_cpu_timer();
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 05d75c4..a84476f 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -84,8 +84,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
  */
 static void vdso_init_data(struct vdso_data *vd)
 {
-	vd->ectg_available =
-		s390_user_mode != HOME_SPACE_MODE && test_facility(31);
+	vd->ectg_available = test_facility(31);
 }
 
 #ifdef CONFIG_64BIT
@@ -102,7 +101,7 @@ int vdso_alloc_per_cpu(struct _lowcore *lowcore)
 
 	lowcore->vdso_per_cpu_data = __LC_PASTE;
 
-	if (s390_user_mode == HOME_SPACE_MODE || !vdso_enabled)
+	if (!vdso_enabled)
 		return 0;
 
 	segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER);
@@ -147,7 +146,7 @@ void vdso_free_per_cpu(struct _lowcore *lowcore)
 	unsigned long segment_table, page_table, page_frame;
 	u32 *psal, *aste;
 
-	if (s390_user_mode == HOME_SPACE_MODE || !vdso_enabled)
+	if (!vdso_enabled)
 		return;
 
 	psal = (u32 *)(addr_t) lowcore->paste[4];
@@ -165,7 +164,7 @@ static void vdso_init_cr5(void)
 {
 	unsigned long cr5;
 
-	if (s390_user_mode == HOME_SPACE_MODE || !vdso_enabled)
+	if (!vdso_enabled)
 		return;
 	cr5 = offsetof(struct _lowcore, paste);
 	__ctl_load(cr5, 5, 5);
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index abcfab5..e312c48 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -161,7 +161,7 @@ void __kprobes vtime_stop_cpu(void)
 	trace_hardirqs_on();
 
 	/* Wait for external, I/O or machine check interrupt. */
-	psw_mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_DAT |
+	psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT |
 		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 	idle->nohz_delay = 0;
 
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index e506c5f..b068729 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -2,7 +2,7 @@
 # Makefile for s390-specific library files..
 #
 
-lib-y += delay.o string.o uaccess_std.o uaccess_pt.o find.o
+lib-y += delay.o string.o uaccess_pt.o find.o
 obj-$(CONFIG_32BIT) += div64.o qrnnd.o ucmpdi2.o mem32.o
 obj-$(CONFIG_64BIT) += mem64.o
 lib-$(CONFIG_64BIT) += uaccess_mvcos.o
diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
index 1829742..4b7993b 100644
--- a/arch/s390/lib/uaccess_mvcos.c
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -65,13 +65,6 @@ static size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
 	return size;
 }
 
-static size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
-{
-	if (size <= 256)
-		return copy_from_user_std(size, ptr, x);
-	return copy_from_user_mvcos(size, ptr, x);
-}
-
 static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
 {
 	register unsigned long reg0 asm("0") = 0x810000UL;
@@ -101,14 +94,6 @@ static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
 	return size;
 }
 
-static size_t copy_to_user_mvcos_check(size_t size, void __user *ptr,
-				       const void *x)
-{
-	if (size <= 256)
-		return copy_to_user_std(size, ptr, x);
-	return copy_to_user_mvcos(size, ptr, x);
-}
-
 static size_t copy_in_user_mvcos(size_t size, void __user *to,
 				 const void __user *from)
 {
@@ -201,23 +186,8 @@ static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
 }
 
 struct uaccess_ops uaccess_mvcos = {
-	.copy_from_user = copy_from_user_mvcos_check,
-	.copy_from_user_small = copy_from_user_std,
-	.copy_to_user = copy_to_user_mvcos_check,
-	.copy_to_user_small = copy_to_user_std,
-	.copy_in_user = copy_in_user_mvcos,
-	.clear_user = clear_user_mvcos,
-	.strnlen_user = strnlen_user_std,
-	.strncpy_from_user = strncpy_from_user_std,
-	.futex_atomic_op = futex_atomic_op_std,
-	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
-};
-
-struct uaccess_ops uaccess_mvcos_switch = {
 	.copy_from_user = copy_from_user_mvcos,
-	.copy_from_user_small = copy_from_user_mvcos,
 	.copy_to_user = copy_to_user_mvcos,
-	.copy_to_user_small = copy_to_user_mvcos,
 	.copy_in_user = copy_in_user_mvcos,
 	.clear_user = clear_user_mvcos,
 	.strnlen_user = strnlen_user_mvcos,
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index 1694d73..97e03ca 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -461,9 +461,7 @@ int futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
 
 struct uaccess_ops uaccess_pt = {
 	.copy_from_user		= copy_from_user_pt,
-	.copy_from_user_small	= copy_from_user_pt,
 	.copy_to_user		= copy_to_user_pt,
-	.copy_to_user_small	= copy_to_user_pt,
 	.copy_in_user		= copy_in_user_pt,
 	.clear_user		= clear_user_pt,
 	.strnlen_user		= strnlen_user_pt,
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
deleted file mode 100644
index 4a75d47..0000000
--- a/arch/s390/lib/uaccess_std.c
+++ /dev/null
@@ -1,305 +0,0 @@
-/*
- *  Standard user space access functions based on mvcp/mvcs and doing
- *  interesting things in the secondary space mode.
- *
- *    Copyright IBM Corp. 2006
- *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
- *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
- */
-
-#include <linux/errno.h>
-#include <linux/mm.h>
-#include <linux/uaccess.h>
-#include <asm/futex.h>
-#include "uaccess.h"
-
-#ifndef CONFIG_64BIT
-#define AHI	"ahi"
-#define ALR	"alr"
-#define CLR	"clr"
-#define LHI	"lhi"
-#define SLR	"slr"
-#else
-#define AHI	"aghi"
-#define ALR	"algr"
-#define CLR	"clgr"
-#define LHI	"lghi"
-#define SLR	"slgr"
-#endif
-
-size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
-{
-	unsigned long tmp1, tmp2;
-
-	tmp1 = -256UL;
-	asm volatile(
-		"0: mvcp  0(%0,%2),0(%1),%3\n"
-		"10:jz    8f\n"
-		"1:"ALR"  %0,%3\n"
-		"   la    %1,256(%1)\n"
-		"   la    %2,256(%2)\n"
-		"2: mvcp  0(%0,%2),0(%1),%3\n"
-		"11:jnz   1b\n"
-		"   j     8f\n"
-		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
-		"  "LHI"  %3,-4096\n"
-		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
-		"  "SLR"  %4,%1\n"
-		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   5f\n"
-		"4: mvcp  0(%4,%2),0(%1),%3\n"
-		"12:"SLR"  %0,%4\n"
-		"  "ALR"  %2,%4\n"
-		"5:"LHI"  %4,-1\n"
-		"  "ALR"  %4,%0\n"	/* copy remaining size, subtract 1 */
-		"   bras  %3,7f\n"	/* memset loop */
-		"   xc    0(1,%2),0(%2)\n"
-		"6: xc    0(256,%2),0(%2)\n"
-		"   la    %2,256(%2)\n"
-		"7:"AHI"  %4,-256\n"
-		"   jnm   6b\n"
-		"   ex    %4,0(%3)\n"
-		"   j     9f\n"
-		"8:"SLR"  %0,%0\n"
-		"9: \n"
-		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
-		EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
-	return size;
-}
-
-static size_t copy_from_user_std_check(size_t size, const void __user *ptr,
-				       void *x)
-{
-	if (size <= 1024)
-		return copy_from_user_std(size, ptr, x);
-	return copy_from_user_pt(size, ptr, x);
-}
-
-size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
-{
-	unsigned long tmp1, tmp2;
-
-	tmp1 = -256UL;
-	asm volatile(
-		"0: mvcs  0(%0,%1),0(%2),%3\n"
-		"7: jz    5f\n"
-		"1:"ALR"  %0,%3\n"
-		"   la    %1,256(%1)\n"
-		"   la    %2,256(%2)\n"
-		"2: mvcs  0(%0,%1),0(%2),%3\n"
-		"8: jnz   1b\n"
-		"   j     5f\n"
-		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
-		"  "LHI"  %3,-4096\n"
-		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
-		"  "SLR"  %4,%1\n"
-		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   6f\n"
-		"4: mvcs  0(%4,%1),0(%2),%3\n"
-		"9:"SLR"  %0,%4\n"
-		"   j     6f\n"
-		"5:"SLR"  %0,%0\n"
-		"6: \n"
-		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
-		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
-	return size;
-}
-
-static size_t copy_to_user_std_check(size_t size, void __user *ptr,
-				     const void *x)
-{
-	if (size <= 1024)
-		return copy_to_user_std(size, ptr, x);
-	return copy_to_user_pt(size, ptr, x);
-}
-
-static size_t copy_in_user_std(size_t size, void __user *to,
-			       const void __user *from)
-{
-	unsigned long tmp1;
-
-	asm volatile(
-		"   sacf  256\n"
-		"  "AHI"  %0,-1\n"
-		"   jo    5f\n"
-		"   bras  %3,3f\n"
-		"0:"AHI"  %0,257\n"
-		"1: mvc   0(1,%1),0(%2)\n"
-		"   la    %1,1(%1)\n"
-		"   la    %2,1(%2)\n"
-		"  "AHI"  %0,-1\n"
-		"   jnz   1b\n"
-		"   j     5f\n"
-		"2: mvc   0(256,%1),0(%2)\n"
-		"   la    %1,256(%1)\n"
-		"   la    %2,256(%2)\n"
-		"3:"AHI"  %0,-256\n"
-		"   jnm   2b\n"
-		"4: ex    %0,1b-0b(%3)\n"
-		"5: "SLR"  %0,%0\n"
-		"6: sacf  0\n"
-		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
-		: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
-		: : "cc", "memory");
-	return size;
-}
-
-static size_t clear_user_std(size_t size, void __user *to)
-{
-	unsigned long tmp1, tmp2;
-
-	asm volatile(
-		"   sacf  256\n"
-		"  "AHI"  %0,-1\n"
-		"   jo    5f\n"
-		"   bras  %3,3f\n"
-		"   xc    0(1,%1),0(%1)\n"
-		"0:"AHI"  %0,257\n"
-		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
-		"   srl   %2,12\n"
-		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
-		"  "SLR"  %2,%1\n"
-		"  "CLR"  %0,%2\n"	/* clear crosses next page boundary? */
-		"   jnh   5f\n"
-		"  "AHI"  %2,-1\n"
-		"1: ex    %2,0(%3)\n"
-		"  "AHI"  %2,1\n"
-		"  "SLR"  %0,%2\n"
-		"   j     5f\n"
-		"2: xc    0(256,%1),0(%1)\n"
-		"   la    %1,256(%1)\n"
-		"3:"AHI"  %0,-256\n"
-		"   jnm   2b\n"
-		"4: ex    %0,0(%3)\n"
-		"5: "SLR"  %0,%0\n"
-		"6: sacf  0\n"
-		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
-		: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
-	return size;
-}
-
-size_t strnlen_user_std(size_t size, const char __user *src)
-{
-	register unsigned long reg0 asm("0") = 0UL;
-	unsigned long tmp1, tmp2;
-
-	if (unlikely(!size))
-		return 0;
-	asm volatile(
-		"   la    %2,0(%1)\n"
-		"   la    %3,0(%0,%1)\n"
-		"  "SLR"  %0,%0\n"
-		"   sacf  256\n"
-		"0: srst  %3,%2\n"
-		"   jo    0b\n"
-		"   la    %0,1(%3)\n"	/* strnlen_user results includes \0 */
-		"  "SLR"  %0,%1\n"
-		"1: sacf  0\n"
-		EX_TABLE(0b,1b)
-		: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
-		: "d" (reg0) : "cc", "memory");
-	return size;
-}
-
-size_t strncpy_from_user_std(size_t count, const char __user *src, char *dst)
-{
-	size_t done, len, offset, len_str;
-
-	if (unlikely(!count))
-		return 0;
-	done = 0;
-	do {
-		offset = (size_t)src & ~PAGE_MASK;
-		len = min(count - done, PAGE_SIZE - offset);
-		if (copy_from_user_std(len, src, dst))
-			return -EFAULT;
-		len_str = strnlen(dst, len);
-		done += len_str;
-		src += len_str;
-		dst += len_str;
-	} while ((len_str == len) && (done < count));
-	return done;
-}
-
-#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
-	asm volatile(							\
-		"   sacf  256\n"					\
-		"0: l     %1,0(%6)\n"					\
-		"1:"insn						\
-		"2: cs    %1,%2,0(%6)\n"				\
-		"3: jl    1b\n"						\
-		"   lhi   %0,0\n"					\
-		"4: sacf  0\n"						\
-		EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)		\
-		: "=d" (ret), "=&d" (oldval), "=&d" (newval),		\
-		  "=m" (*uaddr)						\
-		: "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
-		  "m" (*uaddr) : "cc");
-
-int futex_atomic_op_std(int op, u32 __user *uaddr, int oparg, int *old)
-{
-	int oldval = 0, newval, ret;
-
-	switch (op) {
-	case FUTEX_OP_SET:
-		__futex_atomic_op("lr %2,%5\n",
-				  ret, oldval, newval, uaddr, oparg);
-		break;
-	case FUTEX_OP_ADD:
-		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
-				  ret, oldval, newval, uaddr, oparg);
-		break;
-	case FUTEX_OP_OR:
-		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
-				  ret, oldval, newval, uaddr, oparg);
-		break;
-	case FUTEX_OP_ANDN:
-		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
-				  ret, oldval, newval, uaddr, oparg);
-		break;
-	case FUTEX_OP_XOR:
-		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
-				  ret, oldval, newval, uaddr, oparg);
-		break;
-	default:
-		ret = -ENOSYS;
-	}
-	*old = oldval;
-	return ret;
-}
-
-int futex_atomic_cmpxchg_std(u32 *uval, u32 __user *uaddr,
-			     u32 oldval, u32 newval)
-{
-	int ret;
-
-	asm volatile(
-		"   sacf 256\n"
-		"0: cs   %1,%4,0(%5)\n"
-		"1: la   %0,0\n"
-		"2: sacf 0\n"
-		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
-		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
-		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
-		: "cc", "memory" );
-	*uval = oldval;
-	return ret;
-}
-
-struct uaccess_ops uaccess_std = {
-	.copy_from_user = copy_from_user_std_check,
-	.copy_from_user_small = copy_from_user_std,
-	.copy_to_user = copy_to_user_std_check,
-	.copy_to_user_small = copy_to_user_std,
-	.copy_in_user = copy_in_user_std,
-	.clear_user = clear_user_std,
-	.strnlen_user = strnlen_user_std,
-	.strncpy_from_user = strncpy_from_user_std,
-	.futex_atomic_op = futex_atomic_op_std,
-	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
-};
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index fc66792..8f29762 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -115,13 +115,8 @@ static inline int user_space_fault(unsigned long trans_exc_code)
 	if (trans_exc_code == 2)
 		/* Access via secondary space, set_fs setting decides */
 		return current->thread.mm_segment.ar4;
-	if (s390_user_mode == HOME_SPACE_MODE)
-		/* User space if the access has been done via home space. */
-		return trans_exc_code == 3;
 	/*
-	 * If the user space is not the home space the kernel runs in home
-	 * space. Access via secondary space has already been covered,
-	 * access via primary space or access register is from user space
+	 * Access via primary space or access register is from user space
 	 * and access via home space is from the kernel.
 	 */
 	return trans_exc_code != 3;
@@ -471,7 +466,7 @@ int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
 	int access, fault;
 
 	/* Emulate a uaccess fault from kernel mode. */
-	regs.psw.mask = psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK;
+	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);
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index de8cbc3..94f37a9 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1157,10 +1157,6 @@ int s390_enable_sie(void)
 	struct mm_struct *mm = tsk->mm;
 	struct mmu_gather tlb;
 
-	/* Do we have switched amode? If no, we cannot do sie */
-	if (s390_user_mode == HOME_SPACE_MODE)
-		return -EINVAL;
-
 	/* Do we have pgstes? if yes, we are done */
 	if (mm_has_pgste(tsk->mm))
 		return 0;