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 9f973d8de90e..5d1f950704dc 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 50256f05fbcf..3caaf6548ef5 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 52b56533c57c..9c82cebddabd 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 59880dbaf360..df802ee14af6 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 9c33ed4e666f..79330af9a5f8 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 adaa9e9478d8..ee820079c06d 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 feb719d3c851..633ca7504536 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 c5dbb335716d..e1cdd31acabb 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 9556905bd3ce..e6abd5bd31b0 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 e1c9d1c292fa..d817cce7e72d 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 aeed8a61fa0d..ffe1c53264a7 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 c45becf82e01..b4fa7c0223e5 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 1a4313a1b60f..cca6cf6abacc 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 05d75c413137..a84476f2a9bb 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 abcfab55f99b..e312c48a1c40 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 e506c5fb6f6a..b068729e50ac 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 1829742bf479..4b7993bf69b9 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 1694d738b175..97e03caf7825 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 4a75d475b06a..000000000000
--- 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 fc6679210d83..8f29762671cf 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 de8cbc30dcd1..94f37a9fb1e5 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;