summaryrefslogtreecommitdiffstats
path: root/kernel/arch/s390/lib
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/s390/lib')
-rw-r--r--kernel/arch/s390/lib/Makefile9
-rw-r--r--kernel/arch/s390/lib/delay.c129
-rw-r--r--kernel/arch/s390/lib/find.c77
-rw-r--r--kernel/arch/s390/lib/mem.S88
-rw-r--r--kernel/arch/s390/lib/probes.c159
-rw-r--r--kernel/arch/s390/lib/spinlock.c272
-rw-r--r--kernel/arch/s390/lib/string.c342
-rw-r--r--kernel/arch/s390/lib/uaccess.c392
8 files changed, 1468 insertions, 0 deletions
diff --git a/kernel/arch/s390/lib/Makefile b/kernel/arch/s390/lib/Makefile
new file mode 100644
index 000000000..0e8fefe5b
--- /dev/null
+++ b/kernel/arch/s390/lib/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for s390-specific library files..
+#
+
+lib-y += delay.o string.o uaccess.o find.o
+obj-y += mem.o
+lib-$(CONFIG_SMP) += spinlock.o
+lib-$(CONFIG_KPROBES) += probes.o
+lib-$(CONFIG_UPROBES) += probes.o
diff --git a/kernel/arch/s390/lib/delay.c b/kernel/arch/s390/lib/delay.c
new file mode 100644
index 000000000..16dc42d83
--- /dev/null
+++ b/kernel/arch/s390/lib/delay.c
@@ -0,0 +1,129 @@
+/*
+ * Precise Delay Loops for S390
+ *
+ * Copyright IBM Corp. 1999, 2008
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ * Heiko Carstens <heiko.carstens@de.ibm.com>,
+ */
+
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/timex.h>
+#include <linux/module.h>
+#include <linux/irqflags.h>
+#include <linux/interrupt.h>
+#include <asm/vtimer.h>
+#include <asm/div64.h>
+
+void __delay(unsigned long loops)
+{
+ /*
+ * To end the bloody studid and useless discussion about the
+ * BogoMips number I took the liberty to define the __delay
+ * function in a way that that resulting BogoMips number will
+ * yield the megahertz number of the cpu. The important function
+ * is udelay and that is done using the tod clock. -- martin.
+ */
+ asm volatile("0: brct %0,0b" : : "d" ((loops/2) + 1));
+}
+
+static void __udelay_disabled(unsigned long long usecs)
+{
+ unsigned long cr0, cr6, new;
+ u64 clock_saved, end;
+
+ end = get_tod_clock() + (usecs << 12);
+ clock_saved = local_tick_disable();
+ __ctl_store(cr0, 0, 0);
+ __ctl_store(cr6, 6, 6);
+ new = (cr0 & 0xffff00e0) | 0x00000800;
+ __ctl_load(new , 0, 0);
+ new = 0;
+ __ctl_load(new, 6, 6);
+ lockdep_off();
+ do {
+ set_clock_comparator(end);
+ enabled_wait();
+ } while (get_tod_clock_fast() < end);
+ lockdep_on();
+ __ctl_load(cr0, 0, 0);
+ __ctl_load(cr6, 6, 6);
+ local_tick_enable(clock_saved);
+}
+
+static void __udelay_enabled(unsigned long long usecs)
+{
+ u64 clock_saved, end;
+
+ end = get_tod_clock_fast() + (usecs << 12);
+ do {
+ clock_saved = 0;
+ if (end < S390_lowcore.clock_comparator) {
+ clock_saved = local_tick_disable();
+ set_clock_comparator(end);
+ }
+ enabled_wait();
+ if (clock_saved)
+ local_tick_enable(clock_saved);
+ } while (get_tod_clock_fast() < end);
+}
+
+/*
+ * Waits for 'usecs' microseconds using the TOD clock comparator.
+ */
+void __udelay(unsigned long long usecs)
+{
+ unsigned long flags;
+
+ preempt_disable();
+ local_irq_save(flags);
+ if (in_irq()) {
+ __udelay_disabled(usecs);
+ goto out;
+ }
+ if (in_softirq()) {
+ if (raw_irqs_disabled_flags(flags))
+ __udelay_disabled(usecs);
+ else
+ __udelay_enabled(usecs);
+ goto out;
+ }
+ if (raw_irqs_disabled_flags(flags)) {
+ local_bh_disable();
+ __udelay_disabled(usecs);
+ _local_bh_enable();
+ goto out;
+ }
+ __udelay_enabled(usecs);
+out:
+ local_irq_restore(flags);
+ preempt_enable();
+}
+EXPORT_SYMBOL(__udelay);
+
+/*
+ * Simple udelay variant. To be used on startup and reboot
+ * when the interrupt handler isn't working.
+ */
+void udelay_simple(unsigned long long usecs)
+{
+ u64 end;
+
+ end = get_tod_clock_fast() + (usecs << 12);
+ while (get_tod_clock_fast() < end)
+ cpu_relax();
+}
+
+void __ndelay(unsigned long long nsecs)
+{
+ u64 end;
+
+ nsecs <<= 9;
+ do_div(nsecs, 125);
+ end = get_tod_clock_fast() + nsecs;
+ if (nsecs & ~0xfffUL)
+ __udelay(nsecs >> 12);
+ while (get_tod_clock_fast() < end)
+ barrier();
+}
+EXPORT_SYMBOL(__ndelay);
diff --git a/kernel/arch/s390/lib/find.c b/kernel/arch/s390/lib/find.c
new file mode 100644
index 000000000..922003c1b
--- /dev/null
+++ b/kernel/arch/s390/lib/find.c
@@ -0,0 +1,77 @@
+/*
+ * MSB0 numbered special bitops handling.
+ *
+ * On s390x the bits are numbered:
+ * |0..............63|64............127|128...........191|192...........255|
+ * and on s390:
+ * |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|
+ *
+ * The reason for this bit numbering is the fact that the hardware sets bits
+ * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap
+ * from the 'wrong end'.
+ */
+
+#include <linux/compiler.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+
+unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size)
+{
+ const unsigned long *p = addr;
+ unsigned long result = 0;
+ unsigned long tmp;
+
+ while (size & ~(BITS_PER_LONG - 1)) {
+ if ((tmp = *(p++)))
+ goto found;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = (*p) & (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_first_bit_inv);
+
+unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
+{
+ const unsigned long *p = addr + (offset / BITS_PER_LONG);
+ unsigned long result = offset & ~(BITS_PER_LONG - 1);
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset %= BITS_PER_LONG;
+ if (offset) {
+ tmp = *(p++);
+ tmp &= (~0UL >> offset);
+ if (size < BITS_PER_LONG)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= BITS_PER_LONG;
+ result += BITS_PER_LONG;
+ }
+ while (size & ~(BITS_PER_LONG-1)) {
+ if ((tmp = *(p++)))
+ goto found_middle;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+found_first:
+ tmp &= (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found_middle:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_next_bit_inv);
diff --git a/kernel/arch/s390/lib/mem.S b/kernel/arch/s390/lib/mem.S
new file mode 100644
index 000000000..c6d553e85
--- /dev/null
+++ b/kernel/arch/s390/lib/mem.S
@@ -0,0 +1,88 @@
+/*
+ * String handling functions.
+ *
+ * Copyright IBM Corp. 2012
+ */
+
+#include <linux/linkage.h>
+
+/*
+ * memset implementation
+ *
+ * This code corresponds to the C construct below. We do distinguish
+ * between clearing (c == 0) and setting a memory array (c != 0) simply
+ * because nearly all memset invocations in the kernel clear memory and
+ * the xc instruction is preferred in such cases.
+ *
+ * void *memset(void *s, int c, size_t n)
+ * {
+ * if (likely(c == 0))
+ * return __builtin_memset(s, 0, n);
+ * return __builtin_memset(s, c, n);
+ * }
+ */
+ENTRY(memset)
+ ltgr %r4,%r4
+ bzr %r14
+ ltgr %r3,%r3
+ jnz .Lmemset_fill
+ aghi %r4,-1
+ srlg %r3,%r4,8
+ ltgr %r3,%r3
+ lgr %r1,%r2
+ jz .Lmemset_clear_rest
+.Lmemset_clear_loop:
+ xc 0(256,%r1),0(%r1)
+ la %r1,256(%r1)
+ brctg %r3,.Lmemset_clear_loop
+.Lmemset_clear_rest:
+ larl %r3,.Lmemset_xc
+ ex %r4,0(%r3)
+ br %r14
+.Lmemset_fill:
+ stc %r3,0(%r2)
+ cghi %r4,1
+ lgr %r1,%r2
+ ber %r14
+ aghi %r4,-2
+ srlg %r3,%r4,8
+ ltgr %r3,%r3
+ jz .Lmemset_fill_rest
+.Lmemset_fill_loop:
+ mvc 1(256,%r1),0(%r1)
+ la %r1,256(%r1)
+ brctg %r3,.Lmemset_fill_loop
+.Lmemset_fill_rest:
+ larl %r3,.Lmemset_mvc
+ ex %r4,0(%r3)
+ br %r14
+.Lmemset_xc:
+ xc 0(1,%r1),0(%r1)
+.Lmemset_mvc:
+ mvc 1(1,%r1),0(%r1)
+
+/*
+ * memcpy implementation
+ *
+ * void *memcpy(void *dest, const void *src, size_t n)
+ */
+ENTRY(memcpy)
+ ltgr %r4,%r4
+ bzr %r14
+ aghi %r4,-1
+ srlg %r5,%r4,8
+ ltgr %r5,%r5
+ lgr %r1,%r2
+ jnz .Lmemcpy_loop
+.Lmemcpy_rest:
+ larl %r5,.Lmemcpy_mvc
+ ex %r4,0(%r5)
+ br %r14
+.Lmemcpy_loop:
+ mvc 0(256,%r1),0(%r3)
+ la %r1,256(%r1)
+ la %r3,256(%r3)
+ brctg %r5,.Lmemcpy_loop
+ j .Lmemcpy_rest
+.Lmemcpy_mvc:
+ mvc 0(1,%r1),0(%r3)
diff --git a/kernel/arch/s390/lib/probes.c b/kernel/arch/s390/lib/probes.c
new file mode 100644
index 000000000..ae90e1ae3
--- /dev/null
+++ b/kernel/arch/s390/lib/probes.c
@@ -0,0 +1,159 @@
+/*
+ * Common helper functions for kprobes and uprobes
+ *
+ * Copyright IBM Corp. 2014
+ */
+
+#include <asm/kprobes.h>
+#include <asm/dis.h>
+
+int probe_is_prohibited_opcode(u16 *insn)
+{
+ if (!is_known_insn((unsigned char *)insn))
+ return -EINVAL;
+ switch (insn[0] >> 8) {
+ case 0x0c: /* bassm */
+ case 0x0b: /* bsm */
+ case 0x83: /* diag */
+ case 0x44: /* ex */
+ case 0xac: /* stnsm */
+ case 0xad: /* stosm */
+ return -EINVAL;
+ case 0xc6:
+ switch (insn[0] & 0x0f) {
+ case 0x00: /* exrl */
+ return -EINVAL;
+ }
+ }
+ switch (insn[0]) {
+ case 0x0101: /* pr */
+ case 0xb25a: /* bsa */
+ case 0xb240: /* bakr */
+ case 0xb258: /* bsg */
+ case 0xb218: /* pc */
+ case 0xb228: /* pt */
+ case 0xb98d: /* epsw */
+ case 0xe560: /* tbegin */
+ case 0xe561: /* tbeginc */
+ case 0xb2f8: /* tend */
+ return -EINVAL;
+ }
+ return 0;
+}
+
+int probe_get_fixup_type(u16 *insn)
+{
+ /* default fixup method */
+ int fixup = FIXUP_PSW_NORMAL;
+
+ switch (insn[0] >> 8) {
+ case 0x05: /* balr */
+ case 0x0d: /* basr */
+ fixup = FIXUP_RETURN_REGISTER;
+ /* if r2 = 0, no branch will be taken */
+ if ((insn[0] & 0x0f) == 0)
+ fixup |= FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ case 0x06: /* bctr */
+ case 0x07: /* bcr */
+ fixup = FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ case 0x45: /* bal */
+ case 0x4d: /* bas */
+ fixup = FIXUP_RETURN_REGISTER;
+ break;
+ case 0x47: /* bc */
+ case 0x46: /* bct */
+ case 0x86: /* bxh */
+ case 0x87: /* bxle */
+ fixup = FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ case 0x82: /* lpsw */
+ fixup = FIXUP_NOT_REQUIRED;
+ break;
+ case 0xb2: /* lpswe */
+ if ((insn[0] & 0xff) == 0xb2)
+ fixup = FIXUP_NOT_REQUIRED;
+ break;
+ case 0xa7: /* bras */
+ if ((insn[0] & 0x0f) == 0x05)
+ fixup |= FIXUP_RETURN_REGISTER;
+ break;
+ case 0xc0:
+ if ((insn[0] & 0x0f) == 0x05) /* brasl */
+ fixup |= FIXUP_RETURN_REGISTER;
+ break;
+ case 0xeb:
+ switch (insn[2] & 0xff) {
+ case 0x44: /* bxhg */
+ case 0x45: /* bxleg */
+ fixup = FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ }
+ break;
+ case 0xe3: /* bctg */
+ if ((insn[2] & 0xff) == 0x46)
+ fixup = FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ case 0xec:
+ switch (insn[2] & 0xff) {
+ case 0xe5: /* clgrb */
+ case 0xe6: /* cgrb */
+ case 0xf6: /* crb */
+ case 0xf7: /* clrb */
+ case 0xfc: /* cgib */
+ case 0xfd: /* cglib */
+ case 0xfe: /* cib */
+ case 0xff: /* clib */
+ fixup = FIXUP_BRANCH_NOT_TAKEN;
+ break;
+ }
+ break;
+ }
+ return fixup;
+}
+
+int probe_is_insn_relative_long(u16 *insn)
+{
+ /* Check if we have a RIL-b or RIL-c format instruction which
+ * we need to modify in order to avoid instruction emulation. */
+ switch (insn[0] >> 8) {
+ case 0xc0:
+ if ((insn[0] & 0x0f) == 0x00) /* larl */
+ return true;
+ break;
+ case 0xc4:
+ switch (insn[0] & 0x0f) {
+ case 0x02: /* llhrl */
+ case 0x04: /* lghrl */
+ case 0x05: /* lhrl */
+ case 0x06: /* llghrl */
+ case 0x07: /* sthrl */
+ case 0x08: /* lgrl */
+ case 0x0b: /* stgrl */
+ case 0x0c: /* lgfrl */
+ case 0x0d: /* lrl */
+ case 0x0e: /* llgfrl */
+ case 0x0f: /* strl */
+ return true;
+ }
+ break;
+ case 0xc6:
+ switch (insn[0] & 0x0f) {
+ case 0x02: /* pfdrl */
+ case 0x04: /* cghrl */
+ case 0x05: /* chrl */
+ case 0x06: /* clghrl */
+ case 0x07: /* clhrl */
+ case 0x08: /* cgrl */
+ case 0x0a: /* clgrl */
+ case 0x0c: /* cgfrl */
+ case 0x0d: /* crl */
+ case 0x0e: /* clgfrl */
+ case 0x0f: /* clrl */
+ return true;
+ }
+ break;
+ }
+ return false;
+}
diff --git a/kernel/arch/s390/lib/spinlock.c b/kernel/arch/s390/lib/spinlock.c
new file mode 100644
index 000000000..d6c9991f7
--- /dev/null
+++ b/kernel/arch/s390/lib/spinlock.c
@@ -0,0 +1,272 @@
+/*
+ * Out of line spinlock code.
+ *
+ * Copyright IBM Corp. 2004, 2006
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <asm/io.h>
+
+int spin_retry = -1;
+
+static int __init spin_retry_init(void)
+{
+ if (spin_retry < 0)
+ spin_retry = MACHINE_HAS_CAD ? 10 : 1000;
+ return 0;
+}
+early_initcall(spin_retry_init);
+
+/**
+ * spin_retry= parameter
+ */
+static int __init spin_retry_setup(char *str)
+{
+ spin_retry = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("spin_retry=", spin_retry_setup);
+
+static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old)
+{
+ asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock));
+}
+
+void arch_spin_lock_wait(arch_spinlock_t *lp)
+{
+ unsigned int cpu = SPINLOCK_LOCKVAL;
+ unsigned int owner;
+ int count;
+
+ while (1) {
+ owner = ACCESS_ONCE(lp->lock);
+ /* Try to get the lock if it is free. */
+ if (!owner) {
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+ return;
+ continue;
+ }
+ /* Check if the lock owner is running. */
+ if (!smp_vcpu_scheduled(~owner)) {
+ smp_yield_cpu(~owner);
+ continue;
+ }
+ /* Loop for a while on the lock value. */
+ count = spin_retry;
+ do {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
+ owner = ACCESS_ONCE(lp->lock);
+ } while (owner && count-- > 0);
+ if (!owner)
+ continue;
+ /*
+ * For multiple layers of hypervisors, e.g. z/VM + LPAR
+ * yield the CPU if the lock is still unavailable.
+ */
+ if (!MACHINE_IS_LPAR)
+ smp_yield_cpu(~owner);
+ }
+}
+EXPORT_SYMBOL(arch_spin_lock_wait);
+
+void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
+{
+ unsigned int cpu = SPINLOCK_LOCKVAL;
+ unsigned int owner;
+ int count;
+
+ local_irq_restore(flags);
+ while (1) {
+ owner = ACCESS_ONCE(lp->lock);
+ /* Try to get the lock if it is free. */
+ if (!owner) {
+ local_irq_disable();
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+ return;
+ local_irq_restore(flags);
+ }
+ /* Check if the lock owner is running. */
+ if (!smp_vcpu_scheduled(~owner)) {
+ smp_yield_cpu(~owner);
+ continue;
+ }
+ /* Loop for a while on the lock value. */
+ count = spin_retry;
+ do {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
+ owner = ACCESS_ONCE(lp->lock);
+ } while (owner && count-- > 0);
+ if (!owner)
+ continue;
+ /*
+ * For multiple layers of hypervisors, e.g. z/VM + LPAR
+ * yield the CPU if the lock is still unavailable.
+ */
+ if (!MACHINE_IS_LPAR)
+ smp_yield_cpu(~owner);
+ }
+}
+EXPORT_SYMBOL(arch_spin_lock_wait_flags);
+
+int arch_spin_trylock_retry(arch_spinlock_t *lp)
+{
+ unsigned int cpu = SPINLOCK_LOCKVAL;
+ unsigned int owner;
+ int count;
+
+ for (count = spin_retry; count > 0; count--) {
+ owner = ACCESS_ONCE(lp->lock);
+ /* Try to get the lock if it is free. */
+ if (!owner) {
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+ return 1;
+ } else if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&lp->lock, owner);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(arch_spin_trylock_retry);
+
+void _raw_read_lock_wait(arch_rwlock_t *rw)
+{
+ unsigned int owner, old;
+ int count = spin_retry;
+
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+ __RAW_LOCK(&rw->lock, -1, __RAW_OP_ADD);
+#endif
+ owner = 0;
+ while (1) {
+ if (count-- <= 0) {
+ if (owner && !smp_vcpu_scheduled(~owner))
+ smp_yield_cpu(~owner);
+ count = spin_retry;
+ }
+ old = ACCESS_ONCE(rw->lock);
+ owner = ACCESS_ONCE(rw->owner);
+ if ((int) old < 0) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
+ continue;
+ }
+ if (_raw_compare_and_swap(&rw->lock, old, old + 1))
+ return;
+ }
+}
+EXPORT_SYMBOL(_raw_read_lock_wait);
+
+int _raw_read_trylock_retry(arch_rwlock_t *rw)
+{
+ unsigned int old;
+ int count = spin_retry;
+
+ while (count-- > 0) {
+ old = ACCESS_ONCE(rw->lock);
+ if ((int) old < 0) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
+ continue;
+ }
+ if (_raw_compare_and_swap(&rw->lock, old, old + 1))
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(_raw_read_trylock_retry);
+
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+
+void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
+{
+ unsigned int owner, old;
+ int count = spin_retry;
+
+ owner = 0;
+ while (1) {
+ if (count-- <= 0) {
+ if (owner && !smp_vcpu_scheduled(~owner))
+ smp_yield_cpu(~owner);
+ count = spin_retry;
+ }
+ old = ACCESS_ONCE(rw->lock);
+ owner = ACCESS_ONCE(rw->owner);
+ smp_rmb();
+ if ((int) old >= 0) {
+ prev = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
+ old = prev;
+ }
+ if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
+ break;
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
+ }
+}
+EXPORT_SYMBOL(_raw_write_lock_wait);
+
+#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
+void _raw_write_lock_wait(arch_rwlock_t *rw)
+{
+ unsigned int owner, old, prev;
+ int count = spin_retry;
+
+ prev = 0x80000000;
+ owner = 0;
+ while (1) {
+ if (count-- <= 0) {
+ if (owner && !smp_vcpu_scheduled(~owner))
+ smp_yield_cpu(~owner);
+ count = spin_retry;
+ }
+ old = ACCESS_ONCE(rw->lock);
+ owner = ACCESS_ONCE(rw->owner);
+ if ((int) old >= 0 &&
+ _raw_compare_and_swap(&rw->lock, old, old | 0x80000000))
+ prev = old;
+ else
+ smp_rmb();
+ if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
+ break;
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
+ }
+}
+EXPORT_SYMBOL(_raw_write_lock_wait);
+
+#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
+int _raw_write_trylock_retry(arch_rwlock_t *rw)
+{
+ unsigned int old;
+ int count = spin_retry;
+
+ while (count-- > 0) {
+ old = ACCESS_ONCE(rw->lock);
+ if (old) {
+ if (MACHINE_HAS_CAD)
+ _raw_compare_and_delay(&rw->lock, old);
+ continue;
+ }
+ if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(_raw_write_trylock_retry);
+
+void arch_lock_relax(unsigned int cpu)
+{
+ if (!cpu)
+ return;
+ if (MACHINE_IS_LPAR && smp_vcpu_scheduled(~cpu))
+ return;
+ smp_yield_cpu(~cpu);
+}
+EXPORT_SYMBOL(arch_lock_relax);
diff --git a/kernel/arch/s390/lib/string.c b/kernel/arch/s390/lib/string.c
new file mode 100644
index 000000000..b647d5ff0
--- /dev/null
+++ b/kernel/arch/s390/lib/string.c
@@ -0,0 +1,342 @@
+/*
+ * Optimized string functions
+ *
+ * S390 version
+ * Copyright IBM Corp. 2004
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#define IN_ARCH_STRING_C 1
+
+#include <linux/types.h>
+#include <linux/module.h>
+
+/*
+ * Helper functions to find the end of a string
+ */
+static inline char *__strend(const char *s)
+{
+ register unsigned long r0 asm("0") = 0;
+
+ asm volatile ("0: srst %0,%1\n"
+ " jo 0b"
+ : "+d" (r0), "+a" (s) : : "cc" );
+ return (char *) r0;
+}
+
+static inline char *__strnend(const char *s, size_t n)
+{
+ register unsigned long r0 asm("0") = 0;
+ const char *p = s + n;
+
+ asm volatile ("0: srst %0,%1\n"
+ " jo 0b"
+ : "+d" (p), "+a" (s) : "d" (r0) : "cc" );
+ return (char *) p;
+}
+
+/**
+ * strlen - Find the length of a string
+ * @s: The string to be sized
+ *
+ * returns the length of @s
+ */
+size_t strlen(const char *s)
+{
+ return __strend(s) - s;
+}
+EXPORT_SYMBOL(strlen);
+
+/**
+ * strnlen - Find the length of a length-limited string
+ * @s: The string to be sized
+ * @n: The maximum number of bytes to search
+ *
+ * returns the minimum of the length of @s and @n
+ */
+size_t strnlen(const char * s, size_t n)
+{
+ return __strnend(s, n) - s;
+}
+EXPORT_SYMBOL(strnlen);
+
+/**
+ * strcpy - Copy a %NUL terminated string
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ *
+ * returns a pointer to @dest
+ */
+char *strcpy(char *dest, const char *src)
+{
+ register int r0 asm("0") = 0;
+ char *ret = dest;
+
+ asm volatile ("0: mvst %0,%1\n"
+ " jo 0b"
+ : "+&a" (dest), "+&a" (src) : "d" (r0)
+ : "cc", "memory" );
+ return ret;
+}
+EXPORT_SYMBOL(strcpy);
+
+/**
+ * strlcpy - Copy a %NUL terminated string into a sized buffer
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @size: size of destination buffer
+ *
+ * Compatible with *BSD: the result is always a valid
+ * NUL-terminated string that fits in the buffer (unless,
+ * of course, the buffer size is zero). It does not pad
+ * out the result like strncpy() does.
+ */
+size_t strlcpy(char *dest, const char *src, size_t size)
+{
+ size_t ret = __strend(src) - src;
+
+ if (size) {
+ size_t len = (ret >= size) ? size-1 : ret;
+ dest[len] = '\0';
+ memcpy(dest, src, len);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(strlcpy);
+
+/**
+ * strncpy - Copy a length-limited, %NUL-terminated string
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @n: The maximum number of bytes to copy
+ *
+ * The result is not %NUL-terminated if the source exceeds
+ * @n bytes.
+ */
+char *strncpy(char *dest, const char *src, size_t n)
+{
+ size_t len = __strnend(src, n) - src;
+ memset(dest + len, 0, n - len);
+ memcpy(dest, src, len);
+ return dest;
+}
+EXPORT_SYMBOL(strncpy);
+
+/**
+ * strcat - Append one %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ *
+ * returns a pointer to @dest
+ */
+char *strcat(char *dest, const char *src)
+{
+ register int r0 asm("0") = 0;
+ unsigned long dummy;
+ char *ret = dest;
+
+ asm volatile ("0: srst %0,%1\n"
+ " jo 0b\n"
+ "1: mvst %0,%2\n"
+ " jo 1b"
+ : "=&a" (dummy), "+a" (dest), "+a" (src)
+ : "d" (r0), "0" (0UL) : "cc", "memory" );
+ return ret;
+}
+EXPORT_SYMBOL(strcat);
+
+/**
+ * strlcat - Append a length-limited, %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ * @n: The size of the destination buffer.
+ */
+size_t strlcat(char *dest, const char *src, size_t n)
+{
+ size_t dsize = __strend(dest) - dest;
+ size_t len = __strend(src) - src;
+ size_t res = dsize + len;
+
+ if (dsize < n) {
+ dest += dsize;
+ n -= dsize;
+ if (len >= n)
+ len = n - 1;
+ dest[len] = '\0';
+ memcpy(dest, src, len);
+ }
+ return res;
+}
+EXPORT_SYMBOL(strlcat);
+
+/**
+ * strncat - Append a length-limited, %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ * @n: The maximum numbers of bytes to copy
+ *
+ * returns a pointer to @dest
+ *
+ * Note that in contrast to strncpy, strncat ensures the result is
+ * terminated.
+ */
+char *strncat(char *dest, const char *src, size_t n)
+{
+ size_t len = __strnend(src, n) - src;
+ char *p = __strend(dest);
+
+ p[len] = '\0';
+ memcpy(p, src, len);
+ return dest;
+}
+EXPORT_SYMBOL(strncat);
+
+/**
+ * strcmp - Compare two strings
+ * @cs: One string
+ * @ct: Another string
+ *
+ * returns 0 if @cs and @ct are equal,
+ * < 0 if @cs is less than @ct
+ * > 0 if @cs is greater than @ct
+ */
+int strcmp(const char *cs, const char *ct)
+{
+ register int r0 asm("0") = 0;
+ int ret = 0;
+
+ asm volatile ("0: clst %2,%3\n"
+ " jo 0b\n"
+ " je 1f\n"
+ " ic %0,0(%2)\n"
+ " ic %1,0(%3)\n"
+ " sr %0,%1\n"
+ "1:"
+ : "+d" (ret), "+d" (r0), "+a" (cs), "+a" (ct)
+ : : "cc" );
+ return ret;
+}
+EXPORT_SYMBOL(strcmp);
+
+/**
+ * strrchr - Find the last occurrence of a character in a string
+ * @s: The string to be searched
+ * @c: The character to search for
+ */
+char * strrchr(const char * s, int c)
+{
+ size_t len = __strend(s) - s;
+
+ if (len)
+ do {
+ if (s[len] == (char) c)
+ return (char *) s + len;
+ } while (--len > 0);
+ return NULL;
+}
+EXPORT_SYMBOL(strrchr);
+
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+char * strstr(const char * s1,const char * s2)
+{
+ int l1, l2;
+
+ l2 = __strend(s2) - s2;
+ if (!l2)
+ return (char *) s1;
+ l1 = __strend(s1) - s1;
+ while (l1-- >= l2) {
+ register unsigned long r2 asm("2") = (unsigned long) s1;
+ register unsigned long r3 asm("3") = (unsigned long) l2;
+ register unsigned long r4 asm("4") = (unsigned long) s2;
+ register unsigned long r5 asm("5") = (unsigned long) l2;
+ int cc;
+
+ asm volatile ("0: clcle %1,%3,0\n"
+ " jo 0b\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=&d" (cc), "+a" (r2), "+a" (r3),
+ "+a" (r4), "+a" (r5) : : "cc" );
+ if (!cc)
+ return (char *) s1;
+ s1++;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(strstr);
+
+/**
+ * memchr - Find a character in an area of memory.
+ * @s: The memory area
+ * @c: The byte to search for
+ * @n: The size of the area.
+ *
+ * returns the address of the first occurrence of @c, or %NULL
+ * if @c is not found
+ */
+void *memchr(const void *s, int c, size_t n)
+{
+ register int r0 asm("0") = (char) c;
+ const void *ret = s + n;
+
+ asm volatile ("0: srst %0,%1\n"
+ " jo 0b\n"
+ " jl 1f\n"
+ " la %0,0\n"
+ "1:"
+ : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
+ return (void *) ret;
+}
+EXPORT_SYMBOL(memchr);
+
+/**
+ * memcmp - Compare two areas of memory
+ * @cs: One area of memory
+ * @ct: Another area of memory
+ * @count: The size of the area.
+ */
+int memcmp(const void *cs, const void *ct, size_t n)
+{
+ register unsigned long r2 asm("2") = (unsigned long) cs;
+ register unsigned long r3 asm("3") = (unsigned long) n;
+ register unsigned long r4 asm("4") = (unsigned long) ct;
+ register unsigned long r5 asm("5") = (unsigned long) n;
+ int ret;
+
+ asm volatile ("0: clcle %1,%3,0\n"
+ " jo 0b\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=&d" (ret), "+a" (r2), "+a" (r3), "+a" (r4), "+a" (r5)
+ : : "cc" );
+ if (ret)
+ ret = *(char *) r2 - *(char *) r4;
+ return ret;
+}
+EXPORT_SYMBOL(memcmp);
+
+/**
+ * memscan - Find a character in an area of memory.
+ * @s: The memory area
+ * @c: The byte to search for
+ * @n: The size of the area.
+ *
+ * returns the address of the first occurrence of @c, or 1 byte past
+ * the area if @c is not found
+ */
+void *memscan(void *s, int c, size_t n)
+{
+ register int r0 asm("0") = (char) c;
+ const void *ret = s + n;
+
+ asm volatile ("0: srst %0,%1\n"
+ " jo 0b\n"
+ : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
+ return (void *) ret;
+}
+EXPORT_SYMBOL(memscan);
diff --git a/kernel/arch/s390/lib/uaccess.c b/kernel/arch/s390/lib/uaccess.c
new file mode 100644
index 000000000..4614d415b
--- /dev/null
+++ b/kernel/arch/s390/lib/uaccess.c
@@ -0,0 +1,392 @@
+/*
+ * Standard user space access functions based on mvcp/mvcs and doing
+ * interesting things in the secondary space mode.
+ *
+ * Copyright IBM Corp. 2006,2014
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ * Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <asm/mmu_context.h>
+#include <asm/facility.h>
+
+static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE;
+
+static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
+ unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x81UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+ "9: jz 7f\n"
+ "1: algr %0,%3\n"
+ " slgr %1,%3\n"
+ " slgr %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " slgr %4,%1\n"
+ " clgr %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 4f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+ "10:slgr %0,%4\n"
+ " algr %2,%4\n"
+ "4: lghi %4,-1\n"
+ " algr %4,%0\n" /* copy remaining size, subtract 1 */
+ " bras %3,6f\n" /* memset loop */
+ " xc 0(1,%2),0(%2)\n"
+ "5: xc 0(256,%2),0(%2)\n"
+ " la %2,256(%2)\n"
+ "6: aghi %4,-256\n"
+ " jnm 5b\n"
+ " ex %4,0(%3)\n"
+ " j 8f\n"
+ "7:slgr %0,%0\n"
+ "8:\n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
+ unsigned long size)
+{
+ unsigned long tmp1, tmp2;
+
+ load_kernel_asce();
+ tmp1 = -256UL;
+ asm volatile(
+ " sacf 0\n"
+ "0: mvcp 0(%0,%2),0(%1),%3\n"
+ "10:jz 8f\n"
+ "1: algr %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 */
+ " lghi %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " slgr %4,%1\n"
+ " clgr %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "4: mvcp 0(%4,%2),0(%1),%3\n"
+ "12:slgr %0,%4\n"
+ " algr %2,%4\n"
+ "5: lghi %4,-1\n"
+ " algr %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: aghi %4,-256\n"
+ " jnm 6b\n"
+ " ex %4,0(%3)\n"
+ " j 9f\n"
+ "8:slgr %0,%0\n"
+ "9: sacf 768\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;
+}
+
+unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_from_user_mvcos(to, from, n);
+ return copy_from_user_mvcp(to, from, n);
+}
+EXPORT_SYMBOL(__copy_from_user);
+
+static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
+ unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+ "6: jz 4f\n"
+ "1: algr %0,%3\n"
+ " slgr %1,%3\n"
+ " slgr %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " slgr %4,%1\n"
+ " clgr %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+ "7: slgr %0,%4\n"
+ " j 5f\n"
+ "4: slgr %0,%0\n"
+ "5:\n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
+ unsigned long size)
+{
+ unsigned long tmp1, tmp2;
+
+ load_kernel_asce();
+ tmp1 = -256UL;
+ asm volatile(
+ " sacf 0\n"
+ "0: mvcs 0(%0,%1),0(%2),%3\n"
+ "7: jz 5f\n"
+ "1: algr %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 */
+ " lghi %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " slgr %4,%1\n"
+ " clgr %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 6f\n"
+ "4: mvcs 0(%4,%1),0(%2),%3\n"
+ "9: slgr %0,%4\n"
+ " j 6f\n"
+ "5: slgr %0,%0\n"
+ "6: sacf 768\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;
+}
+
+unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_to_user_mvcos(to, from, n);
+ return copy_to_user_mvcs(to, from, n);
+}
+EXPORT_SYMBOL(__copy_to_user);
+
+static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
+ unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x810081UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ /* FIXME: copy with reduced length. */
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+ " jz 2f\n"
+ "1: algr %0,%3\n"
+ " slgr %1,%3\n"
+ " slgr %2,%3\n"
+ " j 0b\n"
+ "2:slgr %0,%0\n"
+ "3: \n"
+ EX_TABLE(0b,3b)
+ : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
+ unsigned long size)
+{
+ unsigned long tmp1;
+
+ load_kernel_asce();
+ asm volatile(
+ " sacf 256\n"
+ " aghi %0,-1\n"
+ " jo 5f\n"
+ " bras %3,3f\n"
+ "0: aghi %0,257\n"
+ "1: mvc 0(1,%1),0(%2)\n"
+ " la %1,1(%1)\n"
+ " la %2,1(%2)\n"
+ " aghi %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: aghi %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,1b-0b(%3)\n"
+ "5: slgr %0,%0\n"
+ "6: sacf 768\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;
+}
+
+unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_in_user_mvcos(to, from, n);
+ return copy_in_user_mvc(to, from, n);
+}
+EXPORT_SYMBOL(__copy_in_user);
+
+static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+ " jz 4f\n"
+ "1: algr %0,%2\n"
+ " slgr %1,%2\n"
+ " j 0b\n"
+ "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
+ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
+ " slgr %3,%1\n"
+ " clgr %0,%3\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+ " slgr %0,%3\n"
+ " j 5f\n"
+ "4:slgr %0,%0\n"
+ "5:\n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+ : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+ : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
+{
+ unsigned long tmp1, tmp2;
+
+ load_kernel_asce();
+ asm volatile(
+ " sacf 256\n"
+ " aghi %0,-1\n"
+ " jo 5f\n"
+ " bras %3,3f\n"
+ " xc 0(1,%1),0(%1)\n"
+ "0: aghi %0,257\n"
+ " la %2,255(%1)\n" /* %2 = ptr + 255 */
+ " srl %2,12\n"
+ " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
+ " slgr %2,%1\n"
+ " clgr %0,%2\n" /* clear crosses next page boundary? */
+ " jnh 5f\n"
+ " aghi %2,-1\n"
+ "1: ex %2,0(%3)\n"
+ " aghi %2,1\n"
+ " slgr %0,%2\n"
+ " j 5f\n"
+ "2: xc 0(256,%1),0(%1)\n"
+ " la %1,256(%1)\n"
+ "3: aghi %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,0(%3)\n"
+ "5: slgr %0,%0\n"
+ "6: sacf 768\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;
+}
+
+unsigned long __clear_user(void __user *to, unsigned long size)
+{
+ if (static_key_false(&have_mvcos))
+ return clear_user_mvcos(to, size);
+ return clear_user_xc(to, size);
+}
+EXPORT_SYMBOL(__clear_user);
+
+static inline unsigned long strnlen_user_srst(const char __user *src,
+ unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0;
+ unsigned long tmp1, tmp2;
+
+ asm volatile(
+ " la %2,0(%1)\n"
+ " la %3,0(%0,%1)\n"
+ " slgr %0,%0\n"
+ " sacf 256\n"
+ "0: srst %3,%2\n"
+ " jo 0b\n"
+ " la %0,1(%3)\n" /* strnlen_user results includes \0 */
+ " slgr %0,%1\n"
+ "1: sacf 768\n"
+ EX_TABLE(0b,1b)
+ : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+unsigned long __strnlen_user(const char __user *src, unsigned long size)
+{
+ if (unlikely(!size))
+ return 0;
+ load_kernel_asce();
+ return strnlen_user_srst(src, size);
+}
+EXPORT_SYMBOL(__strnlen_user);
+
+long __strncpy_from_user(char *dst, const char __user *src, long size)
+{
+ size_t done, len, offset, len_str;
+
+ if (unlikely(size <= 0))
+ return 0;
+ done = 0;
+ do {
+ offset = (size_t)src & ~PAGE_MASK;
+ len = min(size - done, PAGE_SIZE - offset);
+ if (copy_from_user(dst, src, len))
+ return -EFAULT;
+ len_str = strnlen(dst, len);
+ done += len_str;
+ src += len_str;
+ dst += len_str;
+ } while ((len_str == len) && (done < size));
+ return done;
+}
+EXPORT_SYMBOL(__strncpy_from_user);
+
+/*
+ * The "old" uaccess variant without mvcos can be enforced with the
+ * uaccess_primary kernel parameter. This is mainly for debugging purposes.
+ */
+static int uaccess_primary __initdata;
+
+static int __init parse_uaccess_pt(char *__unused)
+{
+ uaccess_primary = 1;
+ return 0;
+}
+early_param("uaccess_primary", parse_uaccess_pt);
+
+static int __init uaccess_init(void)
+{
+ if (!uaccess_primary && test_facility(27))
+ static_key_slow_inc(&have_mvcos);
+ return 0;
+}
+early_initcall(uaccess_init);