Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

5 files changed, 857 insertions, 0 deletions

diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
new file mode 100644
index 000000000000..a8758b1d20a9
--- /dev/null
+++ b/arch/s390/lib/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for s390-specific library files..
+#
+
+EXTRA_AFLAGS := -traditional
+
+lib-y += delay.o string.o
+lib-$(CONFIG_ARCH_S390_31) += uaccess.o
+lib-$(CONFIG_ARCH_S390X) += uaccess64.o
diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
new file mode 100644
index 000000000000..e96c35bddac7
--- /dev/null
+++ b/arch/s390/lib/delay.c
@@ -0,0 +1,51 @@
+/*
+ *  arch/s390/kernel/delay.c
+ *    Precise Delay Loops for S390
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *
+ *  Derived from "arch/i386/lib/delay.c"
+ *    Copyright (C) 1993 Linus Torvalds
+ *    Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+
+#ifdef CONFIG_SMP
+#include <asm/smp.h>
+#endif
+
+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"
+                : /* no outputs */ : "r" (loops/2) );
+}
+
+/*
+ * Waits for 'usecs' microseconds using the tod clock, giving up the time slice
+ * of the virtual PU inbetween to avoid congestion.
+ */
+void __udelay(unsigned long usecs)
+{
+        uint64_t start_cc, end_cc;
+
+        if (usecs == 0)
+                return;
+        asm volatile ("STCK %0" : "=m" (start_cc));
+        do {
+                cpu_relax();
+                asm volatile ("STCK %0" : "=m" (end_cc));
+        } while (((end_cc - start_cc)/4096) < usecs);
+}
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
new file mode 100644
index 000000000000..8240cc77e06e
--- /dev/null
+++ b/arch/s390/lib/string.c
@@ -0,0 +1,381 @@
+/*
+ *  arch/s390/lib/string.c
+ *    Optimized string functions
+ *
+ *  S390 version
+ *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    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';
+                __builtin_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;
+        __builtin_memset(dest + len, 0, n - len);
+        __builtin_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';
+                __builtin_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';
+        __builtin_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 0;
+}
+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 0;
+}
+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);
+
+/**
+ * memcpy - Copy one area of memory to another
+ * @dest: Where to copy to
+ * @src: Where to copy from
+ * @n: The size of the area.
+ *
+ * returns a pointer to @dest
+ */
+void *memcpy(void *dest, const void *src, size_t n)
+{
+        return __builtin_memcpy(dest, src, n);
+}
+EXPORT_SYMBOL(memcpy);
+
+/**
+ * memset - Fill a region of memory with the given value
+ * @s: Pointer to the start of the area.
+ * @c: The byte to fill the area with
+ * @n: The size of the area.
+ *
+ * returns a pointer to @s
+ */
+void *memset(void *s, int c, size_t n)
+{
+        char *xs;
+
+        if (c == 0)
+                return __builtin_memset(s, 0, n);
+
+        xs = (char *) s;
+        if (n > 0)
+                do {
+                        *xs++ = c;
+                } while (--n > 0);
+        return s;
+}
+EXPORT_SYMBOL(memset);
diff --git a/arch/s390/lib/uaccess.S b/arch/s390/lib/uaccess.S
new file mode 100644
index 000000000000..e8029ef42ef2
--- /dev/null
+++ b/arch/s390/lib/uaccess.S
@@ -0,0 +1,210 @@
+/*
+ *  arch/s390/lib/uaccess.S
+ *    __copy_{from|to}_user functions.
+ *
+ *  s390
+ *    Copyright (C) 2000,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Authors(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  These functions have standard call interface
+ */
+
+#include <linux/errno.h>
+#include <asm/lowcore.h>
+#include <asm/offsets.h>
+
+        .text
+        .align 4
+        .globl __copy_from_user_asm
+        # %r2 = to, %r3 = n, %r4 = from
+__copy_from_user_asm:
+        slr     %r0,%r0
+0:      mvcp    0(%r3,%r2),0(%r4),%r0
+        jnz     1f
+        slr     %r2,%r2
+        br      %r14
+1:      la      %r2,256(%r2)
+        la      %r4,256(%r4)
+        ahi     %r3,-256
+2:      mvcp    0(%r3,%r2),0(%r4),%r0
+        jnz     1b
+3:      slr     %r2,%r2
+        br      %r14
+4:      lhi     %r0,-4096
+        lr      %r5,%r4
+        slr     %r5,%r0
+        nr      %r5,%r0         # %r5 = (%r4 + 4096) & -4096
+        slr     %r5,%r4         # %r5 = #bytes to next user page boundary
+        clr     %r3,%r5         # copy crosses next page boundary ?
+        jnh     6f              # no, the current page faulted
+        # move with the reduced length which is < 256
+5:      mvcp    0(%r5,%r2),0(%r4),%r0
+        slr     %r3,%r5
+6:      lr      %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .long   0b,4b
+        .long   2b,4b
+        .long   5b,6b
+        .previous
+
+        .align 4
+        .text
+        .globl __copy_to_user_asm
+        # %r2 = from, %r3 = n, %r4 = to
+__copy_to_user_asm:
+        slr     %r0,%r0
+0:      mvcs    0(%r3,%r4),0(%r2),%r0
+        jnz     1f
+        slr     %r2,%r2
+        br      %r14
+1:      la      %r2,256(%r2)
+        la      %r4,256(%r4)
+        ahi     %r3,-256
+2:      mvcs    0(%r3,%r4),0(%r2),%r0
+        jnz     1b
+3:      slr     %r2,%r2
+        br      %r14
+4:      lhi     %r0,-4096
+        lr      %r5,%r4
+        slr     %r5,%r0
+        nr      %r5,%r0         # %r5 = (%r4 + 4096) & -4096
+        slr     %r5,%r4         # %r5 = #bytes to next user page boundary
+        clr     %r3,%r5         # copy crosses next page boundary ?
+        jnh     6f              # no, the current page faulted
+        # move with the reduced length which is < 256
+5:      mvcs    0(%r5,%r4),0(%r2),%r0
+        slr     %r3,%r5
+6:      lr      %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .long   0b,4b
+        .long   2b,4b
+        .long   5b,6b
+        .previous
+
+        .align 4
+        .text
+        .globl __copy_in_user_asm
+        # %r2 = from, %r3 = n, %r4 = to
+__copy_in_user_asm:
+        sacf    256
+        bras    1,1f
+        mvc     0(1,%r4),0(%r2)
+0:      mvc     0(256,%r4),0(%r2)
+        la      %r2,256(%r2)
+        la      %r4,256(%r4)
+1:      ahi     %r3,-256
+        jnm     0b
+2:      ex      %r3,0(%r1)
+        sacf    0
+        slr     %r2,%r2
+        br      14
+3:      mvc     0(1,%r4),0(%r2)
+        la      %r2,1(%r2)
+        la      %r4,1(%r4)
+        ahi     %r3,-1
+        jnm     3b
+4:      lr      %r2,%r3
+        sacf    0
+        br      %r14
+        .section __ex_table,"a"
+        .long   0b,3b
+        .long   2b,3b
+        .long   3b,4b
+        .previous
+
+        .align 4
+        .text
+        .globl __clear_user_asm
+        # %r2 = to, %r3 = n
+__clear_user_asm:
+        bras    %r5,0f
+        .long   empty_zero_page
+0:      l       %r5,0(%r5)
+        slr     %r0,%r0
+1:      mvcs    0(%r3,%r2),0(%r5),%r0
+        jnz     2f
+        slr     %r2,%r2
+        br      %r14
+2:      la      %r2,256(%r2)
+        ahi     %r3,-256
+3:      mvcs    0(%r3,%r2),0(%r5),%r0
+        jnz     2b
+4:      slr     %r2,%r2
+        br      %r14
+5:      lhi     %r0,-4096
+        lr      %r4,%r2
+        slr     %r4,%r0
+        nr      %r4,%r0         # %r4 = (%r2 + 4096) & -4096
+        slr     %r4,%r2         # %r4 = #bytes to next user page boundary
+        clr     %r3,%r4         # clear crosses next page boundary ?
+        jnh     7f              # no, the current page faulted
+        # clear with the reduced length which is < 256
+6:      mvcs    0(%r4,%r2),0(%r5),%r0
+        slr     %r3,%r4
+7:      lr      %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .long   1b,5b
+        .long   3b,5b
+        .long   6b,7b
+        .previous
+
+        .align 4
+        .text
+        .globl __strncpy_from_user_asm
+        # %r2 = count, %r3 = dst, %r4 = src
+__strncpy_from_user_asm:
+        lhi     %r0,0
+        lr      %r1,%r4
+        la      %r4,0(%r4)      # clear high order bit from %r4
+        la      %r2,0(%r2,%r4)  # %r2 points to first byte after string
+        sacf    256
+0:      srst    %r2,%r1
+        jo      0b
+        sacf    0
+        lr      %r1,%r2
+        jh      1f              # \0 found in string ?
+        ahi     %r1,1           # include \0 in copy
+1:      slr     %r1,%r4         # %r1 = copy length (without \0)
+        slr     %r2,%r4         # %r2 = return length (including \0)
+2:      mvcp    0(%r1,%r3),0(%r4),%r0
+        jnz     3f
+        br      %r14
+3:      la      %r3,256(%r3)
+        la      %r4,256(%r4)
+        ahi     %r1,-256
+        mvcp    0(%r1,%r3),0(%r4),%r0
+        jnz     3b
+        br      %r14
+4:      sacf    0
+        lhi     %r2,-EFAULT
+        br      %r14
+        .section __ex_table,"a"
+        .long   0b,4b
+        .previous
+
+        .align 4
+        .text
+        .globl __strnlen_user_asm
+        # %r2 = count, %r3 = src
+__strnlen_user_asm:
+        lhi     %r0,0
+        lr      %r1,%r3
+        la      %r3,0(%r3)      # clear high order bit from %r4
+        la      %r2,0(%r2,%r3)  # %r2 points to first byte after string
+        sacf    256
+0:      srst    %r2,%r1
+        jo      0b
+        sacf    0
+        jh      1f              # \0 found in string ?
+        ahi     %r2,1           # strnlen_user result includes the \0
+1:      slr     %r2,%r3
+        br      %r14
+2:      sacf    0
+        lhi     %r2,-EFAULT
+        br      %r14
+        .section __ex_table,"a"
+        .long   0b,2b
+        .previous
diff --git a/arch/s390/lib/uaccess64.S b/arch/s390/lib/uaccess64.S
new file mode 100644
index 000000000000..0ca56972f4f0
--- /dev/null
+++ b/arch/s390/lib/uaccess64.S
@@ -0,0 +1,206 @@
+/*
+ *  arch/s390x/lib/uaccess.S
+ *    __copy_{from|to}_user functions.
+ *
+ *  s390
+ *    Copyright (C) 2000,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Authors(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  These functions have standard call interface
+ */
+
+#include <linux/errno.h>
+#include <asm/lowcore.h>
+#include <asm/offsets.h>
+
+        .text
+        .align 4
+        .globl __copy_from_user_asm
+        # %r2 = to, %r3 = n, %r4 = from
+__copy_from_user_asm:
+        slgr    %r0,%r0
+0:      mvcp    0(%r3,%r2),0(%r4),%r0
+        jnz     1f
+        slgr    %r2,%r2
+        br      %r14
+1:      la      %r2,256(%r2)
+        la      %r4,256(%r4)
+        aghi    %r3,-256
+2:      mvcp    0(%r3,%r2),0(%r4),%r0
+        jnz     1b
+3:      slgr    %r2,%r2
+        br      %r14
+4:      lghi    %r0,-4096
+        lgr     %r5,%r4
+        slgr    %r5,%r0
+        ngr     %r5,%r0         # %r5 = (%r4 + 4096) & -4096
+        slgr    %r5,%r4         # %r5 = #bytes to next user page boundary
+        clgr    %r3,%r5         # copy crosses next page boundary ?
+        jnh     6f              # no, the current page faulted
+        # move with the reduced length which is < 256
+5:      mvcp    0(%r5,%r2),0(%r4),%r0
+        slgr    %r3,%r5
+6:      lgr     %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .quad   0b,4b
+        .quad   2b,4b
+        .quad   5b,6b
+        .previous
+
+        .align 4
+        .text
+        .globl __copy_to_user_asm
+        # %r2 = from, %r3 = n, %r4 = to
+__copy_to_user_asm:
+        slgr    %r0,%r0
+0:      mvcs    0(%r3,%r4),0(%r2),%r0
+        jnz     1f
+        slgr    %r2,%r2
+        br      %r14
+1:      la      %r2,256(%r2)
+        la      %r4,256(%r4)
+        aghi    %r3,-256
+2:      mvcs    0(%r3,%r4),0(%r2),%r0
+        jnz     1b
+3:      slgr    %r2,%r2
+        br      %r14
+4:      lghi    %r0,-4096
+        lgr     %r5,%r4
+        slgr    %r5,%r0
+        ngr     %r5,%r0         # %r5 = (%r4 + 4096) & -4096
+        slgr    %r5,%r4         # %r5 = #bytes to next user page boundary
+        clgr    %r3,%r5         # copy crosses next page boundary ?
+        jnh     6f              # no, the current page faulted
+        # move with the reduced length which is < 256
+5:      mvcs    0(%r5,%r4),0(%r2),%r0
+        slgr    %r3,%r5
+6:      lgr     %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .quad   0b,4b
+        .quad   2b,4b
+        .quad   5b,6b
+        .previous
+
+        .align 4
+        .text
+        .globl __copy_in_user_asm
+        # %r2 = from, %r3 = n, %r4 = to
+__copy_in_user_asm:
+        sacf    256
+        bras    1,1f
+        mvc     0(1,%r4),0(%r2)
+0:      mvc     0(256,%r4),0(%r2)
+        la      %r2,256(%r2)
+        la      %r4,256(%r4)
+1:      aghi    %r3,-256
+        jnm     0b
+2:      ex      %r3,0(%r1)
+        sacf    0
+        slgr    %r2,%r2
+        br      14
+3:      mvc     0(1,%r4),0(%r2)
+        la      %r2,1(%r2)
+        la      %r4,1(%r4)
+        aghi    %r3,-1
+        jnm     3b
+4:      lgr     %r2,%r3
+        sacf    0
+        br      %r14
+        .section __ex_table,"a"
+        .quad   0b,3b
+        .quad   2b,3b
+        .quad   3b,4b
+        .previous
+
+        .align 4
+        .text
+        .globl __clear_user_asm
+        # %r2 = to, %r3 = n
+__clear_user_asm:
+        slgr    %r0,%r0
+        larl    %r5,empty_zero_page
+1:      mvcs    0(%r3,%r2),0(%r5),%r0
+        jnz     2f
+        slgr    %r2,%r2
+        br      %r14
+2:      la      %r2,256(%r2)
+        aghi    %r3,-256
+3:      mvcs    0(%r3,%r2),0(%r5),%r0
+        jnz     2b
+4:      slgr    %r2,%r2
+        br      %r14
+5:      lghi    %r0,-4096
+        lgr     %r4,%r2
+        slgr    %r4,%r0
+        ngr     %r4,%r0         # %r4 = (%r2 + 4096) & -4096
+        slgr    %r4,%r2         # %r4 = #bytes to next user page boundary
+        clgr    %r3,%r4         # clear crosses next page boundary ?
+        jnh     7f              # no, the current page faulted
+        # clear with the reduced length which is < 256
+6:      mvcs    0(%r4,%r2),0(%r5),%r0
+        slgr    %r3,%r4
+7:      lgr     %r2,%r3
+        br      %r14
+        .section __ex_table,"a"
+        .quad   1b,5b
+        .quad   3b,5b
+        .quad   6b,7b
+        .previous
+
+        .align 4
+        .text
+        .globl __strncpy_from_user_asm
+        # %r2 = count, %r3 = dst, %r4 = src
+__strncpy_from_user_asm:
+        lghi    %r0,0
+        lgr     %r1,%r4
+        la      %r2,0(%r2,%r4)  # %r2 points to first byte after string
+        sacf    256
+0:      srst    %r2,%r1
+        jo      0b
+        sacf    0
+        lgr     %r1,%r2
+        jh      1f              # \0 found in string ?
+        aghi    %r1,1           # include \0 in copy
+1:      slgr    %r1,%r4         # %r1 = copy length (without \0)
+        slgr    %r2,%r4         # %r2 = return length (including \0)
+2:      mvcp    0(%r1,%r3),0(%r4),%r0
+        jnz     3f
+        br      %r14
+3:      la      %r3,256(%r3)
+        la      %r4,256(%r4)
+        aghi    %r1,-256
+        mvcp    0(%r1,%r3),0(%r4),%r0
+        jnz     3b
+        br      %r14
+4:      sacf    0
+        lghi    %r2,-EFAULT
+        br      %r14
+        .section __ex_table,"a"
+        .quad   0b,4b
+        .previous
+
+        .align 4
+        .text
+        .globl __strnlen_user_asm
+        # %r2 = count, %r3 = src
+__strnlen_user_asm:
+        lghi    %r0,0
+        lgr     %r1,%r3
+        la      %r2,0(%r2,%r3)  # %r2 points to first byte after string
+        sacf    256
+0:      srst    %r2,%r1
+        jo      0b
+        sacf    0
+        jh      1f              # \0 found in string ?
+        aghi    %r2,1           # strnlen_user result includes the \0
+1:      slgr    %r2,%r3
+        br      %r14
+2:      sacf    0
+        lghi    %r2,-EFAULT
+        br      %r14
+        .section __ex_table,"a"
+        .quad   0b,2b
+        .previous