arch/s390/lib/uaccess_mvcos.c

   1 /*
   2  *  arch/s390/lib/uaccess_mvcos.c
   3  *
   4  *  Optimized user space space access functions based on mvcos.
   5  *
   6  *    Copyright (C) IBM Corp. 2006
   7  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   8  *               Gerald Schaefer (gerald.schaefer@de.ibm.com)
   9  */
  10
  11 #include <linux/errno.h>
  12 #include <linux/mm.h>
  13 #include <asm/uaccess.h>
  14 #include <asm/futex.h>
  15
  16 #ifndef __s390x__
  17 #define AHI     "ahi"
  18 #define ALR     "alr"
  19 #define CLR     "clr"
  20 #define LHI     "lhi"
  21 #define SLR     "slr"
  22 #else
  23 #define AHI     "aghi"
  24 #define ALR     "algr"
  25 #define CLR     "clgr"
  26 #define LHI     "lghi"
  27 #define SLR     "slgr"
  28 #endif
  29
  30 size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
  31 {
  32         register unsigned long reg0 asm("0") = 0x81UL;
  33         unsigned long tmp1, tmp2;
  34
  35         tmp1 = -4096UL;
  36         asm volatile(
  37                 "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
  38                 "   jz    4f\n"
  39                 "1:"ALR"  %0,%3\n"
  40                 "  "SLR"  %1,%3\n"
  41                 "  "SLR"  %2,%3\n"
  42                 "   j     0b\n"
  43                 "2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
  44                 "   nr    %4,%3\n"      /* %4 = (ptr + 4095) & -4096 */
  45                 "  "SLR"  %4,%1\n"
  46                 "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
  47                 "   jnh   5f\n"
  48                 "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
  49                 "  "SLR"  %0,%4\n"
  50                 "   j     5f\n"
  51                 "4:"SLR"  %0,%0\n"
  52                 "5: \n"
  53                 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
  54                 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
  55                 : "d" (reg0) : "cc", "memory");
  56         return size;
  57 }
  58
  59 size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
  60 {
  61         register unsigned long reg0 asm("0") = 0x810000UL;
  62         unsigned long tmp1, tmp2;
  63
  64         tmp1 = -4096UL;
  65         asm volatile(
  66                 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
  67                 "   jz    4f\n"
  68                 "1:"ALR"  %0,%3\n"
  69                 "  "SLR"  %1,%3\n"
  70                 "  "SLR"  %2,%3\n"
  71                 "   j     0b\n"
  72                 "2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
  73                 "   nr    %4,%3\n"      /* %4 = (ptr + 4095) & -4096 */
  74                 "  "SLR"  %4,%1\n"
  75                 "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
  76                 "   jnh   5f\n"
  77                 "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
  78                 "  "SLR"  %0,%4\n"
  79                 "   j     5f\n"
  80                 "4:"SLR"  %0,%0\n"
  81                 "5: \n"
  82                 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
  83                 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
  84                 : "d" (reg0) : "cc", "memory");
  85         return size;
  86 }
  87
  88 size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
  89 {
  90         register unsigned long reg0 asm("0") = 0x810081UL;
  91         unsigned long tmp1, tmp2;
  92
  93         tmp1 = -4096UL;
  94         /* FIXME: copy with reduced length. */
  95         asm volatile(
  96                 "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
  97                 "   jz    2f\n"
  98                 "1:"ALR"  %0,%3\n"
  99                 "  "SLR"  %1,%3\n"
 100                 "  "SLR"  %2,%3\n"
 101                 "   j     0b\n"
 102                 "2:"SLR"  %0,%0\n"
 103                 "3: \n"
 104                 EX_TABLE(0b,3b)
 105                 : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
 106                 : "d" (reg0) : "cc", "memory");
 107         return size;
 108 }
 109
 110 size_t clear_user_mvcos(size_t size, void __user *to)
 111 {
 112         register unsigned long reg0 asm("0") = 0x810000UL;
 113         unsigned long tmp1, tmp2;
 114
 115         tmp1 = -4096UL;
 116         asm volatile(
 117                 "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
 118                 "   jz    4f\n"
 119                 "1:"ALR"  %0,%2\n"
 120                 "  "SLR"  %1,%2\n"
 121                 "   j     0b\n"
 122                 "2: la    %3,4095(%1)\n"/* %4 = to + 4095 */
 123                 "   nr    %3,%2\n"      /* %4 = (to + 4095) & -4096 */
 124                 "  "SLR"  %3,%1\n"
 125                 "  "CLR"  %0,%3\n"      /* copy crosses next page boundary? */
 126                 "   jnh   5f\n"
 127                 "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
 128                 "  "SLR"  %0,%3\n"
 129                 "   j     5f\n"
 130                 "4:"SLR"  %0,%0\n"
 131                 "5: \n"
 132                 EX_TABLE(0b,2b) EX_TABLE(3b,5b)
 133                 : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
 134                 : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
 135         return size;
 136 }
 137
 138 extern size_t copy_from_user_std_small(size_t, const void __user *, void *);
 139 extern size_t copy_to_user_std_small(size_t, void __user *, const void *);
 140 extern size_t strnlen_user_std(size_t, const char __user *);
 141 extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
 142 extern int futex_atomic_op(int, int __user *, int, int *);
 143 extern int futex_atomic_cmpxchg(int __user *, int, int);
 144
 145 struct uaccess_ops uaccess_mvcos = {
 146         .copy_from_user = copy_from_user_mvcos,
 147         .copy_from_user_small = copy_from_user_std_small,
 148         .copy_to_user = copy_to_user_mvcos,
 149         .copy_to_user_small = copy_to_user_std_small,
 150         .copy_in_user = copy_in_user_mvcos,
 151         .clear_user = clear_user_mvcos,
 152         .strnlen_user = strnlen_user_std,
 153         .strncpy_from_user = strncpy_from_user_std,
 154         .futex_atomic_op = futex_atomic_op,
 155         .futex_atomic_cmpxchg = futex_atomic_cmpxchg,
 156 };