LXR linux/arch/parisc/include/asm/uaccess.h

   1#ifndef __PARISC_UACCESS_H
   2#define __PARISC_UACCESS_H
   3
   4/*
   5 * User space memory access functions
   6 */
   7#include <asm/page.h>
   8#include <asm/cache.h>
   9
  10#include <linux/bug.h>
  11#include <linux/string.h>
  12
  13#define KERNEL_DS       ((mm_segment_t){0})
  14#define USER_DS         ((mm_segment_t){1})
  15
  16#define segment_eq(a, b) ((a).seg == (b).seg)
  17
  18#define get_ds()        (KERNEL_DS)
  19#define get_fs()        (current_thread_info()->addr_limit)
  20#define set_fs(x)       (current_thread_info()->addr_limit = (x))
  21
  22/*
  23 * Note that since kernel addresses are in a separate address space on
  24 * parisc, we don't need to do anything for access_ok().
  25 * We just let the page fault handler do the right thing. This also means
  26 * that put_user is the same as __put_user, etc.
  27 */
  28
  29#define access_ok(type, uaddr, size)    \
  30        ( (uaddr) == (uaddr) )
  31
  32#define put_user __put_user
  33#define get_user __get_user
  34
  35#if !defined(CONFIG_64BIT)
  36#define LDD_USER(val, ptr)      __get_user_asm64(val, ptr)
  37#define STD_USER(x, ptr)        __put_user_asm64(x, ptr)
  38#else
  39#define LDD_USER(val, ptr)      __get_user_asm(val, "ldd", ptr)
  40#define STD_USER(x, ptr)        __put_user_asm("std", x, ptr)
  41#endif
  42
  43/*
  44 * The exception table contains two values: the first is the relative offset to
  45 * the address of the instruction that is allowed to fault, and the second is
  46 * the relative offset to the address of the fixup routine. Since relative
  47 * addresses are used, 32bit values are sufficient even on 64bit kernel.
  48 */
  49
  50#define ARCH_HAS_RELATIVE_EXTABLE
  51struct exception_table_entry {
  52        int insn;       /* relative address of insn that is allowed to fault. */
  53        int fixup;      /* relative address of fixup routine */
  54};
  55
  56#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
  57        ".section __ex_table,\"aw\"\n"                     \
  58        ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
  59        ".previous\n"
  60
  61/*
  62 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
  63 * (with lowest bit set) for which the fault handler in fixup_exception() will
  64 * load -EFAULT into %r8 for a read or write fault, and zeroes the target
  65 * register in case of a read fault in get_user().
  66 */
  67#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
  68        ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
  69
  70/*
  71 * load_sr2() preloads the space register %%sr2 - based on the value of
  72 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
  73 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
  74 * memory. The following __get_user_asm() and __put_user_asm() functions have
  75 * %%sr2 hard-coded to access the requested memory.
  76 */
  77#define load_sr2() \
  78        __asm__(" or,=  %0,%%r0,%%r0\n\t"       \
  79                " mfsp %%sr3,%0\n\t"            \
  80                " mtsp %0,%%sr2\n\t"            \
  81                : : "r"(get_fs()) : )
  82
  83#define __get_user_internal(val, ptr)                   \
  84({                                                      \
  85        register long __gu_err __asm__ ("r8") = 0;      \
  86                                                        \
  87        switch (sizeof(*(ptr))) {                       \
  88        case 1: __get_user_asm(val, "ldb", ptr); break; \
  89        case 2: __get_user_asm(val, "ldh", ptr); break; \
  90        case 4: __get_user_asm(val, "ldw", ptr); break; \
  91        case 8: LDD_USER(val, ptr); break;              \
  92        default: BUILD_BUG();                           \
  93        }                                               \
  94                                                        \
  95        __gu_err;                                       \
  96})
  97
  98#define __get_user(val, ptr)                            \
  99({                                                      \
 100        load_sr2();                                     \
 101        __get_user_internal(val, ptr);                  \
 102})
 103
 104#define __get_user_asm(val, ldx, ptr)                   \
 105{                                                       \
 106        register long __gu_val;                         \
 107                                                        \
 108        __asm__("1: " ldx " 0(%%sr2,%2),%0\n"           \
 109                "9:\n"                                  \
 110                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
 111                : "=r"(__gu_val), "=r"(__gu_err)        \
 112                : "r"(ptr), "1"(__gu_err));             \
 113                                                        \
 114        (val) = (__force __typeof__(*(ptr))) __gu_val;  \
 115}
 116
 117#if !defined(CONFIG_64BIT)
 118
 119#define __get_user_asm64(val, ptr)                      \
 120{                                                       \
 121        union {                                         \
 122                unsigned long long      l;              \
 123                __typeof__(*(ptr))      t;              \
 124        } __gu_tmp;                                     \
 125                                                        \
 126        __asm__("   copy %%r0,%R0\n"                    \
 127                "1: ldw 0(%%sr2,%2),%0\n"               \
 128                "2: ldw 4(%%sr2,%2),%R0\n"              \
 129                "9:\n"                                  \
 130                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
 131                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
 132                : "=&r"(__gu_tmp.l), "=r"(__gu_err)     \
 133                : "r"(ptr), "1"(__gu_err));             \
 134                                                        \
 135        (val) = __gu_tmp.t;                             \
 136}
 137
 138#endif /* !defined(CONFIG_64BIT) */
 139
 140
 141#define __put_user_internal(x, ptr)                             \
 142({                                                              \
 143        register long __pu_err __asm__ ("r8") = 0;              \
 144        __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);       \
 145                                                                \
 146        switch (sizeof(*(ptr))) {                               \
 147        case 1: __put_user_asm("stb", __x, ptr); break;         \
 148        case 2: __put_user_asm("sth", __x, ptr); break;         \
 149        case 4: __put_user_asm("stw", __x, ptr); break;         \
 150        case 8: STD_USER(__x, ptr); break;                      \
 151        default: BUILD_BUG();                                   \
 152        }                                                       \
 153                                                                \
 154        __pu_err;                                               \
 155})
 156
 157#define __put_user(x, ptr)                                      \
 158({                                                              \
 159        load_sr2();                                             \
 160        __put_user_internal(x, ptr);                            \
 161})
 162
 163
 164/*
 165 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
 166 * instead of writing. This is because they do not write to any memory
 167 * gcc knows about, so there are no aliasing issues. These macros must
 168 * also be aware that fixups are executed in the context of the fault,
 169 * and any registers used there must be listed as clobbers.
 170 * r8 is already listed as err.
 171 */
 172
 173#define __put_user_asm(stx, x, ptr)                         \
 174        __asm__ __volatile__ (                              \
 175                "1: " stx " %2,0(%%sr2,%1)\n"               \
 176                "9:\n"                                      \
 177                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b)     \
 178                : "=r"(__pu_err)                            \
 179                : "r"(ptr), "r"(x), "0"(__pu_err))
 180
 181
 182#if !defined(CONFIG_64BIT)
 183
 184#define __put_user_asm64(__val, ptr) do {                   \
 185        __asm__ __volatile__ (                              \
 186                "1: stw %2,0(%%sr2,%1)\n"                   \
 187                "2: stw %R2,4(%%sr2,%1)\n"                  \
 188                "9:\n"                                      \
 189                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b)     \
 190                ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b)     \
 191                : "=r"(__pu_err)                            \
 192                : "r"(ptr), "r"(__val), "0"(__pu_err));     \
 193} while (0)
 194
 195#endif /* !defined(CONFIG_64BIT) */
 196
 197
 198/*
 199 * Complex access routines -- external declarations
 200 */
 201
 202extern long strncpy_from_user(char *, const char __user *, long);
 203extern unsigned lclear_user(void __user *, unsigned long);
 204extern long lstrnlen_user(const char __user *, long);
 205/*
 206 * Complex access routines -- macros
 207 */
 208#define user_addr_max() (~0UL)
 209
 210#define strnlen_user lstrnlen_user
 211#define clear_user lclear_user
 212#define __clear_user lclear_user
 213
 214unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src,
 215                                            unsigned long len);
 216unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src,
 217                                            unsigned long len);
 218unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src,
 219                                            unsigned long len);
 220#define INLINE_COPY_TO_USER
 221#define INLINE_COPY_FROM_USER
 222
 223struct pt_regs;
 224int fixup_exception(struct pt_regs *regs);
 225
 226#endif /* __PARISC_UACCESS_H */
 227