/* * Optimized user space space access functions based on mvcos. * * Copyright IBM Corp. 2006 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Gerald Schaefer (gerald.schaefer@de.ibm.com) */ #include #include #include #include #include #include #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 static struct static_key have_mvcos = STATIC_KEY_INIT_TRUE; static inline size_t copy_from_user_mvcos(void *x, const void __user *ptr, size_t 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:"ALR" %0,%3\n" " "SLR" %1,%3\n" " "SLR" %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " "SLR" %4,%1\n" " "CLR" %0,%4\n" /* copy crosses next page boundary? */ " jnh 4f\n" "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n" "10:"SLR" %0,%4\n" " "ALR" %2,%4\n" "4:"LHI" %4,-1\n" " "ALR" %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:"AHI" %4,-256\n" " jnm 5b\n" " ex %4,0(%3)\n" " j 8f\n" "7:"SLR" %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; } size_t __copy_from_user(void *to, const void __user *from, size_t n) { if (static_key_true(&have_mvcos)) return copy_from_user_mvcos(to, from, n); return copy_from_user_pt(to, from, n); } EXPORT_SYMBOL(__copy_from_user); static inline size_t copy_to_user_mvcos(void __user *ptr, const void *x, size_t 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:"ALR" %0,%3\n" " "SLR" %1,%3\n" " "SLR" %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " "SLR" %4,%1\n" " "CLR" %0,%4\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n" "7:"SLR" %0,%4\n" " j 5f\n" "4:"SLR" %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; } size_t __copy_to_user(void __user *to, const void *from, size_t n) { if (static_key_true(&have_mvcos)) return copy_to_user_mvcos(to, from, n); return copy_to_user_pt(to, from, n); } EXPORT_SYMBOL(__copy_to_user); static inline size_t copy_in_user_mvcos(void __user *to, const void __user *from, size_t 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:"ALR" %0,%3\n" " "SLR" %1,%3\n" " "SLR" %2,%3\n" " j 0b\n" "2:"SLR" %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; } size_t __copy_in_user(void __user *to, const void __user *from, size_t n) { if (static_key_true(&have_mvcos)) return copy_in_user_mvcos(to, from, n); return copy_in_user_pt(to, from, n); } EXPORT_SYMBOL(__copy_in_user); static inline size_t clear_user_mvcos(void __user *to, size_t 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:"ALR" %0,%2\n" " "SLR" %1,%2\n" " j 0b\n" "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ " "SLR" %3,%1\n" " "CLR" %0,%3\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n" " "SLR" %0,%3\n" " j 5f\n" "4:"SLR" %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; } size_t __clear_user(void __user *to, size_t size) { if (static_key_true(&have_mvcos)) return clear_user_mvcos(to, size); return clear_user_pt(to, size); } EXPORT_SYMBOL(__clear_user); static inline size_t strnlen_user_mvcos(const char __user *src, size_t count) { size_t done, len, offset, len_str; char buf[256]; done = 0; do { offset = (size_t)src & ~PAGE_MASK; len = min(256UL, PAGE_SIZE - offset); len = min(count - done, len); if (copy_from_user_mvcos(buf, src, len)) return 0; len_str = strnlen(buf, len); done += len_str; src += len_str; } while ((len_str == len) && (done < count)); return done + 1; } size_t __strnlen_user(const char __user *src, size_t count) { if (static_key_true(&have_mvcos)) return strnlen_user_mvcos(src, count); return strnlen_user_pt(src, count); } EXPORT_SYMBOL(__strnlen_user); static inline size_t strncpy_from_user_mvcos(char *dst, const char __user *src, size_t count) { unsigned long 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_mvcos(dst, src, len)) return -EFAULT; len_str = strnlen(dst, len); done += len_str; src += len_str; dst += len_str; } while ((len_str == len) && (done < count)); return done; } long __strncpy_from_user(char *dst, const char __user *src, long count) { if (static_key_true(&have_mvcos)) return strncpy_from_user_mvcos(dst, src, count); return strncpy_from_user_pt(dst, src, count); } EXPORT_SYMBOL(__strncpy_from_user); static int __init uaccess_init(void) { if (!MACHINE_HAS_MVCOS) static_key_slow_dec(&have_mvcos); return 0; } early_initcall(uaccess_init);