/* * arch/s390/lib/uaccess_mvcos.c * * Optimized user space space access functions based on mvcos. * * Copyright (C) IBM Corp. 2006 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Gerald Schaefer (gerald.schaefer@de.ibm.com) */ #include <linux/errno.h> #include <linux/mm.h> #include <asm/uaccess.h> #include <asm/futex.h> #include "uaccess.h" #ifndef __s390x__ #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 size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x) { 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; } static size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x) { if (size <= 256) return copy_from_user_std(size, ptr, x); return copy_from_user_mvcos(size, ptr, x); } static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x) { 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; } static size_t copy_to_user_mvcos_check(size_t size, void __user *ptr, const void *x) { if (size <= 256) return copy_to_user_std(size, ptr, x); return copy_to_user_mvcos(size, ptr, x); } static size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from) { 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; } static size_t clear_user_mvcos(size_t size, void __user *to) { 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; } static size_t strnlen_user_mvcos(size_t count, const char __user *src) { char buf[256]; int rc; size_t done, len, len_str; done = 0; do { len = min(count - done, (size_t) 256); rc = uaccess.copy_from_user(len, src + done, buf); if (unlikely(rc == len)) return 0; len -= rc; len_str = strnlen(buf, len); done += len_str; } while ((len_str == len) && (done < count)); return done + 1; } static size_t strncpy_from_user_mvcos(size_t count, const char __user *src, char *dst) { int rc; size_t done, len, len_str; done = 0; do { len = min(count - done, (size_t) 4096); rc = uaccess.copy_from_user(len, src + done, dst); if (unlikely(rc == len)) return -EFAULT; len -= rc; len_str = strnlen(dst, len); done += len_str; } while ((len_str == len) && (done < count)); return done; } struct uaccess_ops uaccess_mvcos = { .copy_from_user = copy_from_user_mvcos_check, .copy_from_user_small = copy_from_user_std, .copy_to_user = copy_to_user_mvcos_check, .copy_to_user_small = copy_to_user_std, .copy_in_user = copy_in_user_mvcos, .clear_user = clear_user_mvcos, .strnlen_user = strnlen_user_std, .strncpy_from_user = strncpy_from_user_std, .futex_atomic_op = futex_atomic_op_std, .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std, }; struct uaccess_ops uaccess_mvcos_switch = { .copy_from_user = copy_from_user_mvcos, .copy_from_user_small = copy_from_user_mvcos, .copy_to_user = copy_to_user_mvcos, .copy_to_user_small = copy_to_user_mvcos, .copy_in_user = copy_in_user_mvcos, .clear_user = clear_user_mvcos, .strnlen_user = strnlen_user_mvcos, .strncpy_from_user = strncpy_from_user_mvcos, .futex_atomic_op = futex_atomic_op_pt, .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt, };