diff options
Diffstat (limited to 'arch/s390/lib/uaccess.S')
| -rw-r--r-- | arch/s390/lib/uaccess.S | 210 |
1 files changed, 210 insertions, 0 deletions
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 |