1 files changed, 81 insertions, 0 deletions

diff --git a/arch/alpha/lib/strncpy.S b/arch/alpha/lib/strncpy.S
new file mode 100644
index 000000000000..338551c7113c
--- /dev/null
+++ b/arch/alpha/lib/strncpy.S
@@ -0,0 +1,81 @@
+/*
+ * arch/alpha/lib/strncpy.S
+ * Contributed by Richard Henderson (rth@tamu.edu)
+ *
+ * Copy no more than COUNT bytes of the null-terminated string from
+ * SRC to DST.  If SRC does not cover all of COUNT, the balance is
+ * zeroed.
+ *
+ * Or, rather, if the kernel cared about that weird ANSI quirk.  This
+ * version has cropped that bit o' nastiness as well as assuming that
+ * __stxncpy is in range of a branch.
+ */
+
+        .set noat
+        .set noreorder
+
+        .text
+
+        .align 4
+        .globl strncpy
+        .ent strncpy
+strncpy:
+        .frame $30, 0, $26
+        .prologue 0
+
+        mov     $16, $0         # set return value now
+        beq     $18, $zerolen
+        unop
+        bsr     $23, __stxncpy  # do the work of the copy
+
+        unop
+        bne     $18, $multiword # do we have full words left?
+        subq    $24, 1, $3      # nope
+        subq    $27, 1, $4
+
+        or      $3, $24, $3     # clear the bits between the last
+        or      $4, $27, $4     # written byte and the last byte in COUNT
+        andnot  $4, $3, $4
+        zap     $1, $4, $1
+
+        stq_u   $1, 0($16)
+        ret
+
+        .align  4
+$multiword:
+        subq    $24, 1, $2      # clear the final bits in the prev word
+        or      $2, $24, $2
+        zapnot  $1, $2, $1
+        subq    $18, 1, $18
+
+        stq_u   $1, 0($16)
+        addq    $16, 8, $16
+        unop
+        beq     $18, 1f
+
+        nop
+        unop
+        nop
+        blbc    $18, 0f
+
+        stq_u   $31, 0($16)     # zero one word
+        subq    $18, 1, $18
+        addq    $16, 8, $16
+        beq     $18, 1f
+
+0:      stq_u   $31, 0($16)     # zero two words
+        subq    $18, 2, $18
+        stq_u   $31, 8($16)
+        addq    $16, 16, $16
+        bne     $18, 0b
+
+1:      ldq_u   $1, 0($16)      # clear the leading bits in the final word
+        subq    $27, 1, $2
+        or      $2, $27, $2
+
+        zap     $1, $2, $1
+        stq_u   $1, 0($16)
+$zerolen:
+        ret
+
+        .end    strncpy