diff options
Diffstat (limited to 'arch/cris/arch-v10/lib/checksumcopy.S')
-rw-r--r-- | arch/cris/arch-v10/lib/checksumcopy.S | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/arch/cris/arch-v10/lib/checksumcopy.S b/arch/cris/arch-v10/lib/checksumcopy.S deleted file mode 100644 index b21449cb1ad3..000000000000 --- a/arch/cris/arch-v10/lib/checksumcopy.S +++ /dev/null @@ -1,127 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * A fast checksum+copy routine using movem - * Copyright (c) 1998, 2001 Axis Communications AB - * - * Authors: Bjorn Wesen - * - * csum_partial_copy_nocheck(const char *src, char *dst, - * int len, unsigned int sum) - */ - - .globl csum_partial_copy_nocheck -csum_partial_copy_nocheck: - - ;; r10 - src - ;; r11 - dst - ;; r12 - length - ;; r13 - checksum - - ;; check for breakeven length between movem and normal word looping versions - ;; we also do _NOT_ want to compute a checksum over more than the - ;; actual length when length < 40 - - cmpu.w 80, $r12 - blo _word_loop - nop - - ;; need to save the registers we use below in the movem loop - ;; this overhead is why we have a check above for breakeven length - ;; only r0 - r8 have to be saved, the other ones are clobber-able - ;; according to the ABI - - subq 9*4, $sp - movem $r8, [$sp] - - ;; do a movem copy and checksum - - subq 10*4, $r12 ; update length for the first loop - -_mloop: movem [$r10+],$r9 ; read 10 longwords -1: ;; A failing userspace access will have this as PC. - movem $r9,[$r11+] ; write 10 longwords - - ;; perform dword checksumming on the 10 longwords - - add.d $r0,$r13 - ax - add.d $r1,$r13 - ax - add.d $r2,$r13 - ax - add.d $r3,$r13 - ax - add.d $r4,$r13 - ax - add.d $r5,$r13 - ax - add.d $r6,$r13 - ax - add.d $r7,$r13 - ax - add.d $r8,$r13 - ax - add.d $r9,$r13 - - ;; fold the carry into the checksum, to avoid having to loop the carry - ;; back into the top - - ax - addq 0,$r13 - - subq 10*4,$r12 - bge _mloop - nop - - addq 10*4,$r12 ; compensate for last loop underflowing length - - movem [$sp+],$r8 ; restore regs - -_word_loop: - ;; only fold if there is anything to fold. - - cmpq 0,$r13 - beq _no_fold - - ;; fold 32-bit checksum into a 16-bit checksum, to avoid carries below - ;; r9 can be used as temporary. - - move.d $r13,$r9 - lsrq 16,$r9 ; r0 = checksum >> 16 - and.d 0xffff,$r13 ; checksum = checksum & 0xffff - add.d $r9,$r13 ; checksum += r0 - -_no_fold: - cmpq 2,$r12 - blt _no_words - nop - - ;; copy and checksum the rest of the words - - subq 2,$r12 - -_wloop: move.w [$r10+],$r9 -2: ;; A failing userspace access will have this as PC. - addu.w $r9,$r13 - subq 2,$r12 - bge _wloop - move.w $r9,[$r11+] - - addq 2,$r12 - -_no_words: - ;; see if we have one odd byte more - cmpq 1,$r12 - beq _do_byte - nop - ret - move.d $r13, $r10 - -_do_byte: - ;; copy and checksum the last byte - move.b [$r10],$r9 -3: ;; A failing userspace access will have this as PC. - addu.b $r9,$r13 - move.b $r9,[$r11] - ret - move.d $r13, $r10 |