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authorDavid Howells <dhowells@redhat.com>2008-02-08 04:19:31 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-08 09:22:30 -0800
commitb920de1b77b72ca9432ac3f97edb26541e65e5dd (patch)
tree40fa9be1470e929c47927dea7eddf184c0204229 /arch/mn10300/lib/do_csum.S
parentef3d534754f31fed9c3b976fee1ece1b3bc38282 (diff)
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mn10300: add the MN10300/AM33 architecture to the kernel
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the kernel. This patch also adds board support for the ASB2303 with the ASB2308 daughter board, and the ASB2305. The only processor supported is the MN103E010, which is an AM33v2 core plus on-chip devices. [akpm@linux-foundation.org: nuke cvs control strings] Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com> Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/mn10300/lib/do_csum.S')
-rw-r--r--arch/mn10300/lib/do_csum.S162
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/mn10300/lib/do_csum.S b/arch/mn10300/lib/do_csum.S
new file mode 100644
index 000000000000..e138994e1667
--- /dev/null
+++ b/arch/mn10300/lib/do_csum.S
@@ -0,0 +1,162 @@
+/* Optimised simple memory checksum
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <asm/cache.h>
+
+ .section .text
+ .balign L1_CACHE_BYTES
+
+###############################################################################
+#
+# unsigned int do_csum(const unsigned char *buff, size_t len)
+#
+###############################################################################
+ .globl do_csum
+ .type do_csum,@function
+do_csum:
+ movm [d2,d3],(sp)
+ mov d0,(12,sp)
+ mov d1,(16,sp)
+ mov d1,d2 # count
+ mov d0,a0 # buff
+ clr d1 # accumulator
+
+ cmp +0,d2
+ beq do_csum_done # return if zero-length buffer
+
+ # 4-byte align the buffer pointer
+ btst +3,a0
+ beq do_csum_now_4b_aligned
+
+ btst +1,a0
+ beq do_csum_addr_not_odd
+ movbu (a0),d0
+ inc a0
+ asl +8,d0
+ add d0,d1
+ addc +0,d1
+ add -1,d2
+do_csum_addr_not_odd:
+
+ cmp +2,d2
+ bcs do_csum_fewer_than_4
+ btst +2,a0
+ beq do_csum_now_4b_aligned
+ movhu (a0+),d0
+ add d0,d1
+ addc +0,d1
+ add -2,d2
+ cmp +4,d2
+ bcs do_csum_fewer_than_4
+
+do_csum_now_4b_aligned:
+ # we want to checksum as much as we can in chunks of 32 bytes
+ cmp +31,d2
+ bls do_csum_remainder # 4-byte aligned remainder
+
+ add -32,d2
+ mov +32,d3
+
+do_csum_loop:
+ mov (a0+),d0
+ add d0,d1
+ mov (a0+),e0
+ addc e0,d1
+ mov (a0+),e1
+ addc e1,d1
+ mov (a0+),e3
+ addc e3,d1
+ mov (a0+),d0
+ addc d0,d1
+ mov (a0+),e0
+ addc e0,d1
+ mov (a0+),e1
+ addc e1,d1
+ mov (a0+),e3
+ addc e3,d1
+ addc +0,d1
+
+ sub d3,d2
+ bcc do_csum_loop
+
+ add d3,d2
+ beq do_csum_done
+
+do_csum_remainder:
+ # cut 16-31 bytes down to 0-15
+ cmp +16,d2
+ bcs do_csum_fewer_than_16
+ mov (a0+),d0
+ add d0,d1
+ mov (a0+),e0
+ addc e0,d1
+ mov (a0+),e1
+ addc e1,d1
+ mov (a0+),e3
+ addc e3,d1
+ addc +0,d1
+ add -16,d2
+ beq do_csum_done
+
+do_csum_fewer_than_16:
+ # copy the remaining whole words
+ cmp +4,d2
+ bcs do_csum_fewer_than_4
+ cmp +8,d2
+ bcs do_csum_one_word
+ cmp +12,d2
+ bcs do_csum_two_words
+ mov (a0+),d0
+ add d0,d1
+ addc +0,d1
+do_csum_two_words:
+ mov (a0+),d0
+ add d0,d1
+ addc +0,d1
+do_csum_one_word:
+ mov (a0+),d0
+ add d0,d1
+ addc +0,d1
+
+do_csum_fewer_than_4:
+ and +3,d2
+ beq do_csum_done
+ xor_cmp d0,d0,+2,d2
+ bcs do_csum_fewer_than_2
+ movhu (a0+),d0
+do_csum_fewer_than_2:
+ and +1,d2
+ beq do_csum_add_last_bit
+ movbu (a0),d3
+ add d3,d0
+do_csum_add_last_bit:
+ add d0,d1
+ addc +0,d1
+
+do_csum_done:
+ # compress the checksum down to 16 bits
+ mov +0xffff0000,d2
+ and d1,d2
+ asl +16,d1
+ add d2,d1,d0
+ addc +0xffff,d0
+ lsr +16,d0
+
+ # flip the halves of the word result if the buffer was oddly aligned
+ mov (12,sp),d1
+ and +1,d1
+ beq do_csum_not_oddly_aligned
+ swaph d0,d0 # exchange bits 15:8 with 7:0
+
+do_csum_not_oddly_aligned:
+ ret [d2,d3],8
+
+do_csum_end:
+ .size do_csum, do_csum_end-do_csum