1 files changed, 137 insertions, 0 deletions

diff --git a/arch/arm/lib/csumpartial.S b/arch/arm/lib/csumpartial.S
new file mode 100644
index 000000000000..cb5e3708f118
--- /dev/null
+++ b/arch/arm/lib/csumpartial.S
@@ -0,0 +1,137 @@
+/*
+ *  linux/arch/arm/lib/csumpartial.S
+ *
+ *  Copyright (C) 1995-1998 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+                .text
+
+/*
+ * Function: __u32 csum_partial(const char *src, int len, __u32 sum)
+ * Params  : r0 = buffer, r1 = len, r2 = checksum
+ * Returns : r0 = new checksum
+ */
+
+buf     .req    r0
+len     .req    r1
+sum     .req    r2
+td0     .req    r3
+td1     .req    r4      @ save before use
+td2     .req    r5      @ save before use
+td3     .req    lr
+
+.zero:          mov     r0, sum
+                add     sp, sp, #4
+                ldr     pc, [sp], #4
+
+                /*
+                 * Handle 0 to 7 bytes, with any alignment of source and
+                 * destination pointers.  Note that when we get here, C = 0
+                 */
+.less8:         teq     len, #0                 @ check for zero count
+                beq     .zero
+
+                /* we must have at least one byte. */
+                tst     buf, #1                 @ odd address?
+                ldrneb  td0, [buf], #1
+                subne   len, len, #1
+                adcnes  sum, sum, td0, put_byte_1
+
+.less4:         tst     len, #6
+                beq     .less8_byte
+
+                /* we are now half-word aligned */
+
+.less8_wordlp:
+#if __LINUX_ARM_ARCH__ >= 4
+                ldrh    td0, [buf], #2
+                sub     len, len, #2
+#else
+                ldrb    td0, [buf], #1
+                ldrb    td3, [buf], #1
+                sub     len, len, #2
+#ifndef __ARMEB__
+                orr     td0, td0, td3, lsl #8
+#else
+                orr     td0, td3, td0, lsl #8
+#endif
+#endif
+                adcs    sum, sum, td0
+                tst     len, #6
+                bne     .less8_wordlp
+
+.less8_byte:    tst     len, #1                 @ odd number of bytes
+                ldrneb  td0, [buf], #1          @ include last byte
+                adcnes  sum, sum, td0, put_byte_0       @ update checksum
+
+.done:          adc     r0, sum, #0             @ collect up the last carry
+                ldr     td0, [sp], #4
+                tst     td0, #1                 @ check buffer alignment
+                movne   r0, r0, ror #8          @ rotate checksum by 8 bits
+                ldr     pc, [sp], #4            @ return
+
+.not_aligned:   tst     buf, #1                 @ odd address
+                ldrneb  td0, [buf], #1          @ make even
+                subne   len, len, #1
+                adcnes  sum, sum, td0, put_byte_1       @ update checksum
+
+                tst     buf, #2                 @ 32-bit aligned?
+#if __LINUX_ARM_ARCH__ >= 4
+                ldrneh  td0, [buf], #2          @ make 32-bit aligned
+                subne   len, len, #2
+#else
+                ldrneb  td0, [buf], #1
+                ldrneb  ip, [buf], #1
+                subne   len, len, #2
+#ifndef __ARMEB__
+                orrne   td0, td0, ip, lsl #8
+#else
+                orrne   td0, ip, td0, lsl #8
+#endif
+#endif
+                adcnes  sum, sum, td0           @ update checksum
+                mov     pc, lr
+
+ENTRY(csum_partial)
+                stmfd   sp!, {buf, lr}
+                cmp     len, #8                 @ Ensure that we have at least
+                blo     .less8                  @ 8 bytes to copy.
+
+                adds    sum, sum, #0            @ C = 0
+                tst     buf, #3                 @ Test destination alignment
+                blne    .not_aligned            @ aligh destination, return here
+
+1:              bics    ip, len, #31
+                beq     3f
+
+                stmfd   sp!, {r4 - r5}
+2:              ldmia   buf!, {td0, td1, td2, td3}
+                adcs    sum, sum, td0
+                adcs    sum, sum, td1
+                adcs    sum, sum, td2
+                adcs    sum, sum, td3
+                ldmia   buf!, {td0, td1, td2, td3}
+                adcs    sum, sum, td0
+                adcs    sum, sum, td1
+                adcs    sum, sum, td2
+                adcs    sum, sum, td3
+                sub     ip, ip, #32
+                teq     ip, #0
+                bne     2b
+                ldmfd   sp!, {r4 - r5}
+
+3:              tst     len, #0x1c              @ should not change C
+                beq     .less4
+
+4:              ldr     td0, [buf], #4
+                sub     len, len, #4
+                adcs    sum, sum, td0
+                tst     len, #0x1c
+                bne     4b
+                b       .less4