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Diffstat (limited to 'arch/powerpc/lib/checksum_64.S')
| -rw-r--r-- | arch/powerpc/lib/checksum_64.S | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S new file mode 100644 index 000000000..98ff51bd2 --- /dev/null +++ b/arch/powerpc/lib/checksum_64.S @@ -0,0 +1,443 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * This file contains assembly-language implementations + * of IP-style 1's complement checksum routines. + * + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au). + */ + +#include <linux/sys.h> +#include <asm/processor.h> +#include <asm/errno.h> +#include <asm/ppc_asm.h> +#include <asm/export.h> + +/* + * Computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit). + * + * __csum_partial(r3=buff, r4=len, r5=sum) + */ +_GLOBAL(__csum_partial) + addic r0,r5,0 /* clear carry */ + + srdi. r6,r4,3 /* less than 8 bytes? */ + beq .Lcsum_tail_word + + /* + * If only halfword aligned, align to a double word. Since odd + * aligned addresses should be rare and they would require more + * work to calculate the correct checksum, we ignore that case + * and take the potential slowdown of unaligned loads. + */ + rldicl. r6,r3,64-1,64-2 /* r6 = (r3 >> 1) & 0x3 */ + beq .Lcsum_aligned + + li r7,4 + sub r6,r7,r6 + mtctr r6 + +1: + lhz r6,0(r3) /* align to doubleword */ + subi r4,r4,2 + addi r3,r3,2 + adde r0,r0,r6 + bdnz 1b + +.Lcsum_aligned: + /* + * We unroll the loop such that each iteration is 64 bytes with an + * entry and exit limb of 64 bytes, meaning a minimum size of + * 128 bytes. + */ + srdi. r6,r4,7 + beq .Lcsum_tail_doublewords /* len < 128 */ + + srdi r6,r4,6 + subi r6,r6,1 + mtctr r6 + + stdu r1,-STACKFRAMESIZE(r1) + std r14,STK_REG(R14)(r1) + std r15,STK_REG(R15)(r1) + std r16,STK_REG(R16)(r1) + + ld r6,0(r3) + ld r9,8(r3) + + ld r10,16(r3) + ld r11,24(r3) + + /* + * On POWER6 and POWER7 back to back adde instructions take 2 cycles + * because of the XER dependency. This means the fastest this loop can + * go is 16 cycles per iteration. The scheduling of the loop below has + * been shown to hit this on both POWER6 and POWER7. + */ + .align 5 +2: + adde r0,r0,r6 + ld r12,32(r3) + ld r14,40(r3) + + adde r0,r0,r9 + ld r15,48(r3) + ld r16,56(r3) + addi r3,r3,64 + + adde r0,r0,r10 + + adde r0,r0,r11 + + adde r0,r0,r12 + + adde r0,r0,r14 + + adde r0,r0,r15 + ld r6,0(r3) + ld r9,8(r3) + + adde r0,r0,r16 + ld r10,16(r3) + ld r11,24(r3) + bdnz 2b + + + adde r0,r0,r6 + ld r12,32(r3) + ld r14,40(r3) + + adde r0,r0,r9 + ld r15,48(r3) + ld r16,56(r3) + addi r3,r3,64 + + adde r0,r0,r10 + adde r0,r0,r11 + adde r0,r0,r12 + adde r0,r0,r14 + adde r0,r0,r15 + adde r0,r0,r16 + + ld r14,STK_REG(R14)(r1) + ld r15,STK_REG(R15)(r1) + ld r16,STK_REG(R16)(r1) + addi r1,r1,STACKFRAMESIZE + + andi. r4,r4,63 + +.Lcsum_tail_doublewords: /* Up to 127 bytes to go */ + srdi. r6,r4,3 + beq .Lcsum_tail_word + + mtctr r6 +3: + ld r6,0(r3) + addi r3,r3,8 + adde r0,r0,r6 + bdnz 3b + + andi. r4,r4,7 + +.Lcsum_tail_word: /* Up to 7 bytes to go */ + srdi. r6,r4,2 + beq .Lcsum_tail_halfword + + lwz r6,0(r3) + addi r3,r3,4 + adde r0,r0,r6 + subi r4,r4,4 + +.Lcsum_tail_halfword: /* Up to 3 bytes to go */ + srdi. r6,r4,1 + beq .Lcsum_tail_byte + + lhz r6,0(r3) + addi r3,r3,2 + adde r0,r0,r6 + subi r4,r4,2 + +.Lcsum_tail_byte: /* Up to 1 byte to go */ + andi. r6,r4,1 + beq .Lcsum_finish + + lbz r6,0(r3) +#ifdef __BIG_ENDIAN__ + sldi r9,r6,8 /* Pad the byte out to 16 bits */ + adde r0,r0,r9 +#else + adde r0,r0,r6 +#endif + +.Lcsum_finish: + addze r0,r0 /* add in final carry */ + rldicl r4,r0,32,0 /* fold two 32 bit halves together */ + add r3,r4,r0 + srdi r3,r3,32 + blr +EXPORT_SYMBOL(__csum_partial) + + + .macro srcnr +100: + EX_TABLE(100b,.Lerror_nr) + .endm + + .macro source +150: + EX_TABLE(150b,.Lerror) + .endm + + .macro dstnr +200: + EX_TABLE(200b,.Lerror_nr) + .endm + + .macro dest +250: + EX_TABLE(250b,.Lerror) + .endm + +/* + * Computes the checksum of a memory block at src, length len, + * and adds in 0xffffffff (32-bit), while copying the block to dst. + * If an access exception occurs, it returns 0. + * + * csum_partial_copy_generic(r3=src, r4=dst, r5=len) + */ +_GLOBAL(csum_partial_copy_generic) + li r6,-1 + addic r0,r6,0 /* clear carry */ + + srdi. r6,r5,3 /* less than 8 bytes? */ + beq .Lcopy_tail_word + + /* + * If only halfword aligned, align to a double word. Since odd + * aligned addresses should be rare and they would require more + * work to calculate the correct checksum, we ignore that case + * and take the potential slowdown of unaligned loads. + * + * If the source and destination are relatively unaligned we only + * align the source. This keeps things simple. + */ + rldicl. r6,r3,64-1,64-2 /* r6 = (r3 >> 1) & 0x3 */ + beq .Lcopy_aligned + + li r9,4 + sub r6,r9,r6 + mtctr r6 + +1: +srcnr; lhz r6,0(r3) /* align to doubleword */ + subi r5,r5,2 + addi r3,r3,2 + adde r0,r0,r6 +dstnr; sth r6,0(r4) + addi r4,r4,2 + bdnz 1b + +.Lcopy_aligned: + /* + * We unroll the loop such that each iteration is 64 bytes with an + * entry and exit limb of 64 bytes, meaning a minimum size of + * 128 bytes. + */ + srdi. r6,r5,7 + beq .Lcopy_tail_doublewords /* len < 128 */ + + srdi r6,r5,6 + subi r6,r6,1 + mtctr r6 + + stdu r1,-STACKFRAMESIZE(r1) + std r14,STK_REG(R14)(r1) + std r15,STK_REG(R15)(r1) + std r16,STK_REG(R16)(r1) + +source; ld r6,0(r3) +source; ld r9,8(r3) + +source; ld r10,16(r3) +source; ld r11,24(r3) + + /* + * On POWER6 and POWER7 back to back adde instructions take 2 cycles + * because of the XER dependency. This means the fastest this loop can + * go is 16 cycles per iteration. The scheduling of the loop below has + * been shown to hit this on both POWER6 and POWER7. + */ + .align 5 +2: + adde r0,r0,r6 +source; ld r12,32(r3) +source; ld r14,40(r3) + + adde r0,r0,r9 +source; ld r15,48(r3) +source; ld r16,56(r3) + addi r3,r3,64 + + adde r0,r0,r10 +dest; std r6,0(r4) +dest; std r9,8(r4) + + adde r0,r0,r11 +dest; std r10,16(r4) +dest; std r11,24(r4) + + adde r0,r0,r12 +dest; std r12,32(r4) +dest; std r14,40(r4) + + adde r0,r0,r14 +dest; std r15,48(r4) +dest; std r16,56(r4) + addi r4,r4,64 + + adde r0,r0,r15 +source; ld r6,0(r3) +source; ld r9,8(r3) + + adde r0,r0,r16 +source; ld r10,16(r3) +source; ld r11,24(r3) + bdnz 2b + + + adde r0,r0,r6 +source; ld r12,32(r3) +source; ld r14,40(r3) + + adde r0,r0,r9 +source; ld r15,48(r3) +source; ld r16,56(r3) + addi r3,r3,64 + + adde r0,r0,r10 +dest; std r6,0(r4) +dest; std r9,8(r4) + + adde r0,r0,r11 +dest; std r10,16(r4) +dest; std r11,24(r4) + + adde r0,r0,r12 +dest; std r12,32(r4) +dest; std r14,40(r4) + + adde r0,r0,r14 +dest; std r15,48(r4) +dest; std r16,56(r4) + addi r4,r4,64 + + adde r0,r0,r15 + adde r0,r0,r16 + + ld r14,STK_REG(R14)(r1) + ld r15,STK_REG(R15)(r1) + ld r16,STK_REG(R16)(r1) + addi r1,r1,STACKFRAMESIZE + + andi. r5,r5,63 + +.Lcopy_tail_doublewords: /* Up to 127 bytes to go */ + srdi. r6,r5,3 + beq .Lcopy_tail_word + + mtctr r6 +3: +srcnr; ld r6,0(r3) + addi r3,r3,8 + adde r0,r0,r6 +dstnr; std r6,0(r4) + addi r4,r4,8 + bdnz 3b + + andi. r5,r5,7 + +.Lcopy_tail_word: /* Up to 7 bytes to go */ + srdi. r6,r5,2 + beq .Lcopy_tail_halfword + +srcnr; lwz r6,0(r3) + addi r3,r3,4 + adde r0,r0,r6 +dstnr; stw r6,0(r4) + addi r4,r4,4 + subi r5,r5,4 + +.Lcopy_tail_halfword: /* Up to 3 bytes to go */ + srdi. r6,r5,1 + beq .Lcopy_tail_byte + +srcnr; lhz r6,0(r3) + addi r3,r3,2 + adde r0,r0,r6 +dstnr; sth r6,0(r4) + addi r4,r4,2 + subi r5,r5,2 + +.Lcopy_tail_byte: /* Up to 1 byte to go */ + andi. r6,r5,1 + beq .Lcopy_finish + +srcnr; lbz r6,0(r3) +#ifdef __BIG_ENDIAN__ + sldi r9,r6,8 /* Pad the byte out to 16 bits */ + adde r0,r0,r9 +#else + adde r0,r0,r6 +#endif +dstnr; stb r6,0(r4) + +.Lcopy_finish: + addze r0,r0 /* add in final carry */ + rldicl r4,r0,32,0 /* fold two 32 bit halves together */ + add r3,r4,r0 + srdi r3,r3,32 + blr + +.Lerror: + ld r14,STK_REG(R14)(r1) + ld r15,STK_REG(R15)(r1) + ld r16,STK_REG(R16)(r1) + addi r1,r1,STACKFRAMESIZE +.Lerror_nr: + li r3,0 + blr + +EXPORT_SYMBOL(csum_partial_copy_generic) + +/* + * __sum16 csum_ipv6_magic(const struct in6_addr *saddr, + * const struct in6_addr *daddr, + * __u32 len, __u8 proto, __wsum sum) + */ + +_GLOBAL(csum_ipv6_magic) + ld r8, 0(r3) + ld r9, 8(r3) + add r5, r5, r6 + addc r0, r8, r9 + ld r10, 0(r4) + ld r11, 8(r4) +#ifdef CONFIG_CPU_LITTLE_ENDIAN + rotldi r5, r5, 8 +#endif + adde r0, r0, r10 + add r5, r5, r7 + adde r0, r0, r11 + adde r0, r0, r5 + addze r0, r0 + rotldi r3, r0, 32 /* fold two 32 bit halves together */ + add r3, r0, r3 + srdi r0, r3, 32 + rotlwi r3, r0, 16 /* fold two 16 bit halves together */ + add r3, r0, r3 + not r3, r3 + rlwinm r3, r3, 16, 16, 31 + blr +EXPORT_SYMBOL(csum_ipv6_magic) |