diff options
Diffstat (limited to 'arch/arm64/lib')
| -rw-r--r-- | arch/arm64/lib/Makefile | 6 | ||||
| -rw-r--r-- | arch/arm64/lib/copy_page.S | 38 | ||||
| -rw-r--r-- | arch/arm64/lib/csum.c | 126 |
3 files changed, 148 insertions, 22 deletions
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index c21b936dc01d..2fc253466dbf 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -1,9 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 lib-y := clear_user.o delay.o copy_from_user.o \ copy_to_user.o copy_in_user.o copy_page.o \ - clear_page.o memchr.o memcpy.o memmove.o memset.o \ - memcmp.o strcmp.o strncmp.o strlen.o strnlen.o \ - strchr.o strrchr.o tishift.o + clear_page.o csum.o memchr.o memcpy.o memmove.o \ + memset.o memcmp.o strcmp.o strncmp.o strlen.o \ + strnlen.o strchr.o strrchr.o tishift.o ifeq ($(CONFIG_KERNEL_MODE_NEON), y) obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S index bbb8562396af..290dd3c5266c 100644 --- a/arch/arm64/lib/copy_page.S +++ b/arch/arm64/lib/copy_page.S @@ -34,45 +34,45 @@ alternative_else_nop_endif ldp x14, x15, [x1, #96] ldp x16, x17, [x1, #112] - mov x18, #(PAGE_SIZE - 128) + add x0, x0, #256 add x1, x1, #128 1: - subs x18, x18, #128 + tst x0, #(PAGE_SIZE - 1) alternative_if ARM64_HAS_NO_HW_PREFETCH prfm pldl1strm, [x1, #384] alternative_else_nop_endif - stnp x2, x3, [x0] + stnp x2, x3, [x0, #-256] ldp x2, x3, [x1] - stnp x4, x5, [x0, #16] + stnp x4, x5, [x0, #16 - 256] ldp x4, x5, [x1, #16] - stnp x6, x7, [x0, #32] + stnp x6, x7, [x0, #32 - 256] ldp x6, x7, [x1, #32] - stnp x8, x9, [x0, #48] + stnp x8, x9, [x0, #48 - 256] ldp x8, x9, [x1, #48] - stnp x10, x11, [x0, #64] + stnp x10, x11, [x0, #64 - 256] ldp x10, x11, [x1, #64] - stnp x12, x13, [x0, #80] + stnp x12, x13, [x0, #80 - 256] ldp x12, x13, [x1, #80] - stnp x14, x15, [x0, #96] + stnp x14, x15, [x0, #96 - 256] ldp x14, x15, [x1, #96] - stnp x16, x17, [x0, #112] + stnp x16, x17, [x0, #112 - 256] ldp x16, x17, [x1, #112] add x0, x0, #128 add x1, x1, #128 - b.gt 1b + b.ne 1b - stnp x2, x3, [x0] - stnp x4, x5, [x0, #16] - stnp x6, x7, [x0, #32] - stnp x8, x9, [x0, #48] - stnp x10, x11, [x0, #64] - stnp x12, x13, [x0, #80] - stnp x14, x15, [x0, #96] - stnp x16, x17, [x0, #112] + stnp x2, x3, [x0, #-256] + stnp x4, x5, [x0, #16 - 256] + stnp x6, x7, [x0, #32 - 256] + stnp x8, x9, [x0, #48 - 256] + stnp x10, x11, [x0, #64 - 256] + stnp x12, x13, [x0, #80 - 256] + stnp x14, x15, [x0, #96 - 256] + stnp x16, x17, [x0, #112 - 256] ret ENDPROC(copy_page) diff --git a/arch/arm64/lib/csum.c b/arch/arm64/lib/csum.c new file mode 100644 index 000000000000..1f82c66b32ea --- /dev/null +++ b/arch/arm64/lib/csum.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (C) 2019-2020 Arm Ltd. + +#include <linux/compiler.h> +#include <linux/kasan-checks.h> +#include <linux/kernel.h> + +#include <net/checksum.h> + +/* Looks dumb, but generates nice-ish code */ +static u64 accumulate(u64 sum, u64 data) +{ + __uint128_t tmp = (__uint128_t)sum + data; + return tmp + (tmp >> 64); +} + +unsigned int do_csum(const unsigned char *buff, int len) +{ + unsigned int offset, shift, sum; + const u64 *ptr; + u64 data, sum64 = 0; + + if (unlikely(len == 0)) + return 0; + + offset = (unsigned long)buff & 7; + /* + * This is to all intents and purposes safe, since rounding down cannot + * result in a different page or cache line being accessed, and @buff + * should absolutely not be pointing to anything read-sensitive. We do, + * however, have to be careful not to piss off KASAN, which means using + * unchecked reads to accommodate the head and tail, for which we'll + * compensate with an explicit check up-front. + */ + kasan_check_read(buff, len); + ptr = (u64 *)(buff - offset); + len = len + offset - 8; + + /* + * Head: zero out any excess leading bytes. Shifting back by the same + * amount should be at least as fast as any other way of handling the + * odd/even alignment, and means we can ignore it until the very end. + */ + shift = offset * 8; + data = READ_ONCE_NOCHECK(*ptr++); +#ifdef __LITTLE_ENDIAN + data = (data >> shift) << shift; +#else + data = (data << shift) >> shift; +#endif + + /* + * Body: straightforward aligned loads from here on (the paired loads + * underlying the quadword type still only need dword alignment). The + * main loop strictly excludes the tail, so the second loop will always + * run at least once. + */ + while (unlikely(len > 64)) { + __uint128_t tmp1, tmp2, tmp3, tmp4; + + tmp1 = READ_ONCE_NOCHECK(*(__uint128_t *)ptr); + tmp2 = READ_ONCE_NOCHECK(*(__uint128_t *)(ptr + 2)); + tmp3 = READ_ONCE_NOCHECK(*(__uint128_t *)(ptr + 4)); + tmp4 = READ_ONCE_NOCHECK(*(__uint128_t *)(ptr + 6)); + + len -= 64; + ptr += 8; + + /* This is the "don't dump the carry flag into a GPR" idiom */ + tmp1 += (tmp1 >> 64) | (tmp1 << 64); + tmp2 += (tmp2 >> 64) | (tmp2 << 64); + tmp3 += (tmp3 >> 64) | (tmp3 << 64); + tmp4 += (tmp4 >> 64) | (tmp4 << 64); + tmp1 = ((tmp1 >> 64) << 64) | (tmp2 >> 64); + tmp1 += (tmp1 >> 64) | (tmp1 << 64); + tmp3 = ((tmp3 >> 64) << 64) | (tmp4 >> 64); + tmp3 += (tmp3 >> 64) | (tmp3 << 64); + tmp1 = ((tmp1 >> 64) << 64) | (tmp3 >> 64); + tmp1 += (tmp1 >> 64) | (tmp1 << 64); + tmp1 = ((tmp1 >> 64) << 64) | sum64; + tmp1 += (tmp1 >> 64) | (tmp1 << 64); + sum64 = tmp1 >> 64; + } + while (len > 8) { + __uint128_t tmp; + + sum64 = accumulate(sum64, data); + tmp = READ_ONCE_NOCHECK(*(__uint128_t *)ptr); + + len -= 16; + ptr += 2; + +#ifdef __LITTLE_ENDIAN + data = tmp >> 64; + sum64 = accumulate(sum64, tmp); +#else + data = tmp; + sum64 = accumulate(sum64, tmp >> 64); +#endif + } + if (len > 0) { + sum64 = accumulate(sum64, data); + data = READ_ONCE_NOCHECK(*ptr); + len -= 8; + } + /* + * Tail: zero any over-read bytes similarly to the head, again + * preserving odd/even alignment. + */ + shift = len * -8; +#ifdef __LITTLE_ENDIAN + data = (data << shift) >> shift; +#else + data = (data >> shift) << shift; +#endif + sum64 = accumulate(sum64, data); + + /* Finally, folding */ + sum64 += (sum64 >> 32) | (sum64 << 32); + sum = sum64 >> 32; + sum += (sum >> 16) | (sum << 16); + if (offset & 1) + return (u16)swab32(sum); + + return sum >> 16; +} |