Each architecture generally implements fine-tuned checksum functions to
leverage the instruction set. This patch adds the main checksum
functions that are used in networking.
This patch takes heavy use of the Zbb extension using alternatives
patching.
To test this patch, enable the configs for KUNIT, then CHECKSUM_KUNIT.
I have attempted to make these functions as optimal as possible, but I
have not ran anything on actual riscv hardware. My performance testing
has been limited to inspecting the assembly, running the algorithms on
x86 hardware, and running in QEMU.
ip_fast_csum is a relatively small function so even though it is
possible to read 64 bits at a time on compatible hardware, the
bottleneck becomes the clean up and setup code so loading 32 bits at a
time is actually faster.
Relies on https://lore.kernel.org/lkml/[email protected]/
---
The algorithm proposed to replace the default csum_fold can be seen to
compute the same result by running all 2^32 possible inputs.
static inline unsigned int ror32(unsigned int word, unsigned int shift)
{
return (word >> (shift & 31)) | (word << ((-shift) & 31));
}
unsigned short csum_fold(unsigned int csum)
{
unsigned int sum = csum;
sum = (sum & 0xffff) + (sum >> 16);
sum = (sum & 0xffff) + (sum >> 16);
return ~sum;
}
unsigned short csum_fold_arc(unsigned int csum)
{
return ((~csum - ror32(csum, 16)) >> 16);
}
int main()
{
unsigned int start = 0x0;
do {
if (csum_fold(start) != csum_fold_arc(start)) {
printf("Not the same %u\n", start);
return -1;
}
start += 1;
} while(start != 0x0);
printf("The same\n");
return 0;
}
Cc: Paul Walmsley <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Arnd Bergmann <[email protected]>
To: Charlie Jenkins <[email protected]>
To: Palmer Dabbelt <[email protected]>
To: Conor Dooley <[email protected]>
To: Samuel Holland <[email protected]>
To: David Laight <[email protected]>
To: Xiao Wang <[email protected]>
To: Evan Green <[email protected]>
To: [email protected]
To: [email protected]
To: [email protected]
Signed-off-by: Charlie Jenkins <[email protected]>
---
Changes in v10:
- Move tests that were riscv-specific to be arch agnostic (Arnd)
- Link to v9: https://lore.kernel.org/r/[email protected]
Changes in v9:
- Use ror64 (Xiao)
- Move do_csum and csum_ipv6_magic headers to patch 4 (Xiao)
- Remove word "IP" from checksum headers (Xiao)
- Swap to using ifndef CONFIG_32BIT instead of ifdef CONFIG_64BIT (Xiao)
- Run no alignment code when buff is aligned (Xiao)
- Consolidate two do_csum implementations overlap into do_csum_common
- Link to v8: https://lore.kernel.org/r/[email protected]
Changes in v8:
- Speedups of 12% without Zbb and 21% with Zbb when cpu supports fast
misaligned accesses for do_csum
- Various formatting updates
- Patch now relies on https://lore.kernel.org/lkml/[email protected]/
- Link to v7: https://lore.kernel.org/r/[email protected]
Changes in v7:
- Included linux/bitops.h in asm-generic/checksum.h to use ror (Conor)
- Optimized loop in do_csum (David)
- Used ror instead of shifting (David)
- Unfortunately had to reintroduce ifdefs because gcc is not smart
enough to not throw warnings on code that will never execute
- Use ifdef instead of IS_ENABLED on __LITTLE_ENDIAN because IS_ENABLED
does not work on that
- Only optimize for zbb when alternatives is enabled in do_csum
- Link to v6: https://lore.kernel.org/r/[email protected]
Changes in v6:
- Fix accuracy of commit message for csum_fold
- Fix indentation
- Link to v5: https://lore.kernel.org/r/[email protected]
Changes in v5:
- Drop vector patches
- Check ZBB enabled before doing any ZBB code (Conor)
- Check endianness in IS_ENABLED
- Revert to the simpler non-tree based version of ipv6_csum_magic since
David pointed out that the tree based version is not better.
- Link to v4: https://lore.kernel.org/r/[email protected]
Changes in v4:
- Suggestion by David Laight to use an improved checksum used in
arch/arc.
- Eliminates zero-extension on rv32, but not on rv64.
- Reduces data dependency which should improve execution speed on
rv32 and rv64
- Still passes CHECKSUM_KUNIT and RISCV_CHECKSUM_KUNIT on rv32 and
rv64 with and without zbb.
- Link to v3: https://lore.kernel.org/r/[email protected]
Changes in v3:
- Use riscv_has_extension_likely and has_vector where possible (Conor)
- Reduce ifdefs by using IS_ENABLED where possible (Conor)
- Use kernel_vector_begin in the vector code (Samuel)
- Link to v2: https://lore.kernel.org/r/[email protected]
Changes in v2:
- After more benchmarking, rework functions to improve performance.
- Remove tests that overlapped with the already existing checksum
tests and make tests more extensive.
- Use alternatives to activate code with Zbb and vector extensions
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Charlie Jenkins (5):
asm-generic: Improve csum_fold
riscv: Add static key for misaligned accesses
riscv: Checksum header
riscv: Add checksum library
kunit: Add tests for csum_ipv6_magic and ip_fast_csum
arch/riscv/include/asm/checksum.h | 92 ++++++++++
arch/riscv/include/asm/cpufeature.h | 3 +
arch/riscv/kernel/cpufeature.c | 30 ++++
arch/riscv/lib/Makefile | 1 +
arch/riscv/lib/csum.c | 326 ++++++++++++++++++++++++++++++++++++
include/asm-generic/checksum.h | 6 +-
lib/checksum_kunit.c | 284 ++++++++++++++++++++++++++++++-
7 files changed, 738 insertions(+), 4 deletions(-)
---
base-commit: 8d68c506cd34a142331623fd23eb1c4e680e1955
change-id: 20230804-optimize_checksum-db145288ac21
--
- Charlie
Provide checksum algorithms that have been designed to leverage riscv
instructions such as rotate. In 64-bit, can take advantage of the larger
register to avoid some overflow checking.
Signed-off-by: Charlie Jenkins <[email protected]>
Acked-by: Conor Dooley <[email protected]>
---
arch/riscv/include/asm/checksum.h | 81 +++++++++++++++++++++++++++++++++++++++
1 file changed, 81 insertions(+)
diff --git a/arch/riscv/include/asm/checksum.h b/arch/riscv/include/asm/checksum.h
new file mode 100644
index 000000000000..3d77cac338fe
--- /dev/null
+++ b/arch/riscv/include/asm/checksum.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Checksum routines
+ *
+ * Copyright (C) 2023 Rivos Inc.
+ */
+#ifndef __ASM_RISCV_CHECKSUM_H
+#define __ASM_RISCV_CHECKSUM_H
+
+#include <linux/in6.h>
+#include <linux/uaccess.h>
+
+#define ip_fast_csum ip_fast_csum
+
+/* Define riscv versions of functions before importing asm-generic/checksum.h */
+#include <asm-generic/checksum.h>
+
+/*
+ * Quickly compute an IP checksum with the assumption that IPv4 headers will
+ * always be in multiples of 32-bits, and have an ihl of at least 5.
+ * @ihl is the number of 32 bit segments and must be greater than or equal to 5.
+ * @iph is assumed to be word aligned given that NET_IP_ALIGN is set to 2 on
+ * riscv, defining IP headers to be aligned.
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+ unsigned long csum = 0;
+ int pos = 0;
+
+ do {
+ csum += ((const unsigned int *)iph)[pos];
+ if (IS_ENABLED(CONFIG_32BIT))
+ csum += csum < ((const unsigned int *)iph)[pos];
+ } while (++pos < ihl);
+
+ /*
+ * ZBB only saves three instructions on 32-bit and five on 64-bit so not
+ * worth checking if supported without Alternatives.
+ */
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZBB) &&
+ IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
+ unsigned long fold_temp;
+
+ asm_volatile_goto(ALTERNATIVE("j %l[no_zbb]", "nop", 0,
+ RISCV_ISA_EXT_ZBB, 1)
+ :
+ :
+ :
+ : no_zbb);
+
+ if (IS_ENABLED(CONFIG_32BIT)) {
+ asm(".option push \n\
+ .option arch,+zbb \n\
+ not %[fold_temp], %[csum] \n\
+ rori %[csum], %[csum], 16 \n\
+ sub %[csum], %[fold_temp], %[csum] \n\
+ .option pop"
+ : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp));
+ } else {
+ asm(".option push \n\
+ .option arch,+zbb \n\
+ rori %[fold_temp], %[csum], 32 \n\
+ add %[csum], %[fold_temp], %[csum] \n\
+ srli %[csum], %[csum], 32 \n\
+ not %[fold_temp], %[csum] \n\
+ roriw %[csum], %[csum], 16 \n\
+ subw %[csum], %[fold_temp], %[csum] \n\
+ .option pop"
+ : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp));
+ }
+ return csum >> 16;
+ }
+no_zbb:
+#ifndef CONFIG_32BIT
+ csum += ror64(csum, 32);
+ csum >>= 32;
+#endif
+ return csum_fold((__force __wsum)csum);
+}
+
+#endif /* __ASM_RISCV_CHECKSUM_H */
--
2.34.1
Supplement existing checksum tests with tests for csum_ipv6_magic and
ip_fast_csum.
Signed-off-by: Charlie Jenkins <[email protected]>
---
lib/checksum_kunit.c | 284 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 283 insertions(+), 1 deletion(-)
diff --git a/lib/checksum_kunit.c b/lib/checksum_kunit.c
index 0eed92b77ba3..af3e5ca4e170 100644
--- a/lib/checksum_kunit.c
+++ b/lib/checksum_kunit.c
@@ -1,15 +1,21 @@
// SPDX-License-Identifier: GPL-2.0+
/*
- * Test cases csum_partial and csum_fold
+ * Test cases csum_partial, csum_fold, ip_fast_csum, csum_ipv6_magic
*/
#include <kunit/test.h>
#include <asm/checksum.h>
+#include <net/ip6_checksum.h>
#define MAX_LEN 512
#define MAX_ALIGN 64
#define TEST_BUFLEN (MAX_LEN + MAX_ALIGN)
+#define IPv4_MIN_WORDS 5
+#define IPv4_MAX_WORDS 15
+#define NUM_IPv6_TESTS 200
+#define NUM_IP_FAST_CSUM_TESTS 181
+
/* Values for a little endian CPU. Byte swap each half on big endian CPU. */
static const u32 random_init_sum = 0x2847aab;
static const u8 random_buf[] = {
@@ -209,6 +215,237 @@ static const u32 init_sums_no_overflow[] = {
0xffff0000, 0xfffffffb,
};
+static const __sum16 expected_csum_ipv6_magic[] = {
+ 0x18d4, 0x3085, 0x2e4b, 0xd9f4, 0xbdc8, 0x78f, 0x1034, 0x8422, 0x6fc0,
+ 0xd2f6, 0xbeb5, 0x9d3, 0x7e2a, 0x312e, 0x778e, 0xc1bb, 0x7cf2, 0x9d1e,
+ 0xca21, 0xf3ff, 0x7569, 0xb02e, 0xca86, 0x7e76, 0x4539, 0x45e3, 0xf28d,
+ 0xdf81, 0x8fd5, 0x3b5d, 0x8324, 0xf471, 0x83be, 0x1daf, 0x8c46, 0xe682,
+ 0xd1fb, 0x6b2e, 0xe687, 0x2a33, 0x4833, 0x2d67, 0x660f, 0x2e79, 0xd65e,
+ 0x6b62, 0x6672, 0x5dbd, 0x8680, 0xbaa5, 0x2229, 0x2125, 0x2d01, 0x1cc0,
+ 0x6d36, 0x33c0, 0xee36, 0xd832, 0x9820, 0x8a31, 0x53c5, 0x2e2, 0xdb0e,
+ 0x49ed, 0x17a7, 0x77a0, 0xd72e, 0x3d72, 0x7dc8, 0x5b17, 0xf55d, 0xa4d9,
+ 0x1446, 0x5d56, 0x6b2e, 0x69a5, 0xadb6, 0xff2a, 0x92e, 0xe044, 0x3402,
+ 0xbb60, 0xec7f, 0xe7e6, 0x1986, 0x32f4, 0x8f8, 0x5e00, 0x47c6, 0x3059,
+ 0x3969, 0xe957, 0x4388, 0x2854, 0x3334, 0xea71, 0xa6de, 0x33f9, 0x83fc,
+ 0x37b4, 0x5531, 0x3404, 0x1010, 0xed30, 0x610a, 0xc95, 0x9aed, 0x6ff,
+ 0x5136, 0x2741, 0x660e, 0x8b80, 0xf71, 0xa263, 0x88af, 0x7a73, 0x3c37,
+ 0x1908, 0x6db5, 0x2e92, 0x1cd2, 0x70c8, 0xee16, 0xe80, 0xcd55, 0x6e6,
+ 0x6434, 0x127, 0x655d, 0x2ea0, 0xb4f4, 0xdc20, 0x5671, 0xe462, 0xe52b,
+ 0xdb44, 0x3589, 0xc48f, 0xe60b, 0xd2d2, 0x66ad, 0x498, 0x436, 0xb917,
+ 0xf0ca, 0x1a6e, 0x1cb7, 0xbf61, 0x2870, 0xc7e8, 0x5b30, 0xe4a5, 0x168,
+ 0xadfc, 0xd035, 0xe690, 0xe283, 0xfb27, 0xe4ad, 0xb1a5, 0xf2d5, 0xc4b6,
+ 0x8a30, 0xd7d5, 0x7df9, 0x91d5, 0x63ed, 0x2d21, 0x312b, 0xab19, 0xa632,
+ 0x8d2e, 0xef06, 0x57b9, 0xc373, 0xbd1f, 0xa41f, 0x8444, 0x9975, 0x90cb,
+ 0xc49c, 0xe965, 0x4eff, 0x5a, 0xef6d, 0xe81a, 0xe260, 0x853a, 0xff7a,
+ 0x99aa, 0xb06b, 0xee19, 0xcc2c, 0xf34c, 0x7c49, 0xdac3, 0xa71e, 0xc988,
+ 0x3845, 0x1014
+};
+
+static const __sum16 expected_fast_csum[] = {
+ 0xda83, 0x45da, 0x4f46, 0x4e4f, 0x34e, 0xe902, 0xa5e9, 0x87a5, 0x7187,
+ 0x5671, 0xf556, 0x6df5, 0x816d, 0x8f81, 0xbb8f, 0xfbba, 0x5afb, 0xbe5a,
+ 0xedbe, 0xabee, 0x6aac, 0xe6b, 0xea0d, 0x67ea, 0x7e68, 0x8a7e, 0x6f8a,
+ 0x3a70, 0x9f3a, 0xe89e, 0x75e8, 0x7976, 0xfa79, 0x2cfa, 0x3c2c, 0x463c,
+ 0x7146, 0x7a71, 0x547a, 0xfd53, 0x99fc, 0xb699, 0x92b6, 0xdb91, 0xe8da,
+ 0x5fe9, 0x1e60, 0xae1d, 0x39ae, 0xf439, 0xa1f4, 0xdda1, 0xede, 0x790f,
+ 0x579, 0x1206, 0x9012, 0x2490, 0xd224, 0x5cd2, 0xa65d, 0xca7, 0x220d,
+ 0xf922, 0xbf9, 0x920b, 0x1b92, 0x361c, 0x2e36, 0x4d2e, 0x24d, 0x2,
+ 0xcfff, 0x90cf, 0xa591, 0x93a5, 0x7993, 0x9579, 0xc894, 0x50c8, 0x5f50,
+ 0xd55e, 0xcad5, 0xf3c9, 0x8f4, 0x4409, 0x5043, 0x5b50, 0x55b, 0x2205,
+ 0x1e22, 0x801e, 0x3780, 0xe137, 0x7ee0, 0xf67d, 0x3cf6, 0xa53c, 0x2ea5,
+ 0x472e, 0x5147, 0xcf51, 0x1bcf, 0x951c, 0x1e95, 0xc71e, 0xe4c7, 0xc3e4,
+ 0x3dc3, 0xee3d, 0xa4ed, 0xf9a4, 0xcbf8, 0x75cb, 0xb375, 0x50b4, 0x3551,
+ 0xf835, 0x19f8, 0x8c1a, 0x538c, 0xad52, 0xa3ac, 0xb0a3, 0x5cb0, 0x6c5c,
+ 0x5b6c, 0xc05a, 0x92c0, 0x4792, 0xbe47, 0x53be, 0x1554, 0x5715, 0x4b57,
+ 0xe54a, 0x20e5, 0x21, 0xd500, 0xa1d4, 0xa8a1, 0x57a9, 0xca57, 0x5ca,
+ 0x1c06, 0x4f1c, 0xe24e, 0xd9e2, 0xf0d9, 0x4af1, 0x474b, 0x8146, 0xe81,
+ 0xfd0e, 0x84fd, 0x7c85, 0xba7c, 0x17ba, 0x4a17, 0x964a, 0xf595, 0xff5,
+ 0x5310, 0x3253, 0x6432, 0x4263, 0x2242, 0xe121, 0x32e1, 0xf632, 0xc5f5,
+ 0x21c6, 0x7d22, 0x8e7c, 0x418e, 0x5641, 0x3156, 0x7c31, 0x737c, 0x373,
+ 0x2503, 0xc22a, 0x3c2, 0x4a04, 0x8549, 0x5285, 0xa352, 0xe8a3, 0x6fe8,
+ 0x1a6f, 0x211a, 0xe021, 0x38e0, 0x7638, 0xf575, 0x9df5, 0x169e, 0xf116,
+ 0x23f1, 0xcd23, 0xece, 0x660f, 0x4866, 0x6a48, 0x716a, 0xee71, 0xa2ee,
+ 0xb8a2, 0x61b9, 0xa361, 0xf7a2, 0x26f7, 0x1127, 0x6611, 0xe065, 0x36e0,
+ 0x1837, 0x3018, 0x1c30, 0x721b, 0x3e71, 0xe43d, 0x99e4, 0x9e9a, 0xb79d,
+ 0xa9b7, 0xcaa, 0xeb0c, 0x4eb, 0x1305, 0x8813, 0xb687, 0xa9b6, 0xfba9,
+ 0xd7fb, 0xccd8, 0x2ecd, 0x652f, 0xae65, 0x3fae, 0x3a40, 0x563a, 0x7556,
+ 0x2776, 0x1228, 0xef12, 0xf9ee, 0xcef9, 0x56cf, 0xa956, 0x24a9, 0xba24,
+ 0x5fba, 0x665f, 0xf465, 0x8ff4, 0x6d8f, 0x346d, 0x5f34, 0x385f, 0xd137,
+ 0xb8d0, 0xacb8, 0x55ac, 0x7455, 0xe874, 0x89e8, 0xd189, 0xa0d1, 0xb2a0,
+ 0xb8b2, 0x36b8, 0x5636, 0xd355, 0x8d3, 0x1908, 0x2118, 0xc21, 0x990c,
+ 0x8b99, 0x158c, 0x7815, 0x9e78, 0x6f9e, 0x4470, 0x1d44, 0x341d, 0x2634,
+ 0x3f26, 0x793e, 0xc79, 0xcc0b, 0x26cc, 0xd126, 0x1fd1, 0xb41f, 0xb6b4,
+ 0x22b7, 0xa122, 0xa1, 0x7f01, 0x837e, 0x3b83, 0xaf3b, 0x6fae, 0x916f,
+ 0xb490, 0xffb3, 0xceff, 0x50cf, 0x7550, 0x7275, 0x1272, 0x2613, 0xaa26,
+ 0xd5aa, 0x7d5, 0x9607, 0x96, 0xb100, 0xf8b0, 0x4bf8, 0xdd4c, 0xeddd,
+ 0x98ed, 0x2599, 0x9325, 0xeb92, 0x8feb, 0xcc8f, 0x2acd, 0x392b, 0x3b39,
+ 0xcb3b, 0x6acb, 0xd46a, 0xb8d4, 0x6ab8, 0x106a, 0x2f10, 0x892f, 0x789,
+ 0xc806, 0x45c8, 0x7445, 0x3c74, 0x3a3c, 0xcf39, 0xd7ce, 0x58d8, 0x6e58,
+ 0x336e, 0x1034, 0xee10, 0xe9ed, 0xc2e9, 0x3fc2, 0xd53e, 0xd2d4, 0xead2,
+ 0x8fea, 0x2190, 0x1162, 0xbe11, 0x8cbe, 0x6d8c, 0xfb6c, 0x6dfb, 0xd36e,
+ 0x3ad3, 0xf3a, 0x870e, 0xc287, 0x53c3, 0xc54, 0x5b0c, 0x7d5a, 0x797d,
+ 0xec79, 0x5dec, 0x4d5e, 0x184e, 0xd618, 0x60d6, 0xb360, 0x98b3, 0xf298,
+ 0xb1f2, 0x69b1, 0xf969, 0xef9, 0xab0e, 0x21ab, 0xe321, 0x24e3, 0x8224,
+ 0x5481, 0x5954, 0x7a59, 0xff7a, 0x7dff, 0x1a7d, 0xa51a, 0x46a5, 0x6b47,
+ 0xe6b, 0x830e, 0xa083, 0xff9f, 0xd0ff, 0xffd0, 0xe6ff, 0x7de7, 0xc67d,
+ 0xd0c6, 0x61d1, 0x3a62, 0xc3b, 0x150c, 0x1715, 0x4517, 0x5345, 0x3954,
+ 0xdd39, 0xdadd, 0x32db, 0x6a33, 0xd169, 0x86d1, 0xb687, 0x3fb6, 0x883f,
+ 0xa487, 0x39a4, 0x2139, 0xbe20, 0xffbe, 0xedfe, 0x8ded, 0x368e, 0xc335,
+ 0x51c3, 0x9851, 0xf297, 0xd6f2, 0xb9d6, 0x95ba, 0x2096, 0xea1f, 0x76e9,
+ 0x4e76, 0xe04d, 0xd0df, 0x80d0, 0xa280, 0xfca2, 0x75fc, 0xef75, 0x32ef,
+ 0x6833, 0xdf68, 0xc4df, 0x76c4, 0xb77, 0xb10a, 0xbfb1, 0x58bf, 0x5258,
+ 0x4d52, 0x6c4d, 0x7e6c, 0xb67e, 0xccb5, 0x8ccc, 0xbe8c, 0xc8bd, 0x9ac8,
+ 0xa99b, 0x52a9, 0x2f53, 0xc30, 0x3e0c, 0xb83d, 0x83b7, 0x5383, 0x7e53,
+ 0x4f7e, 0xe24e, 0xb3e1, 0x8db3, 0x618e, 0xc861, 0xfcc8, 0x34fc, 0x9b35,
+ 0xaa9b, 0xb1aa, 0x5eb1, 0x395e, 0x8639, 0xd486, 0x8bd4, 0x558b, 0x2156,
+ 0xf721, 0x4ef6, 0x14f, 0x7301, 0xdd72, 0x49de, 0x894a, 0x9889, 0x8898,
+ 0x7788, 0x7b77, 0x637b, 0xb963, 0xabb9, 0x7cab, 0xc87b, 0x21c8, 0xcb21,
+ 0xdfca, 0xbfdf, 0xf2bf, 0x6af2, 0x626b, 0xb261, 0x3cb2, 0xc63c, 0xc9c6,
+ 0xc9c9, 0xb4c9, 0xf9b4, 0x91f9, 0x4091, 0x3a40, 0xcc39, 0xd1cb, 0x7ed1,
+ 0x537f, 0x6753, 0xa167, 0xba49, 0x88ba, 0x7789, 0x3877, 0xf037, 0xd3ef,
+ 0xb5d4, 0x55b6, 0xa555, 0xeca4, 0xa1ec, 0xb6a2, 0x7b7, 0x9507, 0xfd94,
+ 0x82fd, 0x5c83, 0x765c, 0x9676, 0x3f97, 0xda3f, 0x6fda, 0x646f, 0x3064,
+ 0x5e30, 0x655e, 0x6465, 0xcb64, 0xcdca, 0x4ccd, 0x3f4c, 0x243f, 0x6f24,
+ 0x656f, 0x6065, 0x3560, 0x3b36, 0xac3b, 0x4aac, 0x714a, 0x7e71, 0xda7e,
+ 0x7fda, 0xda7f, 0x6fda, 0xff6f, 0xc6ff, 0xedc6, 0xd4ed, 0x70d5, 0xeb70,
+ 0xa3eb, 0x80a3, 0xca80, 0x3fcb, 0x2540, 0xf825, 0x7ef8, 0xf87e, 0x73f8,
+ 0xb474, 0xb4b4, 0x92b5, 0x9293, 0x93, 0x3500, 0x7134, 0x9071, 0xfa8f,
+ 0x51fa, 0x1452, 0xba13, 0x7ab9, 0x957a, 0x8a95, 0x6e8a, 0x6d6e, 0x7c6d,
+ 0x447c, 0x9744, 0x4597, 0x8945, 0xef88, 0x8fee, 0x3190, 0x4831, 0x8447,
+ 0xa183, 0x1da1, 0xd41d, 0x2dd4, 0x4f2e, 0xc94e, 0xcbc9, 0xc9cb, 0x9ec9,
+ 0x319e, 0xd531, 0x20d5, 0x4021, 0xb23f, 0x29b2, 0xd828, 0xecd8, 0x5ded,
+ 0xfc5d, 0x4dfc, 0xd24d, 0x6bd2, 0x5f6b, 0xb35e, 0x7fb3, 0xee7e, 0x56ee,
+ 0xa657, 0x68a6, 0x8768, 0x7787, 0xb077, 0x4cb1, 0x764c, 0xb175, 0x7b1,
+ 0x3d07, 0x603d, 0x3560, 0x3e35, 0xb03d, 0xd6b0, 0xc8d6, 0xd8c8, 0x8bd8,
+ 0x3e8c, 0x303f, 0xd530, 0xf1d4, 0x42f1, 0xca42, 0xddca, 0x41dd, 0x3141,
+ 0x132, 0xe901, 0x8e9, 0xbe09, 0xe0bd, 0x2ce0, 0x862d, 0x3986, 0x9139,
+ 0x6d91, 0x6a6d, 0x8d6a, 0x1b8d, 0xac1b, 0xedab, 0x54ed, 0xc054, 0xcebf,
+ 0xc1ce, 0x5c2, 0x3805, 0x6038, 0x5960, 0xd359, 0xdd3, 0xbe0d, 0xafbd,
+ 0x6daf, 0x206d, 0x2c20, 0x862c, 0x8e86, 0xec8d, 0xa2ec, 0xa3a2, 0x51a3,
+ 0x8051, 0xfd7f, 0x91fd, 0xa292, 0xaf14, 0xeeae, 0x59ef, 0x535a, 0x8653,
+ 0x3986, 0x9539, 0xb895, 0xa0b8, 0x26a0, 0x2227, 0xc022, 0x77c0, 0xad77,
+ 0x46ad, 0xaa46, 0x60aa, 0x8560, 0x4785, 0xd747, 0x45d7, 0x2346, 0x5f23,
+ 0x25f, 0x1d02, 0x71d, 0x8206, 0xc82, 0x180c, 0x3018, 0x4b30, 0x4b,
+ 0x3001, 0x1230, 0x2d12, 0x8c2d, 0x148d, 0x4015, 0x5f3f, 0x3d5f, 0x6b3d,
+ 0x396b, 0x473a, 0xf746, 0x44f7, 0x8945, 0x3489, 0xcb34, 0x84ca, 0xd984,
+ 0xf0d9, 0xbcf0, 0x63bd, 0x3264, 0xf332, 0x45f3, 0x7346, 0x5673, 0xb056,
+ 0xd3b0, 0x4ad4, 0x184b, 0x7d18, 0x6c7d, 0xbb6c, 0xfeba, 0xe0fe, 0x10e1,
+ 0x5410, 0x2954, 0x9f28, 0x3a9f, 0x5a3a, 0xdb59, 0xbdc, 0xb40b, 0x1ab4,
+ 0x131b, 0x5d12, 0x6d5c, 0xe16c, 0xb0e0, 0x89b0, 0xba88, 0xbb, 0x3c01,
+ 0xe13b, 0x6fe1, 0x446f, 0xa344, 0x81a3, 0xfe81, 0xc7fd, 0x38c8, 0xb38,
+ 0x1a0b, 0x6d19, 0xf36c, 0x47f3, 0x6d48, 0xb76d, 0xd3b7, 0xd8d2, 0x52d9,
+ 0x4b53, 0xa54a, 0x34a5, 0xc534, 0x9bc4, 0xed9b, 0xbeed, 0x3ebe, 0x233e,
+ 0x9f22, 0x4a9f, 0x774b, 0x4577, 0xa545, 0x64a5, 0xb65, 0x870b, 0x487,
+ 0x9204, 0x5f91, 0xd55f, 0x35d5, 0x1a35, 0x71a, 0x7a07, 0x4e7a, 0xfc4e,
+ 0x1efc, 0x481f, 0x7448, 0xde74, 0xa7dd, 0x1ea7, 0xaa1e, 0xcfaa, 0xfbcf,
+ 0xedfb, 0x6eee, 0x386f, 0x4538, 0x6e45, 0xd96d, 0x11d9, 0x7912, 0x4b79,
+ 0x494b, 0x6049, 0xac5f, 0x65ac, 0x1366, 0x5913, 0xe458, 0x7ae4, 0x387a,
+ 0x3c38, 0xb03c, 0x76b0, 0x9376, 0xe193, 0x42e1, 0x7742, 0x6476, 0x3564,
+ 0x3c35, 0x6a3c, 0xcc69, 0x94cc, 0x5d95, 0xe5e, 0xee0d, 0x4ced, 0xce4c,
+ 0x52ce, 0xaa52, 0xdaaa, 0xe4da, 0x1de5, 0x4530, 0x5445, 0x3954, 0xb639,
+ 0x81b6, 0x7381, 0x1574, 0xc215, 0x10c2, 0x3f10, 0x6b3f, 0xe76b, 0x7be7,
+ 0xbc7b, 0xf7bb, 0x41f7, 0xcc41, 0x38cc, 0x4239, 0xa942, 0x4a9, 0xc504,
+ 0x7cc4, 0x437c, 0x6743, 0xea67, 0x8dea, 0xe88d, 0xd8e8, 0xdcd8, 0x17dd,
+ 0x5718, 0x958, 0xa609, 0x41a5, 0x5842, 0x159, 0x9f01, 0x269f, 0x5a26,
+ 0x405a, 0xc340, 0xb4c3, 0xd4b4, 0xf4d3, 0xf1f4, 0x39f2, 0xe439, 0x67e4,
+ 0x4168, 0xa441, 0xdda3, 0xdedd, 0x9df, 0xab0a, 0xa5ab, 0x9a6, 0xba09,
+ 0x9ab9, 0xad9a, 0x5ae, 0xe205, 0xece2, 0xecec, 0x14ed, 0xd614, 0x6bd5,
+ 0x916c, 0x3391, 0x6f33, 0x206f, 0x8020, 0x780, 0x7207, 0x2472, 0x8a23,
+ 0xb689, 0x3ab6, 0xf739, 0x97f6, 0xb097, 0xa4b0, 0xe6a4, 0x88e6, 0x2789,
+ 0xb28, 0x350b, 0x1f35, 0x431e, 0x1043, 0xc30f, 0x79c3, 0x379, 0x5703,
+ 0x3256, 0x4732, 0x7247, 0x9d72, 0x489d, 0xd348, 0xa4d3, 0x7ca4, 0xbf7b,
+ 0x45c0, 0x7b45, 0x337b, 0x4034, 0x843f, 0xd083, 0x35d0, 0x6335, 0x4d63,
+ 0xe14c, 0xcce0, 0xfecc, 0x35ff, 0x5636, 0xf856, 0xeef8, 0x2def, 0xfc2d,
+ 0x4fc, 0x6e04, 0xb66d, 0x78b6, 0xbb78, 0x3dbb, 0x9a3d, 0x839a, 0x9283,
+ 0x593, 0xd504, 0x23d5, 0x5424, 0xd054, 0x61d0, 0xdb61, 0x17db, 0x1f18,
+ 0x381f, 0x9e37, 0x679e, 0x1d68, 0x381d, 0x8038, 0x917f, 0x491, 0xbb04,
+ 0x23bb, 0x4124, 0xd41, 0xa30c, 0x8ba3, 0x8b8b, 0xc68b, 0xd2c6, 0xebd2,
+ 0x93eb, 0xbd93, 0x99bd, 0x1a99, 0xea19, 0x58ea, 0xcf58, 0x73cf, 0x1073,
+ 0x9e10, 0x139e, 0xea13, 0xcde9, 0x3ecd, 0x883f, 0xf89, 0x180f, 0x2a18,
+ 0x212a, 0xce20, 0x73ce, 0xf373, 0x60f3, 0xad60, 0x4093, 0x8e40, 0xb98e,
+ 0xbfb9, 0xf1bf, 0x8bf1, 0x5e8c, 0xe95e, 0x14e9, 0x4e14, 0x1c4e, 0x7f1c,
+ 0xe77e, 0x6fe7, 0xf26f, 0x13f2, 0x8b13, 0xda8a, 0x5fda, 0xea5f, 0x4eea,
+ 0xa84f, 0x88a8, 0x1f88, 0x2820, 0x9728, 0x5a97, 0x3f5b, 0xb23f, 0x70b2,
+ 0x2c70, 0x232d, 0xf623, 0x4f6, 0x905, 0x7509, 0xd675, 0x28d7, 0x9428,
+ 0x3794, 0xf036, 0x2bf0, 0xba2c, 0xedb9, 0xd7ed, 0x59d8, 0xed59, 0x4ed,
+ 0xe304, 0x18e3, 0x5c19, 0x3d5c, 0x753d, 0x6d75, 0x956d, 0x7f95, 0xc47f,
+ 0x83c4, 0xa84, 0x2e0a, 0x5f2e, 0xb95f, 0x77b9, 0x6d78, 0xf46d, 0x1bf4,
+ 0xed1b, 0xd6ed, 0xe0d6, 0x5e1, 0x3905, 0x5638, 0xa355, 0x99a2, 0xbe99,
+ 0xb4bd, 0x85b4, 0x2e86, 0x542e, 0x6654, 0xd765, 0x73d7, 0x3a74, 0x383a,
+ 0x2638, 0x7826, 0x7677, 0x9a76, 0x7e99, 0x2e7e, 0xea2d, 0xa6ea, 0x8a7,
+ 0x109, 0x3300, 0xad32, 0x5fad, 0x465f, 0x2f46, 0xc62f, 0xd4c5, 0xad5,
+ 0xcb0a, 0x4cb, 0xb004, 0x7baf, 0xe47b, 0x92e4, 0x8e92, 0x638e, 0x1763,
+ 0xc17, 0xf20b, 0x1ff2, 0x8920, 0x5889, 0xcb58, 0xf8cb, 0xcaf8, 0x84cb,
+ 0x9f84, 0x8a9f, 0x918a, 0x4991, 0x8249, 0xff81, 0x46ff, 0x5046, 0x5f50,
+ 0x725f, 0xf772, 0x8ef7, 0xe08f, 0xc1e0, 0x1fc2, 0x9e1f, 0x8b9d, 0x108b,
+ 0x411, 0x2b04, 0xb02a, 0x1fb0, 0x1020, 0x7a0f, 0x587a, 0x8958, 0xb188,
+ 0xb1b1, 0x49b2, 0xb949, 0x7ab9, 0x917a, 0xfc91, 0xe6fc, 0x47e7, 0xbc47,
+ 0x8fbb, 0xea8e, 0x34ea, 0x2635, 0x1726, 0x9616, 0xc196, 0xa6c1, 0xf3a6,
+ 0x11f3, 0x4811, 0x3e48, 0xeb3e, 0xf7ea, 0x1bf8, 0xdb1c, 0x8adb, 0xe18a,
+ 0x42e1, 0x9d42, 0x5d9c, 0x6e5d, 0x286e, 0x4928, 0x9a49, 0xb09c, 0xa6b0,
+ 0x2a7, 0xe702, 0xf5e6, 0x9af5, 0xf9b, 0x810f, 0x8080, 0x180, 0x1702,
+ 0x5117, 0xa650, 0x11a6, 0x1011, 0x550f, 0xd554, 0xbdd5, 0x6bbe, 0xc66b,
+ 0xfc7, 0x5510, 0x5555, 0x7655, 0x177, 0x2b02, 0x6f2a, 0xb70, 0x9f0b,
+ 0xcf9e, 0xf3cf, 0x3ff4, 0xcb40, 0x8ecb, 0x768e, 0x5277, 0x8652, 0x9186,
+ 0x9991, 0x5099, 0xd350, 0x93d3, 0x6d94, 0xe6d, 0x530e, 0x3153, 0xa531,
+ 0x64a5, 0x7964, 0x7c79, 0x467c, 0x1746, 0x3017, 0x3730, 0x538, 0x5,
+ 0x1e00, 0x5b1e, 0x955a, 0xae95, 0x3eaf, 0xff3e, 0xf8ff, 0xb2f9, 0xa1b3,
+ 0xb2a1, 0x5b2, 0xad05, 0x7cac, 0x2d7c, 0xd32c, 0x80d2, 0x7280, 0x8d72,
+ 0x1b8e, 0x831b, 0xac82, 0xfdac, 0xa7fd, 0x15a8, 0xd614, 0xe0d5, 0x7be0,
+ 0xb37b, 0x61b3, 0x9661, 0x9d95, 0xc79d, 0x83c7, 0xd883, 0xead7, 0xceb,
+ 0xf60c, 0xa9f5, 0x19a9, 0xa019, 0x8f9f, 0xd48f, 0x3ad5, 0x853a, 0x985,
+ 0x5309, 0x6f52, 0x1370, 0x6e13, 0xa96d, 0x98a9, 0x5198, 0x9f51, 0xb69f,
+ 0xa1b6, 0x2ea1, 0x672e, 0x2067, 0x6520, 0xaf65, 0x6eaf, 0x7e6f, 0xee7e,
+ 0x17ef, 0xa917, 0xcea8, 0x9ace, 0xff99, 0x5dff, 0xdf5d, 0x38df, 0xa39,
+ 0x1c0b, 0xe01b, 0x46e0, 0xcb46, 0x90cb, 0xba90, 0x4bb, 0x9104, 0x9d90,
+ 0xc89c, 0xf6c8, 0x6cf6, 0x886c, 0x1789, 0xbd17, 0x70bc, 0x7e71, 0x17e,
+ 0x1f01, 0xa01f, 0xbaa0, 0x14bb, 0xfc14, 0x7afb, 0xa07a, 0x3da0, 0xbf3d,
+ 0x48bf, 0x8c48, 0x968b, 0x9d96, 0xfd9d, 0x96fd, 0x9796, 0x6b97, 0xd16b,
+ 0xf4d1, 0x3bf4, 0x253c, 0x9125, 0x6691, 0xc166, 0x34c1, 0x5735, 0x1a57,
+ 0xdc19, 0x77db, 0x8577, 0x4a85, 0x824a, 0x9182, 0x7f91, 0xfd7f, 0xb4c3,
+ 0xb5b4, 0xb3b5, 0x7eb3, 0x617e, 0x4e61, 0xa4f, 0x530a, 0x3f52, 0xa33e,
+ 0x34a3, 0x9234, 0xf091, 0xf4f0, 0x1bf5, 0x311b, 0x9631, 0x6a96, 0x386b,
+ 0x1d39, 0xe91d, 0xe8e9, 0x69e8, 0x426a, 0xee42, 0x89ee, 0x368a, 0x2837,
+ 0x7428, 0x5974, 0x6159, 0x1d62, 0x7b1d, 0xf77a, 0x7bf7, 0x6b7c, 0x696c,
+ 0xf969, 0x4cf9, 0x714c, 0x4e71, 0x6b4e, 0x256c, 0x6e25, 0xe96d, 0x94e9,
+ 0x8f94, 0x3e8f, 0x343e, 0x4634, 0xb646, 0x97b5, 0x8997, 0xe8a, 0x900e,
+ 0x8090, 0xfd80, 0xa0fd, 0x16a1, 0xf416, 0xebf4, 0x95ec, 0x1196, 0x8911,
+ 0x3d89, 0xda3c, 0x9fd9, 0xd79f, 0x4bd7, 0x214c, 0x3021, 0x4f30, 0x994e,
+ 0x5c99, 0x6f5d, 0x326f, 0xab31, 0x6aab, 0xe969, 0x90e9, 0x1190, 0xff10,
+ 0xa2fe, 0xe0a2, 0x66e1, 0x4067, 0x9e3f, 0x2d9e, 0x712d, 0x8170, 0xd180,
+ 0xffd1, 0x25ff, 0x3826, 0x2538, 0x5f24, 0xc45e, 0x1cc4, 0xdf1c, 0x93df,
+ 0xc793, 0x80c7, 0x2380, 0xd223, 0x7ed2, 0xfc7e, 0x22fd, 0x7422, 0x1474,
+ 0xb714, 0x7db6, 0x857d, 0xa85, 0xa60a, 0x88a6, 0x4289, 0x7842, 0xc278,
+ 0xf7c2, 0xcdf7, 0x84cd, 0xae84, 0x8cae, 0xb98c, 0x1aba, 0x4d1a, 0x884c,
+ 0x4688, 0xcc46, 0xd8cb, 0x2bd9, 0xbe2b, 0xa2be, 0x72a2, 0xf772, 0xd2f6,
+ 0x75d2, 0xc075, 0xa3c0, 0x63a3, 0xae63, 0x8fae, 0x2a90, 0x5f2a, 0xef5f,
+ 0x5cef, 0xa05c, 0x89a0, 0x5e89, 0x6b5e, 0x736b, 0x773, 0x9d07, 0xe99c,
+ 0x27ea, 0x2028, 0xc20, 0x980b, 0x4797, 0x2848, 0x9828, 0xc197, 0x48c2,
+ 0x2449, 0x7024, 0x570, 0x3e05, 0xd3e, 0xf60c, 0xbbf5, 0x69bb, 0x3f6a,
+ 0x740, 0xf006, 0xe0ef, 0xbbe0, 0xadbb, 0x56ad, 0xcf56, 0xbfce, 0xa9bf,
+ 0x205b, 0x6920, 0xae69, 0x50ae, 0x2050, 0xf01f, 0x27f0, 0x9427, 0x8993,
+ 0x8689, 0x4087, 0x6e40, 0xb16e, 0xa1b1, 0xe8a1, 0x87e8, 0x6f88, 0xfe6f,
+ 0x4cfe, 0xe94d, 0xd5e9, 0x47d6, 0x3148, 0x5f31, 0xc35f, 0x13c4, 0xa413,
+ 0x5a5, 0x2405, 0xc223, 0x66c2, 0x3667, 0x5e37, 0x5f5e, 0x2f5f, 0x8c2f,
+ 0xe48c, 0xd0e4, 0x4d1, 0xd104, 0xe4d0, 0xcee4, 0xfcf, 0x480f, 0xa447,
+ 0x5ea4, 0xff5e, 0xbefe, 0x8dbe, 0x1d8e, 0x411d, 0x1841, 0x6918, 0x5469,
+ 0x1155, 0xc611, 0xaac6, 0x37ab, 0x2f37, 0xca2e, 0x87ca, 0xbd87, 0xabbd,
+ 0xb3ab, 0xcb4, 0xce0c, 0xfccd, 0xa5fd, 0x72a5, 0xf072, 0x83f0, 0xfe83,
+ 0x97fd, 0xc997, 0xb0c9, 0xadb0, 0xe6ac, 0x88e6, 0x1088, 0xbe10, 0x16be,
+ 0xa916, 0xa3a8, 0x46a3, 0x5447, 0xe953, 0x84e8, 0x2085, 0xa11f, 0xfa1,
+ 0xdd0f, 0xbedc, 0x5abe, 0x805a, 0xc97f, 0x6dc9, 0x826d, 0x4a82, 0x934a,
+ 0x5293, 0xd852, 0xd3d8, 0xadd3, 0xf4ad, 0xf3f4, 0xfcf3, 0xfefc, 0xcafe,
+ 0xb7ca, 0x3cb8, 0xa13c, 0x18a1, 0x1418, 0xea13, 0x91ea, 0xf891, 0x53f8,
+ 0xa254, 0xe9a2, 0x87ea, 0x4188, 0x1c41, 0xdc1b, 0xf5db, 0xcaf5, 0x45ca,
+ 0x6d45, 0x396d, 0xde39, 0x90dd, 0x1e91, 0x1e, 0x7b00, 0x6a7b, 0xa46a,
+ 0xc9a3, 0x9bc9, 0x389b, 0x1139, 0x5211, 0x1f52, 0xeb1f, 0xabeb, 0x48ab,
+ 0x9348, 0xb392, 0x17b3, 0x1618, 0x5b16, 0x175b, 0xdc17, 0xdedb, 0x1cdf,
+ 0xeb1c, 0xd1ea, 0x4ad2, 0xd4b, 0xc20c, 0x24c2, 0x7b25, 0x137b, 0x8b13,
+ 0x618b, 0xa061, 0xff9f, 0xfffe, 0x72ff, 0xf572, 0xe2f5, 0xcfe2, 0xd2cf,
+ 0x75d3, 0x6a76, 0xc469, 0x1ec4, 0xfc1d, 0x59fb, 0x455a, 0x7a45, 0xa479,
+ 0xb7a4
+};
+
static u8 tmp_buf[TEST_BUFLEN];
#define full_csum(buff, len, sum) csum_fold(csum_partial(buff, len, sum))
@@ -338,10 +575,55 @@ static void test_csum_no_carry_inputs(struct kunit *test)
}
}
+static void test_ip_fast_csum(struct kunit *test)
+{
+ __sum16 csum_result, expected;
+
+ for (int len = IPv4_MIN_WORDS; len < IPv4_MAX_WORDS; len++) {
+ for (int index = 0; index < NUM_IP_FAST_CSUM_TESTS; index++) {
+ csum_result = ip_fast_csum(random_buf + index, len);
+ expected =
+ expected_fast_csum[(len - IPv4_MIN_WORDS) *
+ NUM_IP_FAST_CSUM_TESTS +
+ index];
+ CHECK_EQ(expected, csum_result);
+ }
+ }
+}
+
+static void test_csum_ipv6_magic(struct kunit *test)
+{
+ const struct in6_addr *saddr;
+ const struct in6_addr *daddr;
+ unsigned int len;
+ unsigned char proto;
+ unsigned int csum;
+
+ const int daddr_offset = sizeof(struct in6_addr);
+ const int len_offset = sizeof(struct in6_addr) + sizeof(struct in6_addr);
+ const int proto_offset = sizeof(struct in6_addr) + sizeof(struct in6_addr) +
+ sizeof(int);
+ const int csum_offset = sizeof(struct in6_addr) + sizeof(struct in6_addr) +
+ sizeof(int) + sizeof(char);
+
+ for (int i = 0; i < NUM_IPv6_TESTS; i++) {
+ saddr = (const struct in6_addr *)(random_buf + i);
+ daddr = (const struct in6_addr *)(random_buf + i +
+ daddr_offset);
+ len = *(unsigned int *)(random_buf + i + len_offset);
+ proto = *(random_buf + i + proto_offset);
+ csum = *(unsigned int *)(random_buf + i + csum_offset);
+ CHECK_EQ(expected_csum_ipv6_magic[i],
+ csum_ipv6_magic(saddr, daddr, len, proto, csum));
+ }
+}
+
static struct kunit_case __refdata checksum_test_cases[] = {
KUNIT_CASE(test_csum_fixed_random_inputs),
KUNIT_CASE(test_csum_all_carry_inputs),
KUNIT_CASE(test_csum_no_carry_inputs),
+ KUNIT_CASE(test_ip_fast_csum),
+ KUNIT_CASE(test_csum_ipv6_magic),
{}
};
--
2.34.1
> -----Original Message-----
> From: Charlie Jenkins <[email protected]>
> Sent: Thursday, November 2, 2023 6:48 AM
> To: Charlie Jenkins <[email protected]>; Palmer Dabbelt
> <[email protected]>; Conor Dooley <[email protected]>; Samuel Holland
> <[email protected]>; David Laight <[email protected]>;
> Wang, Xiao W <[email protected]>; Evan Green <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]
> Cc: Paul Walmsley <[email protected]>; Albert Ou
> <[email protected]>; Arnd Bergmann <[email protected]>; Conor Dooley
> <[email protected]>
> Subject: [PATCH v10 3/5] riscv: Checksum header
Is it better to make the title more descriptive as "riscv: Add checksum header"?
>
> Provide checksum algorithms that have been designed to leverage riscv
> instructions such as rotate. In 64-bit, can take advantage of the larger
> register to avoid some overflow checking.
>
> Signed-off-by: Charlie Jenkins <[email protected]>
> Acked-by: Conor Dooley <[email protected]>
> ---
> arch/riscv/include/asm/checksum.h | 81
> +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 81 insertions(+)
>
> diff --git a/arch/riscv/include/asm/checksum.h
> b/arch/riscv/include/asm/checksum.h
> new file mode 100644
> index 000000000000..3d77cac338fe
> --- /dev/null
> +++ b/arch/riscv/include/asm/checksum.h
> @@ -0,0 +1,81 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Checksum routines
> + *
> + * Copyright (C) 2023 Rivos Inc.
> + */
> +#ifndef __ASM_RISCV_CHECKSUM_H
> +#define __ASM_RISCV_CHECKSUM_H
> +
> +#include <linux/in6.h>
> +#include <linux/uaccess.h>
> +
> +#define ip_fast_csum ip_fast_csum
> +
> +/* Define riscv versions of functions before importing asm-
> generic/checksum.h */
> +#include <asm-generic/checksum.h>
> +
> +/*
> + * Quickly compute an IP checksum with the assumption that IPv4 headers
> will
> + * always be in multiples of 32-bits, and have an ihl of at least 5.
> + * @ihl is the number of 32 bit segments and must be greater than or equal
> to 5.
> + * @iph is assumed to be word aligned given that NET_IP_ALIGN is set to 2 on
> + * riscv, defining IP headers to be aligned.
> + */
For comments on API parameters, it's better to follow the "@para: xxx" standard format
and indention alignment used in other places.
> +static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
> +{
> + unsigned long csum = 0;
> + int pos = 0;
> +
> + do {
> + csum += ((const unsigned int *)iph)[pos];
> + if (IS_ENABLED(CONFIG_32BIT))
> + csum += csum < ((const unsigned int *)iph)[pos];
> + } while (++pos < ihl);
> +
> + /*
> + * ZBB only saves three instructions on 32-bit and five on 64-bit so not
> + * worth checking if supported without Alternatives.
> + */
> + if (IS_ENABLED(CONFIG_RISCV_ISA_ZBB) &&
> + IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
> + unsigned long fold_temp;
> +
> + asm_volatile_goto(ALTERNATIVE("j %l[no_zbb]", "nop", 0,
> + RISCV_ISA_EXT_ZBB, 1)
> + :
> + :
> + :
> + : no_zbb);
> +
> + if (IS_ENABLED(CONFIG_32BIT)) {
> + asm(".option push \n\
> + .option arch,+zbb \n\
> + not %[fold_temp], %[csum]
> \n\
> + rori %[csum], %[csum], 16 \n\
> + sub %[csum], %[fold_temp], %[csum]
> \n\
> + .option pop"
> + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp));
> + } else {
> + asm(".option push \n\
> + .option arch,+zbb \n\
> + rori %[fold_temp], %[csum], 32 \n\
> + add %[csum], %[fold_temp], %[csum]
> \n\
> + srli %[csum], %[csum], 32 \n\
> + not %[fold_temp], %[csum]
> \n\
> + roriw %[csum], %[csum], 16 \n\
> + subw %[csum], %[fold_temp], %[csum]
> \n\
> + .option pop"
> + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp));
> + }
> + return csum >> 16;
> + }
> +no_zbb:
> +#ifndef CONFIG_32BIT
> + csum += ror64(csum, 32);
> + csum >>= 32;
> +#endif
> + return csum_fold((__force __wsum)csum);
> +}
The algorithm looks good to me.
BRs,
Xiao
> +
> +#endif /* __ASM_RISCV_CHECKSUM_H */
>
> --
> 2.34.1