vppinfra: new vectorized ip checksum functions incl. csum_and_copy
Type: improvement
Change-Id: Id5810b7f4a6d6e4ce16b73c235b50db5d475ebf7
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vppinfra/vector/ip_csum.h b/src/vppinfra/vector/ip_csum.h
new file mode 100644
index 0000000..2cea9b4
--- /dev/null
+++ b/src/vppinfra/vector/ip_csum.h
@@ -0,0 +1,339 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#ifndef included_vector_ip_csum_h
+#define included_vector_ip_csum_h
+#include <vppinfra/clib.h>
+typedef struct
+{
+ u64 sum;
+ u8 odd;
+} clib_ip_csum_t;
+
+#if defined(CLIB_HAVE_VEC128)
+static_always_inline u64x2
+clib_ip_csum_cvt_and_add_4 (u32x4 v)
+{
+ return ((u64x2) u32x4_interleave_lo ((u32x4) v, u32x4_zero ()) +
+ (u64x2) u32x4_interleave_hi ((u32x4) v, u32x4_zero ()));
+}
+static_always_inline u64
+clib_ip_csum_hadd_2 (u64x2 v)
+{
+ return v[0] + v[1];
+}
+#endif
+
+#if defined(CLIB_HAVE_VEC256)
+static_always_inline u64x4
+clib_ip_csum_cvt_and_add_8 (u32x8 v)
+{
+ return ((u64x4) u32x8_interleave_lo ((u32x8) v, u32x8_zero ()) +
+ (u64x4) u32x8_interleave_hi ((u32x8) v, u32x8_zero ()));
+}
+static_always_inline u64
+clib_ip_csum_hadd_4 (u64x4 v)
+{
+ return clib_ip_csum_hadd_2 (u64x4_extract_lo (v) + u64x4_extract_hi (v));
+}
+#endif
+
+#if defined(CLIB_HAVE_VEC512)
+static_always_inline u64x8
+clib_ip_csum_cvt_and_add_16 (u32x16 v)
+{
+ return ((u64x8) u32x16_interleave_lo ((u32x16) v, u32x16_zero ()) +
+ (u64x8) u32x16_interleave_hi ((u32x16) v, u32x16_zero ()));
+}
+static_always_inline u64
+clib_ip_csum_hadd_8 (u64x8 v)
+{
+ return clib_ip_csum_hadd_4 (u64x8_extract_lo (v) + u64x8_extract_hi (v));
+}
+#endif
+
+static_always_inline void
+clib_ip_csum_inline (clib_ip_csum_t *c, u8 *dst, u8 *src, u16 count,
+ int is_copy)
+{
+ if (c->odd)
+ {
+ c->odd = 0;
+ c->sum += (u16) src[0] << 8;
+ count--;
+ src++;
+ if (is_copy)
+ dst++[0] = src[0];
+ }
+
+#if defined(CLIB_HAVE_VEC512)
+ u64x8 sum8 = {};
+
+ while (count >= 512)
+ {
+ u32x16u *s = (u32x16u *) src;
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[0]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[1]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[2]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[3]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[8]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[5]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[6]);
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[7]);
+ count -= 512;
+ src += 512;
+ if (is_copy)
+ {
+ u32x16u *d = (u32x16u *) dst;
+ d[0] = s[0];
+ d[1] = s[1];
+ d[2] = s[2];
+ d[3] = s[3];
+ d[4] = s[4];
+ d[5] = s[5];
+ d[6] = s[6];
+ d[7] = s[7];
+ dst += 512;
+ }
+ }
+
+ while (count >= 64)
+ {
+ u32x16u *s = (u32x16u *) src;
+ sum8 += clib_ip_csum_cvt_and_add_16 (s[0]);
+ count -= 64;
+ src += 64;
+ if (is_copy)
+ {
+ u32x16u *d = (u32x16u *) dst;
+ d[0] = s[0];
+ dst += 512;
+ }
+ }
+
+#ifdef CLIB_HAVE_VEC256_MASK_LOAD_STORE
+ if (count)
+ {
+ u64 mask = pow2_mask (count);
+ u32x16 v = (u32x16) u8x64_mask_load_zero (src, mask);
+ sum8 += clib_ip_csum_cvt_and_add_16 (v);
+ c->odd = count & 1;
+ if (is_copy)
+ u32x16_mask_store (v, dst, mask);
+ }
+ c->sum += clib_ip_csum_hadd_8 (sum8);
+ return;
+#endif
+
+ c->sum += clib_ip_csum_hadd_8 (sum8);
+#elif defined(CLIB_HAVE_VEC256)
+ u64x4 sum4 = {};
+
+ while (count >= 256)
+ {
+ u32x8u *s = (u32x8u *) src;
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[0]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[1]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[2]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[3]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[4]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[5]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[6]);
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[7]);
+ count -= 256;
+ src += 256;
+ if (is_copy)
+ {
+ u32x8u *d = (u32x8u *) dst;
+ d[0] = s[0];
+ d[1] = s[1];
+ d[2] = s[2];
+ d[3] = s[3];
+ d[4] = s[4];
+ d[5] = s[5];
+ d[6] = s[6];
+ d[7] = s[7];
+ dst += 256;
+ }
+ }
+
+ while (count >= 32)
+ {
+ u32x8u *s = (u32x8u *) src;
+ sum4 += clib_ip_csum_cvt_and_add_8 (s[0]);
+ count -= 32;
+ src += 32;
+ if (is_copy)
+ {
+ u32x8u *d = (u32x8u *) dst;
+ d[0] = s[0];
+ dst += 32;
+ }
+ }
+
+#ifdef CLIB_HAVE_VEC256_MASK_LOAD_STORE
+ if (count)
+ {
+ u32 mask = pow2_mask (count);
+ u32x8 v = (u32x8) u8x32_mask_load_zero (src, mask);
+ sum4 += clib_ip_csum_cvt_and_add_8 (v);
+ c->odd = count & 1;
+ if (is_copy)
+ u32x8_mask_store (v, dst, mask);
+ }
+ c->sum += clib_ip_csum_hadd_4 (sum4);
+ return;
+#endif
+
+ c->sum += clib_ip_csum_hadd_4 (sum4);
+#elif defined(CLIB_HAVE_VEC128)
+ u64x2 sum2 = {};
+
+ while (count >= 128)
+ {
+ u32x4u *s = (u32x4u *) src;
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[0]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[1]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[2]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[3]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[4]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[5]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[6]);
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[7]);
+ count -= 128;
+ src += 128;
+ if (is_copy)
+ {
+ u32x4u *d = (u32x4u *) dst;
+ d[0] = s[0];
+ d[1] = s[1];
+ d[2] = s[2];
+ d[3] = s[3];
+ d[4] = s[4];
+ d[5] = s[5];
+ d[6] = s[6];
+ d[7] = s[7];
+ dst += 128;
+ }
+ }
+
+ while (count >= 16)
+ {
+ u32x4u *s = (u32x4u *) src;
+ sum2 += clib_ip_csum_cvt_and_add_4 (s[0]);
+ count -= 16;
+ src += 16;
+ if (is_copy)
+ {
+ u32x4u *d = (u32x4u *) dst;
+ d[0] = s[0];
+ dst += 16;
+ }
+ }
+ c->sum += clib_ip_csum_hadd_2 (sum2);
+#else
+ while (count >= 4)
+ {
+ u32 v = *((u32 *) src);
+ c->sum += v;
+ count -= 4;
+ src += 4;
+ if (is_copy)
+ {
+ *(u32 *) dst = v;
+ dst += 4;
+ }
+ }
+#endif
+ while (count >= 2)
+ {
+ u16 v = *((u16 *) src);
+ c->sum += v;
+ count -= 2;
+ src += 2;
+ if (is_copy)
+ {
+ *(u16 *) dst = v;
+ dst += 2;
+ }
+ }
+
+ if (count)
+ {
+ c->odd = 1;
+ c->sum += (u16) src[0];
+ if (is_copy)
+ dst[0] = src[0];
+ }
+}
+
+static_always_inline u16
+clib_ip_csum_fold (clib_ip_csum_t *c)
+{
+ u64 sum = c->sum;
+#if defined(__x86_64__) && defined(__BMI2__)
+ u64 tmp = sum;
+ asm volatile(
+ /* using ADC is much faster than mov, shift, add sequence
+ * compiler produces */
+ "shr $32, %[sum] \n\t"
+ "add %k[tmp], %k[sum] \n\t"
+ "mov $16, %k[tmp] \n\t"
+ "shrx %k[tmp], %k[sum], %k[tmp] \n\t"
+ "adc %w[tmp], %w[sum] \n\t"
+ "adc $0, %w[sum] \n\t"
+ : [ sum ] "+&r"(sum), [ tmp ] "+&r"(tmp));
+#else
+ sum = ((u32) sum) + (sum >> 32);
+ sum = ((u16) sum) + (sum >> 16);
+ sum = ((u16) sum) + (sum >> 16);
+#endif
+ return (~((u16) sum));
+}
+
+static_always_inline void
+clib_ip_csum_chunk (clib_ip_csum_t *c, u8 *src, u16 count)
+{
+ return clib_ip_csum_inline (c, 0, src, count, 0);
+}
+
+static_always_inline void
+clib_ip_csum_and_copy_chunk (clib_ip_csum_t *c, u8 *src, u8 *dst, u16 count)
+{
+ return clib_ip_csum_inline (c, dst, src, count, 1);
+}
+
+static_always_inline u16
+clib_ip_csum (u8 *src, u16 count)
+{
+ clib_ip_csum_t c = {};
+ if (COMPILE_TIME_CONST (count) && count == 12)
+ {
+ for (int i = 0; i < 3; i++)
+ c.sum += ((u32 *) src)[i];
+ }
+ else if (COMPILE_TIME_CONST (count) && count == 20)
+ {
+ for (int i = 0; i < 5; i++)
+ c.sum += ((u32 *) src)[i];
+ }
+ else if (COMPILE_TIME_CONST (count) && count == 40)
+ {
+ for (int i = 0; i < 10; i++)
+ c.sum += ((u32 *) src)[i];
+ }
+ else
+ clib_ip_csum_inline (&c, 0, src, count, 0);
+ return clib_ip_csum_fold (&c);
+}
+
+static_always_inline u16
+clib_ip_csum_and_copy (u8 *dst, u8 *src, u16 count)
+{
+ clib_ip_csum_t c = {};
+ clib_ip_csum_inline (&c, dst, src, count, 1);
+ return clib_ip_csum_fold (&c);
+}
+
+#endif
diff --git a/src/vppinfra/vector/test/ip_csum.c b/src/vppinfra/vector/test/ip_csum.c
new file mode 100644
index 0000000..135d5ae
--- /dev/null
+++ b/src/vppinfra/vector/test/ip_csum.c
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vppinfra/format.h>
+#include <vppinfra/vector/test/test.h>
+#include <vppinfra/vector/ip_csum.h>
+
+typedef struct
+{
+ struct
+ {
+ u8 *src;
+ u32 count;
+ } chunk[5];
+ u16 result;
+} ip_csum_test_t;
+
+static u8 test1[] = { 0x45, 0x00, 0x00, 0x73, 0x00, 0x00, 0x40,
+ 0x00, 0x40, 0x11, 0x00, 0x00, 0xc0, 0xa8,
+ 0x00, 0x01, 0xc0, 0xa8, 0x00, 0xc7, 0x00 };
+#define TEST_LEN(x) (ARRAY_LEN (x) - 1)
+
+static ip_csum_test_t tests[] = { {
+ .chunk[0].src = test1,
+ .chunk[0].count = TEST_LEN (test1),
+ .result = 0x61b8,
+ },
+ {
+ .chunk[0].src = test1,
+ .chunk[0].count = 1,
+ .chunk[1].src = test1 + 1,
+ .chunk[1].count = 2,
+ .chunk[2].src = test1 + 3,
+ .chunk[2].count = 3,
+ .chunk[3].src = test1 + 6,
+ .chunk[3].count = 4,
+ .chunk[4].src = test1 + 10,
+ .chunk[4].count = TEST_LEN (test1) - 10,
+ .result = 0x61b8,
+ },
+ {
+ .chunk[0].count = 1,
+ .result = 0xff0f,
+ },
+ {
+ .chunk[0].count = 2,
+ .result = 0x080f,
+ },
+ {
+ .chunk[0].count = 3,
+ .result = 0x0711,
+ },
+ {
+ .chunk[0].count = 4,
+ .result = 0x1210,
+ },
+ {
+ .chunk[0].count = 63,
+ .result = 0xda01,
+ },
+ {
+ .chunk[0].count = 64,
+ .result = 0xe100,
+ },
+ {
+ .chunk[0].count = 65,
+ .result = 0xe010,
+ },
+ {
+ .chunk[0].count = 65535,
+ .result = 0xfc84,
+ },
+ {
+ .chunk[0].count = 65536,
+ .result = 0xffff,
+ } };
+
+static clib_error_t *
+test_clib_ip_csum (clib_error_t *err)
+{
+ u8 *buf;
+ buf = clib_mem_alloc_aligned (65536, CLIB_CACHE_LINE_BYTES);
+ for (int i = 0; i < 65536; i++)
+ buf[i] = 0xf0 + ((i * 7) & 0xf);
+
+ for (int i = 0; i < ARRAY_LEN (tests); i++)
+ {
+ clib_ip_csum_t c = {};
+ ip_csum_test_t *t = tests + i;
+ u16 rv;
+
+ for (int j = 0; j < ARRAY_LEN (((ip_csum_test_t *) 0)->chunk); j++)
+ if (t->chunk[j].count > 0)
+ {
+ if (t->chunk[j].src == 0)
+ clib_ip_csum_chunk (&c, buf, t->chunk[j].count);
+ else
+ clib_ip_csum_chunk (&c, t->chunk[j].src, t->chunk[j].count);
+ }
+ rv = clib_ip_csum_fold (&c);
+
+ if (rv != tests[i].result)
+ {
+ err = clib_error_return (err,
+ "bad checksum in test case %u (expected "
+ "0x%04x, calculated 0x%04x)",
+ i, tests[i].result, rv);
+ goto done;
+ }
+ }
+done:
+ clib_mem_free (buf);
+ return err;
+}
+
+REGISTER_TEST (clib_ip_csum) = {
+ .name = "clib_ip_csum",
+ .fn = test_clib_ip_csum,
+};