xref: /dpdk/examples/common/pkt_group.h (revision 732115ce38c63184cb706b9179c02ed04b961afa)

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2016-2018 Intel Corporation.
 * Copyright(c) 2017-2018 Linaro Limited.
 * Copyright(C) 2022 Marvell.
 */

#ifndef PKT_GROUP_H
#define PKT_GROUP_H

#define FWDSTEP	4

/*
 * Group consecutive packets with the same destination port into one burst.
 * To avoid extra latency this is done together with some other packet
 * processing, but after we made a final decision about packet's destination.
 * To do this we maintain:
 * pnum - array of number of consecutive packets with the same dest port for
 * each packet in the input burst.
 * lp - pointer to the last updated element in the pnum.
 * dlp - dest port value lp corresponds to.
 */

#define	GRPSZ	(1 << FWDSTEP)
#define	GRPMSK	(GRPSZ - 1)

#define GROUP_PORT_STEP(dlp, dcp, lp, pn, idx)	do { \
	if (likely((dlp) == (dcp)[(idx)])) {         \
		(lp)[0]++;                           \
	} else {                                     \
		(dlp) = (dcp)[idx];                  \
		(lp) = (pn) + (idx);                 \
		(lp)[0] = 1;                         \
	}                                            \
} while (0)

static const struct {
	uint64_t pnum; /* prebuild 4 values for pnum[]. */
	int32_t  idx;  /* index for new last updated elemnet. */
	uint16_t lpv;  /* add value to the last updated element. */
} gptbl[GRPSZ] = {
	{
		/* 0: a != b, b != c, c != d, d != e */
		.pnum = UINT64_C(0x0001000100010001),
		.idx = 4,
		.lpv = 0,
	},
	{
		/* 1: a == b, b != c, c != d, d != e */
		.pnum = UINT64_C(0x0001000100010002),
		.idx = 4,
		.lpv = 1,
	},
	{
		/* 2: a != b, b == c, c != d, d != e */
		.pnum = UINT64_C(0x0001000100020001),
		.idx = 4,
		.lpv = 0,
	},
	{
		/* 3: a == b, b == c, c != d, d != e */
		.pnum = UINT64_C(0x0001000100020003),
		.idx = 4,
		.lpv = 2,
	},
	{
		/* 4: a != b, b != c, c == d, d != e */
		.pnum = UINT64_C(0x0001000200010001),
		.idx = 4,
		.lpv = 0,
	},
	{
		/* 5: a == b, b != c, c == d, d != e */
		.pnum = UINT64_C(0x0001000200010002),
		.idx = 4,
		.lpv = 1,
	},
	{
		/* 6: a != b, b == c, c == d, d != e */
		.pnum = UINT64_C(0x0001000200030001),
		.idx = 4,
		.lpv = 0,
	},
	{
		/* 7: a == b, b == c, c == d, d != e */
		.pnum = UINT64_C(0x0001000200030004),
		.idx = 4,
		.lpv = 3,
	},
	{
		/* 8: a != b, b != c, c != d, d == e */
		.pnum = UINT64_C(0x0002000100010001),
		.idx = 3,
		.lpv = 0,
	},
	{
		/* 9: a == b, b != c, c != d, d == e */
		.pnum = UINT64_C(0x0002000100010002),
		.idx = 3,
		.lpv = 1,
	},
	{
		/* 0xa: a != b, b == c, c != d, d == e */
		.pnum = UINT64_C(0x0002000100020001),
		.idx = 3,
		.lpv = 0,
	},
	{
		/* 0xb: a == b, b == c, c != d, d == e */
		.pnum = UINT64_C(0x0002000100020003),
		.idx = 3,
		.lpv = 2,
	},
	{
		/* 0xc: a != b, b != c, c == d, d == e */
		.pnum = UINT64_C(0x0002000300010001),
		.idx = 2,
		.lpv = 0,
	},
	{
		/* 0xd: a == b, b != c, c == d, d == e */
		.pnum = UINT64_C(0x0002000300010002),
		.idx = 2,
		.lpv = 1,
	},
	{
		/* 0xe: a != b, b == c, c == d, d == e */
		.pnum = UINT64_C(0x0002000300040001),
		.idx = 1,
		.lpv = 0,
	},
	{
		/* 0xf: a == b, b == c, c == d, d == e */
		.pnum = UINT64_C(0x0002000300040005),
		.idx = 0,
		.lpv = 4,
	},
};

#endif /* PKT_GROUP_H */