numam-dpdk/lib/table/rte_swx_table_selector.c
Cristian Dumitrescu f7598a62d1 table: support selector table
A selector table is made up of groups of weighted members, with a
given member potentially part of several groups. The select operation
returns a member ID by first selecting a group based on an input group
ID and then selecting a member within that group based on hashing one
or several input header/meta-data fields. It is very useful for
implementing an ECMP/WCMP-enabled FIB or a load balancer. It is part
of the action selector described by the P4 Portable Switch
Architecture (PSA) specification.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
2021-07-09 23:31:54 +02:00

582 lines
12 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2021 Intel Corporation
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <rte_common.h>
#include <rte_prefetch.h>
#include "rte_swx_table_selector.h"
#ifndef RTE_SWX_TABLE_SELECTOR_HUGE_PAGES_DISABLE
#include <rte_malloc.h>
static void *
env_calloc(size_t size, size_t alignment, int numa_node)
{
return rte_zmalloc_socket(NULL, size, alignment, numa_node);
}
static void
env_free(void *start, size_t size __rte_unused)
{
rte_free(start);
}
#else
#include <numa.h>
static void *
env_calloc(size_t size, size_t alignment __rte_unused, int numa_node)
{
void *start;
if (numa_available() == -1)
return NULL;
start = numa_alloc_onnode(size, numa_node);
if (!start)
return NULL;
memset(start, 0, size);
return start;
}
static void
env_free(void *start, size_t size)
{
if ((numa_available() == -1) || !start)
return;
numa_free(start, size);
}
#endif
#if defined(RTE_ARCH_X86_64)
#include <x86intrin.h>
#define crc32_u64(crc, v) _mm_crc32_u64(crc, v)
#else
static inline uint64_t
crc32_u64_generic(uint64_t crc, uint64_t value)
{
int i;
crc = (crc & 0xFFFFFFFFLLU) ^ value;
for (i = 63; i >= 0; i--) {
uint64_t mask;
mask = -(crc & 1LLU);
crc = (crc >> 1LLU) ^ (0x82F63B78LLU & mask);
}
return crc;
}
#define crc32_u64(crc, v) crc32_u64_generic(crc, v)
#endif
/* Key size needs to be one of: 8, 16, 32 or 64. */
static inline uint32_t
hash(void *key, void *key_mask, uint32_t key_size, uint32_t seed)
{
uint64_t *k = key;
uint64_t *m = key_mask;
uint64_t k0, k2, k5, crc0, crc1, crc2, crc3, crc4, crc5;
switch (key_size) {
case 8:
crc0 = crc32_u64(seed, k[0] & m[0]);
return crc0;
case 16:
k0 = k[0] & m[0];
crc0 = crc32_u64(k0, seed);
crc1 = crc32_u64(k0 >> 32, k[1] & m[1]);
crc0 ^= crc1;
return crc0;
case 32:
k0 = k[0] & m[0];
k2 = k[2] & m[2];
crc0 = crc32_u64(k0, seed);
crc1 = crc32_u64(k0 >> 32, k[1] & m[1]);
crc2 = crc32_u64(k2, k[3] & m[3]);
crc3 = k2 >> 32;
crc0 = crc32_u64(crc0, crc1);
crc1 = crc32_u64(crc2, crc3);
crc0 ^= crc1;
return crc0;
case 64:
k0 = k[0] & m[0];
k2 = k[2] & m[2];
k5 = k[5] & m[5];
crc0 = crc32_u64(k0, seed);
crc1 = crc32_u64(k0 >> 32, k[1] & m[1]);
crc2 = crc32_u64(k2, k[3] & m[3]);
crc3 = crc32_u64(k2 >> 32, k[4] & m[4]);
crc4 = crc32_u64(k5, k[6] & m[6]);
crc5 = crc32_u64(k5 >> 32, k[7] & m[7]);
crc0 = crc32_u64(crc0, (crc1 << 32) ^ crc2);
crc1 = crc32_u64(crc3, (crc4 << 32) ^ crc5);
crc0 ^= crc1;
return crc0;
default:
crc0 = 0;
return crc0;
}
}
struct group_member_info {
uint32_t member_id;
uint32_t member_weight;
uint32_t member_weight_normalized;
uint32_t count;
};
struct table {
/* Input parameters */
struct rte_swx_table_selector_params params;
/* Internal. */
uint32_t *group_table;
uint64_t group_table_size;
struct group_member_info *members;
uint32_t n_members_per_group_max_log2;
};
uint64_t
rte_swx_table_selector_footprint_get(uint32_t n_groups_max, uint32_t n_members_per_group_max)
{
uint64_t group_table_size, members_size;
group_table_size = n_groups_max * n_members_per_group_max * sizeof(uint32_t);
members_size = n_members_per_group_max * sizeof(struct group_member_info);
return sizeof(struct table) + group_table_size + members_size;
}
void
rte_swx_table_selector_free(void *table)
{
struct table *t = table;
if (!t)
return;
free(t->members);
env_free(t->group_table, t->group_table_size);
free(t->params.selector_mask);
free(t);
}
static int
table_create_check(struct rte_swx_table_selector_params *params)
{
if (!params)
return -1;
if (!params->selector_size ||
(params->selector_size > 64) ||
!params->n_groups_max ||
(params->n_groups_max > 1U << 31) ||
!params->n_members_per_group_max ||
(params->n_members_per_group_max > 1U << 31))
return -EINVAL;
return 0;
}
static int
table_params_copy(struct table *t, struct rte_swx_table_selector_params *params)
{
uint32_t selector_size, i;
selector_size = rte_align32pow2(params->selector_size);
if (selector_size < 8)
selector_size = 8;
memcpy(&t->params, params, sizeof(struct rte_swx_table_selector_params));
t->params.selector_size = selector_size;
t->params.selector_mask = NULL;
t->params.n_groups_max = rte_align32pow2(params->n_groups_max);
t->params.n_members_per_group_max = rte_align32pow2(params->n_members_per_group_max);
for (i = 0; i < 32; i++)
if (params->n_members_per_group_max == 1U << i)
t->n_members_per_group_max_log2 = i;
/* t->params.selector_mask */
t->params.selector_mask = calloc(selector_size, sizeof(uint8_t));
if (!t->params.selector_mask)
goto error;
if (params->selector_mask)
memcpy(t->params.selector_mask, params->selector_mask, params->selector_size);
else
memset(t->params.selector_mask, 0xFF, params->selector_size);
return 0;
error:
free(t->params.selector_mask);
t->params.selector_mask = NULL;
return -ENOMEM;
}
static int
group_set(struct table *t,
uint32_t group_id,
struct rte_swx_table_selector_group *group);
void *
rte_swx_table_selector_create(struct rte_swx_table_selector_params *params,
struct rte_swx_table_selector_group **groups,
int numa_node)
{
struct table *t = NULL;
uint32_t group_size, i;
int status;
/* Check input arguments. */
status = table_create_check(params);
if (status)
goto error;
/* Table object. */
t = calloc(1, sizeof(struct table));
if (!t)
goto error;
/* Parameter copy. */
status = table_params_copy(t, params);
if (status)
goto error;
/* Group. */
group_size = params->n_members_per_group_max * sizeof(uint32_t);
t->group_table_size = params->n_groups_max * group_size;
t->group_table = env_calloc(t->group_table_size, RTE_CACHE_LINE_SIZE, numa_node);
if (!t->group_table)
goto error;
t->members = calloc(params->n_members_per_group_max, sizeof(struct group_member_info));
if (!t->members)
goto error;
if (groups)
for (i = 0; i < params->n_groups_max; i++)
if (groups[i]) {
status = group_set(t, i, groups[i]);
if (status)
goto error;
}
return t;
error:
rte_swx_table_selector_free(t);
return NULL;
}
static int
group_check(struct table *t, struct rte_swx_table_selector_group *group)
{
struct rte_swx_table_selector_member *elem;
uint32_t n_members = 0;
if (!group)
return 0;
TAILQ_FOREACH(elem, &group->members, node) {
struct rte_swx_table_selector_member *e;
uint32_t n = 0;
/* Check group size. */
if (n_members >= t->params.n_members_per_group_max)
return -ENOSPC;
/* Check attributes of the current group member. */
if (elem->member_id >= t->params.n_members_per_group_max ||
!elem->member_weight)
return -ENOSPC;
/* Check against duplicate member IDs. */
TAILQ_FOREACH(e, &group->members, node)
if (e->member_id == elem->member_id)
n++;
if (n != 1)
return -EINVAL;
/* Update group size. */
n_members++;
}
return 0;
}
static uint32_t
members_read(struct group_member_info *members,
struct rte_swx_table_selector_group *group)
{
struct rte_swx_table_selector_member *elem;
uint32_t n_members = 0;
if (!group)
return 0;
TAILQ_FOREACH(elem, &group->members, node) {
struct group_member_info *m = &members[n_members];
memset(m, 0, sizeof(struct group_member_info));
m->member_id = elem->member_id;
m->member_weight = elem->member_weight;
m->member_weight_normalized = elem->member_weight;
n_members++;
}
return n_members;
}
static uint32_t
members_min_weight_find(struct group_member_info *members, uint32_t n_members)
{
uint32_t min = UINT32_MAX, i;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
if (m->member_weight < min)
min = m->member_weight;
}
return min;
}
static uint32_t
members_weight_divisor_check(struct group_member_info *members,
uint32_t n_members,
uint32_t divisor)
{
uint32_t i;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
if (m->member_weight_normalized % divisor)
return 0; /* FALSE. */
}
return 1; /* TRUE. */
}
static void
members_weight_divisor_apply(struct group_member_info *members,
uint32_t n_members,
uint32_t divisor)
{
uint32_t i;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
m->member_weight_normalized /= divisor;
}
}
static uint32_t
members_weight_sum(struct group_member_info *members, uint32_t n_members)
{
uint32_t result = 0, i;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
result += m->member_weight_normalized;
}
return result;
}
static void
members_weight_scale(struct group_member_info *members,
uint32_t n_members,
uint32_t n_members_per_group_max,
uint32_t weight_sum)
{
uint32_t multiplier, remainder, i;
multiplier = n_members_per_group_max / weight_sum;
remainder = n_members_per_group_max % weight_sum;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
m->count = m->member_weight_normalized * multiplier;
}
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
uint32_t min;
min = m->member_weight_normalized;
if (remainder < m->member_weight_normalized)
min = remainder;
m->count += min;
remainder -= min;
if (!remainder)
break;
}
}
static void
members_write(struct group_member_info *members,
uint32_t n_members,
uint32_t *group_table)
{
uint32_t pos = 0, i;
for (i = 0; i < n_members; i++) {
struct group_member_info *m = &members[i];
uint32_t j;
for (j = 0; j < m->count; j++)
group_table[pos++] = m->member_id;
}
}
static int
group_set(struct table *t,
uint32_t group_id,
struct rte_swx_table_selector_group *group)
{
uint32_t *gt = &t->group_table[group_id * t->params.n_members_per_group_max];
struct group_member_info *members = t->members;
uint32_t n_members, weight_min, weight_sum, divisor;
int status = 0;
/* Check input arguments. */
if (group_id >= t->params.n_groups_max)
return -EINVAL;
status = group_check(t, group);
if (status)
return status;
/* Read group members. */
n_members = members_read(members, group);
if (!n_members) {
memset(gt, 0, t->params.n_members_per_group_max * sizeof(uint32_t));
return 0;
}
/* Normalize weights. */
weight_min = members_min_weight_find(members, n_members);
for (divisor = 2; divisor <= weight_min; divisor++)
if (members_weight_divisor_check(members, n_members, divisor))
members_weight_divisor_apply(members, n_members, divisor);
/* Scale weights. */
weight_sum = members_weight_sum(members, n_members);
if (weight_sum > t->params.n_members_per_group_max)
return -ENOSPC;
members_weight_scale(members, n_members, t->params.n_members_per_group_max, weight_sum);
/* Write group members to the group table. */
members_write(members, n_members, gt);
return 0;
}
int
rte_swx_table_selector_group_set(void *table,
uint32_t group_id,
struct rte_swx_table_selector_group *group)
{
struct table *t = table;
return group_set(t, group_id, group);
}
struct mailbox {
};
uint64_t
rte_swx_table_selector_mailbox_size_get(void)
{
return sizeof(struct mailbox);
}
int
rte_swx_table_selector_select(void *table,
void *mailbox __rte_unused,
uint8_t **group_id_buffer,
uint8_t **selector_buffer,
uint8_t **member_id_buffer)
{
struct table *t = table;
uint32_t *group_id_ptr, *member_id_ptr, group_id, member_id, selector, group_member_index;
group_id_ptr = (uint32_t *)&(*group_id_buffer)[t->params.group_id_offset];
member_id_ptr = (uint32_t *)&(*member_id_buffer)[t->params.member_id_offset];
group_id = *group_id_ptr & (t->params.n_groups_max - 1);
selector = hash(&(*selector_buffer)[t->params.selector_offset],
t->params.selector_mask,
t->params.selector_size,
0);
group_member_index = selector & (t->params.n_members_per_group_max - 1);
member_id = t->group_table[(group_id << t->n_members_per_group_max_log2) +
group_member_index];
*member_id_ptr = member_id;
return 1;
}