// SPDX-License-Identifier: GPL-2.0-only
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#ifndef _NFT_SET_PIPAPO_H
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#include <linux/log2.h>
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#include <net/ipv6.h> /* For the maximum length of a field */
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/* Count of concatenated fields depends on count of 32-bit nftables registers */
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#define NFT_PIPAPO_MAX_FIELDS NFT_REG32_COUNT
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/* Restrict usage to multiple fields, make sure rbtree is used otherwise */
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#define NFT_PIPAPO_MIN_FIELDS 2
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/* Largest supported field size */
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#define NFT_PIPAPO_MAX_BYTES (sizeof(struct in6_addr))
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#define NFT_PIPAPO_MAX_BITS (NFT_PIPAPO_MAX_BYTES * BITS_PER_BYTE)
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/* Bits to be grouped together in table buckets depending on set size */
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#define NFT_PIPAPO_GROUP_BITS_INIT NFT_PIPAPO_GROUP_BITS_SMALL_SET
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#define NFT_PIPAPO_GROUP_BITS_SMALL_SET 8
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#define NFT_PIPAPO_GROUP_BITS_LARGE_SET 4
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#define NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4 \
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BUILD_BUG_ON((NFT_PIPAPO_GROUP_BITS_SMALL_SET != 8) || \
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(NFT_PIPAPO_GROUP_BITS_LARGE_SET != 4))
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#define NFT_PIPAPO_GROUPS_PER_BYTE(f) (BITS_PER_BYTE / (f)->bb)
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/* If a lookup table gets bigger than NFT_PIPAPO_LT_SIZE_HIGH, switch to the
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* small group width, and switch to the big group width if the table gets
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* smaller than NFT_PIPAPO_LT_SIZE_LOW.
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*
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* Picking 2MiB as threshold (for a single table) avoids as much as possible
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* crossing page boundaries on most architectures (x86-64 and MIPS huge pages,
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* ARMv7 supersections, POWER "large" pages, SPARC Level 1 regions, etc.), which
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* keeps performance nice in case kvmalloc() gives us non-contiguous areas.
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*/
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#define NFT_PIPAPO_LT_SIZE_THRESHOLD (1 << 21)
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#define NFT_PIPAPO_LT_SIZE_HYSTERESIS (1 << 16)
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#define NFT_PIPAPO_LT_SIZE_HIGH NFT_PIPAPO_LT_SIZE_THRESHOLD
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#define NFT_PIPAPO_LT_SIZE_LOW NFT_PIPAPO_LT_SIZE_THRESHOLD - \
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NFT_PIPAPO_LT_SIZE_HYSTERESIS
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/* Fields are padded to 32 bits in input registers */
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#define NFT_PIPAPO_GROUPS_PADDED_SIZE(f) \
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(round_up((f)->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f), sizeof(u32)))
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#define NFT_PIPAPO_GROUPS_PADDING(f) \
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(NFT_PIPAPO_GROUPS_PADDED_SIZE(f) - (f)->groups / \
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NFT_PIPAPO_GROUPS_PER_BYTE(f))
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/* Number of buckets given by 2 ^ n, with n bucket bits */
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#define NFT_PIPAPO_BUCKETS(bb) (1 << (bb))
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/* Each n-bit range maps to up to n * 2 rules */
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#define NFT_PIPAPO_MAP_NBITS (const_ilog2(NFT_PIPAPO_MAX_BITS * 2))
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/* Use the rest of mapping table buckets for rule indices, but it makes no sense
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* to exceed 32 bits
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*/
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#if BITS_PER_LONG == 64
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#define NFT_PIPAPO_MAP_TOBITS 32
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#else
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#define NFT_PIPAPO_MAP_TOBITS (BITS_PER_LONG - NFT_PIPAPO_MAP_NBITS)
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#endif
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/* ...which gives us the highest allowed index for a rule */
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#define NFT_PIPAPO_RULE0_MAX ((1UL << (NFT_PIPAPO_MAP_TOBITS - 1)) \
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- (1UL << NFT_PIPAPO_MAP_NBITS))
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/* Definitions for vectorised implementations */
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#ifdef NFT_PIPAPO_ALIGN
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#define NFT_PIPAPO_ALIGN_HEADROOM \
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(NFT_PIPAPO_ALIGN - ARCH_KMALLOC_MINALIGN)
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#define NFT_PIPAPO_LT_ALIGN(lt) (PTR_ALIGN((lt), NFT_PIPAPO_ALIGN))
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#define NFT_PIPAPO_LT_ASSIGN(field, x) \
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do { \
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(field)->lt_aligned = NFT_PIPAPO_LT_ALIGN(x); \
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(field)->lt = (x); \
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} while (0)
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#else
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#define NFT_PIPAPO_ALIGN_HEADROOM 0
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#define NFT_PIPAPO_LT_ALIGN(lt) (lt)
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#define NFT_PIPAPO_LT_ASSIGN(field, x) ((field)->lt = (x))
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#endif /* NFT_PIPAPO_ALIGN */
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#define nft_pipapo_for_each_field(field, index, match) \
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for ((field) = (match)->f, (index) = 0; \
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(index) < (match)->field_count; \
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(index)++, (field)++)
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/**
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* union nft_pipapo_map_bucket - Bucket of mapping table
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* @to: First rule number (in next field) this rule maps to
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* @n: Number of rules (in next field) this rule maps to
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* @e: If there's no next field, pointer to element this rule maps to
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*/
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union nft_pipapo_map_bucket {
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struct {
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#if BITS_PER_LONG == 64
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static_assert(NFT_PIPAPO_MAP_TOBITS <= 32);
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u32 to;
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static_assert(NFT_PIPAPO_MAP_NBITS <= 32);
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u32 n;
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#else
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unsigned long to:NFT_PIPAPO_MAP_TOBITS;
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unsigned long n:NFT_PIPAPO_MAP_NBITS;
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#endif
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};
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struct nft_pipapo_elem *e;
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};
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/**
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* struct nft_pipapo_field - Lookup, mapping tables and related data for a field
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* @groups: Amount of bit groups
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* @rules: Number of inserted rules
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* @bsize: Size of each bucket in lookup table, in longs
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* @bb: Number of bits grouped together in lookup table buckets
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* @lt: Lookup table: 'groups' rows of buckets
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* @lt_aligned: Version of @lt aligned to NFT_PIPAPO_ALIGN bytes
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* @mt: Mapping table: one bucket per rule
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*/
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struct nft_pipapo_field {
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int groups;
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unsigned long rules;
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size_t bsize;
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int bb;
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#ifdef NFT_PIPAPO_ALIGN
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unsigned long *lt_aligned;
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#endif
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unsigned long *lt;
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union nft_pipapo_map_bucket *mt;
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};
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/**
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* struct nft_pipapo_match - Data used for lookup and matching
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* @field_count Amount of fields in set
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* @scratch: Preallocated per-CPU maps for partial matching results
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* @scratch_aligned: Version of @scratch aligned to NFT_PIPAPO_ALIGN bytes
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* @bsize_max: Maximum lookup table bucket size of all fields, in longs
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* @rcu Matching data is swapped on commits
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* @f: Fields, with lookup and mapping tables
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*/
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struct nft_pipapo_match {
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int field_count;
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#ifdef NFT_PIPAPO_ALIGN
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unsigned long * __percpu *scratch_aligned;
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#endif
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unsigned long * __percpu *scratch;
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size_t bsize_max;
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struct rcu_head rcu;
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struct nft_pipapo_field f[];
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};
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/**
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* struct nft_pipapo - Representation of a set
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* @match: Currently in-use matching data
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* @clone: Copy where pending insertions and deletions are kept
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* @width: Total bytes to be matched for one packet, including padding
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* @dirty: Working copy has pending insertions or deletions
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* @last_gc: Timestamp of last garbage collection run, jiffies
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*/
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struct nft_pipapo {
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struct nft_pipapo_match __rcu *match;
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struct nft_pipapo_match *clone;
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int width;
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bool dirty;
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unsigned long last_gc;
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};
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struct nft_pipapo_elem;
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/**
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* struct nft_pipapo_elem - API-facing representation of single set element
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* @ext: nftables API extensions
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*/
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struct nft_pipapo_elem {
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struct nft_set_ext ext;
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};
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int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst,
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union nft_pipapo_map_bucket *mt, bool match_only);
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bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
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const u32 *key, const struct nft_set_ext **ext);
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/**
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* pipapo_and_field_buckets_4bit() - Intersect 4-bit buckets
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* @f: Field including lookup table
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* @dst: Area to store result
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* @data: Input data selecting table buckets
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*/
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static inline void pipapo_and_field_buckets_4bit(struct nft_pipapo_field *f,
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unsigned long *dst,
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const u8 *data)
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{
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unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt);
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int group;
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for (group = 0; group < f->groups; group += BITS_PER_BYTE / 4, data++) {
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u8 v;
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v = *data >> 4;
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__bitmap_and(dst, dst, lt + v * f->bsize,
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f->bsize * BITS_PER_LONG);
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lt += f->bsize * NFT_PIPAPO_BUCKETS(4);
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v = *data & 0x0f;
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__bitmap_and(dst, dst, lt + v * f->bsize,
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f->bsize * BITS_PER_LONG);
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lt += f->bsize * NFT_PIPAPO_BUCKETS(4);
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}
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}
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/**
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* pipapo_and_field_buckets_8bit() - Intersect 8-bit buckets
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* @f: Field including lookup table
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* @dst: Area to store result
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* @data: Input data selecting table buckets
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*/
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static inline void pipapo_and_field_buckets_8bit(struct nft_pipapo_field *f,
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unsigned long *dst,
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const u8 *data)
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{
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unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt);
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int group;
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for (group = 0; group < f->groups; group++, data++) {
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__bitmap_and(dst, dst, lt + *data * f->bsize,
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f->bsize * BITS_PER_LONG);
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lt += f->bsize * NFT_PIPAPO_BUCKETS(8);
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}
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}
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/**
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* pipapo_estimate_size() - Estimate worst-case for set size
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* @desc: Set description, element count and field description used here
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*
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* The size for this set type can vary dramatically, as it depends on the number
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* of rules (composing netmasks) the entries expand to. We compute the worst
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* case here.
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*
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* In general, for a non-ranged entry or a single composing netmask, we need
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* one bit in each of the sixteen NFT_PIPAPO_BUCKETS, for each 4-bit group (that
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* is, each input bit needs four bits of matching data), plus a bucket in the
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* mapping table for each field.
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*
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* Return: worst-case set size in bytes, 0 on any overflow
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*/
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static u64 pipapo_estimate_size(const struct nft_set_desc *desc)
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{
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unsigned long entry_size;
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u64 size;
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int i;
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for (i = 0, entry_size = 0; i < desc->field_count; i++) {
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unsigned long rules;
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if (desc->field_len[i] > NFT_PIPAPO_MAX_BYTES)
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return 0;
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/* Worst-case ranges for each concatenated field: each n-bit
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* field can expand to up to n * 2 rules in each bucket, and
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* each rule also needs a mapping bucket.
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*/
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rules = ilog2(desc->field_len[i] * BITS_PER_BYTE) * 2;
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entry_size += rules *
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NFT_PIPAPO_BUCKETS(NFT_PIPAPO_GROUP_BITS_INIT) /
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BITS_PER_BYTE;
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entry_size += rules * sizeof(union nft_pipapo_map_bucket);
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}
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/* Rules in lookup and mapping tables are needed for each entry */
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size = desc->size * entry_size;
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if (size && div_u64(size, desc->size) != entry_size)
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return 0;
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size += sizeof(struct nft_pipapo) + sizeof(struct nft_pipapo_match) * 2;
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size += sizeof(struct nft_pipapo_field) * desc->field_count;
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return size;
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}
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#endif /* _NFT_SET_PIPAPO_H */
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