+++ /dev/null
-/*
- * Copyright 2017 Advanced Micro Devices, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- *
- */
-
-#ifndef _LINUX_CHASH_H
-#define _LINUX_CHASH_H
-
-#include <linux/types.h>
-#include <linux/hash.h>
-#include <linux/bug.h>
-#include <asm/bitsperlong.h>
-
-#if BITS_PER_LONG == 32
-# define _CHASH_LONG_SHIFT 5
-#elif BITS_PER_LONG == 64
-# define _CHASH_LONG_SHIFT 6
-#else
-# error "Unexpected BITS_PER_LONG"
-#endif
-
-struct __chash_table {
- u8 bits;
- u8 key_size;
- unsigned int value_size;
- u32 size_mask;
- unsigned long *occup_bitmap, *valid_bitmap;
- union {
- u32 *keys32;
- u64 *keys64;
- };
- u8 *values;
-
-#ifdef CONFIG_CHASH_STATS
- u64 hits, hits_steps, hits_time_ns;
- u64 miss, miss_steps, miss_time_ns;
- u64 relocs, reloc_dist;
-#endif
-};
-
-#define __CHASH_BITMAP_SIZE(bits) \
- (((1 << (bits)) + BITS_PER_LONG - 1) / BITS_PER_LONG)
-#define __CHASH_ARRAY_SIZE(bits, size) \
- ((((size) << (bits)) + sizeof(long) - 1) / sizeof(long))
-
-#define __CHASH_DATA_SIZE(bits, key_size, value_size) \
- (__CHASH_BITMAP_SIZE(bits) * 2 + \
- __CHASH_ARRAY_SIZE(bits, key_size) + \
- __CHASH_ARRAY_SIZE(bits, value_size))
-
-#define STRUCT_CHASH_TABLE(bits, key_size, value_size) \
- struct { \
- struct __chash_table table; \
- unsigned long data \
- [__CHASH_DATA_SIZE(bits, key_size, value_size)];\
- }
-
-/**
- * struct chash_table - Dynamically allocated closed hash table
- *
- * Use this struct for dynamically allocated hash tables (using
- * chash_table_alloc and chash_table_free), where the size is
- * determined at runtime.
- */
-struct chash_table {
- struct __chash_table table;
- unsigned long *data;
-};
-
-/**
- * DECLARE_CHASH_TABLE - macro to declare a closed hash table
- * @table: name of the declared hash table
- * @bts: Table size will be 2^bits entries
- * @key_sz: Size of hash keys in bytes, 4 or 8
- * @val_sz: Size of data values in bytes, can be 0
- *
- * This declares the hash table variable with a static size.
- *
- * The closed hash table stores key-value pairs with low memory and
- * lookup overhead. In operation it performs no dynamic memory
- * management. The data being stored does not require any
- * list_heads. The hash table performs best with small @val_sz and as
- * long as some space (about 50%) is left free in the table. But the
- * table can still work reasonably efficiently even when filled up to
- * about 90%. If bigger data items need to be stored and looked up,
- * store the pointer to it as value in the hash table.
- *
- * @val_sz may be 0. This can be useful when all the stored
- * information is contained in the key itself and the fact that it is
- * in the hash table (or not).
- */
-#define DECLARE_CHASH_TABLE(table, bts, key_sz, val_sz) \
- STRUCT_CHASH_TABLE(bts, key_sz, val_sz) table
-
-#ifdef CONFIG_CHASH_STATS
-#define __CHASH_STATS_INIT(prefix), \
- prefix.hits = 0, \
- prefix.hits_steps = 0, \
- prefix.hits_time_ns = 0, \
- prefix.miss = 0, \
- prefix.miss_steps = 0, \
- prefix.miss_time_ns = 0, \
- prefix.relocs = 0, \
- prefix.reloc_dist = 0
-#else
-#define __CHASH_STATS_INIT(prefix)
-#endif
-
-#define __CHASH_TABLE_INIT(prefix, data, bts, key_sz, val_sz) \
- prefix.bits = (bts), \
- prefix.key_size = (key_sz), \
- prefix.value_size = (val_sz), \
- prefix.size_mask = ((1 << bts) - 1), \
- prefix.occup_bitmap = &data[0], \
- prefix.valid_bitmap = &data \
- [__CHASH_BITMAP_SIZE(bts)], \
- prefix.keys64 = (u64 *)&data \
- [__CHASH_BITMAP_SIZE(bts) * 2], \
- prefix.values = (u8 *)&data \
- [__CHASH_BITMAP_SIZE(bts) * 2 + \
- __CHASH_ARRAY_SIZE(bts, key_sz)] \
- __CHASH_STATS_INIT(prefix)
-
-/**
- * DEFINE_CHASH_TABLE - macro to define and initialize a closed hash table
- * @tbl: name of the declared hash table
- * @bts: Table size will be 2^bits entries
- * @key_sz: Size of hash keys in bytes, 4 or 8
- * @val_sz: Size of data values in bytes, can be 0
- *
- * Note: the macro can be used for global and local hash table variables.
- */
-#define DEFINE_CHASH_TABLE(tbl, bts, key_sz, val_sz) \
- DECLARE_CHASH_TABLE(tbl, bts, key_sz, val_sz) = { \
- .table = { \
- __CHASH_TABLE_INIT(, (tbl).data, bts, key_sz, val_sz) \
- }, \
- .data = {0} \
- }
-
-/**
- * INIT_CHASH_TABLE - Initialize a hash table declared by DECLARE_CHASH_TABLE
- * @tbl: name of the declared hash table
- * @bts: Table size will be 2^bits entries
- * @key_sz: Size of hash keys in bytes, 4 or 8
- * @val_sz: Size of data values in bytes, can be 0
- */
-#define INIT_CHASH_TABLE(tbl, bts, key_sz, val_sz) \
- __CHASH_TABLE_INIT(((tbl).table), (tbl).data, bts, key_sz, val_sz)
-
-int chash_table_alloc(struct chash_table *table, u8 bits, u8 key_size,
- unsigned int value_size, gfp_t gfp_mask);
-void chash_table_free(struct chash_table *table);
-
-/**
- * chash_table_dump_stats - Dump statistics of a closed hash table
- * @tbl: Pointer to the table structure
- *
- * Dumps some performance statistics of the table gathered in operation
- * in the kernel log using pr_debug. If CONFIG_DYNAMIC_DEBUG is enabled,
- * user must turn on messages for chash.c (file chash.c +p).
- */
-#ifdef CONFIG_CHASH_STATS
-#define chash_table_dump_stats(tbl) __chash_table_dump_stats(&(*tbl).table)
-
-void __chash_table_dump_stats(struct __chash_table *table);
-#else
-#define chash_table_dump_stats(tbl)
-#endif
-
-/**
- * chash_table_reset_stats - Reset statistics of a closed hash table
- * @tbl: Pointer to the table structure
- */
-#ifdef CONFIG_CHASH_STATS
-#define chash_table_reset_stats(tbl) __chash_table_reset_stats(&(*tbl).table)
-
-static inline void __chash_table_reset_stats(struct __chash_table *table)
-{
- (void)table __CHASH_STATS_INIT((*table));
-}
-#else
-#define chash_table_reset_stats(tbl)
-#endif
-
-/**
- * chash_table_copy_in - Copy a new value into the hash table
- * @tbl: Pointer to the table structure
- * @key: Key of the entry to add or update
- * @value: Pointer to value to copy, may be NULL
- *
- * If @key already has an entry, its value is replaced. Otherwise a
- * new entry is added. If @value is NULL, the value is left unchanged
- * or uninitialized. Returns 1 if an entry already existed, 0 if a new
- * entry was added or %-ENOMEM if there was no free space in the
- * table.
- */
-#define chash_table_copy_in(tbl, key, value) \
- __chash_table_copy_in(&(*tbl).table, key, value)
-
-int __chash_table_copy_in(struct __chash_table *table, u64 key,
- const void *value);
-
-/**
- * chash_table_copy_out - Copy a value out of the hash table
- * @tbl: Pointer to the table structure
- * @key: Key of the entry to find
- * @value: Pointer to value to copy, may be NULL
- *
- * If @value is not NULL and the table has a non-0 value_size, the
- * value at @key is copied to @value. Returns the slot index of the
- * entry or %-EINVAL if @key was not found.
- */
-#define chash_table_copy_out(tbl, key, value) \
- __chash_table_copy_out(&(*tbl).table, key, value, false)
-
-int __chash_table_copy_out(struct __chash_table *table, u64 key,
- void *value, bool remove);
-
-/**
- * chash_table_remove - Remove an entry from the hash table
- * @tbl: Pointer to the table structure
- * @key: Key of the entry to find
- * @value: Pointer to value to copy, may be NULL
- *
- * If @value is not NULL and the table has a non-0 value_size, the
- * value at @key is copied to @value. The entry is removed from the
- * table. Returns the slot index of the removed entry or %-EINVAL if
- * @key was not found.
- */
-#define chash_table_remove(tbl, key, value) \
- __chash_table_copy_out(&(*tbl).table, key, value, true)
-
-/*
- * Low level iterator API used internally by the above functions.
- */
-struct chash_iter {
- struct __chash_table *table;
- unsigned long mask;
- int slot;
-};
-
-/**
- * CHASH_ITER_INIT - Initialize a hash table iterator
- * @tbl: Pointer to hash table to iterate over
- * @s: Initial slot number
- */
-#define CHASH_ITER_INIT(table, s) { \
- table, \
- 1UL << ((s) & (BITS_PER_LONG - 1)), \
- s \
- }
-/**
- * CHASH_ITER_SET - Set hash table iterator to new slot
- * @iter: Iterator
- * @s: Slot number
- */
-#define CHASH_ITER_SET(iter, s) \
- (iter).mask = 1UL << ((s) & (BITS_PER_LONG - 1)), \
- (iter).slot = (s)
-/**
- * CHASH_ITER_INC - Increment hash table iterator
- * @table: Hash table to iterate over
- *
- * Wraps around at the end.
- */
-#define CHASH_ITER_INC(iter) do { \
- (iter).mask = (iter).mask << 1 | \
- (iter).mask >> (BITS_PER_LONG - 1); \
- (iter).slot = ((iter).slot + 1) & (iter).table->size_mask; \
- } while (0)
-
-static inline bool chash_iter_is_valid(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return !!(iter.table->valid_bitmap[iter.slot >> _CHASH_LONG_SHIFT] &
- iter.mask);
-}
-static inline bool chash_iter_is_empty(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return !(iter.table->occup_bitmap[iter.slot >> _CHASH_LONG_SHIFT] &
- iter.mask);
-}
-
-static inline void chash_iter_set_valid(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- iter.table->valid_bitmap[iter.slot >> _CHASH_LONG_SHIFT] |= iter.mask;
- iter.table->occup_bitmap[iter.slot >> _CHASH_LONG_SHIFT] |= iter.mask;
-}
-static inline void chash_iter_set_invalid(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- iter.table->valid_bitmap[iter.slot >> _CHASH_LONG_SHIFT] &= ~iter.mask;
-}
-static inline void chash_iter_set_empty(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- iter.table->occup_bitmap[iter.slot >> _CHASH_LONG_SHIFT] &= ~iter.mask;
-}
-
-static inline u32 chash_iter_key32(const struct chash_iter iter)
-{
- BUG_ON(iter.table->key_size != 4);
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return iter.table->keys32[iter.slot];
-}
-static inline u64 chash_iter_key64(const struct chash_iter iter)
-{
- BUG_ON(iter.table->key_size != 8);
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return iter.table->keys64[iter.slot];
-}
-static inline u64 chash_iter_key(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return (iter.table->key_size == 4) ?
- iter.table->keys32[iter.slot] : iter.table->keys64[iter.slot];
-}
-
-static inline u32 chash_iter_hash32(const struct chash_iter iter)
-{
- BUG_ON(iter.table->key_size != 4);
- return hash_32(chash_iter_key32(iter), iter.table->bits);
-}
-
-static inline u32 chash_iter_hash64(const struct chash_iter iter)
-{
- BUG_ON(iter.table->key_size != 8);
- return hash_64(chash_iter_key64(iter), iter.table->bits);
-}
-
-static inline u32 chash_iter_hash(const struct chash_iter iter)
-{
- return (iter.table->key_size == 4) ?
- hash_32(chash_iter_key32(iter), iter.table->bits) :
- hash_64(chash_iter_key64(iter), iter.table->bits);
-}
-
-static inline void *chash_iter_value(const struct chash_iter iter)
-{
- BUG_ON((unsigned)iter.slot >= (1 << iter.table->bits));
- return iter.table->values +
- ((unsigned long)iter.slot * iter.table->value_size);
-}
-
-#endif /* _LINUX_CHASH_H */
+++ /dev/null
-/*
- * Copyright 2017 Advanced Micro Devices, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- *
- */
-
-#include <linux/types.h>
-#include <linux/hash.h>
-#include <linux/bug.h>
-#include <linux/slab.h>
-#include <linux/module.h>
-#include <linux/sched/clock.h>
-#include <asm/div64.h>
-#include <linux/chash.h>
-
-/**
- * chash_table_alloc - Allocate closed hash table
- * @table: Pointer to the table structure
- * @bits: Table size will be 2^bits entries
- * @key_size: Size of hash keys in bytes, 4 or 8
- * @value_size: Size of data values in bytes, can be 0
- */
-int chash_table_alloc(struct chash_table *table, u8 bits, u8 key_size,
- unsigned int value_size, gfp_t gfp_mask)
-{
- if (bits > 31)
- return -EINVAL;
-
- if (key_size != 4 && key_size != 8)
- return -EINVAL;
-
- table->data = kcalloc(__CHASH_DATA_SIZE(bits, key_size, value_size),
- sizeof(long), gfp_mask);
- if (!table->data)
- return -ENOMEM;
-
- __CHASH_TABLE_INIT(table->table, table->data,
- bits, key_size, value_size);
-
- return 0;
-}
-EXPORT_SYMBOL(chash_table_alloc);
-
-/**
- * chash_table_free - Free closed hash table
- * @table: Pointer to the table structure
- */
-void chash_table_free(struct chash_table *table)
-{
- kfree(table->data);
-}
-EXPORT_SYMBOL(chash_table_free);
-
-#ifdef CONFIG_CHASH_STATS
-
-#define DIV_FRAC(nom, denom, quot, frac, frac_digits) do { \
- u64 __nom = (nom); \
- u64 __denom = (denom); \
- u64 __quot, __frac; \
- u32 __rem; \
- \
- while (__denom >> 32) { \
- __nom >>= 1; \
- __denom >>= 1; \
- } \
- __quot = __nom; \
- __rem = do_div(__quot, __denom); \
- __frac = __rem * (frac_digits) + (__denom >> 1); \
- do_div(__frac, __denom); \
- (quot) = __quot; \
- (frac) = __frac; \
- } while (0)
-
-void __chash_table_dump_stats(struct __chash_table *table)
-{
- struct chash_iter iter = CHASH_ITER_INIT(table, 0);
- u32 filled = 0, empty = 0, tombstones = 0;
- u64 quot1, quot2;
- u32 frac1, frac2;
-
- do {
- if (chash_iter_is_valid(iter))
- filled++;
- else if (chash_iter_is_empty(iter))
- empty++;
- else
- tombstones++;
- CHASH_ITER_INC(iter);
- } while (iter.slot);
-
- pr_debug("chash: key size %u, value size %u\n",
- table->key_size, table->value_size);
- pr_debug(" Slots total/filled/empty/tombstones: %u / %u / %u / %u\n",
- 1 << table->bits, filled, empty, tombstones);
- if (table->hits > 0) {
- DIV_FRAC(table->hits_steps, table->hits, quot1, frac1, 1000);
- DIV_FRAC(table->hits * 1000, table->hits_time_ns,
- quot2, frac2, 1000);
- } else {
- quot1 = quot2 = 0;
- frac1 = frac2 = 0;
- }
- pr_debug(" Hits (avg.cost, rate): %llu (%llu.%03u, %llu.%03u M/s)\n",
- table->hits, quot1, frac1, quot2, frac2);
- if (table->miss > 0) {
- DIV_FRAC(table->miss_steps, table->miss, quot1, frac1, 1000);
- DIV_FRAC(table->miss * 1000, table->miss_time_ns,
- quot2, frac2, 1000);
- } else {
- quot1 = quot2 = 0;
- frac1 = frac2 = 0;
- }
- pr_debug(" Misses (avg.cost, rate): %llu (%llu.%03u, %llu.%03u M/s)\n",
- table->miss, quot1, frac1, quot2, frac2);
- if (table->hits + table->miss > 0) {
- DIV_FRAC(table->hits_steps + table->miss_steps,
- table->hits + table->miss, quot1, frac1, 1000);
- DIV_FRAC((table->hits + table->miss) * 1000,
- (table->hits_time_ns + table->miss_time_ns),
- quot2, frac2, 1000);
- } else {
- quot1 = quot2 = 0;
- frac1 = frac2 = 0;
- }
- pr_debug(" Total (avg.cost, rate): %llu (%llu.%03u, %llu.%03u M/s)\n",
- table->hits + table->miss, quot1, frac1, quot2, frac2);
- if (table->relocs > 0) {
- DIV_FRAC(table->hits + table->miss, table->relocs,
- quot1, frac1, 1000);
- DIV_FRAC(table->reloc_dist, table->relocs, quot2, frac2, 1000);
- pr_debug(" Relocations (freq, avg.dist): %llu (1:%llu.%03u, %llu.%03u)\n",
- table->relocs, quot1, frac1, quot2, frac2);
- } else {
- pr_debug(" No relocations\n");
- }
-}
-EXPORT_SYMBOL(__chash_table_dump_stats);
-
-#undef DIV_FRAC
-#endif
-
-#define CHASH_INC(table, a) ((a) = ((a) + 1) & (table)->size_mask)
-#define CHASH_ADD(table, a, b) (((a) + (b)) & (table)->size_mask)
-#define CHASH_SUB(table, a, b) (((a) - (b)) & (table)->size_mask)
-#define CHASH_IN_RANGE(table, slot, first, last) \
- (CHASH_SUB(table, slot, first) <= CHASH_SUB(table, last, first))
-
-/*#define CHASH_DEBUG Uncomment this to enable verbose debug output*/
-#ifdef CHASH_DEBUG
-static void chash_table_dump(struct __chash_table *table)
-{
- struct chash_iter iter = CHASH_ITER_INIT(table, 0);
-
- do {
- if ((iter.slot & 3) == 0)
- pr_debug("%04x: ", iter.slot);
-
- if (chash_iter_is_valid(iter))
- pr_debug("[%016llx] ", chash_iter_key(iter));
- else if (chash_iter_is_empty(iter))
- pr_debug("[ <empty> ] ");
- else
- pr_debug("[ <tombstone> ] ");
-
- if ((iter.slot & 3) == 3)
- pr_debug("\n");
-
- CHASH_ITER_INC(iter);
- } while (iter.slot);
-
- if ((iter.slot & 3) != 0)
- pr_debug("\n");
-}
-
-static int chash_table_check(struct __chash_table *table)
-{
- u32 hash;
- struct chash_iter iter = CHASH_ITER_INIT(table, 0);
- struct chash_iter cur = CHASH_ITER_INIT(table, 0);
-
- do {
- if (!chash_iter_is_valid(iter)) {
- CHASH_ITER_INC(iter);
- continue;
- }
-
- hash = chash_iter_hash(iter);
- CHASH_ITER_SET(cur, hash);
- while (cur.slot != iter.slot) {
- if (chash_iter_is_empty(cur)) {
- pr_err("Path to element at %x with hash %x broken at slot %x\n",
- iter.slot, hash, cur.slot);
- chash_table_dump(table);
- return -EINVAL;
- }
- CHASH_ITER_INC(cur);
- }
-
- CHASH_ITER_INC(iter);
- } while (iter.slot);
-
- return 0;
-}
-#endif
-
-static void chash_iter_relocate(struct chash_iter dst, struct chash_iter src)
-{
- BUG_ON(src.table == dst.table && src.slot == dst.slot);
- BUG_ON(src.table->key_size != dst.table->key_size);
- BUG_ON(src.table->value_size != dst.table->value_size);
-
- if (dst.table->key_size == 4)
- dst.table->keys32[dst.slot] = src.table->keys32[src.slot];
- else
- dst.table->keys64[dst.slot] = src.table->keys64[src.slot];
-
- if (dst.table->value_size)
- memcpy(chash_iter_value(dst), chash_iter_value(src),
- dst.table->value_size);
-
- chash_iter_set_valid(dst);
- chash_iter_set_invalid(src);
-
-#ifdef CONFIG_CHASH_STATS
- if (src.table == dst.table) {
- dst.table->relocs++;
- dst.table->reloc_dist +=
- CHASH_SUB(dst.table, src.slot, dst.slot);
- }
-#endif
-}
-
-/**
- * __chash_table_find - Helper for looking up a hash table entry
- * @iter: Pointer to hash table iterator
- * @key: Key of the entry to find
- * @for_removal: set to true if the element will be removed soon
- *
- * Searches for an entry in the hash table with a given key. iter must
- * be initialized by the caller to point to the home position of the
- * hypothetical entry, i.e. it must be initialized with the hash table
- * and the key's hash as the initial slot for the search.
- *
- * This function also does some local clean-up to speed up future
- * look-ups by relocating entries to better slots and removing
- * tombstones that are no longer needed.
- *
- * If @for_removal is true, the function avoids relocating the entry
- * that is being returned.
- *
- * Returns 0 if the search is successful. In this case iter is updated
- * to point to the found entry. Otherwise %-EINVAL is returned and the
- * iter is updated to point to the first available slot for the given
- * key. If the table is full, the slot is set to -1.
- */
-static int chash_table_find(struct chash_iter *iter, u64 key,
- bool for_removal)
-{
-#ifdef CONFIG_CHASH_STATS
- u64 ts1 = local_clock();
-#endif
- u32 hash = iter->slot;
- struct chash_iter first_redundant = CHASH_ITER_INIT(iter->table, -1);
- int first_avail = (for_removal ? -2 : -1);
-
- while (!chash_iter_is_valid(*iter) || chash_iter_key(*iter) != key) {
- if (chash_iter_is_empty(*iter)) {
- /* Found an empty slot, which ends the
- * search. Clean up any preceding tombstones
- * that are no longer needed because they lead
- * to no-where
- */
- if ((int)first_redundant.slot < 0)
- goto not_found;
- while (first_redundant.slot != iter->slot) {
- if (!chash_iter_is_valid(first_redundant))
- chash_iter_set_empty(first_redundant);
- CHASH_ITER_INC(first_redundant);
- }
-#ifdef CHASH_DEBUG
- chash_table_check(iter->table);
-#endif
- goto not_found;
- } else if (!chash_iter_is_valid(*iter)) {
- /* Found a tombstone. Remember it as candidate
- * for relocating the entry we're looking for
- * or for adding a new entry with the given key
- */
- if (first_avail == -1)
- first_avail = iter->slot;
- /* Or mark it as the start of a series of
- * potentially redundant tombstones
- */
- else if (first_redundant.slot == -1)
- CHASH_ITER_SET(first_redundant, iter->slot);
- } else if (first_redundant.slot >= 0) {
- /* Found a valid, occupied slot with a
- * preceding series of tombstones. Relocate it
- * to a better position that no longer depends
- * on those tombstones
- */
- u32 cur_hash = chash_iter_hash(*iter);
-
- if (!CHASH_IN_RANGE(iter->table, cur_hash,
- first_redundant.slot + 1,
- iter->slot)) {
- /* This entry has a hash at or before
- * the first tombstone we found. We
- * can relocate it to that tombstone
- * and advance to the next tombstone
- */
- chash_iter_relocate(first_redundant, *iter);
- do {
- CHASH_ITER_INC(first_redundant);
- } while (chash_iter_is_valid(first_redundant));
- } else if (cur_hash != iter->slot) {
- /* Relocate entry to its home position
- * or as close as possible so it no
- * longer depends on any preceding
- * tombstones
- */
- struct chash_iter new_iter =
- CHASH_ITER_INIT(iter->table, cur_hash);
-
- while (new_iter.slot != iter->slot &&
- chash_iter_is_valid(new_iter))
- CHASH_ITER_INC(new_iter);
-
- if (new_iter.slot != iter->slot)
- chash_iter_relocate(new_iter, *iter);
- }
- }
-
- CHASH_ITER_INC(*iter);
- if (iter->slot == hash) {
- iter->slot = -1;
- goto not_found;
- }
- }
-
-#ifdef CONFIG_CHASH_STATS
- iter->table->hits++;
- iter->table->hits_steps += CHASH_SUB(iter->table, iter->slot, hash) + 1;
-#endif
-
- if (first_avail >= 0) {
- CHASH_ITER_SET(first_redundant, first_avail);
- chash_iter_relocate(first_redundant, *iter);
- iter->slot = first_redundant.slot;
- iter->mask = first_redundant.mask;
- }
-
-#ifdef CONFIG_CHASH_STATS
- iter->table->hits_time_ns += local_clock() - ts1;
-#endif
-
- return 0;
-
-not_found:
-#ifdef CONFIG_CHASH_STATS
- iter->table->miss++;
- iter->table->miss_steps += (iter->slot < 0) ?
- (1 << iter->table->bits) :
- CHASH_SUB(iter->table, iter->slot, hash) + 1;
-#endif
-
- if (first_avail >= 0)
- CHASH_ITER_SET(*iter, first_avail);
-
-#ifdef CONFIG_CHASH_STATS
- iter->table->miss_time_ns += local_clock() - ts1;
-#endif
-
- return -EINVAL;
-}
-
-int __chash_table_copy_in(struct __chash_table *table, u64 key,
- const void *value)
-{
- u32 hash = (table->key_size == 4) ?
- hash_32(key, table->bits) : hash_64(key, table->bits);
- struct chash_iter iter = CHASH_ITER_INIT(table, hash);
- int r = chash_table_find(&iter, key, false);
-
- /* Found an existing entry */
- if (!r) {
- if (value && table->value_size)
- memcpy(chash_iter_value(iter), value,
- table->value_size);
- return 1;
- }
-
- /* Is there a place to add a new entry? */
- if (iter.slot < 0) {
- pr_err("Hash table overflow\n");
- return -ENOMEM;
- }
-
- chash_iter_set_valid(iter);
-
- if (table->key_size == 4)
- table->keys32[iter.slot] = key;
- else
- table->keys64[iter.slot] = key;
- if (value && table->value_size)
- memcpy(chash_iter_value(iter), value, table->value_size);
-
- return 0;
-}
-EXPORT_SYMBOL(__chash_table_copy_in);
-
-int __chash_table_copy_out(struct __chash_table *table, u64 key,
- void *value, bool remove)
-{
- u32 hash = (table->key_size == 4) ?
- hash_32(key, table->bits) : hash_64(key, table->bits);
- struct chash_iter iter = CHASH_ITER_INIT(table, hash);
- int r = chash_table_find(&iter, key, remove);
-
- if (r < 0)
- return r;
-
- if (value && table->value_size)
- memcpy(value, chash_iter_value(iter), table->value_size);
-
- if (remove)
- chash_iter_set_invalid(iter);
-
- return iter.slot;
-}
-EXPORT_SYMBOL(__chash_table_copy_out);
-
-#ifdef CONFIG_CHASH_SELFTEST
-/**
- * chash_self_test - Run a self-test of the hash table implementation
- * @bits: Table size will be 2^bits entries
- * @key_size: Size of hash keys in bytes, 4 or 8
- * @min_fill: Minimum fill level during the test
- * @max_fill: Maximum fill level during the test
- * @iterations: Number of test iterations
- *
- * The test adds and removes entries from a hash table, cycling the
- * fill level between min_fill and max_fill entries. Also tests lookup
- * and value retrieval.
- */
-static int __init chash_self_test(u8 bits, u8 key_size,
- int min_fill, int max_fill,
- u64 iterations)
-{
- struct chash_table table;
- int ret;
- u64 add_count, rmv_count;
- u64 value;
-
- if (key_size == 4 && iterations > 0xffffffff)
- return -EINVAL;
- if (min_fill >= max_fill)
- return -EINVAL;
-
- ret = chash_table_alloc(&table, bits, key_size, sizeof(u64),
- GFP_KERNEL);
- if (ret) {
- pr_err("chash_table_alloc failed: %d\n", ret);
- return ret;
- }
-
- for (add_count = 0, rmv_count = 0; add_count < iterations;
- add_count++) {
- /* When we hit the max_fill level, remove entries down
- * to min_fill
- */
- if (add_count - rmv_count == max_fill) {
- u64 find_count = rmv_count;
-
- /* First try to find all entries that we're
- * about to remove, confirm their value, test
- * writing them back a second time.
- */
- for (; add_count - find_count > min_fill;
- find_count++) {
- ret = chash_table_copy_out(&table, find_count,
- &value);
- if (ret < 0) {
- pr_err("chash_table_copy_out failed: %d\n",
- ret);
- goto out;
- }
- if (value != ~find_count) {
- pr_err("Wrong value retrieved for key 0x%llx, expected 0x%llx got 0x%llx\n",
- find_count, ~find_count, value);
-#ifdef CHASH_DEBUG
- chash_table_dump(&table.table);
-#endif
- ret = -EFAULT;
- goto out;
- }
- ret = chash_table_copy_in(&table, find_count,
- &value);
- if (ret != 1) {
- pr_err("copy_in second time returned %d, expected 1\n",
- ret);
- ret = -EFAULT;
- goto out;
- }
- }
- /* Remove them until we hit min_fill level */
- for (; add_count - rmv_count > min_fill; rmv_count++) {
- ret = chash_table_remove(&table, rmv_count,
- NULL);
- if (ret < 0) {
- pr_err("chash_table_remove failed: %d\n",
- ret);
- goto out;
- }
- }
- }
-
- /* Add a new value */
- value = ~add_count;
- ret = chash_table_copy_in(&table, add_count, &value);
- if (ret != 0) {
- pr_err("copy_in first time returned %d, expected 0\n",
- ret);
- ret = -EFAULT;
- goto out;
- }
- }
-
- chash_table_dump_stats(&table);
- chash_table_reset_stats(&table);
-
-out:
- chash_table_free(&table);
- return ret;
-}
-
-static unsigned int chash_test_bits = 10;
-MODULE_PARM_DESC(test_bits,
- "Selftest number of hash bits ([4..20], default=10)");
-module_param_named(test_bits, chash_test_bits, uint, 0444);
-
-static unsigned int chash_test_keysize = 8;
-MODULE_PARM_DESC(test_keysize, "Selftest keysize (4 or 8, default=8)");
-module_param_named(test_keysize, chash_test_keysize, uint, 0444);
-
-static unsigned int chash_test_minfill;
-MODULE_PARM_DESC(test_minfill, "Selftest minimum #entries (default=50%)");
-module_param_named(test_minfill, chash_test_minfill, uint, 0444);
-
-static unsigned int chash_test_maxfill;
-MODULE_PARM_DESC(test_maxfill, "Selftest maximum #entries (default=80%)");
-module_param_named(test_maxfill, chash_test_maxfill, uint, 0444);
-
-static unsigned long chash_test_iters;
-MODULE_PARM_DESC(test_iters, "Selftest iterations (default=1000 x #entries)");
-module_param_named(test_iters, chash_test_iters, ulong, 0444);
-
-static int __init chash_init(void)
-{
- int ret;
- u64 ts1_ns;
-
- /* Skip self test on user errors */
- if (chash_test_bits < 4 || chash_test_bits > 20) {
- pr_err("chash: test_bits out of range [4..20].\n");
- return 0;
- }
- if (chash_test_keysize != 4 && chash_test_keysize != 8) {
- pr_err("chash: test_keysize invalid. Must be 4 or 8.\n");
- return 0;
- }
-
- if (!chash_test_minfill)
- chash_test_minfill = (1 << chash_test_bits) / 2;
- if (!chash_test_maxfill)
- chash_test_maxfill = (1 << chash_test_bits) * 4 / 5;
- if (!chash_test_iters)
- chash_test_iters = (1 << chash_test_bits) * 1000;
-
- if (chash_test_minfill >= (1 << chash_test_bits)) {
- pr_err("chash: test_minfill too big. Must be < table size.\n");
- return 0;
- }
- if (chash_test_maxfill >= (1 << chash_test_bits)) {
- pr_err("chash: test_maxfill too big. Must be < table size.\n");
- return 0;
- }
- if (chash_test_minfill >= chash_test_maxfill) {
- pr_err("chash: test_minfill must be < test_maxfill.\n");
- return 0;
- }
- if (chash_test_keysize == 4 && chash_test_iters > 0xffffffff) {
- pr_err("chash: test_iters must be < 4G for 4 byte keys.\n");
- return 0;
- }
-
- ts1_ns = local_clock();
- ret = chash_self_test(chash_test_bits, chash_test_keysize,
- chash_test_minfill, chash_test_maxfill,
- chash_test_iters);
- if (!ret) {
- u64 ts_delta_us = local_clock() - ts1_ns;
- u64 iters_per_second = (u64)chash_test_iters * 1000000;
-
- do_div(ts_delta_us, 1000);
- do_div(iters_per_second, ts_delta_us);
- pr_info("chash: self test took %llu us, %llu iterations/s\n",
- ts_delta_us, iters_per_second);
- } else {
- pr_err("chash: self test failed: %d\n", ret);
- }
-
- return ret;
-}
-
-module_init(chash_init);
-
-#endif /* CONFIG_CHASH_SELFTEST */
-
-MODULE_DESCRIPTION("Closed hash table");
-MODULE_LICENSE("GPL and additional rights");
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