kernel_samsung_a34x-permissive/drivers/gpu/drm/amd/lib/chash.c

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/*
* 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");