mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-09-01 15:14:52 +00:00
4164e1525d
Patch series "lib/interval_tree: add some test cases and cleanup", v2. Since rbtree/augmented tree/interval tree share similar data structure, besides new cases for interval tree, this patch set also does cleanup for others. This patch (of 7): Currently we have some tests for rbtree related data structure, e.g. rbtree, augmented rbtree, interval tree, in lib/ as kernel module. To facilitate the test and debug for those fundamental data structure, this patch enable those tests in userland. Link: https://lkml.kernel.org/r/20250310074938.26756-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20250310074938.26756-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michel Lespinasse <michel@lespinasse.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
52 lines
1.4 KiB
C
52 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __TOOLS_LINUX_PRANDOM_H
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#define __TOOLS_LINUX_PRANDOM_H
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#include <linux/types.h>
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struct rnd_state {
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__u32 s1, s2, s3, s4;
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};
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/*
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* Handle minimum values for seeds
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*/
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static inline u32 __seed(u32 x, u32 m)
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{
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return (x < m) ? x + m : x;
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}
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/**
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* prandom_seed_state - set seed for prandom_u32_state().
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* @state: pointer to state structure to receive the seed.
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* @seed: arbitrary 64-bit value to use as a seed.
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*/
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static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
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{
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u32 i = ((seed >> 32) ^ (seed << 10) ^ seed) & 0xffffffffUL;
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state->s1 = __seed(i, 2U);
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state->s2 = __seed(i, 8U);
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state->s3 = __seed(i, 16U);
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state->s4 = __seed(i, 128U);
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}
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/**
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* prandom_u32_state - seeded pseudo-random number generator.
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* @state: pointer to state structure holding seeded state.
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*
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* This is used for pseudo-randomness with no outside seeding.
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* For more random results, use get_random_u32().
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*/
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static inline u32 prandom_u32_state(struct rnd_state *state)
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{
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#define TAUSWORTHE(s, a, b, c, d) (((s & c) << d) ^ (((s << a) ^ s) >> b))
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state->s1 = TAUSWORTHE(state->s1, 6U, 13U, 4294967294U, 18U);
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state->s2 = TAUSWORTHE(state->s2, 2U, 27U, 4294967288U, 2U);
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state->s3 = TAUSWORTHE(state->s3, 13U, 21U, 4294967280U, 7U);
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state->s4 = TAUSWORTHE(state->s4, 3U, 12U, 4294967168U, 13U);
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return (state->s1 ^ state->s2 ^ state->s3 ^ state->s4);
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}
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#endif // __TOOLS_LINUX_PRANDOM_H
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