lib: zstd: Upgrade to latest upstream zstd version 1.4.10

Upgrade to the latest upstream zstd version 1.4.10.

This patch is 100% generated from upstream zstd commit 20821a46f412 [0].

This patch is very large because it is transitioning from the custom
kernel zstd to using upstream directly. The new zstd follows upstreams
file structure which is different. Future update patches will be much
smaller because they will only contain the changes from one upstream
zstd release.

As an aid for review I've created a commit [1] that shows the diff
between upstream zstd as-is (which doesn't compile), and the zstd
code imported in this patch. The verion of zstd in this patch is
generated from upstream with changes applied by automation to replace
upstreams libc dependencies, remove unnecessary portability macros,
replace `/**` comments with `/*` comments, and use the kernel's xxhash
instead of bundling it.

The benefits of this patch are as follows:
1. Using upstream directly with automated script to generate kernel
   code. This allows us to update the kernel every upstream release, so
   the kernel gets the latest bug fixes and performance improvements,
   and doesn't get 3 years out of date again. The automation and the
   translated code are tested every upstream commit to ensure it
   continues to work.
2. Upgrades from a custom zstd based on 1.3.1 to 1.4.10, getting 3 years
   of performance improvements and bug fixes. On x86_64 I've measured
   15% faster BtrFS and SquashFS decompression+read speeds, 35% faster
   kernel decompression, and 30% faster ZRAM decompression+read speeds.
3. Zstd-1.4.10 supports negative compression levels, which allow zstd to
   match or subsume lzo's performance.
4. Maintains the same kernel-specific wrapper API, so no callers have to
   be modified with zstd version updates.

One concern that was brought up was stack usage. Upstream zstd had
already removed most of its heavy stack usage functions, but I just
removed the last functions that allocate arrays on the stack. I've
measured the high water mark for both compression and decompression
before and after this patch. Decompression is approximately neutral,
using about 1.2KB of stack space. Compression levels up to 3 regressed
from 1.4KB -> 1.6KB, and higher compression levels regressed from 1.5KB
-> 2KB. We've added unit tests upstream to prevent further regression.
I believe that this is a reasonable increase, and if it does end up
causing problems, this commit can be cleanly reverted, because it only
touches zstd.

I chose the bulk update instead of replaying upstream commits because
there have been ~3500 upstream commits since the 1.3.1 release, zstd
wasn't ready to be used in the kernel as-is before a month ago, and not
all upstream zstd commits build. The bulk update preserves bisectablity
because bugs can be bisected to the zstd version update. At that point
the update can be reverted, and we can work with upstream to find and
fix the bug.

Note that upstream zstd release 1.4.10 doesn't exist yet. I have cut a
staging branch at 20821a46f412 [0] and will apply any changes requested
to the staging branch. Once we're ready to merge this update I will cut
a zstd release at the commit we merge, so we have a known zstd release
in the kernel.

The implementation of the kernel API is contained in
zstd_compress_module.c and zstd_decompress_module.c.

[0] https://github.com/facebook/zstd/commit/20821a46f4122f9abd7c7b245d28162dde8129c9
[1] https://github.com/terrelln/linux/commit/e0fa481d0e3df26918da0a13749740a1f6777574

Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>

1 files changed, 0 insertions, 273 deletions

diff --git a/lib/zstd/zstd_internal.h b/lib/zstd/zstd_internal.h
deleted file mode 100644
index dac753397f86..000000000000
--- a/lib/zstd/zstd_internal.h
+++ /dev/null
@@ -1,273 +0,0 @@
-/**
- * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of https://github.com/facebook/zstd.
- * An additional grant of patent rights can be found in the PATENTS file in the
- * same directory.
- *
- * This program is free software; you can redistribute it and/or modify it under
- * the terms of the GNU General Public License version 2 as published by the
- * Free Software Foundation. This program is dual-licensed; you may select
- * either version 2 of the GNU General Public License ("GPL") or BSD license
- * ("BSD").
- */
-
-#ifndef ZSTD_CCOMMON_H_MODULE
-#define ZSTD_CCOMMON_H_MODULE
-
-/*-*******************************************************
-*  Compiler specifics
-*********************************************************/
-#define FORCE_INLINE static __always_inline
-#define FORCE_NOINLINE static noinline
-
-/*-*************************************
-*  Dependencies
-***************************************/
-#include "error_private.h"
-#include "mem.h"
-#include <linux/compiler.h>
-#include <linux/kernel.h>
-#include <linux/xxhash.h>
-#include <linux/zstd.h>
-
-/*-*************************************
-*  shared macros
-***************************************/
-#define MIN(a, b) ((a) < (b) ? (a) : (b))
-#define MAX(a, b) ((a) > (b) ? (a) : (b))
-#define CHECK_F(f)                       \
-	{                                \
-		size_t const errcod = f; \
-		if (ERR_isError(errcod)) \
-			return errcod;   \
-	} /* check and Forward error code */
-#define CHECK_E(f, e)                    \
-	{                                \
-		size_t const errcod = f; \
-		if (ERR_isError(errcod)) \
-			return ERROR(e); \
-	} /* check and send Error code */
-#define ZSTD_STATIC_ASSERT(c)                                   \
-	{                                                       \
-		enum { ZSTD_static_assert = 1 / (int)(!!(c)) }; \
-	}
-
-/*-*************************************
-*  Common constants
-***************************************/
-#define ZSTD_OPT_NUM (1 << 12)
-#define ZSTD_DICT_MAGIC 0xEC30A437 /* v0.7+ */
-
-#define ZSTD_REP_NUM 3		      /* number of repcodes */
-#define ZSTD_REP_CHECK (ZSTD_REP_NUM) /* number of repcodes to check by the optimal parser */
-#define ZSTD_REP_MOVE (ZSTD_REP_NUM - 1)
-#define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)
-static const U32 repStartValue[ZSTD_REP_NUM] = {1, 4, 8};
-
-#define KB *(1 << 10)
-#define MB *(1 << 20)
-#define GB *(1U << 30)
-
-#define BIT7 128
-#define BIT6 64
-#define BIT5 32
-#define BIT4 16
-#define BIT1 2
-#define BIT0 1
-
-#define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
-static const size_t ZSTD_fcs_fieldSize[4] = {0, 2, 4, 8};
-static const size_t ZSTD_did_fieldSize[4] = {0, 1, 2, 4};
-
-#define ZSTD_BLOCKHEADERSIZE 3 /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
-static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
-typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
-
-#define MIN_SEQUENCES_SIZE 1									  /* nbSeq==0 */
-#define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */) /* for a non-null block */
-
-#define HufLog 12
-typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;
-
-#define LONGNBSEQ 0x7F00
-
-#define MINMATCH 3
-#define EQUAL_READ32 4
-
-#define Litbits 8
-#define MaxLit ((1 << Litbits) - 1)
-#define MaxML 52
-#define MaxLL 35
-#define MaxOff 28
-#define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */
-#define MLFSELog 9
-#define LLFSELog 9
-#define OffFSELog 8
-
-static const U32 LL_bits[MaxLL + 1] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
-static const S16 LL_defaultNorm[MaxLL + 1] = {4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, -1, -1, -1, -1};
-#define LL_DEFAULTNORMLOG 6 /* for static allocation */
-static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
-
-static const U32 ML_bits[MaxML + 1] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0,  0,  0,  0,  0,  0, 0,
-				       0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
-static const S16 ML_defaultNorm[MaxML + 1] = {1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,  1,  1,  1,  1, 1,
-					      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1};
-#define ML_DEFAULTNORMLOG 6 /* for static allocation */
-static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
-
-static const S16 OF_defaultNorm[MaxOff + 1] = {1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1};
-#define OF_DEFAULTNORMLOG 5 /* for static allocation */
-static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
-
-/*-*******************************************
-*  Shared functions to include for inlining
-*********************************************/
-ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) {
-	/*
-	 * zstd relies heavily on gcc being able to analyze and inline this
-	 * memcpy() call, since it is called in a tight loop. Preboot mode
-	 * is compiled in freestanding mode, which stops gcc from analyzing
-	 * memcpy(). Use __builtin_memcpy() to tell gcc to analyze this as a
-	 * regular memcpy().
-	 */
-	__builtin_memcpy(dst, src, 8);
-}
-/*! ZSTD_wildcopy() :
-*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
-#define WILDCOPY_OVERLENGTH 8
-ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length)
-{
-	const BYTE* ip = (const BYTE*)src;
-	BYTE* op = (BYTE*)dst;
-	BYTE* const oend = op + length;
-#if defined(GCC_VERSION) && GCC_VERSION >= 70000 && GCC_VERSION < 70200
-	/*
-	 * Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.
-	 * Avoid the bad case where the loop only runs once by handling the
-	 * special case separately. This doesn't trigger the bug because it
-	 * doesn't involve pointer/integer overflow.
-	 */
-	if (length <= 8)
-		return ZSTD_copy8(dst, src);
-#endif
-	do {
-		ZSTD_copy8(op, ip);
-		op += 8;
-		ip += 8;
-	} while (op < oend);
-}
-
-/*-*******************************************
-*  Private interfaces
-*********************************************/
-typedef struct ZSTD_stats_s ZSTD_stats_t;
-
-typedef struct {
-	U32 off;
-	U32 len;
-} ZSTD_match_t;
-
-typedef struct {
-	U32 price;
-	U32 off;
-	U32 mlen;
-	U32 litlen;
-	U32 rep[ZSTD_REP_NUM];
-} ZSTD_optimal_t;
-
-typedef struct seqDef_s {
-	U32 offset;
-	U16 litLength;
-	U16 matchLength;
-} seqDef;
-
-typedef struct {
-	seqDef *sequencesStart;
-	seqDef *sequences;
-	BYTE *litStart;
-	BYTE *lit;
-	BYTE *llCode;
-	BYTE *mlCode;
-	BYTE *ofCode;
-	U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
-	U32 longLengthPos;
-	/* opt */
-	ZSTD_optimal_t *priceTable;
-	ZSTD_match_t *matchTable;
-	U32 *matchLengthFreq;
-	U32 *litLengthFreq;
-	U32 *litFreq;
-	U32 *offCodeFreq;
-	U32 matchLengthSum;
-	U32 matchSum;
-	U32 litLengthSum;
-	U32 litSum;
-	U32 offCodeSum;
-	U32 log2matchLengthSum;
-	U32 log2matchSum;
-	U32 log2litLengthSum;
-	U32 log2litSum;
-	U32 log2offCodeSum;
-	U32 factor;
-	U32 staticPrices;
-	U32 cachedPrice;
-	U32 cachedLitLength;
-	const BYTE *cachedLiterals;
-} seqStore_t;
-
-const seqStore_t *ZSTD_getSeqStore(const ZSTD_CCtx *ctx);
-void ZSTD_seqToCodes(const seqStore_t *seqStorePtr);
-int ZSTD_isSkipFrame(ZSTD_DCtx *dctx);
-
-/*= Custom memory allocation functions */
-typedef void *(*ZSTD_allocFunction)(void *opaque, size_t size);
-typedef void (*ZSTD_freeFunction)(void *opaque, void *address);
-typedef struct {
-	ZSTD_allocFunction customAlloc;
-	ZSTD_freeFunction customFree;
-	void *opaque;
-} ZSTD_customMem;
-
-void *ZSTD_malloc(size_t size, ZSTD_customMem customMem);
-void ZSTD_free(void *ptr, ZSTD_customMem customMem);
-
-/*====== stack allocation  ======*/
-
-typedef struct {
-	void *ptr;
-	const void *end;
-} ZSTD_stack;
-
-#define ZSTD_ALIGN(x) ALIGN(x, sizeof(size_t))
-#define ZSTD_PTR_ALIGN(p) PTR_ALIGN(p, sizeof(size_t))
-
-ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize);
-
-void *ZSTD_stackAllocAll(void *opaque, size_t *size);
-void *ZSTD_stackAlloc(void *opaque, size_t size);
-void ZSTD_stackFree(void *opaque, void *address);
-
-/*======  common function  ======*/
-
-ZSTD_STATIC U32 ZSTD_highbit32(U32 val) { return 31 - __builtin_clz(val); }
-
-/* hidden functions */
-
-/* ZSTD_invalidateRepCodes() :
- * ensures next compression will not use repcodes from previous block.
- * Note : only works with regular variant;
- *        do not use with extDict variant ! */
-void ZSTD_invalidateRepCodes(ZSTD_CCtx *cctx);
-
-size_t ZSTD_freeCCtx(ZSTD_CCtx *cctx);
-size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx);
-size_t ZSTD_freeCDict(ZSTD_CDict *cdict);
-size_t ZSTD_freeDDict(ZSTD_DDict *cdict);
-size_t ZSTD_freeCStream(ZSTD_CStream *zcs);
-size_t ZSTD_freeDStream(ZSTD_DStream *zds);
-
-#endif /* ZSTD_CCOMMON_H_MODULE */