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/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only */
#include <commonlib/bsd/compression.h>
#include <commonlib/bsd/helpers.h>
#include <commonlib/bsd/sysincludes.h>
#include <stdint.h>
#include <string.h>
/* LZ4 comes with its own supposedly portable memory access functions, but they
* seem to be very inefficient in practice (at least on ARM64). Since coreboot
* knows about endinaness and allows some basic assumptions (such as unaligned
* access support), we can easily write the ones we need ourselves. */
static uint16_t LZ4_readLE16(const void *src)
{
return le16toh(*(const uint16_t *)src);
}
static void LZ4_copy8(void *dst, const void *src)
{
/* ARM32 needs to be a special snowflake to prevent GCC from coalescing the
* access into LDRD/STRD (which don't support unaligned accesses). */
#ifdef __arm__ /* ARMv < 6 doesn't support unaligned accesses at all. */
#if defined(__COREBOOT_ARM_ARCH__) && __COREBOOT_ARM_ARCH__ < 6
int i;
for (i = 0; i < 8; i++)
((uint8_t *)dst)[i] = ((uint8_t *)src)[i];
#else
uint32_t x0, x1;
__asm__ ("ldr %[x0], [%[src]]"
: [x0]"=r"(x0)
: [src]"r"(src), "m"(*(const uint32_t *)src));
__asm__ ("ldr %[x1], [%[src], #4]"
: [x1]"=r"(x1)
: [src]"r"(src), "m"(*(const uint32_t *)(src + 4)));
__asm__ ("str %[x0], [%[dst]]"
: "=m"(*(uint32_t *)dst)
: [x0]"r"(x0), [dst]"r"(dst));
__asm__ ("str %[x1], [%[dst], #4]"
: "=m"(*(uint32_t *)(dst + 4))
: [x1]"r"(x1), [dst]"r"(dst));
#endif
#elif defined(__riscv)
/* RISC-V implementations may trap on any unaligned access. */
int i;
for (i = 0; i < 8; i++)
((uint8_t *)dst)[i] = ((uint8_t *)src)[i];
#else
*(uint64_t *)dst = *(const uint64_t *)src;
#endif
}
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
#define FORCE_INLINE static __always_inline
#define likely(expr) __builtin_expect((expr) != 0, 1)
#define unlikely(expr) __builtin_expect((expr) != 0, 0)
/* Unaltered (just removed unrelated code) from github.com/Cyan4973/lz4/dev. */
#include "lz4.c.inc" /* #include for inlining, do not link! */
#define LZ4F_MAGICNUMBER 0x184D2204
/* Bit field endianness is implementation-defined. Use masks instead.
* https://stackoverflow.com/a/6044223 */
#define RESERVED0 0x03
#define HAS_CONTENT_CHECKSUM 0x04
#define HAS_CONTENT_SIZE 0x08
#define HAS_BLOCK_CHECKSUM 0x10
#define INDEPENDENT_BLOCKS 0x20
#define VERSION 0xC0
#define VERSION_SHIFT 6
#define RESERVED1_2 0x8F
#define MAX_BLOCK_SIZE 0x70
struct lz4_frame_header {
uint32_t magic;
uint8_t flags;
uint8_t block_descriptor;
/* + uint64_t content_size iff has_content_size is set */
/* + uint8_t header_checksum */
} __packed;
#define BH_SIZE 0x7FFFFFFF
#define NOT_COMPRESSED 0x80000000
struct lz4_block_header {
uint32_t raw;
/* + size bytes of data */
/* + uint32_t block_checksum iff has_block_checksum is set */
} __packed;
size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn)
{
const void *in = src;
void *out = dst;
size_t out_size = 0;
int has_block_checksum;
{ /* With in-place decompression the header may become invalid later. */
const struct lz4_frame_header *h = in;
if (srcn < sizeof(*h) + sizeof(uint64_t) + sizeof(uint8_t))
return 0; /* input overrun */
/* We assume there's always only a single, standard frame. */
if (le32toh(h->magic) != LZ4F_MAGICNUMBER
|| (h->flags & VERSION) != (1 << VERSION_SHIFT))
return 0; /* unknown format */
if ((h->flags & RESERVED0) || (h->block_descriptor & RESERVED1_2))
return 0; /* reserved must be zero */
if (!(h->flags & INDEPENDENT_BLOCKS))
return 0; /* we don't support block dependency */
has_block_checksum = h->flags & HAS_BLOCK_CHECKSUM;
in += sizeof(*h);
if (h->flags & HAS_CONTENT_SIZE)
in += sizeof(uint64_t);
in += sizeof(uint8_t);
}
while (1) {
if ((size_t)(in - src) + sizeof(struct lz4_block_header) > srcn)
break; /* input overrun */
struct lz4_block_header b = {
.raw = le32toh(*(const uint32_t *)in)
};
in += sizeof(struct lz4_block_header);
if ((size_t)(in - src) + (b.raw & BH_SIZE) > srcn)
break; /* input overrun */
if (!(b.raw & BH_SIZE)) {
out_size = out - dst;
break; /* decompression successful */
}
if (b.raw & NOT_COMPRESSED) {
size_t size = MIN((uintptr_t)(b.raw & BH_SIZE), (uintptr_t)dst
+ dstn - (uintptr_t)out);
memcpy(out, in, size);
if (size < (b.raw & BH_SIZE))
break; /* output overrun */
out += size;
} else {
/* constant folding essential, do not touch params! */
int ret = LZ4_decompress_generic(in, out, (b.raw & BH_SIZE),
dst + dstn - out, endOnInputSize,
full, 0, noDict, out, NULL, 0);
if (ret < 0)
break; /* decompression error */
out += ret;
}
in += (b.raw & BH_SIZE);
if (has_block_checksum)
in += sizeof(uint32_t);
}
return out_size;
}
size_t ulz4f(const void *src, void *dst)
{
/* LZ4 uses signed size parameters, so can't just use ((u32)-1) here. */
return ulz4fn(src, 1*GiB, dst, 1*GiB);
}
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