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xz: add RISC-V BCJ filter

Browse source 
A later commit updates lib/decompress_unxz.c to enable this filter for
kernel decompression.  lib/decompress_unxz.c is already used if
CONFIG_EFI_ZBOOT=y && CONFIG_KERNEL_XZ=y.

This filter can be used by Squashfs without modifications to the Squashfs
kernel code (only needs support in userspace Squashfs-tools).

Link: https://lkml.kernel.org/r/20240721133633.47721-13-lasse.collin@tukaani.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Reviewed-by: Sam James <sam@gentoo.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Jules Maselbas <jmaselbas@zdiv.net>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rui Li <me@lirui.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Lasse Collin 2024-07-21 16:36:27 +03:00 committed by Andrew Morton
parent 4b62813f5e
commit 93d09773d1
4 changed files with 114 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
lib/xz/Kconfig
View file

@ -40,6 +40,11 @@ config XZ_DEC_SPARC
default y
select XZ_DEC_BCJ
config XZ_DEC_RISCV
bool "RISC-V BCJ filter decoder" if EXPERT
default y
select XZ_DEC_BCJ
config XZ_DEC_MICROLZMA
bool "MicroLZMA decoder"
default n

104
lib/xz/xz_dec_bcj.c
View file

@ -24,7 +24,8 @@ struct xz_dec_bcj {
BCJ_ARM = 7, /* Little endian only */
BCJ_ARMTHUMB = 8, /* Little endian only */
BCJ_SPARC = 9, /* Big or little endian */
BCJ_ARM64 = 10 /* AArch64 */
BCJ_ARM64 = 10, /* AArch64 */
BCJ_RISCV = 11 /* RV32GQC_Zfh, RV64GQC_Zfh */
} type;
/*
@ -388,6 +389,99 @@ static size_t bcj_arm64(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
}
#endif
#ifdef XZ_DEC_RISCV
static size_t bcj_riscv(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
{
size_t i;
uint32_t b1;
uint32_t b2;
uint32_t b3;
uint32_t instr;
uint32_t instr2;
uint32_t instr2_rs1;
uint32_t addr;
if (size < 8)
return 0;
size -= 8;
for (i = 0; i <= size; i += 2) {
instr = buf[i];
if (instr == 0xEF) {
/* JAL */
b1 = buf[i + 1];
if ((b1 & 0x0D) != 0)
continue;
b2 = buf[i + 2];
b3 = buf[i + 3];
addr = ((b1 & 0xF0) << 13) | (b2 << 9) | (b3 << 1);
addr -= s->pos + (uint32_t)i;
buf[i + 1] = (uint8_t)((b1 & 0x0F)
| ((addr >> 8) & 0xF0));
buf[i + 2] = (uint8_t)(((addr >> 16) & 0x0F)
| ((addr >> 7) & 0x10)
| ((addr << 4) & 0xE0));
buf[i + 3] = (uint8_t)(((addr >> 4) & 0x7F)
| ((addr >> 13) & 0x80));
i += 4 - 2;
} else if ((instr & 0x7F) == 0x17) {
/* AUIPC */
instr |= (uint32_t)buf[i + 1] << 8;
instr |= (uint32_t)buf[i + 2] << 16;
instr |= (uint32_t)buf[i + 3] << 24;
if (instr & 0xE80) {
/* AUIPC's rd doesn't equal x0 or x2. */
instr2 = get_unaligned_le32(buf + i + 4);
if (((instr << 8) ^ (instr2 - 3)) & 0xF8003) {
i += 6 - 2;
continue;
}
addr = (instr & 0xFFFFF000) + (instr2 >> 20);
instr = 0x17 | (2 << 7) | (instr2 << 12);
instr2 = addr;
} else {
/* AUIPC's rd equals x0 or x2. */
instr2_rs1 = instr >> 27;
if ((uint32_t)((instr - 0x3117) << 18)
>= (instr2_rs1 & 0x1D)) {
i += 4 - 2;
continue;
}
addr = get_unaligned_be32(buf + i + 4);
addr -= s->pos + (uint32_t)i;
instr2 = (instr >> 12) | (addr << 20);
instr = 0x17 | (instr2_rs1 << 7)
| ((addr + 0x800) & 0xFFFFF000);
}
put_unaligned_le32(instr, buf + i);
put_unaligned_le32(instr2, buf + i + 4);
i += 8 - 2;
}
}
return i;
}
#endif
/*
* Apply the selected BCJ filter. Update *pos and s->pos to match the amount
* of data that got filtered.
@ -439,6 +533,11 @@ static void bcj_apply(struct xz_dec_bcj *s,
case BCJ_ARM64:
filtered = bcj_arm64(s, buf, size);
break;
#endif
#ifdef XZ_DEC_RISCV
case BCJ_RISCV:
filtered = bcj_riscv(s, buf, size);
break;
#endif
default:
/* Never reached but silence compiler warnings. */
@ -615,6 +714,9 @@ XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id)
#endif
#ifdef XZ_DEC_ARM64
case BCJ_ARM64:
#endif
#ifdef XZ_DEC_RISCV
case BCJ_RISCV:
#endif
break;

2
lib/xz/xz_dec_syms.c
View file

@ -22,6 +22,6 @@ EXPORT_SYMBOL(xz_dec_microlzma_end);
#endif
MODULE_DESCRIPTION("XZ decompressor");
MODULE_VERSION("1.1");
MODULE_VERSION("1.2");
MODULE_AUTHOR("Lasse Collin <lasse.collin@tukaani.org> and Igor Pavlov");
MODULE_LICENSE("Dual BSD/GPL");

6
lib/xz/xz_private.h
View file

@ -39,6 +39,9 @@
# ifdef CONFIG_XZ_DEC_ARM64
# define XZ_DEC_ARM64
# endif
# ifdef CONFIG_XZ_DEC_RISCV
# define XZ_DEC_RISCV
# endif
# ifdef CONFIG_XZ_DEC_MICROLZMA
# define XZ_DEC_MICROLZMA
# endif
@ -102,7 +105,8 @@
# if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
|| defined(XZ_DEC_IA64) \
|| defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
|| defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64)
|| defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64) \
|| defined(XZ_DEC_RISCV)
# define XZ_DEC_BCJ
# endif
#endif