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xz: Add ARM64 BCJ filter

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Also omit a duplicated check for XZ_DEC_ARM in xz_private.h.

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/20240721133633.47721-12-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 16:36:26 +03:00 committed by Andrew Morton
parent bdfc041171
commit 4b62813f5e
3 changed files with 61 additions and 3 deletions
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5
lib/xz/Kconfig
View file

@ -30,6 +30,11 @@ config XZ_DEC_ARMTHUMB
default y
select XZ_DEC_BCJ
config XZ_DEC_ARM64
bool "ARM64 BCJ filter decoder" if EXPERT
default y
select XZ_DEC_BCJ
config XZ_DEC_SPARC
bool "SPARC BCJ filter decoder" if EXPERT
default y

52
lib/xz/xz_dec_bcj.c
View file

@ -23,7 +23,8 @@ struct xz_dec_bcj {
BCJ_IA64 = 6, /* Big or little endian */
BCJ_ARM = 7, /* Little endian only */
BCJ_ARMTHUMB = 8, /* Little endian only */
BCJ_SPARC = 9 /* Big or little endian */
BCJ_SPARC = 9, /* Big or little endian */
BCJ_ARM64 = 10 /* AArch64 */
} type;
/*
@ -346,6 +347,47 @@ static size_t bcj_sparc(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
}
#endif
#ifdef XZ_DEC_ARM64
static size_t bcj_arm64(struct xz_dec_bcj *s, uint8_t *buf, size_t size)
{
size_t i;
uint32_t instr;
uint32_t addr;
size &= ~(size_t)3;
for (i = 0; i < size; i += 4) {
instr = get_unaligned_le32(buf + i);
if ((instr >> 26) == 0x25) {
/* BL instruction */
addr = instr - ((s->pos + (uint32_t)i) >> 2);
instr = 0x94000000 | (addr & 0x03FFFFFF);
put_unaligned_le32(instr, buf + i);
} else if ((instr & 0x9F000000) == 0x90000000) {
/* ADRP instruction */
addr = ((instr >> 29) & 3) | ((instr >> 3) & 0x1FFFFC);
/* Only convert values in the range +/-512 MiB. */
if ((addr + 0x020000) & 0x1C0000)
continue;
addr -= (s->pos + (uint32_t)i) >> 12;
instr &= 0x9000001F;
instr |= (addr & 3) << 29;
instr |= (addr & 0x03FFFC) << 3;
instr |= (0U - (addr & 0x020000)) & 0xE00000;
put_unaligned_le32(instr, buf + i);
}
}
return i;
}
#endif
/*
* Apply the selected BCJ filter. Update *pos and s->pos to match the amount
* of data that got filtered.
@ -392,6 +434,11 @@ static void bcj_apply(struct xz_dec_bcj *s,
case BCJ_SPARC:
filtered = bcj_sparc(s, buf, size);
break;
#endif
#ifdef XZ_DEC_ARM64
case BCJ_ARM64:
filtered = bcj_arm64(s, buf, size);
break;
#endif
default:
/* Never reached but silence compiler warnings. */
@ -565,6 +612,9 @@ XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id)
#endif
#ifdef XZ_DEC_SPARC
case BCJ_SPARC:
#endif
#ifdef XZ_DEC_ARM64
case BCJ_ARM64:
#endif
break;

7
lib/xz/xz_private.h
View file

@ -36,6 +36,9 @@
# ifdef CONFIG_XZ_DEC_SPARC
# define XZ_DEC_SPARC
# endif
# ifdef CONFIG_XZ_DEC_ARM64
# define XZ_DEC_ARM64
# endif
# ifdef CONFIG_XZ_DEC_MICROLZMA
# define XZ_DEC_MICROLZMA
# endif
@ -97,9 +100,9 @@
*/
#ifndef XZ_DEC_BCJ
# if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
|| defined(XZ_DEC_IA64) || defined(XZ_DEC_ARM) \
|| defined(XZ_DEC_IA64) \
|| defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
|| defined(XZ_DEC_SPARC)
|| defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64)
# define XZ_DEC_BCJ
# endif
#endif