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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/parisc/kernel/jump_label.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/parisc/kernel/jump_label.c')
-rw-r--r-- | arch/parisc/kernel/jump_label.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/parisc/kernel/jump_label.c b/arch/parisc/kernel/jump_label.c new file mode 100644 index 000000000..e253b1345 --- /dev/null +++ b/arch/parisc/kernel/jump_label.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Helge Deller <deller@gmx.de> + * + * Based on arch/arm64/kernel/jump_label.c + */ +#include <linux/kernel.h> +#include <linux/jump_label.h> +#include <linux/bug.h> +#include <asm/alternative.h> +#include <asm/patch.h> + +static inline int reassemble_17(int as17) +{ + return (((as17 & 0x10000) >> 16) | + ((as17 & 0x0f800) << 5) | + ((as17 & 0x00400) >> 8) | + ((as17 & 0x003ff) << 3)); +} + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + void *addr = (void *)jump_entry_code(entry); + u32 insn; + + if (type == JUMP_LABEL_JMP) { + void *target = (void *)jump_entry_target(entry); + int distance = target - addr; + /* + * Encode the PA1.1 "b,n" instruction with a 17-bit + * displacement. In case we hit the BUG(), we could use + * another branch instruction with a 22-bit displacement on + * 64-bit CPUs instead. But this seems sufficient for now. + */ + distance -= 8; + BUG_ON(distance > 262143 || distance < -262144); + insn = 0xe8000002 | reassemble_17(distance >> 2); + } else { + insn = INSN_NOP; + } + + patch_text(addr, insn); +} |