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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm/kernel/insn.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/arm/kernel/insn.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm/kernel/insn.c b/arch/arm/kernel/insn.c new file mode 100644 index 000000000..db0acbb7d --- /dev/null +++ b/arch/arm/kernel/insn.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bug.h> +#include <linux/kernel.h> +#include <asm/opcodes.h> + +static unsigned long __arm_gen_branch_thumb2(unsigned long pc, + unsigned long addr, bool link, + bool warn) +{ + unsigned long s, j1, j2, i1, i2, imm10, imm11; + unsigned long first, second; + long offset; + + offset = (long)addr - (long)(pc + 4); + if (offset < -16777216 || offset > 16777214) { + WARN_ON_ONCE(warn); + return 0; + } + + s = (offset >> 24) & 0x1; + i1 = (offset >> 23) & 0x1; + i2 = (offset >> 22) & 0x1; + imm10 = (offset >> 12) & 0x3ff; + imm11 = (offset >> 1) & 0x7ff; + + j1 = (!i1) ^ s; + j2 = (!i2) ^ s; + + first = 0xf000 | (s << 10) | imm10; + second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11; + if (link) + second |= 1 << 14; + + return __opcode_thumb32_compose(first, second); +} + +static unsigned long __arm_gen_branch_arm(unsigned long pc, unsigned long addr, + bool link, bool warn) +{ + unsigned long opcode = 0xea000000; + long offset; + + if (link) + opcode |= 1 << 24; + + offset = (long)addr - (long)(pc + 8); + if (unlikely(offset < -33554432 || offset > 33554428)) { + WARN_ON_ONCE(warn); + return 0; + } + + offset = (offset >> 2) & 0x00ffffff; + + return opcode | offset; +} + +unsigned long +__arm_gen_branch(unsigned long pc, unsigned long addr, bool link, bool warn) +{ + if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) + return __arm_gen_branch_thumb2(pc, addr, link, warn); + else + return __arm_gen_branch_arm(pc, addr, link, warn); +} |