// 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) { 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(1); 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) { 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(1); return 0; } offset = (offset >> 2) & 0x00ffffff; return opcode | offset; } unsigned long __arm_gen_branch(unsigned long pc, unsigned long addr, bool link) { if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) return __arm_gen_branch_thumb2(pc, addr, link); else return __arm_gen_branch_arm(pc, addr, link); }