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63 lines
1.4 KiB
63 lines
1.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/bug.h> |
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#include <linux/kernel.h> |
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#include <asm/opcodes.h> |
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static unsigned long |
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__arm_gen_branch_thumb2(unsigned long pc, unsigned long addr, bool link) |
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{ |
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unsigned long s, j1, j2, i1, i2, imm10, imm11; |
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unsigned long first, second; |
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long offset; |
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offset = (long)addr - (long)(pc + 4); |
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if (offset < -16777216 || offset > 16777214) { |
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WARN_ON_ONCE(1); |
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return 0; |
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} |
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s = (offset >> 24) & 0x1; |
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i1 = (offset >> 23) & 0x1; |
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i2 = (offset >> 22) & 0x1; |
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imm10 = (offset >> 12) & 0x3ff; |
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imm11 = (offset >> 1) & 0x7ff; |
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j1 = (!i1) ^ s; |
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j2 = (!i2) ^ s; |
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first = 0xf000 | (s << 10) | imm10; |
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second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11; |
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if (link) |
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second |= 1 << 14; |
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return __opcode_thumb32_compose(first, second); |
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} |
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static unsigned long |
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__arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link) |
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{ |
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unsigned long opcode = 0xea000000; |
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long offset; |
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if (link) |
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opcode |= 1 << 24; |
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offset = (long)addr - (long)(pc + 8); |
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if (unlikely(offset < -33554432 || offset > 33554428)) { |
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WARN_ON_ONCE(1); |
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return 0; |
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} |
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offset = (offset >> 2) & 0x00ffffff; |
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return opcode | offset; |
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} |
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unsigned long |
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__arm_gen_branch(unsigned long pc, unsigned long addr, bool link) |
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{ |
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if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) |
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return __arm_gen_branch_thumb2(pc, addr, link); |
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else |
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return __arm_gen_branch_arm(pc, addr, link); |
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}
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