65 lines
1.4 KiB
C
65 lines
1.4 KiB
C
// 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);
|
|
}
|