blob: bacf53fd0b70c6307e74ef8601d8dcc7db292700 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 * The ARM LDRD and Thumb LDRSB instructions use bit 20/11 (ARM/Thumb)
4 * differently than every other instruction, so it is set to 0 (write)
5 * even though the instructions are read instructions. This means that
6 * during an abort the instructions will be treated as a write and the
7 * handler will raise a signal from unwriteable locations if they
8 * fault. We have to specifically check for these instructions
9 * from the abort handlers to treat them properly.
10 *
11 */
12
Russell Kingbe020f82011-06-26 13:42:01 +010013 .macro do_thumb_abort, fsr, pc, psr, tmp
14 tst \psr, #PSR_T_BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 beq not_thumb
Russell Kingbe020f82011-06-26 13:42:01 +010016 ldrh \tmp, [\pc] @ Read aborted Thumb instruction
Russell King2190fed2015-08-20 10:32:02 +010017 uaccess_disable ip @ disable userspace access
Russell Kingbe020f82011-06-26 13:42:01 +010018 and \tmp, \tmp, # 0xfe00 @ Mask opcode field
19 cmp \tmp, # 0x5600 @ Is it ldrsb?
20 orreq \tmp, \tmp, #1 << 11 @ Set L-bit if yes
21 tst \tmp, #1 << 11 @ L = 0 -> write
Janusz Krzysztofik6c6d8de2011-09-08 18:45:40 +010022 orreq \fsr, \fsr, #1 << 11 @ yes.
Russell Kingda740472011-06-26 16:01:26 +010023 b do_DataAbort
Linus Torvalds1da177e2005-04-16 15:20:36 -070024not_thumb:
25 .endm
26
27/*
Russell Kingbe020f82011-06-26 13:42:01 +010028 * We check for the following instruction encoding for LDRD.
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 *
Russell Kingbe020f82011-06-26 13:42:01 +010030 * [27:25] == 000
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * [7:4] == 1101
32 * [20] == 0
33 */
Russell King08446b12015-08-25 14:59:15 +010034 .macro teq_ldrd, tmp, insn
35 mov \tmp, #0x0e100000
36 orr \tmp, #0x000000f0
37 and \tmp, \insn, \tmp
38 teq \tmp, #0x000000d0
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 .endm