xref: /arm-trusted-firmware/bl32/sp_min/wa_cve_2017_5715_icache_inv.S (revision 91f16700b400a8c0651d24a598fc48ee2997a0d7)
1*91f16700Schasinglulu/*
2*91f16700Schasinglulu * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
3*91f16700Schasinglulu *
4*91f16700Schasinglulu * SPDX-License-Identifier: BSD-3-Clause
5*91f16700Schasinglulu */
6*91f16700Schasinglulu
7*91f16700Schasinglulu#include <asm_macros.S>
8*91f16700Schasinglulu
9*91f16700Schasinglulu	.globl	wa_cve_2017_5715_icache_inv_vbar
10*91f16700Schasinglulu
11*91f16700Schasingluluvector_base wa_cve_2017_5715_icache_inv_vbar
12*91f16700Schasinglulu	/* We encode the exception entry in the bottom 3 bits of SP */
13*91f16700Schasinglulu	add	sp, sp, #1	/* Reset: 0b111 */
14*91f16700Schasinglulu	add	sp, sp, #1	/* Undef: 0b110 */
15*91f16700Schasinglulu	add	sp, sp, #1	/* Syscall: 0b101 */
16*91f16700Schasinglulu	add	sp, sp, #1	/* Prefetch abort: 0b100 */
17*91f16700Schasinglulu	add	sp, sp, #1	/* Data abort: 0b011 */
18*91f16700Schasinglulu	add	sp, sp, #1	/* Reserved: 0b010 */
19*91f16700Schasinglulu	add	sp, sp, #1	/* IRQ: 0b001 */
20*91f16700Schasinglulu	nop			/* FIQ: 0b000 */
21*91f16700Schasinglulu
22*91f16700Schasinglulu	/*
23*91f16700Schasinglulu	 * Invalidate the instruction cache, which we assume also
24*91f16700Schasinglulu	 * invalidates the branch predictor.  This may depend on
25*91f16700Schasinglulu	 * other CPU specific changes (e.g. an ACTLR setting).
26*91f16700Schasinglulu	 */
27*91f16700Schasinglulu	stcopr	r0, ICIALLU
28*91f16700Schasinglulu	isb
29*91f16700Schasinglulu
30*91f16700Schasinglulu	/*
31*91f16700Schasinglulu	 * As we cannot use any temporary registers and cannot
32*91f16700Schasinglulu	 * clobber SP, we can decode the exception entry using
33*91f16700Schasinglulu	 * an unrolled binary search.
34*91f16700Schasinglulu	 *
35*91f16700Schasinglulu	 * Note, if this code is re-used by other secure payloads,
36*91f16700Schasinglulu	 * the below exception entry vectors must be changed to
37*91f16700Schasinglulu	 * the vectors specific to that secure payload.
38*91f16700Schasinglulu	 */
39*91f16700Schasinglulu
40*91f16700Schasinglulu	tst	sp, #4
41*91f16700Schasinglulu	bne	1f
42*91f16700Schasinglulu
43*91f16700Schasinglulu	tst	sp, #2
44*91f16700Schasinglulu	bne	3f
45*91f16700Schasinglulu
46*91f16700Schasinglulu	/* Expected encoding: 0x1 and 0x0 */
47*91f16700Schasinglulu	tst	sp, #1
48*91f16700Schasinglulu	/* Restore original value of SP by clearing the bottom 3 bits */
49*91f16700Schasinglulu	bic	sp, sp, #0x7
50*91f16700Schasinglulu	bne	plat_panic_handler	/* IRQ */
51*91f16700Schasinglulu	b	sp_min_handle_fiq	/* FIQ */
52*91f16700Schasinglulu
53*91f16700Schasinglulu1:
54*91f16700Schasinglulu	/* Expected encoding: 0x4 and 0x5 */
55*91f16700Schasinglulu	tst	sp, #2
56*91f16700Schasinglulu	bne	2f
57*91f16700Schasinglulu
58*91f16700Schasinglulu	tst	sp, #1
59*91f16700Schasinglulu	bic	sp, sp, #0x7
60*91f16700Schasinglulu	bne	sp_min_handle_smc	/* Syscall */
61*91f16700Schasinglulu	b	plat_panic_handler	/* Prefetch abort */
62*91f16700Schasinglulu
63*91f16700Schasinglulu2:
64*91f16700Schasinglulu	/* Expected encoding: 0x7 and 0x6 */
65*91f16700Schasinglulu	tst	sp, #1
66*91f16700Schasinglulu	bic	sp, sp, #0x7
67*91f16700Schasinglulu	bne	sp_min_entrypoint	/* Reset */
68*91f16700Schasinglulu	b	plat_panic_handler	/* Undef */
69*91f16700Schasinglulu
70*91f16700Schasinglulu3:
71*91f16700Schasinglulu	/* Expected encoding: 0x2 and 0x3 */
72*91f16700Schasinglulu	tst	sp, #1
73*91f16700Schasinglulu	bic	sp, sp, #0x7
74*91f16700Schasinglulu	bne	plat_panic_handler	/* Data abort */
75*91f16700Schasinglulu	b	plat_panic_handler	/* Reserved */
76