xref: /openbmc/u-boot/arch/arm/cpu/armv7m/cpu.c (revision ae485b54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2010,2011
4  * Vladimir Khusainov, Emcraft Systems, vlad@emcraft.com
5  *
6  * (C) Copyright 2015
7  * Kamil Lulko, <kamil.lulko@gmail.com>
8  */
9 
10 #include <common.h>
11 #include <asm/io.h>
12 #include <asm/armv7m.h>
13 
14 /*
15  * This is called right before passing control to
16  * the Linux kernel point.
17  */
18 int cleanup_before_linux(void)
19 {
20 	/*
21 	 * this function is called just before we call linux
22 	 * it prepares the processor for linux
23 	 *
24 	 * disable interrupt and turn off caches etc ...
25 	 */
26 	disable_interrupts();
27 	/*
28 	 * turn off D-cache
29 	 * dcache_disable() in turn flushes the d-cache
30 	 * MPU is still enabled & can't be disabled as the u-boot
31 	 * code might be running in sdram which by default is not
32 	 * executable area.
33 	 */
34 	dcache_disable();
35 	/* invalidate to make sure no cache line gets dirty between
36 	 * dcache flushing and disabling dcache */
37 	invalidate_dcache_all();
38 
39 	icache_disable();
40 	invalidate_icache_all();
41 
42 	return 0;
43 }
44 
45 /*
46  * Perform the low-level reset.
47  */
48 void reset_cpu(ulong addr)
49 {
50 	/*
51 	 * Perform reset but keep priority group unchanged.
52 	 */
53 	writel((V7M_AIRCR_VECTKEY << V7M_AIRCR_VECTKEY_SHIFT)
54 		| (V7M_SCB->aircr & V7M_AIRCR_PRIGROUP_MSK)
55 		| V7M_AIRCR_SYSRESET, &V7M_SCB->aircr);
56 }
57