xref: /openbmc/u-boot/arch/mips/cpu/cm_init.S (revision 83d290c56fab2d38cd1ab4c4cc7099559c1d5046)
1*83d290c5STom Rini/* SPDX-License-Identifier: GPL-2.0+ */
2b2b135d9SPaul Burton/*
3b2b135d9SPaul Burton * MIPS Coherence Manager (CM) Initialisation
4b2b135d9SPaul Burton *
5b2b135d9SPaul Burton * Copyright (c) 2016 Imagination Technologies Ltd.
6b2b135d9SPaul Burton */
7b2b135d9SPaul Burton
8b2b135d9SPaul Burton#include <asm/addrspace.h>
9b2b135d9SPaul Burton#include <asm/asm.h>
10b2b135d9SPaul Burton#include <asm/cm.h>
11b2b135d9SPaul Burton#include <asm/mipsregs.h>
12b2b135d9SPaul Burton#include <asm/regdef.h>
13b2b135d9SPaul Burton
14b2b135d9SPaul BurtonLEAF(mips_cm_map)
15b2b135d9SPaul Burton	/* Config3 must exist for a CM to be present */
16b2b135d9SPaul Burton	mfc0		t0, CP0_CONFIG, 1
17b2b135d9SPaul Burton	bgez		t0, 2f
18b2b135d9SPaul Burton	mfc0		t0, CP0_CONFIG, 2
19b2b135d9SPaul Burton	bgez		t0, 2f
20b2b135d9SPaul Burton
21b2b135d9SPaul Burton	/* Check Config3.CMGCR to determine CM presence */
22b2b135d9SPaul Burton	mfc0		t0, CP0_CONFIG, 3
23b2b135d9SPaul Burton	and		t0, t0, MIPS_CONF3_CMGCR
24b2b135d9SPaul Burton	beqz		t0, 2f
25b2b135d9SPaul Burton
26b2b135d9SPaul Burton	/* Find the current physical GCR base address */
27b2b135d9SPaul Burton1:	MFC0		t0, CP0_CMGCRBASE
28b2b135d9SPaul Burton	PTR_SLL		t0, t0, 4
29b2b135d9SPaul Burton
30b2b135d9SPaul Burton	/* If the GCRs are where we want, we're done */
31b2b135d9SPaul Burton	PTR_LI		t1, CONFIG_MIPS_CM_BASE
32b2b135d9SPaul Burton	beq		t0, t1, 2f
33b2b135d9SPaul Burton
34b2b135d9SPaul Burton	/* Move the GCRs to our configured base address */
35b2b135d9SPaul Burton	PTR_LI		t2, CKSEG1
36b2b135d9SPaul Burton	PTR_ADDU	t0, t0, t2
37b2b135d9SPaul Burton	sw		zero, GCR_BASE_UPPER(t0)
38b2b135d9SPaul Burton	sw		t1, GCR_BASE(t0)
39b2b135d9SPaul Burton
40b2b135d9SPaul Burton	/* Re-check the GCR base */
41b2b135d9SPaul Burton	b		1b
42b2b135d9SPaul Burton
43b2b135d9SPaul Burton2:	jr		ra
44b2b135d9SPaul Burton	END(mips_cm_map)
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