xref: /openbmc/u-boot/arch/mips/cpu/cm_init.S (revision 274bced8)
1/*
2 * MIPS Coherence Manager (CM) Initialisation
3 *
4 * Copyright (c) 2016 Imagination Technologies Ltd.
5 *
6 * SPDX-License-Identifier:	GPL-2.0+
7 */
8
9#include <asm/addrspace.h>
10#include <asm/asm.h>
11#include <asm/cm.h>
12#include <asm/mipsregs.h>
13#include <asm/regdef.h>
14
15LEAF(mips_cm_map)
16	/* Config3 must exist for a CM to be present */
17	mfc0		t0, CP0_CONFIG, 1
18	bgez		t0, 2f
19	mfc0		t0, CP0_CONFIG, 2
20	bgez		t0, 2f
21
22	/* Check Config3.CMGCR to determine CM presence */
23	mfc0		t0, CP0_CONFIG, 3
24	and		t0, t0, MIPS_CONF3_CMGCR
25	beqz		t0, 2f
26
27	/* Find the current physical GCR base address */
281:	MFC0		t0, CP0_CMGCRBASE
29	PTR_SLL		t0, t0, 4
30
31	/* If the GCRs are where we want, we're done */
32	PTR_LI		t1, CONFIG_MIPS_CM_BASE
33	beq		t0, t1, 2f
34
35	/* Move the GCRs to our configured base address */
36	PTR_LI		t2, CKSEG1
37	PTR_ADDU	t0, t0, t2
38	sw		zero, GCR_BASE_UPPER(t0)
39	sw		t1, GCR_BASE(t0)
40
41	/* Re-check the GCR base */
42	b		1b
43
442:	jr		ra
45	END(mips_cm_map)
46