xref: /openbmc/u-boot/arch/mips/cpu/cm_init.S (revision dd1033e4)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * MIPS Coherence Manager (CM) Initialisation
4 *
5 * Copyright (c) 2016 Imagination Technologies Ltd.
6 */
7
8#include <asm/addrspace.h>
9#include <asm/asm.h>
10#include <asm/cm.h>
11#include <asm/mipsregs.h>
12#include <asm/regdef.h>
13
14LEAF(mips_cm_map)
15	/* Config3 must exist for a CM to be present */
16	mfc0		t0, CP0_CONFIG, 1
17	bgez		t0, 2f
18	mfc0		t0, CP0_CONFIG, 2
19	bgez		t0, 2f
20
21	/* Check Config3.CMGCR to determine CM presence */
22	mfc0		t0, CP0_CONFIG, 3
23	and		t0, t0, MIPS_CONF3_CMGCR
24	beqz		t0, 2f
25
26	/* Find the current physical GCR base address */
271:	MFC0		t0, CP0_CMGCRBASE
28	PTR_SLL		t0, t0, 4
29
30	/* If the GCRs are where we want, we're done */
31	PTR_LI		t1, CONFIG_MIPS_CM_BASE
32	beq		t0, t1, 2f
33
34	/* Move the GCRs to our configured base address */
35	PTR_LI		t2, CKSEG1
36	PTR_ADDU	t0, t0, t2
37	sw		zero, GCR_BASE_UPPER(t0)
38	sw		t1, GCR_BASE(t0)
39
40	/* Re-check the GCR base */
41	b		1b
42
432:	jr		ra
44	END(mips_cm_map)
45