1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PPC476 board specific routines
4 *
5 * Copyright 2010 Torez Smith, IBM Corporation.
6 *
7 * Based on earlier code:
8 *    Matt Porter <mporter@kernel.crashing.org>
9 *    Copyright 2002-2005 MontaVista Software Inc.
10 *
11 *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
12 *    Copyright (c) 2003-2005 Zultys Technologies
13 *
14 *    Rewritten and ported to the merged powerpc tree:
15 *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
16 */
17
18#include <linux/init.h>
19#include <linux/of_platform.h>
20#include <linux/rtc.h>
21
22#include <asm/machdep.h>
23#include <asm/prom.h>
24#include <asm/udbg.h>
25#include <asm/time.h>
26#include <asm/uic.h>
27#include <asm/ppc4xx.h>
28#include <asm/mpic.h>
29#include <asm/mmu.h>
30
31static const struct of_device_id iss4xx_of_bus[] __initconst = {
32	{ .compatible = "ibm,plb4", },
33	{ .compatible = "ibm,plb6", },
34	{ .compatible = "ibm,opb", },
35	{ .compatible = "ibm,ebc", },
36	{},
37};
38
39static int __init iss4xx_device_probe(void)
40{
41	of_platform_bus_probe(NULL, iss4xx_of_bus, NULL);
42	of_instantiate_rtc();
43
44	return 0;
45}
46machine_device_initcall(iss4xx, iss4xx_device_probe);
47
48/* We can have either UICs or MPICs */
49static void __init iss4xx_init_irq(void)
50{
51	struct device_node *np;
52
53	/* Find top level interrupt controller */
54	for_each_node_with_property(np, "interrupt-controller") {
55		if (!of_property_present(np, "interrupts"))
56			break;
57	}
58	if (np == NULL)
59		panic("Can't find top level interrupt controller");
60
61	/* Check type and do appropriate initialization */
62	if (of_device_is_compatible(np, "ibm,uic")) {
63		uic_init_tree();
64		ppc_md.get_irq = uic_get_irq;
65#ifdef CONFIG_MPIC
66	} else if (of_device_is_compatible(np, "chrp,open-pic")) {
67		/* The MPIC driver will get everything it needs from the
68		 * device-tree, just pass 0 to all arguments
69		 */
70		struct mpic *mpic = mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
71		BUG_ON(mpic == NULL);
72		mpic_init(mpic);
73		ppc_md.get_irq = mpic_get_irq;
74#endif
75	} else
76		panic("Unrecognized top level interrupt controller");
77}
78
79#ifdef CONFIG_SMP
80static void smp_iss4xx_setup_cpu(int cpu)
81{
82	mpic_setup_this_cpu();
83}
84
85static int smp_iss4xx_kick_cpu(int cpu)
86{
87	struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
88	const u64 *spin_table_addr_prop;
89	u32 *spin_table;
90	extern void start_secondary_47x(void);
91
92	BUG_ON(cpunode == NULL);
93
94	/* Assume spin table. We could test for the enable-method in
95	 * the device-tree but currently there's little point as it's
96	 * our only supported method
97	 */
98	spin_table_addr_prop = of_get_property(cpunode, "cpu-release-addr",
99					       NULL);
100	if (spin_table_addr_prop == NULL) {
101		pr_err("CPU%d: Can't start, missing cpu-release-addr !\n", cpu);
102		return -ENOENT;
103	}
104
105	/* Assume it's mapped as part of the linear mapping. This is a bit
106	 * fishy but will work fine for now
107	 */
108	spin_table = (u32 *)__va(*spin_table_addr_prop);
109	pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);
110
111	spin_table[3] = cpu;
112	smp_wmb();
113	spin_table[1] = __pa(start_secondary_47x);
114	mb();
115
116	return 0;
117}
118
119static struct smp_ops_t iss_smp_ops = {
120	.probe		= smp_mpic_probe,
121	.message_pass	= smp_mpic_message_pass,
122	.setup_cpu	= smp_iss4xx_setup_cpu,
123	.kick_cpu	= smp_iss4xx_kick_cpu,
124	.give_timebase	= smp_generic_give_timebase,
125	.take_timebase	= smp_generic_take_timebase,
126};
127
128static void __init iss4xx_smp_init(void)
129{
130	if (mmu_has_feature(MMU_FTR_TYPE_47x))
131		smp_ops = &iss_smp_ops;
132}
133
134#else /* CONFIG_SMP */
135static void __init iss4xx_smp_init(void) { }
136#endif /* CONFIG_SMP */
137
138static void __init iss4xx_setup_arch(void)
139{
140	iss4xx_smp_init();
141}
142
143define_machine(iss4xx) {
144	.name			= "ISS-4xx",
145	.compatible		= "ibm,iss-4xx",
146	.progress		= udbg_progress,
147	.init_IRQ		= iss4xx_init_irq,
148	.setup_arch		= iss4xx_setup_arch,
149	.restart		= ppc4xx_reset_system,
150};
151