1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2011 Freescale Semiconductor, Inc.
4 * Copyright 2011 Linaro Ltd.
5 */
6
7#include <linux/init.h>
8#include <linux/of_address.h>
9#include <linux/of.h>
10#include <linux/smp.h>
11
12#include <asm/cacheflush.h>
13#include <asm/page.h>
14#include <asm/smp_scu.h>
15#include <asm/mach/map.h>
16
17#include "common.h"
18#include "hardware.h"
19
20u32 g_diag_reg;
21static void __iomem *scu_base;
22
23static struct map_desc scu_io_desc __initdata = {
24 /* .virtual and .pfn are run-time assigned */
25 .length = SZ_4K,
26 .type = MT_DEVICE,
27};
28
29void __init imx_scu_map_io(void)
30{
31 unsigned long base;
32
33 /* Get SCU base */
34 asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (base));
35
36 scu_io_desc.virtual = IMX_IO_P2V(base);
37 scu_io_desc.pfn = __phys_to_pfn(base);
38 iotable_init(&scu_io_desc, 1);
39
40 scu_base = IMX_IO_ADDRESS(base);
41}
42
43static int imx_boot_secondary(unsigned int cpu, struct task_struct *idle)
44{
45 imx_set_cpu_jump(cpu, jump_addr: v7_secondary_startup);
46 imx_enable_cpu(cpu, enable: true);
47 return 0;
48}
49
50/*
51 * Initialise the CPU possible map early - this describes the CPUs
52 * which may be present or become present in the system.
53 */
54static void __init imx_smp_init_cpus(void)
55{
56 int i, ncores;
57
58 ncores = scu_get_core_count(scu_base);
59
60 for (i = ncores; i < NR_CPUS; i++)
61 set_cpu_possible(cpu: i, possible: false);
62}
63
64void imx_smp_prepare(void)
65{
66 scu_enable(scu_base);
67}
68
69static void __init imx_smp_prepare_cpus(unsigned int max_cpus)
70{
71 imx_smp_prepare();
72
73 /*
74 * The diagnostic register holds the errata bits. Mostly bootloader
75 * does not bring up secondary cores, so that when errata bits are set
76 * in bootloader, they are set only for boot cpu. But on a SMP
77 * configuration, it should be equally done on every single core.
78 * Read the register from boot cpu here, and will replicate it into
79 * secondary cores when booting them.
80 */
81 asm("mrc p15, 0, %0, c15, c0, 1" : "=r" (g_diag_reg) : : "cc");
82 sync_cache_w(&g_diag_reg);
83}
84
85const struct smp_operations imx_smp_ops __initconst = {
86 .smp_init_cpus = imx_smp_init_cpus,
87 .smp_prepare_cpus = imx_smp_prepare_cpus,
88 .smp_boot_secondary = imx_boot_secondary,
89#ifdef CONFIG_HOTPLUG_CPU
90 .cpu_die = imx_cpu_die,
91 .cpu_kill = imx_cpu_kill,
92#endif
93};
94
95/*
96 * Initialise the CPU possible map early - this describes the CPUs
97 * which may be present or become present in the system.
98 */
99static void __init imx7_smp_init_cpus(void)
100{
101 struct device_node *np;
102 int i, ncores = 0;
103
104 /* The iMX7D SCU does not report core count, get it from DT */
105 for_each_of_cpu_node(np)
106 ncores++;
107
108 for (i = ncores; i < NR_CPUS; i++)
109 set_cpu_possible(cpu: i, possible: false);
110}
111
112const struct smp_operations imx7_smp_ops __initconst = {
113 .smp_init_cpus = imx7_smp_init_cpus,
114 .smp_boot_secondary = imx_boot_secondary,
115#ifdef CONFIG_HOTPLUG_CPU
116 .cpu_die = imx_cpu_die,
117 .cpu_kill = imx_cpu_kill,
118#endif
119};
120
121#define DCFG_CCSR_SCRATCHRW1 0x200
122
123static int ls1021a_boot_secondary(unsigned int cpu, struct task_struct *idle)
124{
125 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
126
127 return 0;
128}
129
130static void __init ls1021a_smp_prepare_cpus(unsigned int max_cpus)
131{
132 struct device_node *np;
133 void __iomem *dcfg_base;
134 unsigned long paddr;
135
136 np = of_find_compatible_node(NULL, NULL, compat: "fsl,ls1021a-dcfg");
137 dcfg_base = of_iomap(node: np, index: 0);
138 of_node_put(node: np);
139 BUG_ON(!dcfg_base);
140
141 paddr = __pa_symbol(secondary_startup);
142 writel_relaxed(cpu_to_be32(paddr), dcfg_base + DCFG_CCSR_SCRATCHRW1);
143
144 iounmap(addr: dcfg_base);
145}
146
147const struct smp_operations ls1021a_smp_ops __initconst = {
148 .smp_prepare_cpus = ls1021a_smp_prepare_cpus,
149 .smp_boot_secondary = ls1021a_boot_secondary,
150};
151

source code of linux/arch/arm/mach-imx/platsmp.c