1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Actions Semi Leopard
4 *
5 * This file is based on arm realview smp platform.
6 *
7 * Copyright 2012 Actions Semi Inc.
8 * Author: Actions Semi, Inc.
9 *
10 * Copyright (c) 2017 Andreas Färber
11 */
12
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/smp.h>
18 #include <linux/soc/actions/owl-sps.h>
19 #include <asm/cacheflush.h>
20 #include <asm/smp_plat.h>
21 #include <asm/smp_scu.h>
22
23 #include <trace/events/ipi.h>
24
25 #define OWL_CPU1_ADDR 0x50
26 #define OWL_CPU1_FLAG 0x5c
27
28 #define OWL_CPUx_FLAG_BOOT 0x55aa
29
30 #define OWL_SPS_PG_CTL_PWR_CPU2 BIT(5)
31 #define OWL_SPS_PG_CTL_PWR_CPU3 BIT(6)
32 #define OWL_SPS_PG_CTL_ACK_CPU2 BIT(21)
33 #define OWL_SPS_PG_CTL_ACK_CPU3 BIT(22)
34
35 static void __iomem *scu_base_addr;
36 static void __iomem *sps_base_addr;
37 static void __iomem *timer_base_addr;
38 static int ncores;
39
40 static int s500_wakeup_secondary(unsigned int cpu)
41 {
42 int ret;
43
44 if (cpu > 3)
45 return -EINVAL;
46
47 /* The generic PM domain driver is not available this early. */
48 switch (cpu) {
49 case 2:
50 ret = owl_sps_set_pg(sps_base_addr,
51 OWL_SPS_PG_CTL_PWR_CPU2,
52 OWL_SPS_PG_CTL_ACK_CPU2, true);
53 if (ret)
54 return ret;
55 break;
56 case 3:
57 ret = owl_sps_set_pg(sps_base_addr,
58 OWL_SPS_PG_CTL_PWR_CPU3,
59 OWL_SPS_PG_CTL_ACK_CPU3, true);
60 if (ret)
61 return ret;
62 break;
63 }
64
65 /* wait for CPUx to run to WFE instruction */
66 udelay(200);
67
68 writel(__pa_symbol(secondary_startup),
69 timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
70 writel(OWL_CPUx_FLAG_BOOT,
71 timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
72
73 dsb_sev();
74 mb();
75
76 return 0;
77 }
78
79 static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
80 {
81 int ret;
82
83 ret = s500_wakeup_secondary(cpu);
84 if (ret)
85 return ret;
86
87 udelay(10);
88
89 smp_send_reschedule(cpu);
90
91 writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
92 writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
93
94 return 0;
95 }
96
97 static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
98 {
99 struct device_node *node;
100
101 node = of_find_compatible_node(NULL, NULL, "actions,s500-timer");
102 if (!node) {
103 pr_err("%s: missing timer\n", __func__);
104 return;
105 }
106
107 timer_base_addr = of_iomap(node, 0);
108 if (!timer_base_addr) {
109 pr_err("%s: could not map timer registers\n", __func__);
110 return;
111 }
112
113 node = of_find_compatible_node(NULL, NULL, "actions,s500-sps");
114 if (!node) {
115 pr_err("%s: missing sps\n", __func__);
116 return;
117 }
118
119 sps_base_addr = of_iomap(node, 0);
120 if (!sps_base_addr) {
121 pr_err("%s: could not map sps registers\n", __func__);
122 return;
123 }
124
125 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
126 node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
127 if (!node) {
128 pr_err("%s: missing scu\n", __func__);
129 return;
130 }
131
132 scu_base_addr = of_iomap(node, 0);
133 if (!scu_base_addr) {
134 pr_err("%s: could not map scu registers\n", __func__);
135 return;
136 }
137
138 /*
139 * While the number of cpus is gathered from dt, also get the
140 * number of cores from the scu to verify this value when
141 * booting the cores.
142 */
143 ncores = scu_get_core_count(scu_base_addr);
144 pr_debug("%s: ncores %d\n", __func__, ncores);
145
146 scu_enable(scu_base_addr);
147 }
148 }
149
150 static const struct smp_operations s500_smp_ops __initconst = {
151 .smp_prepare_cpus = s500_smp_prepare_cpus,
152 .smp_boot_secondary = s500_smp_boot_secondary,
153 };
154 CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops);
155
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