1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * This file contains Xilinx specific SMP code, used to start up
4 * the second processor.
5 *
6 * Copyright (C) 2011-2013 Xilinx
7 *
8 * based on linux/arch/arm/mach-realview/platsmp.c
9 *
10 * Copyright (C) 2002 ARM Ltd.
11 */
12
13 #include <linux/export.h>
14 #include <linux/jiffies.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <asm/cacheflush.h>
18 #include <asm/smp_plat.h>
19 #include <asm/smp_scu.h>
20 #include <linux/irqchip/arm-gic.h>
21 #include "common.h"
22
23 /*
24 * Store number of cores in the system
25 * Because of scu_get_core_count() must be in __init section and can't
26 * be called from zynq_cpun_start() because it is not in __init section.
27 */
28 static int ncores;
29
zynq_cpun_start(u32 address,int cpu)30 int zynq_cpun_start(u32 address, int cpu)
31 {
32 u32 trampoline_code_size = &zynq_secondary_trampoline_end -
33 &zynq_secondary_trampoline;
34 u32 phy_cpuid = cpu_logical_map(cpu);
35
36 /* MS: Expectation that SLCR are directly map and accessible */
37 /* Not possible to jump to non aligned address */
38 if (!(address & 3) && (!address || (address >= trampoline_code_size))) {
39 /* Store pointer to ioremap area which points to address 0x0 */
40 static u8 __iomem *zero;
41 u32 trampoline_size = &zynq_secondary_trampoline_jump -
42 &zynq_secondary_trampoline;
43
44 zynq_slcr_cpu_stop(phy_cpuid);
45 if (address) {
46 if (__pa(PAGE_OFFSET)) {
47 zero = ioremap(0, trampoline_code_size);
48 if (!zero) {
49 pr_warn("BOOTUP jump vectors not accessible\n");
50 return -1;
51 }
52 } else {
53 zero = (__force u8 __iomem *)PAGE_OFFSET;
54 }
55
56 /*
57 * This is elegant way how to jump to any address
58 * 0x0: Load address at 0x8 to r0
59 * 0x4: Jump by mov instruction
60 * 0x8: Jumping address
61 */
62 memcpy_toio(zero, &zynq_secondary_trampoline,
63 trampoline_size);
64 writel(address, zero + trampoline_size);
65
66 flush_cache_all();
67 outer_flush_range(0, trampoline_code_size);
68 smp_wmb();
69
70 if (__pa(PAGE_OFFSET))
71 iounmap(zero);
72 }
73 zynq_slcr_cpu_start(phy_cpuid);
74
75 return 0;
76 }
77
78 pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address);
79
80 return -1;
81 }
82 EXPORT_SYMBOL(zynq_cpun_start);
83
zynq_boot_secondary(unsigned int cpu,struct task_struct * idle)84 static int zynq_boot_secondary(unsigned int cpu, struct task_struct *idle)
85 {
86 return zynq_cpun_start(__pa_symbol(secondary_startup_arm), cpu);
87 }
88
89 /*
90 * Initialise the CPU possible map early - this describes the CPUs
91 * which may be present or become present in the system.
92 */
zynq_smp_init_cpus(void)93 static void __init zynq_smp_init_cpus(void)
94 {
95 int i;
96
97 ncores = scu_get_core_count(zynq_scu_base);
98
99 for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++)
100 set_cpu_possible(i, true);
101 }
102
zynq_smp_prepare_cpus(unsigned int max_cpus)103 static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
104 {
105 scu_enable(zynq_scu_base);
106 }
107
108 /**
109 * zynq_secondary_init - Initialize secondary CPU cores
110 * @cpu: CPU that is initialized
111 *
112 * This function is in the hotplug path. Don't move it into the
113 * init section!!
114 */
zynq_secondary_init(unsigned int cpu)115 static void zynq_secondary_init(unsigned int cpu)
116 {
117 zynq_core_pm_init();
118 }
119
120 #ifdef CONFIG_HOTPLUG_CPU
zynq_cpu_kill(unsigned cpu)121 static int zynq_cpu_kill(unsigned cpu)
122 {
123 unsigned long timeout = jiffies + msecs_to_jiffies(50);
124
125 while (zynq_slcr_cpu_state_read(cpu))
126 if (time_after(jiffies, timeout))
127 return 0;
128
129 zynq_slcr_cpu_stop(cpu);
130 return 1;
131 }
132
133 /**
134 * zynq_cpu_die - Let a CPU core die
135 * @cpu: Dying CPU
136 *
137 * Platform-specific code to shutdown a CPU.
138 * Called with IRQs disabled on the dying CPU.
139 */
zynq_cpu_die(unsigned int cpu)140 static void zynq_cpu_die(unsigned int cpu)
141 {
142 zynq_slcr_cpu_state_write(cpu, true);
143
144 /*
145 * there is no power-control hardware on this platform, so all
146 * we can do is put the core into WFI; this is safe as the calling
147 * code will have already disabled interrupts
148 */
149 for (;;)
150 cpu_do_idle();
151 }
152 #endif
153
154 const struct smp_operations zynq_smp_ops __initconst = {
155 .smp_init_cpus = zynq_smp_init_cpus,
156 .smp_prepare_cpus = zynq_smp_prepare_cpus,
157 .smp_boot_secondary = zynq_boot_secondary,
158 .smp_secondary_init = zynq_secondary_init,
159 #ifdef CONFIG_HOTPLUG_CPU
160 .cpu_die = zynq_cpu_die,
161 .cpu_kill = zynq_cpu_kill,
162 #endif
163 };
164