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 */
28static int ncores;
29
30int 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}
82EXPORT_SYMBOL(zynq_cpun_start);
83
84static 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 */
93static 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
103static 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 */
115static void zynq_secondary_init(unsigned int cpu)
116{
117	zynq_core_pm_init();
118}
119
120#ifdef CONFIG_HOTPLUG_CPU
121static 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 */
140static 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
154const 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