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