1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * machine_kexec.c - handle transition of Linux booting another kernel 4 */ 5 6 #include <linux/mm.h> 7 #include <linux/kexec.h> 8 #include <linux/delay.h> 9 #include <linux/reboot.h> 10 #include <linux/io.h> 11 #include <linux/irq.h> 12 #include <linux/memblock.h> 13 #include <linux/of_fdt.h> 14 #include <asm/pgalloc.h> 15 #include <asm/mmu_context.h> 16 #include <asm/cacheflush.h> 17 #include <asm/fncpy.h> 18 #include <asm/mach-types.h> 19 #include <asm/smp_plat.h> 20 #include <asm/system_misc.h> 21 #include <asm/set_memory.h> 22 23 extern void relocate_new_kernel(void); 24 extern const unsigned int relocate_new_kernel_size; 25 26 extern unsigned long kexec_start_address; 27 extern unsigned long kexec_indirection_page; 28 extern unsigned long kexec_mach_type; 29 extern unsigned long kexec_boot_atags; 30 31 static atomic_t waiting_for_crash_ipi; 32 33 /* 34 * Provide a dummy crash_notes definition while crash dump arrives to arm. 35 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. 36 */ 37 38 int machine_kexec_prepare(struct kimage *image) 39 { 40 struct kexec_segment *current_segment; 41 __be32 header; 42 int i, err; 43 44 image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET 45 + KEXEC_ARM_ATAGS_OFFSET; 46 47 /* 48 * Validate that if the current HW supports SMP, then the SW supports 49 * and implements CPU hotplug for the current HW. If not, we won't be 50 * able to kexec reliably, so fail the prepare operation. 51 */ 52 if (num_possible_cpus() > 1 && platform_can_secondary_boot() && 53 !platform_can_cpu_hotplug()) 54 return -EINVAL; 55 56 /* 57 * No segment at default ATAGs address. try to locate 58 * a dtb using magic. 59 */ 60 for (i = 0; i < image->nr_segments; i++) { 61 current_segment = &image->segment[i]; 62 63 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem), 64 current_segment->memsz)) 65 return -EINVAL; 66 67 err = get_user(header, (__be32*)current_segment->buf); 68 if (err) 69 return err; 70 71 if (header == cpu_to_be32(OF_DT_HEADER)) 72 image->arch.kernel_r2 = current_segment->mem; 73 } 74 return 0; 75 } 76 77 void machine_kexec_cleanup(struct kimage *image) 78 { 79 } 80 81 void machine_crash_nonpanic_core(void *unused) 82 { 83 struct pt_regs regs; 84 85 crash_setup_regs(®s, get_irq_regs()); 86 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", 87 smp_processor_id()); 88 crash_save_cpu(®s, smp_processor_id()); 89 flush_cache_all(); 90 91 set_cpu_online(smp_processor_id(), false); 92 atomic_dec(&waiting_for_crash_ipi); 93 94 while (1) { 95 cpu_relax(); 96 wfe(); 97 } 98 } 99 100 void crash_smp_send_stop(void) 101 { 102 static int cpus_stopped; 103 unsigned long msecs; 104 105 if (cpus_stopped) 106 return; 107 108 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 109 smp_call_function(machine_crash_nonpanic_core, NULL, false); 110 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 111 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 112 mdelay(1); 113 msecs--; 114 } 115 if (atomic_read(&waiting_for_crash_ipi) > 0) 116 pr_warn("Non-crashing CPUs did not react to IPI\n"); 117 118 cpus_stopped = 1; 119 } 120 121 static void machine_kexec_mask_interrupts(void) 122 { 123 unsigned int i; 124 struct irq_desc *desc; 125 126 for_each_irq_desc(i, desc) { 127 struct irq_chip *chip; 128 129 chip = irq_desc_get_chip(desc); 130 if (!chip) 131 continue; 132 133 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 134 chip->irq_eoi(&desc->irq_data); 135 136 if (chip->irq_mask) 137 chip->irq_mask(&desc->irq_data); 138 139 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 140 chip->irq_disable(&desc->irq_data); 141 } 142 } 143 144 void machine_crash_shutdown(struct pt_regs *regs) 145 { 146 local_irq_disable(); 147 crash_smp_send_stop(); 148 149 crash_save_cpu(regs, smp_processor_id()); 150 machine_kexec_mask_interrupts(); 151 152 pr_info("Loading crashdump kernel...\n"); 153 } 154 155 /* 156 * Function pointer to optional machine-specific reinitialization 157 */ 158 void (*kexec_reinit)(void); 159 160 void machine_kexec(struct kimage *image) 161 { 162 unsigned long page_list, reboot_entry_phys; 163 void (*reboot_entry)(void); 164 void *reboot_code_buffer; 165 166 /* 167 * This can only happen if machine_shutdown() failed to disable some 168 * CPU, and that can only happen if the checks in 169 * machine_kexec_prepare() were not correct. If this fails, we can't 170 * reliably kexec anyway, so BUG_ON is appropriate. 171 */ 172 BUG_ON(num_online_cpus() > 1); 173 174 page_list = image->head & PAGE_MASK; 175 176 reboot_code_buffer = page_address(image->control_code_page); 177 178 /* Prepare parameters for reboot_code_buffer*/ 179 set_kernel_text_rw(); 180 kexec_start_address = image->start; 181 kexec_indirection_page = page_list; 182 kexec_mach_type = machine_arch_type; 183 kexec_boot_atags = image->arch.kernel_r2; 184 185 /* copy our kernel relocation code to the control code page */ 186 reboot_entry = fncpy(reboot_code_buffer, 187 &relocate_new_kernel, 188 relocate_new_kernel_size); 189 190 /* get the identity mapping physical address for the reboot code */ 191 reboot_entry_phys = virt_to_idmap(reboot_entry); 192 193 pr_info("Bye!\n"); 194 195 if (kexec_reinit) 196 kexec_reinit(); 197 198 soft_restart(reboot_entry_phys); 199 } 200 201 void arch_crash_save_vmcoreinfo(void) 202 { 203 #ifdef CONFIG_ARM_LPAE 204 VMCOREINFO_CONFIG(ARM_LPAE); 205 #endif 206 } 207