1 /* 2 * machine_kexec.c - handle transition of Linux booting another kernel 3 */ 4 5 #include <linux/mm.h> 6 #include <linux/kexec.h> 7 #include <linux/delay.h> 8 #include <linux/reboot.h> 9 #include <linux/io.h> 10 #include <linux/irq.h> 11 #include <linux/memblock.h> 12 #include <asm/pgtable.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/mach-types.h> 18 #include <asm/system_misc.h> 19 20 extern const unsigned char relocate_new_kernel[]; 21 extern const unsigned int relocate_new_kernel_size; 22 23 extern unsigned long kexec_start_address; 24 extern unsigned long kexec_indirection_page; 25 extern unsigned long kexec_mach_type; 26 extern unsigned long kexec_boot_atags; 27 28 static atomic_t waiting_for_crash_ipi; 29 30 /* 31 * Provide a dummy crash_notes definition while crash dump arrives to arm. 32 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. 33 */ 34 35 int machine_kexec_prepare(struct kimage *image) 36 { 37 struct kexec_segment *current_segment; 38 __be32 header; 39 int i, err; 40 41 /* 42 * No segment at default ATAGs address. try to locate 43 * a dtb using magic. 44 */ 45 for (i = 0; i < image->nr_segments; i++) { 46 current_segment = &image->segment[i]; 47 48 if (!memblock_is_region_memory(current_segment->mem, 49 current_segment->memsz)) 50 return -EINVAL; 51 52 err = get_user(header, (__be32*)current_segment->buf); 53 if (err) 54 return err; 55 56 if (be32_to_cpu(header) == OF_DT_HEADER) 57 kexec_boot_atags = current_segment->mem; 58 } 59 return 0; 60 } 61 62 void machine_kexec_cleanup(struct kimage *image) 63 { 64 } 65 66 void machine_crash_nonpanic_core(void *unused) 67 { 68 struct pt_regs regs; 69 70 crash_setup_regs(®s, NULL); 71 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", 72 smp_processor_id()); 73 crash_save_cpu(®s, smp_processor_id()); 74 flush_cache_all(); 75 76 atomic_dec(&waiting_for_crash_ipi); 77 while (1) 78 cpu_relax(); 79 } 80 81 static void machine_kexec_mask_interrupts(void) 82 { 83 unsigned int i; 84 struct irq_desc *desc; 85 86 for_each_irq_desc(i, desc) { 87 struct irq_chip *chip; 88 89 chip = irq_desc_get_chip(desc); 90 if (!chip) 91 continue; 92 93 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 94 chip->irq_eoi(&desc->irq_data); 95 96 if (chip->irq_mask) 97 chip->irq_mask(&desc->irq_data); 98 99 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 100 chip->irq_disable(&desc->irq_data); 101 } 102 } 103 104 void machine_crash_shutdown(struct pt_regs *regs) 105 { 106 unsigned long msecs; 107 108 local_irq_disable(); 109 110 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 111 smp_call_function(machine_crash_nonpanic_core, NULL, false); 112 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 113 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 114 mdelay(1); 115 msecs--; 116 } 117 if (atomic_read(&waiting_for_crash_ipi) > 0) 118 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n"); 119 120 crash_save_cpu(regs, smp_processor_id()); 121 machine_kexec_mask_interrupts(); 122 123 printk(KERN_INFO "Loading crashdump kernel...\n"); 124 } 125 126 /* 127 * Function pointer to optional machine-specific reinitialization 128 */ 129 void (*kexec_reinit)(void); 130 131 void machine_kexec(struct kimage *image) 132 { 133 unsigned long page_list; 134 unsigned long reboot_code_buffer_phys; 135 void *reboot_code_buffer; 136 137 138 page_list = image->head & PAGE_MASK; 139 140 /* we need both effective and real address here */ 141 reboot_code_buffer_phys = 142 page_to_pfn(image->control_code_page) << PAGE_SHIFT; 143 reboot_code_buffer = page_address(image->control_code_page); 144 145 /* Prepare parameters for reboot_code_buffer*/ 146 kexec_start_address = image->start; 147 kexec_indirection_page = page_list; 148 kexec_mach_type = machine_arch_type; 149 if (!kexec_boot_atags) 150 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET; 151 152 153 /* copy our kernel relocation code to the control code page */ 154 memcpy(reboot_code_buffer, 155 relocate_new_kernel, relocate_new_kernel_size); 156 157 158 flush_icache_range((unsigned long) reboot_code_buffer, 159 (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE); 160 printk(KERN_INFO "Bye!\n"); 161 162 if (kexec_reinit) 163 kexec_reinit(); 164 165 soft_restart(reboot_code_buffer_phys); 166 } 167