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 err = memblock_is_region_memory(current_segment->mem, 49 current_segment->memsz); 50 if (err) 51 return - EINVAL; 52 53 err = get_user(header, (__be32*)current_segment->buf); 54 if (err) 55 return err; 56 57 if (be32_to_cpu(header) == OF_DT_HEADER) 58 kexec_boot_atags = current_segment->mem; 59 } 60 return 0; 61 } 62 63 void machine_kexec_cleanup(struct kimage *image) 64 { 65 } 66 67 void machine_crash_nonpanic_core(void *unused) 68 { 69 struct pt_regs regs; 70 71 crash_setup_regs(®s, NULL); 72 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", 73 smp_processor_id()); 74 crash_save_cpu(®s, smp_processor_id()); 75 flush_cache_all(); 76 77 atomic_dec(&waiting_for_crash_ipi); 78 while (1) 79 cpu_relax(); 80 } 81 82 static void machine_kexec_mask_interrupts(void) 83 { 84 unsigned int i; 85 struct irq_desc *desc; 86 87 for_each_irq_desc(i, desc) { 88 struct irq_chip *chip; 89 90 chip = irq_desc_get_chip(desc); 91 if (!chip) 92 continue; 93 94 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 95 chip->irq_eoi(&desc->irq_data); 96 97 if (chip->irq_mask) 98 chip->irq_mask(&desc->irq_data); 99 100 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 101 chip->irq_disable(&desc->irq_data); 102 } 103 } 104 105 void machine_crash_shutdown(struct pt_regs *regs) 106 { 107 unsigned long msecs; 108 109 local_irq_disable(); 110 111 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 112 smp_call_function(machine_crash_nonpanic_core, NULL, false); 113 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 114 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 115 mdelay(1); 116 msecs--; 117 } 118 if (atomic_read(&waiting_for_crash_ipi) > 0) 119 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n"); 120 121 crash_save_cpu(regs, smp_processor_id()); 122 machine_kexec_mask_interrupts(); 123 124 printk(KERN_INFO "Loading crashdump kernel...\n"); 125 } 126 127 /* 128 * Function pointer to optional machine-specific reinitialization 129 */ 130 void (*kexec_reinit)(void); 131 132 void machine_kexec(struct kimage *image) 133 { 134 unsigned long page_list; 135 unsigned long reboot_code_buffer_phys; 136 void *reboot_code_buffer; 137 138 139 page_list = image->head & PAGE_MASK; 140 141 /* we need both effective and real address here */ 142 reboot_code_buffer_phys = 143 page_to_pfn(image->control_code_page) << PAGE_SHIFT; 144 reboot_code_buffer = page_address(image->control_code_page); 145 146 /* Prepare parameters for reboot_code_buffer*/ 147 kexec_start_address = image->start; 148 kexec_indirection_page = page_list; 149 kexec_mach_type = machine_arch_type; 150 if (!kexec_boot_atags) 151 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET; 152 153 154 /* copy our kernel relocation code to the control code page */ 155 memcpy(reboot_code_buffer, 156 relocate_new_kernel, relocate_new_kernel_size); 157 158 159 flush_icache_range((unsigned long) reboot_code_buffer, 160 (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE); 161 printk(KERN_INFO "Bye!\n"); 162 163 if (kexec_reinit) 164 kexec_reinit(); 165 166 soft_restart(reboot_code_buffer_phys); 167 } 168