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/fncpy.h> 18 #include <asm/mach-types.h> 19 #include <asm/smp_plat.h> 20 #include <asm/system_misc.h> 21 22 extern void relocate_new_kernel(void); 23 extern const unsigned int relocate_new_kernel_size; 24 25 extern unsigned long kexec_start_address; 26 extern unsigned long kexec_indirection_page; 27 extern unsigned long kexec_mach_type; 28 extern unsigned long kexec_boot_atags; 29 30 static atomic_t waiting_for_crash_ipi; 31 32 static unsigned long dt_mem; 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 /* 45 * Validate that if the current HW supports SMP, then the SW supports 46 * and implements CPU hotplug for the current HW. If not, we won't be 47 * able to kexec reliably, so fail the prepare operation. 48 */ 49 if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug()) 50 return -EINVAL; 51 52 /* 53 * No segment at default ATAGs address. try to locate 54 * a dtb using magic. 55 */ 56 for (i = 0; i < image->nr_segments; i++) { 57 current_segment = &image->segment[i]; 58 59 if (!memblock_is_region_memory(current_segment->mem, 60 current_segment->memsz)) 61 return -EINVAL; 62 63 err = get_user(header, (__be32*)current_segment->buf); 64 if (err) 65 return err; 66 67 if (be32_to_cpu(header) == OF_DT_HEADER) 68 dt_mem = current_segment->mem; 69 } 70 return 0; 71 } 72 73 void machine_kexec_cleanup(struct kimage *image) 74 { 75 } 76 77 void machine_crash_nonpanic_core(void *unused) 78 { 79 struct pt_regs regs; 80 81 crash_setup_regs(®s, NULL); 82 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", 83 smp_processor_id()); 84 crash_save_cpu(®s, smp_processor_id()); 85 flush_cache_all(); 86 87 set_cpu_online(smp_processor_id(), false); 88 atomic_dec(&waiting_for_crash_ipi); 89 while (1) 90 cpu_relax(); 91 } 92 93 static void machine_kexec_mask_interrupts(void) 94 { 95 unsigned int i; 96 struct irq_desc *desc; 97 98 for_each_irq_desc(i, desc) { 99 struct irq_chip *chip; 100 101 chip = irq_desc_get_chip(desc); 102 if (!chip) 103 continue; 104 105 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 106 chip->irq_eoi(&desc->irq_data); 107 108 if (chip->irq_mask) 109 chip->irq_mask(&desc->irq_data); 110 111 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 112 chip->irq_disable(&desc->irq_data); 113 } 114 } 115 116 void machine_crash_shutdown(struct pt_regs *regs) 117 { 118 unsigned long msecs; 119 120 local_irq_disable(); 121 122 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 123 smp_call_function(machine_crash_nonpanic_core, NULL, false); 124 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 125 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 126 mdelay(1); 127 msecs--; 128 } 129 if (atomic_read(&waiting_for_crash_ipi) > 0) 130 pr_warn("Non-crashing CPUs did not react to IPI\n"); 131 132 crash_save_cpu(regs, smp_processor_id()); 133 machine_kexec_mask_interrupts(); 134 135 pr_info("Loading crashdump kernel...\n"); 136 } 137 138 /* 139 * Function pointer to optional machine-specific reinitialization 140 */ 141 void (*kexec_reinit)(void); 142 143 void machine_kexec(struct kimage *image) 144 { 145 unsigned long page_list; 146 unsigned long reboot_code_buffer_phys; 147 unsigned long reboot_entry = (unsigned long)relocate_new_kernel; 148 unsigned long reboot_entry_phys; 149 void *reboot_code_buffer; 150 151 /* 152 * This can only happen if machine_shutdown() failed to disable some 153 * CPU, and that can only happen if the checks in 154 * machine_kexec_prepare() were not correct. If this fails, we can't 155 * reliably kexec anyway, so BUG_ON is appropriate. 156 */ 157 BUG_ON(num_online_cpus() > 1); 158 159 page_list = image->head & PAGE_MASK; 160 161 /* we need both effective and real address here */ 162 reboot_code_buffer_phys = 163 page_to_pfn(image->control_code_page) << PAGE_SHIFT; 164 reboot_code_buffer = page_address(image->control_code_page); 165 166 /* Prepare parameters for reboot_code_buffer*/ 167 set_kernel_text_rw(); 168 kexec_start_address = image->start; 169 kexec_indirection_page = page_list; 170 kexec_mach_type = machine_arch_type; 171 kexec_boot_atags = dt_mem ?: image->start - KEXEC_ARM_ZIMAGE_OFFSET 172 + KEXEC_ARM_ATAGS_OFFSET; 173 174 /* copy our kernel relocation code to the control code page */ 175 reboot_entry = fncpy(reboot_code_buffer, 176 reboot_entry, 177 relocate_new_kernel_size); 178 reboot_entry_phys = (unsigned long)reboot_entry + 179 (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer); 180 181 pr_info("Bye!\n"); 182 183 if (kexec_reinit) 184 kexec_reinit(); 185 186 soft_restart(reboot_entry_phys); 187 } 188 189 void arch_crash_save_vmcoreinfo(void) 190 { 191 #ifdef CONFIG_ARM_LPAE 192 VMCOREINFO_CONFIG(ARM_LPAE); 193 #endif 194 } 195