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