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 #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 static unsigned long dt_mem; 34 /* 35 * Provide a dummy crash_notes definition while crash dump arrives to arm. 36 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. 37 */ 38 39 int machine_kexec_prepare(struct kimage *image) 40 { 41 struct kexec_segment *current_segment; 42 __be32 header; 43 int i, err; 44 45 /* 46 * Validate that if the current HW supports SMP, then the SW supports 47 * and implements CPU hotplug for the current HW. If not, we won't be 48 * able to kexec reliably, so fail the prepare operation. 49 */ 50 if (num_possible_cpus() > 1 && platform_can_secondary_boot() && 51 !platform_can_cpu_hotplug()) 52 return -EINVAL; 53 54 /* 55 * No segment at default ATAGs address. try to locate 56 * a dtb using magic. 57 */ 58 for (i = 0; i < image->nr_segments; i++) { 59 current_segment = &image->segment[i]; 60 61 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem), 62 current_segment->memsz)) 63 return -EINVAL; 64 65 err = get_user(header, (__be32*)current_segment->buf); 66 if (err) 67 return err; 68 69 if (be32_to_cpu(header) == OF_DT_HEADER) 70 dt_mem = current_segment->mem; 71 } 72 return 0; 73 } 74 75 void machine_kexec_cleanup(struct kimage *image) 76 { 77 } 78 79 void machine_crash_nonpanic_core(void *unused) 80 { 81 struct pt_regs regs; 82 83 crash_setup_regs(®s, NULL); 84 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", 85 smp_processor_id()); 86 crash_save_cpu(®s, smp_processor_id()); 87 flush_cache_all(); 88 89 set_cpu_online(smp_processor_id(), false); 90 atomic_dec(&waiting_for_crash_ipi); 91 while (1) 92 cpu_relax(); 93 } 94 95 static void machine_kexec_mask_interrupts(void) 96 { 97 unsigned int i; 98 struct irq_desc *desc; 99 100 for_each_irq_desc(i, desc) { 101 struct irq_chip *chip; 102 103 chip = irq_desc_get_chip(desc); 104 if (!chip) 105 continue; 106 107 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 108 chip->irq_eoi(&desc->irq_data); 109 110 if (chip->irq_mask) 111 chip->irq_mask(&desc->irq_data); 112 113 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 114 chip->irq_disable(&desc->irq_data); 115 } 116 } 117 118 void machine_crash_shutdown(struct pt_regs *regs) 119 { 120 unsigned long msecs; 121 122 local_irq_disable(); 123 124 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 125 smp_call_function(machine_crash_nonpanic_core, NULL, false); 126 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 127 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 128 mdelay(1); 129 msecs--; 130 } 131 if (atomic_read(&waiting_for_crash_ipi) > 0) 132 pr_warn("Non-crashing CPUs did not react to IPI\n"); 133 134 crash_save_cpu(regs, smp_processor_id()); 135 machine_kexec_mask_interrupts(); 136 137 pr_info("Loading crashdump kernel...\n"); 138 } 139 140 /* 141 * Function pointer to optional machine-specific reinitialization 142 */ 143 void (*kexec_reinit)(void); 144 145 void machine_kexec(struct kimage *image) 146 { 147 unsigned long page_list, reboot_entry_phys; 148 void (*reboot_entry)(void); 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 reboot_code_buffer = page_address(image->control_code_page); 162 163 /* Prepare parameters for reboot_code_buffer*/ 164 set_kernel_text_rw(); 165 kexec_start_address = image->start; 166 kexec_indirection_page = page_list; 167 kexec_mach_type = machine_arch_type; 168 kexec_boot_atags = dt_mem ?: image->start - KEXEC_ARM_ZIMAGE_OFFSET 169 + KEXEC_ARM_ATAGS_OFFSET; 170 171 /* copy our kernel relocation code to the control code page */ 172 reboot_entry = fncpy(reboot_code_buffer, 173 &relocate_new_kernel, 174 relocate_new_kernel_size); 175 176 /* get the identity mapping physical address for the reboot code */ 177 reboot_entry_phys = virt_to_idmap(reboot_entry); 178 179 pr_info("Bye!\n"); 180 181 if (kexec_reinit) 182 kexec_reinit(); 183 184 soft_restart(reboot_entry_phys); 185 } 186 187 void arch_crash_save_vmcoreinfo(void) 188 { 189 #ifdef CONFIG_ARM_LPAE 190 VMCOREINFO_CONFIG(ARM_LPAE); 191 #endif 192 } 193