1 /* 2 * arch/s390/kernel/machine_kexec.c 3 * 4 * (C) Copyright IBM Corp. 2005 5 * 6 * Author(s): Rolf Adelsberger <adelsberger@de.ibm.com> 7 * 8 */ 9 10 /* 11 * s390_machine_kexec.c - handle the transition of Linux booting another kernel 12 * on the S390 architecture. 13 */ 14 15 #include <asm/cio.h> 16 #include <asm/setup.h> 17 #include <linux/device.h> 18 #include <linux/mm.h> 19 #include <linux/kexec.h> 20 #include <linux/delay.h> 21 #include <asm/pgtable.h> 22 #include <asm/pgalloc.h> 23 #include <asm/system.h> 24 25 static void kexec_halt_all_cpus(void *); 26 27 typedef void (*relocate_kernel_t) (kimage_entry_t *, unsigned long); 28 29 const extern unsigned char relocate_kernel[]; 30 const extern unsigned long long relocate_kernel_len; 31 32 int 33 machine_kexec_prepare(struct kimage *image) 34 { 35 unsigned long reboot_code_buffer; 36 37 /* We don't support anything but the default image type for now. */ 38 if (image->type != KEXEC_TYPE_DEFAULT) 39 return -EINVAL; 40 41 /* Get the destination where the assembler code should be copied to.*/ 42 reboot_code_buffer = page_to_pfn(image->control_code_page)<<PAGE_SHIFT; 43 44 /* Then copy it */ 45 memcpy((void *) reboot_code_buffer, relocate_kernel, 46 relocate_kernel_len); 47 return 0; 48 } 49 50 void 51 machine_kexec_cleanup(struct kimage *image) 52 { 53 } 54 55 void 56 machine_shutdown(void) 57 { 58 printk(KERN_INFO "kexec: machine_shutdown called\n"); 59 } 60 61 NORET_TYPE void 62 machine_kexec(struct kimage *image) 63 { 64 clear_all_subchannels(); 65 66 /* Disable lowcore protection */ 67 ctl_clear_bit(0,28); 68 69 on_each_cpu(kexec_halt_all_cpus, image, 0, 0); 70 for (;;); 71 } 72 73 static void 74 kexec_halt_all_cpus(void *kernel_image) 75 { 76 static atomic_t cpuid = ATOMIC_INIT(-1); 77 int cpu; 78 struct kimage *image; 79 relocate_kernel_t data_mover; 80 81 if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid)) 82 signal_processor(smp_processor_id(), sigp_stop); 83 84 /* Wait for all other cpus to enter stopped state */ 85 for_each_online_cpu(cpu) { 86 if (cpu == smp_processor_id()) 87 continue; 88 while (!smp_cpu_not_running(cpu)) 89 cpu_relax(); 90 } 91 92 image = (struct kimage *) kernel_image; 93 data_mover = (relocate_kernel_t) 94 (page_to_pfn(image->control_code_page) << PAGE_SHIFT); 95 96 /* Call the moving routine */ 97 (*data_mover) (&image->head, image->start); 98 } 99