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/arch/mips/kernel/machine_kexec.c

http://github.com/mirrors/linux
C | 264 lines | 169 code | 55 blank | 40 comment | 20 complexity | 2cf1a4a474e0f611bd80a0bd329e4b30 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * machine_kexec.c for kexec
  4 * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
  5 */
  6#include <linux/compiler.h>
  7#include <linux/kexec.h>
  8#include <linux/mm.h>
  9#include <linux/delay.h>
 10#include <linux/libfdt.h>
 11
 12#include <asm/cacheflush.h>
 13#include <asm/page.h>
 14
 15extern const unsigned char relocate_new_kernel[];
 16extern const size_t relocate_new_kernel_size;
 17
 18extern unsigned long kexec_start_address;
 19extern unsigned long kexec_indirection_page;
 20
 21static unsigned long reboot_code_buffer;
 22
 23#ifdef CONFIG_SMP
 24static void (*relocated_kexec_smp_wait)(void *);
 25
 26atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
 27void (*_crash_smp_send_stop)(void) = NULL;
 28#endif
 29
 30void (*_machine_kexec_shutdown)(void) = NULL;
 31void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
 32
 33static void kexec_image_info(const struct kimage *kimage)
 34{
 35	unsigned long i;
 36
 37	pr_debug("kexec kimage info:\n");
 38	pr_debug("  type:        %d\n", kimage->type);
 39	pr_debug("  start:       %lx\n", kimage->start);
 40	pr_debug("  head:        %lx\n", kimage->head);
 41	pr_debug("  nr_segments: %lu\n", kimage->nr_segments);
 42
 43	for (i = 0; i < kimage->nr_segments; i++) {
 44		pr_debug("    segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
 45			i,
 46			kimage->segment[i].mem,
 47			kimage->segment[i].mem + kimage->segment[i].memsz,
 48			(unsigned long)kimage->segment[i].memsz,
 49			(unsigned long)kimage->segment[i].memsz /  PAGE_SIZE);
 50	}
 51}
 52
 53#ifdef CONFIG_UHI_BOOT
 54
 55static int uhi_machine_kexec_prepare(struct kimage *kimage)
 56{
 57	int i;
 58
 59	/*
 60	 * In case DTB file is not passed to the new kernel, a flat device
 61	 * tree will be created by kexec tool. It holds modified command
 62	 * line for the new kernel.
 63	 */
 64	for (i = 0; i < kimage->nr_segments; i++) {
 65		struct fdt_header fdt;
 66
 67		if (kimage->segment[i].memsz <= sizeof(fdt))
 68			continue;
 69
 70		if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
 71			continue;
 72
 73		if (fdt_check_header(&fdt))
 74			continue;
 75
 76		kexec_args[0] = -2;
 77		kexec_args[1] = (unsigned long)
 78			phys_to_virt((unsigned long)kimage->segment[i].mem);
 79		break;
 80	}
 81
 82	return 0;
 83}
 84
 85int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;
 86
 87#else
 88
 89int (*_machine_kexec_prepare)(struct kimage *) = NULL;
 90
 91#endif /* CONFIG_UHI_BOOT */
 92
 93int
 94machine_kexec_prepare(struct kimage *kimage)
 95{
 96#ifdef CONFIG_SMP
 97	if (!kexec_nonboot_cpu_func())
 98		return -EINVAL;
 99#endif
100
101	kexec_image_info(kimage);
102
103	if (_machine_kexec_prepare)
104		return _machine_kexec_prepare(kimage);
105
106	return 0;
107}
108
109void
110machine_kexec_cleanup(struct kimage *kimage)
111{
112}
113
114#ifdef CONFIG_SMP
115static void kexec_shutdown_secondary(void *param)
116{
117	int cpu = smp_processor_id();
118
119	if (!cpu_online(cpu))
120		return;
121
122	/* We won't be sent IPIs any more. */
123	set_cpu_online(cpu, false);
124
125	local_irq_disable();
126	while (!atomic_read(&kexec_ready_to_reboot))
127		cpu_relax();
128
129	kexec_reboot();
130
131	/* NOTREACHED */
132}
133#endif
134
135void
136machine_shutdown(void)
137{
138	if (_machine_kexec_shutdown)
139		_machine_kexec_shutdown();
140
141#ifdef CONFIG_SMP
142	smp_call_function(kexec_shutdown_secondary, NULL, 0);
143
144	while (num_online_cpus() > 1) {
145		cpu_relax();
146		mdelay(1);
147	}
148#endif
149}
150
151void
152machine_crash_shutdown(struct pt_regs *regs)
153{
154	if (_machine_crash_shutdown)
155		_machine_crash_shutdown(regs);
156	else
157		default_machine_crash_shutdown(regs);
158}
159
160#ifdef CONFIG_SMP
161void kexec_nonboot_cpu_jump(void)
162{
163	local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
164				 reboot_code_buffer + relocate_new_kernel_size);
165
166	relocated_kexec_smp_wait(NULL);
167}
168#endif
169
170void kexec_reboot(void)
171{
172	void (*do_kexec)(void) __noreturn;
173
174	/*
175	 * We know we were online, and there will be no incoming IPIs at
176	 * this point. Mark online again before rebooting so that the crash
177	 * analysis tool will see us correctly.
178	 */
179	set_cpu_online(smp_processor_id(), true);
180
181	/* Ensure remote CPUs observe that we're online before rebooting. */
182	smp_mb__after_atomic();
183
184#ifdef CONFIG_SMP
185	if (smp_processor_id() > 0) {
186		/*
187		 * Instead of cpu_relax() or wait, this is needed for kexec
188		 * smp reboot. Kdump usually doesn't require an smp new
189		 * kernel, but kexec may do.
190		 */
191		kexec_nonboot_cpu();
192
193		/* NOTREACHED */
194	}
195#endif
196
197	/*
198	 * Make sure we get correct instructions written by the
199	 * machine_kexec() CPU.
200	 */
201	local_flush_icache_range(reboot_code_buffer,
202				 reboot_code_buffer + relocate_new_kernel_size);
203
204	do_kexec = (void *)reboot_code_buffer;
205	do_kexec();
206}
207
208void
209machine_kexec(struct kimage *image)
210{
211	unsigned long entry;
212	unsigned long *ptr;
213
214	reboot_code_buffer =
215	  (unsigned long)page_address(image->control_code_page);
216
217	kexec_start_address =
218		(unsigned long) phys_to_virt(image->start);
219
220	if (image->type == KEXEC_TYPE_DEFAULT) {
221		kexec_indirection_page =
222			(unsigned long) phys_to_virt(image->head & PAGE_MASK);
223	} else {
224		kexec_indirection_page = (unsigned long)&image->head;
225	}
226
227	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
228	       relocate_new_kernel_size);
229
230	/*
231	 * The generic kexec code builds a page list with physical
232	 * addresses. they are directly accessible through KSEG0 (or
233	 * CKSEG0 or XPHYS if on 64bit system), hence the
234	 * phys_to_virt() call.
235	 */
236	for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
237	     ptr = (entry & IND_INDIRECTION) ?
238	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
239		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
240		    *ptr & IND_DESTINATION)
241			*ptr = (unsigned long) phys_to_virt(*ptr);
242	}
243
244	/* Mark offline BEFORE disabling local irq. */
245	set_cpu_online(smp_processor_id(), false);
246
247	/*
248	 * we do not want to be bothered.
249	 */
250	local_irq_disable();
251
252	printk("Will call new kernel at %08lx\n", image->start);
253	printk("Bye ...\n");
254	/* Make reboot code buffer available to the boot CPU. */
255	__flush_cache_all();
256#ifdef CONFIG_SMP
257	/* All secondary cpus now may jump to kexec_wait cycle */
258	relocated_kexec_smp_wait = reboot_code_buffer +
259		(void *)(kexec_smp_wait - relocate_new_kernel);
260	smp_wmb();
261	atomic_set(&kexec_ready_to_reboot, 1);
262#endif
263	kexec_reboot();
264}