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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 <asm/pgtable.h>
12#include <asm/pgalloc.h>
13#include <asm/mmu_context.h>
14#include <asm/cacheflush.h>
15#include <asm/mach-types.h>
16#include <asm/system_misc.h>
17
18extern const unsigned char relocate_new_kernel[];
19extern const unsigned int relocate_new_kernel_size;
20
21extern unsigned long kexec_start_address;
22extern unsigned long kexec_indirection_page;
23extern unsigned long kexec_mach_type;
24extern unsigned long kexec_boot_atags;
25
26static atomic_t waiting_for_crash_ipi;
27
28/*
29 * Provide a dummy crash_notes definition while crash dump arrives to arm.
30 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
31 */
32
33int machine_kexec_prepare(struct kimage *image)
34{
35 return 0;
36}
37
38void machine_kexec_cleanup(struct kimage *image)
39{
40}
41
42void machine_crash_nonpanic_core(void *unused)
43{
44 struct pt_regs regs;
45
46 crash_setup_regs(®s, NULL);
47 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
48 smp_processor_id());
49 crash_save_cpu(®s, smp_processor_id());
50 flush_cache_all();
51
52 atomic_dec(&waiting_for_crash_ipi);
53 while (1)
54 cpu_relax();
55}
56
57static void machine_kexec_mask_interrupts(void)
58{
59 unsigned int i;
60 struct irq_desc *desc;
61
62 for_each_irq_desc(i, desc) {
63 struct irq_chip *chip;
64
65 chip = irq_desc_get_chip(desc);
66 if (!chip)
67 continue;
68
69 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
70 chip->irq_eoi(&desc->irq_data);
71
72 if (chip->irq_mask)
73 chip->irq_mask(&desc->irq_data);
74
75 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
76 chip->irq_disable(&desc->irq_data);
77 }
78}
79
80void machine_crash_shutdown(struct pt_regs *regs)
81{
82 unsigned long msecs;
83
84 local_irq_disable();
85
86 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
87 smp_call_function(machine_crash_nonpanic_core, NULL, false);
88 msecs = 1000; /* Wait at most a second for the other cpus to stop */
89 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
90 mdelay(1);
91 msecs--;
92 }
93 if (atomic_read(&waiting_for_crash_ipi) > 0)
94 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
95
96 crash_save_cpu(regs, smp_processor_id());
97 machine_kexec_mask_interrupts();
98
99 printk(KERN_INFO "Loading crashdump kernel...\n");
100}
101
102/*
103 * Function pointer to optional machine-specific reinitialization
104 */
105void (*kexec_reinit)(void);
106
107void machine_kexec(struct kimage *image)
108{
109 unsigned long page_list;
110 unsigned long reboot_code_buffer_phys;
111 void *reboot_code_buffer;
112
113
114 page_list = image->head & PAGE_MASK;
115
116 /* we need both effective and real address here */
117 reboot_code_buffer_phys =
118 page_to_pfn(image->control_code_page) << PAGE_SHIFT;
119 reboot_code_buffer = page_address(image->control_code_page);
120
121 /* Prepare parameters for reboot_code_buffer*/
122 kexec_start_address = image->start;
123 kexec_indirection_page = page_list;
124 kexec_mach_type = machine_arch_type;
125 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
126
127 /* copy our kernel relocation code to the control code page */
128 memcpy(reboot_code_buffer,
129 relocate_new_kernel, relocate_new_kernel_size);
130
131
132 flush_icache_range((unsigned long) reboot_code_buffer,
133 (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
134 printk(KERN_INFO "Bye!\n");
135
136 if (kexec_reinit)
137 kexec_reinit();
138
139 soft_restart(reboot_code_buffer_phys);
140}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * machine_kexec.c - handle transition of Linux booting another kernel
4 */
5
6#include <linux/mm.h>
7#include <linux/kexec.h>
8#include <linux/delay.h>
9#include <linux/reboot.h>
10#include <linux/io.h>
11#include <linux/irq.h>
12#include <linux/memblock.h>
13#include <linux/of_fdt.h>
14#include <asm/mmu_context.h>
15#include <asm/cacheflush.h>
16#include <asm/kexec-internal.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
23extern void relocate_new_kernel(void);
24extern const unsigned int relocate_new_kernel_size;
25
26static atomic_t waiting_for_crash_ipi;
27
28/*
29 * Provide a dummy crash_notes definition while crash dump arrives to arm.
30 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
31 */
32
33int machine_kexec_prepare(struct kimage *image)
34{
35 struct kexec_segment *current_segment;
36 __be32 header;
37 int i, err;
38
39 image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
40 + KEXEC_ARM_ATAGS_OFFSET;
41
42 /*
43 * Validate that if the current HW supports SMP, then the SW supports
44 * and implements CPU hotplug for the current HW. If not, we won't be
45 * able to kexec reliably, so fail the prepare operation.
46 */
47 if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
48 !platform_can_cpu_hotplug())
49 return -EINVAL;
50
51 /*
52 * No segment at default ATAGs address. try to locate
53 * a dtb using magic.
54 */
55 for (i = 0; i < image->nr_segments; i++) {
56 current_segment = &image->segment[i];
57
58 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
59 current_segment->memsz))
60 return -EINVAL;
61
62 err = get_user(header, (__be32*)current_segment->buf);
63 if (err)
64 return err;
65
66 if (header == cpu_to_be32(OF_DT_HEADER))
67 image->arch.kernel_r2 = current_segment->mem;
68 }
69 return 0;
70}
71
72void machine_kexec_cleanup(struct kimage *image)
73{
74}
75
76void machine_crash_nonpanic_core(void *unused)
77{
78 struct pt_regs regs;
79
80 crash_setup_regs(®s, get_irq_regs());
81 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
82 smp_processor_id());
83 crash_save_cpu(®s, smp_processor_id());
84 flush_cache_all();
85
86 set_cpu_online(smp_processor_id(), false);
87 atomic_dec(&waiting_for_crash_ipi);
88
89 while (1) {
90 cpu_relax();
91 wfe();
92 }
93}
94
95void crash_smp_send_stop(void)
96{
97 static int cpus_stopped;
98 unsigned long msecs;
99
100 if (cpus_stopped)
101 return;
102
103 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
104 smp_call_function(machine_crash_nonpanic_core, NULL, false);
105 msecs = 1000; /* Wait at most a second for the other cpus to stop */
106 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
107 mdelay(1);
108 msecs--;
109 }
110 if (atomic_read(&waiting_for_crash_ipi) > 0)
111 pr_warn("Non-crashing CPUs did not react to IPI\n");
112
113 cpus_stopped = 1;
114}
115
116static void machine_kexec_mask_interrupts(void)
117{
118 unsigned int i;
119 struct irq_desc *desc;
120
121 for_each_irq_desc(i, desc) {
122 struct irq_chip *chip;
123
124 chip = irq_desc_get_chip(desc);
125 if (!chip)
126 continue;
127
128 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
129 chip->irq_eoi(&desc->irq_data);
130
131 if (chip->irq_mask)
132 chip->irq_mask(&desc->irq_data);
133
134 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
135 chip->irq_disable(&desc->irq_data);
136 }
137}
138
139void machine_crash_shutdown(struct pt_regs *regs)
140{
141 local_irq_disable();
142 crash_smp_send_stop();
143
144 crash_save_cpu(regs, smp_processor_id());
145 machine_kexec_mask_interrupts();
146
147 pr_info("Loading crashdump kernel...\n");
148}
149
150void machine_kexec(struct kimage *image)
151{
152 unsigned long page_list, reboot_entry_phys;
153 struct kexec_relocate_data *data;
154 void (*reboot_entry)(void);
155 void *reboot_code_buffer;
156
157 /*
158 * This can only happen if machine_shutdown() failed to disable some
159 * CPU, and that can only happen if the checks in
160 * machine_kexec_prepare() were not correct. If this fails, we can't
161 * reliably kexec anyway, so BUG_ON is appropriate.
162 */
163 BUG_ON(num_online_cpus() > 1);
164
165 page_list = image->head & PAGE_MASK;
166
167 reboot_code_buffer = page_address(image->control_code_page);
168
169 /* copy our kernel relocation code to the control code page */
170 reboot_entry = fncpy(reboot_code_buffer,
171 &relocate_new_kernel,
172 relocate_new_kernel_size);
173
174 data = reboot_code_buffer + relocate_new_kernel_size;
175 data->kexec_start_address = image->start;
176 data->kexec_indirection_page = page_list;
177 data->kexec_mach_type = machine_arch_type;
178 data->kexec_r2 = image->arch.kernel_r2;
179
180 /* get the identity mapping physical address for the reboot code */
181 reboot_entry_phys = virt_to_idmap(reboot_entry);
182
183 pr_info("Bye!\n");
184
185 soft_restart(reboot_entry_phys);
186}
187
188void arch_crash_save_vmcoreinfo(void)
189{
190#ifdef CONFIG_ARM_LPAE
191 VMCOREINFO_CONFIG(ARM_LPAE);
192#endif
193}