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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 <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
22extern void relocate_new_kernel(void);
23extern const unsigned int relocate_new_kernel_size;
24
25extern unsigned long kexec_start_address;
26extern unsigned long kexec_indirection_page;
27extern unsigned long kexec_mach_type;
28extern unsigned long kexec_boot_atags;
29
30static atomic_t waiting_for_crash_ipi;
31
32/*
33 * Provide a dummy crash_notes definition while crash dump arrives to arm.
34 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
35 */
36
37int machine_kexec_prepare(struct kimage *image)
38{
39 struct kexec_segment *current_segment;
40 __be32 header;
41 int i, err;
42
43 /*
44 * Validate that if the current HW supports SMP, then the SW supports
45 * and implements CPU hotplug for the current HW. If not, we won't be
46 * able to kexec reliably, so fail the prepare operation.
47 */
48 if (num_possible_cpus() > 1 && !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(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 (be32_to_cpu(header) == OF_DT_HEADER)
67 kexec_boot_atags = 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, NULL);
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 while (1)
89 cpu_relax();
90}
91
92static void machine_kexec_mask_interrupts(void)
93{
94 unsigned int i;
95 struct irq_desc *desc;
96
97 for_each_irq_desc(i, desc) {
98 struct irq_chip *chip;
99
100 chip = irq_desc_get_chip(desc);
101 if (!chip)
102 continue;
103
104 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
105 chip->irq_eoi(&desc->irq_data);
106
107 if (chip->irq_mask)
108 chip->irq_mask(&desc->irq_data);
109
110 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
111 chip->irq_disable(&desc->irq_data);
112 }
113}
114
115void machine_crash_shutdown(struct pt_regs *regs)
116{
117 unsigned long msecs;
118
119 local_irq_disable();
120
121 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
122 smp_call_function(machine_crash_nonpanic_core, NULL, false);
123 msecs = 1000; /* Wait at most a second for the other cpus to stop */
124 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
125 mdelay(1);
126 msecs--;
127 }
128 if (atomic_read(&waiting_for_crash_ipi) > 0)
129 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
130
131 crash_save_cpu(regs, smp_processor_id());
132 machine_kexec_mask_interrupts();
133
134 printk(KERN_INFO "Loading crashdump kernel...\n");
135}
136
137/*
138 * Function pointer to optional machine-specific reinitialization
139 */
140void (*kexec_reinit)(void);
141
142void machine_kexec(struct kimage *image)
143{
144 unsigned long page_list;
145 unsigned long reboot_code_buffer_phys;
146 unsigned long reboot_entry = (unsigned long)relocate_new_kernel;
147 unsigned long reboot_entry_phys;
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 /* we need both effective and real address here */
161 reboot_code_buffer_phys =
162 page_to_pfn(image->control_code_page) << PAGE_SHIFT;
163 reboot_code_buffer = page_address(image->control_code_page);
164
165 /* Prepare parameters for reboot_code_buffer*/
166 kexec_start_address = image->start;
167 kexec_indirection_page = page_list;
168 kexec_mach_type = machine_arch_type;
169 if (!kexec_boot_atags)
170 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
171
172
173 /* copy our kernel relocation code to the control code page */
174 reboot_entry = fncpy(reboot_code_buffer,
175 reboot_entry,
176 relocate_new_kernel_size);
177 reboot_entry_phys = (unsigned long)reboot_entry +
178 (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer);
179
180 printk(KERN_INFO "Bye!\n");
181
182 if (kexec_reinit)
183 kexec_reinit();
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}
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}