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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/fncpy.h>
17#include <asm/mach-types.h>
18#include <asm/smp_plat.h>
19#include <asm/system_misc.h>
20#include <asm/set_memory.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 image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
44 + KEXEC_ARM_ATAGS_OFFSET;
45
46 /*
47 * Validate that if the current HW supports SMP, then the SW supports
48 * and implements CPU hotplug for the current HW. If not, we won't be
49 * able to kexec reliably, so fail the prepare operation.
50 */
51 if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
52 !platform_can_cpu_hotplug())
53 return -EINVAL;
54
55 /*
56 * No segment at default ATAGs address. try to locate
57 * a dtb using magic.
58 */
59 for (i = 0; i < image->nr_segments; i++) {
60 current_segment = &image->segment[i];
61
62 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
63 current_segment->memsz))
64 return -EINVAL;
65
66 err = get_user(header, (__be32*)current_segment->buf);
67 if (err)
68 return err;
69
70 if (header == cpu_to_be32(OF_DT_HEADER))
71 image->arch.kernel_r2 = current_segment->mem;
72 }
73 return 0;
74}
75
76void machine_kexec_cleanup(struct kimage *image)
77{
78}
79
80void machine_crash_nonpanic_core(void *unused)
81{
82 struct pt_regs regs;
83
84 crash_setup_regs(®s, get_irq_regs());
85 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
86 smp_processor_id());
87 crash_save_cpu(®s, smp_processor_id());
88 flush_cache_all();
89
90 set_cpu_online(smp_processor_id(), false);
91 atomic_dec(&waiting_for_crash_ipi);
92
93 while (1) {
94 cpu_relax();
95 wfe();
96 }
97}
98
99void crash_smp_send_stop(void)
100{
101 static int cpus_stopped;
102 unsigned long msecs;
103
104 if (cpus_stopped)
105 return;
106
107 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
108 smp_call_function(machine_crash_nonpanic_core, NULL, false);
109 msecs = 1000; /* Wait at most a second for the other cpus to stop */
110 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
111 mdelay(1);
112 msecs--;
113 }
114 if (atomic_read(&waiting_for_crash_ipi) > 0)
115 pr_warn("Non-crashing CPUs did not react to IPI\n");
116
117 cpus_stopped = 1;
118}
119
120static void machine_kexec_mask_interrupts(void)
121{
122 unsigned int i;
123 struct irq_desc *desc;
124
125 for_each_irq_desc(i, desc) {
126 struct irq_chip *chip;
127
128 chip = irq_desc_get_chip(desc);
129 if (!chip)
130 continue;
131
132 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
133 chip->irq_eoi(&desc->irq_data);
134
135 if (chip->irq_mask)
136 chip->irq_mask(&desc->irq_data);
137
138 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
139 chip->irq_disable(&desc->irq_data);
140 }
141}
142
143void machine_crash_shutdown(struct pt_regs *regs)
144{
145 local_irq_disable();
146 crash_smp_send_stop();
147
148 crash_save_cpu(regs, smp_processor_id());
149 machine_kexec_mask_interrupts();
150
151 pr_info("Loading crashdump kernel...\n");
152}
153
154/*
155 * Function pointer to optional machine-specific reinitialization
156 */
157void (*kexec_reinit)(void);
158
159void machine_kexec(struct kimage *image)
160{
161 unsigned long page_list, reboot_entry_phys;
162 void (*reboot_entry)(void);
163 void *reboot_code_buffer;
164
165 /*
166 * This can only happen if machine_shutdown() failed to disable some
167 * CPU, and that can only happen if the checks in
168 * machine_kexec_prepare() were not correct. If this fails, we can't
169 * reliably kexec anyway, so BUG_ON is appropriate.
170 */
171 BUG_ON(num_online_cpus() > 1);
172
173 page_list = image->head & PAGE_MASK;
174
175 reboot_code_buffer = page_address(image->control_code_page);
176
177 /* Prepare parameters for reboot_code_buffer*/
178 set_kernel_text_rw();
179 kexec_start_address = image->start;
180 kexec_indirection_page = page_list;
181 kexec_mach_type = machine_arch_type;
182 kexec_boot_atags = image->arch.kernel_r2;
183
184 /* copy our kernel relocation code to the control code page */
185 reboot_entry = fncpy(reboot_code_buffer,
186 &relocate_new_kernel,
187 relocate_new_kernel_size);
188
189 /* get the identity mapping physical address for the reboot code */
190 reboot_entry_phys = virt_to_idmap(reboot_entry);
191
192 pr_info("Bye!\n");
193
194 if (kexec_reinit)
195 kexec_reinit();
196
197 soft_restart(reboot_entry_phys);
198}
199
200void arch_crash_save_vmcoreinfo(void)
201{
202#ifdef CONFIG_ARM_LPAE
203 VMCOREINFO_CONFIG(ARM_LPAE);
204#endif
205}
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 <asm/pgtable.h>
14#include <linux/of_fdt.h>
15#include <asm/pgalloc.h>
16#include <asm/mmu_context.h>
17#include <asm/cacheflush.h>
18#include <asm/fncpy.h>
19#include <asm/mach-types.h>
20#include <asm/smp_plat.h>
21#include <asm/system_misc.h>
22#include <asm/set_memory.h>
23
24extern void relocate_new_kernel(void);
25extern const unsigned int relocate_new_kernel_size;
26
27extern unsigned long kexec_start_address;
28extern unsigned long kexec_indirection_page;
29extern unsigned long kexec_mach_type;
30extern unsigned long kexec_boot_atags;
31
32static atomic_t waiting_for_crash_ipi;
33
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
39int machine_kexec_prepare(struct kimage *image)
40{
41 struct kexec_segment *current_segment;
42 __be32 header;
43 int i, err;
44
45 image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
46 + KEXEC_ARM_ATAGS_OFFSET;
47
48 /*
49 * Validate that if the current HW supports SMP, then the SW supports
50 * and implements CPU hotplug for the current HW. If not, we won't be
51 * able to kexec reliably, so fail the prepare operation.
52 */
53 if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
54 !platform_can_cpu_hotplug())
55 return -EINVAL;
56
57 /*
58 * No segment at default ATAGs address. try to locate
59 * a dtb using magic.
60 */
61 for (i = 0; i < image->nr_segments; i++) {
62 current_segment = &image->segment[i];
63
64 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
65 current_segment->memsz))
66 return -EINVAL;
67
68 err = get_user(header, (__be32*)current_segment->buf);
69 if (err)
70 return err;
71
72 if (header == cpu_to_be32(OF_DT_HEADER))
73 image->arch.kernel_r2 = current_segment->mem;
74 }
75 return 0;
76}
77
78void machine_kexec_cleanup(struct kimage *image)
79{
80}
81
82void machine_crash_nonpanic_core(void *unused)
83{
84 struct pt_regs regs;
85
86 crash_setup_regs(®s, get_irq_regs());
87 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
88 smp_processor_id());
89 crash_save_cpu(®s, smp_processor_id());
90 flush_cache_all();
91
92 set_cpu_online(smp_processor_id(), false);
93 atomic_dec(&waiting_for_crash_ipi);
94 while (1)
95 cpu_relax();
96}
97
98void crash_smp_send_stop(void)
99{
100 static int cpus_stopped;
101 unsigned long msecs;
102
103 if (cpus_stopped)
104 return;
105
106 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
107 smp_call_function(machine_crash_nonpanic_core, NULL, false);
108 msecs = 1000; /* Wait at most a second for the other cpus to stop */
109 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
110 mdelay(1);
111 msecs--;
112 }
113 if (atomic_read(&waiting_for_crash_ipi) > 0)
114 pr_warn("Non-crashing CPUs did not react to IPI\n");
115
116 cpus_stopped = 1;
117}
118
119static void machine_kexec_mask_interrupts(void)
120{
121 unsigned int i;
122 struct irq_desc *desc;
123
124 for_each_irq_desc(i, desc) {
125 struct irq_chip *chip;
126
127 chip = irq_desc_get_chip(desc);
128 if (!chip)
129 continue;
130
131 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
132 chip->irq_eoi(&desc->irq_data);
133
134 if (chip->irq_mask)
135 chip->irq_mask(&desc->irq_data);
136
137 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
138 chip->irq_disable(&desc->irq_data);
139 }
140}
141
142void machine_crash_shutdown(struct pt_regs *regs)
143{
144 local_irq_disable();
145 crash_smp_send_stop();
146
147 crash_save_cpu(regs, smp_processor_id());
148 machine_kexec_mask_interrupts();
149
150 pr_info("Loading crashdump kernel...\n");
151}
152
153/*
154 * Function pointer to optional machine-specific reinitialization
155 */
156void (*kexec_reinit)(void);
157
158void machine_kexec(struct kimage *image)
159{
160 unsigned long page_list, reboot_entry_phys;
161 void (*reboot_entry)(void);
162 void *reboot_code_buffer;
163
164 /*
165 * This can only happen if machine_shutdown() failed to disable some
166 * CPU, and that can only happen if the checks in
167 * machine_kexec_prepare() were not correct. If this fails, we can't
168 * reliably kexec anyway, so BUG_ON is appropriate.
169 */
170 BUG_ON(num_online_cpus() > 1);
171
172 page_list = image->head & PAGE_MASK;
173
174 reboot_code_buffer = page_address(image->control_code_page);
175
176 /* Prepare parameters for reboot_code_buffer*/
177 set_kernel_text_rw();
178 kexec_start_address = image->start;
179 kexec_indirection_page = page_list;
180 kexec_mach_type = machine_arch_type;
181 kexec_boot_atags = image->arch.kernel_r2;
182
183 /* copy our kernel relocation code to the control code page */
184 reboot_entry = fncpy(reboot_code_buffer,
185 &relocate_new_kernel,
186 relocate_new_kernel_size);
187
188 /* get the identity mapping physical address for the reboot code */
189 reboot_entry_phys = virt_to_idmap(reboot_entry);
190
191 pr_info("Bye!\n");
192
193 if (kexec_reinit)
194 kexec_reinit();
195
196 soft_restart(reboot_entry_phys);
197}
198
199void arch_crash_save_vmcoreinfo(void)
200{
201#ifdef CONFIG_ARM_LPAE
202 VMCOREINFO_CONFIG(ARM_LPAE);
203#endif
204}