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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/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
76static void machine_crash_nonpanic_core(void *unused)
77{
78 struct pt_regs regs;
79
80 local_fiq_disable();
81
82 crash_setup_regs(®s, get_irq_regs());
83 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
84 smp_processor_id());
85 crash_save_cpu(®s, smp_processor_id());
86 flush_cache_all();
87
88 set_cpu_online(smp_processor_id(), false);
89 atomic_dec(&waiting_for_crash_ipi);
90
91 while (1) {
92 cpu_relax();
93 wfe();
94 }
95}
96
97static DEFINE_PER_CPU(call_single_data_t, cpu_stop_csd) =
98 CSD_INIT(machine_crash_nonpanic_core, NULL);
99
100void crash_smp_send_stop(void)
101{
102 static int cpus_stopped;
103 unsigned long msecs;
104 call_single_data_t *csd;
105 int cpu, this_cpu = raw_smp_processor_id();
106
107 if (cpus_stopped)
108 return;
109
110 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
111 for_each_online_cpu(cpu) {
112 if (cpu == this_cpu)
113 continue;
114
115 csd = &per_cpu(cpu_stop_csd, cpu);
116 smp_call_function_single_async(cpu, csd);
117 }
118
119 msecs = 1000; /* Wait at most a second for the other cpus to stop */
120 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
121 mdelay(1);
122 msecs--;
123 }
124 if (atomic_read(&waiting_for_crash_ipi) > 0)
125 pr_warn("Non-crashing CPUs did not react to IPI\n");
126
127 cpus_stopped = 1;
128}
129
130static void machine_kexec_mask_interrupts(void)
131{
132 unsigned int i;
133 struct irq_desc *desc;
134
135 for_each_irq_desc(i, desc) {
136 struct irq_chip *chip;
137
138 chip = irq_desc_get_chip(desc);
139 if (!chip)
140 continue;
141
142 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
143 chip->irq_eoi(&desc->irq_data);
144
145 if (chip->irq_mask)
146 chip->irq_mask(&desc->irq_data);
147
148 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
149 chip->irq_disable(&desc->irq_data);
150 }
151}
152
153void machine_crash_shutdown(struct pt_regs *regs)
154{
155 local_irq_disable();
156 crash_smp_send_stop();
157
158 crash_save_cpu(regs, smp_processor_id());
159 machine_kexec_mask_interrupts();
160
161 pr_info("Loading crashdump kernel...\n");
162}
163
164void machine_kexec(struct kimage *image)
165{
166 unsigned long page_list, reboot_entry_phys;
167 struct kexec_relocate_data *data;
168 void (*reboot_entry)(void);
169 void *reboot_code_buffer;
170
171 /*
172 * This can only happen if machine_shutdown() failed to disable some
173 * CPU, and that can only happen if the checks in
174 * machine_kexec_prepare() were not correct. If this fails, we can't
175 * reliably kexec anyway, so BUG_ON is appropriate.
176 */
177 BUG_ON(num_online_cpus() > 1);
178
179 page_list = image->head & PAGE_MASK;
180
181 reboot_code_buffer = page_address(image->control_code_page);
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 data = reboot_code_buffer + relocate_new_kernel_size;
189 data->kexec_start_address = image->start;
190 data->kexec_indirection_page = page_list;
191 data->kexec_mach_type = machine_arch_type;
192 data->kexec_r2 = image->arch.kernel_r2;
193
194 /* get the identity mapping physical address for the reboot code */
195 reboot_entry_phys = virt_to_idmap(reboot_entry);
196
197 pr_info("Bye!\n");
198
199 soft_restart(reboot_entry_phys);
200}
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
95 while (1) {
96 cpu_relax();
97 wfe();
98 }
99}
100
101void crash_smp_send_stop(void)
102{
103 static int cpus_stopped;
104 unsigned long msecs;
105
106 if (cpus_stopped)
107 return;
108
109 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
110 smp_call_function(machine_crash_nonpanic_core, NULL, false);
111 msecs = 1000; /* Wait at most a second for the other cpus to stop */
112 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
113 mdelay(1);
114 msecs--;
115 }
116 if (atomic_read(&waiting_for_crash_ipi) > 0)
117 pr_warn("Non-crashing CPUs did not react to IPI\n");
118
119 cpus_stopped = 1;
120}
121
122static void machine_kexec_mask_interrupts(void)
123{
124 unsigned int i;
125 struct irq_desc *desc;
126
127 for_each_irq_desc(i, desc) {
128 struct irq_chip *chip;
129
130 chip = irq_desc_get_chip(desc);
131 if (!chip)
132 continue;
133
134 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
135 chip->irq_eoi(&desc->irq_data);
136
137 if (chip->irq_mask)
138 chip->irq_mask(&desc->irq_data);
139
140 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
141 chip->irq_disable(&desc->irq_data);
142 }
143}
144
145void machine_crash_shutdown(struct pt_regs *regs)
146{
147 local_irq_disable();
148 crash_smp_send_stop();
149
150 crash_save_cpu(regs, smp_processor_id());
151 machine_kexec_mask_interrupts();
152
153 pr_info("Loading crashdump kernel...\n");
154}
155
156/*
157 * Function pointer to optional machine-specific reinitialization
158 */
159void (*kexec_reinit)(void);
160
161void machine_kexec(struct kimage *image)
162{
163 unsigned long page_list, reboot_entry_phys;
164 void (*reboot_entry)(void);
165 void *reboot_code_buffer;
166
167 /*
168 * This can only happen if machine_shutdown() failed to disable some
169 * CPU, and that can only happen if the checks in
170 * machine_kexec_prepare() were not correct. If this fails, we can't
171 * reliably kexec anyway, so BUG_ON is appropriate.
172 */
173 BUG_ON(num_online_cpus() > 1);
174
175 page_list = image->head & PAGE_MASK;
176
177 reboot_code_buffer = page_address(image->control_code_page);
178
179 /* Prepare parameters for reboot_code_buffer*/
180 set_kernel_text_rw();
181 kexec_start_address = image->start;
182 kexec_indirection_page = page_list;
183 kexec_mach_type = machine_arch_type;
184 kexec_boot_atags = image->arch.kernel_r2;
185
186 /* copy our kernel relocation code to the control code page */
187 reboot_entry = fncpy(reboot_code_buffer,
188 &relocate_new_kernel,
189 relocate_new_kernel_size);
190
191 /* get the identity mapping physical address for the reboot code */
192 reboot_entry_phys = virt_to_idmap(reboot_entry);
193
194 pr_info("Bye!\n");
195
196 if (kexec_reinit)
197 kexec_reinit();
198
199 soft_restart(reboot_entry_phys);
200}
201
202void arch_crash_save_vmcoreinfo(void)
203{
204#ifdef CONFIG_ARM_LPAE
205 VMCOREINFO_CONFIG(ARM_LPAE);
206#endif
207}