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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
32static unsigned long dt_mem;
33/*
34 * Provide a dummy crash_notes definition while crash dump arrives to arm.
35 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
36 */
37
38int machine_kexec_prepare(struct kimage *image)
39{
40 struct kexec_segment *current_segment;
41 __be32 header;
42 int i, err;
43
44 /*
45 * Validate that if the current HW supports SMP, then the SW supports
46 * and implements CPU hotplug for the current HW. If not, we won't be
47 * able to kexec reliably, so fail the prepare operation.
48 */
49 if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
50 !platform_can_cpu_hotplug())
51 return -EINVAL;
52
53 /*
54 * No segment at default ATAGs address. try to locate
55 * a dtb using magic.
56 */
57 for (i = 0; i < image->nr_segments; i++) {
58 current_segment = &image->segment[i];
59
60 if (!memblock_is_region_memory(current_segment->mem,
61 current_segment->memsz))
62 return -EINVAL;
63
64 err = get_user(header, (__be32*)current_segment->buf);
65 if (err)
66 return err;
67
68 if (be32_to_cpu(header) == OF_DT_HEADER)
69 dt_mem = current_segment->mem;
70 }
71 return 0;
72}
73
74void machine_kexec_cleanup(struct kimage *image)
75{
76}
77
78void machine_crash_nonpanic_core(void *unused)
79{
80 struct pt_regs regs;
81
82 crash_setup_regs(®s, NULL);
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 while (1)
91 cpu_relax();
92}
93
94static void machine_kexec_mask_interrupts(void)
95{
96 unsigned int i;
97 struct irq_desc *desc;
98
99 for_each_irq_desc(i, desc) {
100 struct irq_chip *chip;
101
102 chip = irq_desc_get_chip(desc);
103 if (!chip)
104 continue;
105
106 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
107 chip->irq_eoi(&desc->irq_data);
108
109 if (chip->irq_mask)
110 chip->irq_mask(&desc->irq_data);
111
112 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
113 chip->irq_disable(&desc->irq_data);
114 }
115}
116
117void machine_crash_shutdown(struct pt_regs *regs)
118{
119 unsigned long msecs;
120
121 local_irq_disable();
122
123 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
124 smp_call_function(machine_crash_nonpanic_core, NULL, false);
125 msecs = 1000; /* Wait at most a second for the other cpus to stop */
126 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
127 mdelay(1);
128 msecs--;
129 }
130 if (atomic_read(&waiting_for_crash_ipi) > 0)
131 pr_warn("Non-crashing CPUs did not react to IPI\n");
132
133 crash_save_cpu(regs, smp_processor_id());
134 machine_kexec_mask_interrupts();
135
136 pr_info("Loading crashdump kernel...\n");
137}
138
139/*
140 * Function pointer to optional machine-specific reinitialization
141 */
142void (*kexec_reinit)(void);
143
144void machine_kexec(struct kimage *image)
145{
146 unsigned long page_list, reboot_entry_phys;
147 void (*reboot_entry)(void);
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 reboot_code_buffer = page_address(image->control_code_page);
161
162 /* Prepare parameters for reboot_code_buffer*/
163 set_kernel_text_rw();
164 kexec_start_address = image->start;
165 kexec_indirection_page = page_list;
166 kexec_mach_type = machine_arch_type;
167 kexec_boot_atags = dt_mem ?: image->start - KEXEC_ARM_ZIMAGE_OFFSET
168 + KEXEC_ARM_ATAGS_OFFSET;
169
170 /* copy our kernel relocation code to the control code page */
171 reboot_entry = fncpy(reboot_code_buffer,
172 &relocate_new_kernel,
173 relocate_new_kernel_size);
174
175 /* get the identity mapping physical address for the reboot code */
176 reboot_entry_phys = virt_to_idmap(reboot_entry);
177
178 pr_info("Bye!\n");
179
180 if (kexec_reinit)
181 kexec_reinit();
182
183 soft_restart(reboot_entry_phys);
184}
185
186void arch_crash_save_vmcoreinfo(void)
187{
188#ifdef CONFIG_ARM_LPAE
189 VMCOREINFO_CONFIG(ARM_LPAE);
190#endif
191}
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}