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 | |
23 | extern void relocate_new_kernel(void); |
24 | extern const unsigned int relocate_new_kernel_size; |
25 | |
26 | static 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 | |
33 | int machine_kexec_prepare(struct kimage *image) |
34 | { |
35 | struct kexec_segment *current_segment; |
36 | __be32 ; |
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(base: idmap_to_phys(current_segment->mem), |
59 | size: 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 | |
72 | void machine_kexec_cleanup(struct kimage *image) |
73 | { |
74 | } |
75 | |
76 | static void machine_crash_nonpanic_core(void *unused) |
77 | { |
78 | struct pt_regs regs; |
79 | |
80 | local_fiq_disable(); |
81 | |
82 | crash_setup_regs(newregs: ®s, oldregs: 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(regs: ®s, smp_processor_id()); |
86 | flush_cache_all(); |
87 | |
88 | set_cpu_online(smp_processor_id(), online: false); |
89 | atomic_dec(v: &waiting_for_crash_ipi); |
90 | |
91 | while (1) { |
92 | cpu_relax(); |
93 | wfe(); |
94 | } |
95 | } |
96 | |
97 | static DEFINE_PER_CPU(call_single_data_t, cpu_stop_csd) = |
98 | CSD_INIT(machine_crash_nonpanic_core, NULL); |
99 | |
100 | void 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(v: &waiting_for_crash_ipi, i: 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(v: &waiting_for_crash_ipi) > 0) && msecs) { |
121 | mdelay(1); |
122 | msecs--; |
123 | } |
124 | if (atomic_read(v: &waiting_for_crash_ipi) > 0) |
125 | pr_warn("Non-crashing CPUs did not react to IPI\n" ); |
126 | |
127 | cpus_stopped = 1; |
128 | } |
129 | |
130 | static 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(d: &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(d: &desc->irq_data)) |
149 | chip->irq_disable(&desc->irq_data); |
150 | } |
151 | } |
152 | |
153 | void 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 | |
164 | void 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 | } |
201 | |
202 | void arch_crash_save_vmcoreinfo(void) |
203 | { |
204 | #ifdef CONFIG_ARM_LPAE |
205 | VMCOREINFO_CONFIG(ARM_LPAE); |
206 | #endif |
207 | } |
208 | |