Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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 | |
| 24 | extern void relocate_new_kernel(void); |
| 25 | extern const unsigned int relocate_new_kernel_size; |
| 26 | |
| 27 | extern unsigned long kexec_start_address; |
| 28 | extern unsigned long kexec_indirection_page; |
| 29 | extern unsigned long kexec_mach_type; |
| 30 | extern unsigned long kexec_boot_atags; |
| 31 | |
| 32 | static 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 | |
| 39 | int 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 | |
| 78 | void machine_kexec_cleanup(struct kimage *image) |
| 79 | { |
| 80 | } |
| 81 | |
| 82 | void 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 | |
| 98 | void 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 | |
| 119 | static 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 | |
| 142 | void 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 | */ |
| 156 | void (*kexec_reinit)(void); |
| 157 | |
| 158 | void 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 | |
| 199 | void arch_crash_save_vmcoreinfo(void) |
| 200 | { |
| 201 | #ifdef CONFIG_ARM_LPAE |
| 202 | VMCOREINFO_CONFIG(ARM_LPAE); |
| 203 | #endif |
| 204 | } |