diff options
Diffstat (limited to 'arch/arm/kernel/machine_kexec.c')
| -rw-r--r-- | arch/arm/kernel/machine_kexec.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c new file mode 100644 index 000000000..734adeb42 --- /dev/null +++ b/arch/arm/kernel/machine_kexec.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * machine_kexec.c - handle transition of Linux booting another kernel + */ + +#include <linux/mm.h> +#include <linux/kexec.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/memblock.h> +#include <asm/pgtable.h> +#include <linux/of_fdt.h> +#include <asm/pgalloc.h> +#include <asm/mmu_context.h> +#include <asm/cacheflush.h> +#include <asm/kexec-internal.h> +#include <asm/fncpy.h> +#include <asm/mach-types.h> +#include <asm/smp_plat.h> +#include <asm/system_misc.h> +#include <asm/set_memory.h> + +extern void relocate_new_kernel(void); +extern const unsigned int relocate_new_kernel_size; + +static atomic_t waiting_for_crash_ipi; + +/* + * Provide a dummy crash_notes definition while crash dump arrives to arm. + * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. + */ + +int machine_kexec_prepare(struct kimage *image) +{ + struct kexec_segment *current_segment; + __be32 header; + int i, err; + + image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET + + KEXEC_ARM_ATAGS_OFFSET; + + /* + * Validate that if the current HW supports SMP, then the SW supports + * and implements CPU hotplug for the current HW. If not, we won't be + * able to kexec reliably, so fail the prepare operation. + */ + if (num_possible_cpus() > 1 && platform_can_secondary_boot() && + !platform_can_cpu_hotplug()) + return -EINVAL; + + /* + * No segment at default ATAGs address. try to locate + * a dtb using magic. + */ + for (i = 0; i < image->nr_segments; i++) { + current_segment = &image->segment[i]; + + if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem), + current_segment->memsz)) + return -EINVAL; + + err = get_user(header, (__be32*)current_segment->buf); + if (err) + return err; + + if (header == cpu_to_be32(OF_DT_HEADER)) + image->arch.kernel_r2 = current_segment->mem; + } + return 0; +} + +void machine_kexec_cleanup(struct kimage *image) +{ +} + +void machine_crash_nonpanic_core(void *unused) +{ + struct pt_regs regs; + + crash_setup_regs(®s, get_irq_regs()); + printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n", + smp_processor_id()); + crash_save_cpu(®s, smp_processor_id()); + flush_cache_all(); + + set_cpu_online(smp_processor_id(), false); + atomic_dec(&waiting_for_crash_ipi); + + while (1) { + cpu_relax(); + wfe(); + } +} + +void crash_smp_send_stop(void) +{ + static int cpus_stopped; + unsigned long msecs; + + if (cpus_stopped) + return; + + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + smp_call_function(machine_crash_nonpanic_core, NULL, false); + msecs = 1000; /* Wait at most a second for the other cpus to stop */ + while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { + mdelay(1); + msecs--; + } + if (atomic_read(&waiting_for_crash_ipi) > 0) + pr_warn("Non-crashing CPUs did not react to IPI\n"); + + cpus_stopped = 1; +} + +static void machine_kexec_mask_interrupts(void) +{ + unsigned int i; + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ + local_irq_disable(); + crash_smp_send_stop(); + + crash_save_cpu(regs, smp_processor_id()); + machine_kexec_mask_interrupts(); + + pr_info("Loading crashdump kernel...\n"); +} + +/* + * Function pointer to optional machine-specific reinitialization + */ +void (*kexec_reinit)(void); + +void machine_kexec(struct kimage *image) +{ + unsigned long page_list, reboot_entry_phys; + struct kexec_relocate_data *data; + void (*reboot_entry)(void); + void *reboot_code_buffer; + + /* + * This can only happen if machine_shutdown() failed to disable some + * CPU, and that can only happen if the checks in + * machine_kexec_prepare() were not correct. If this fails, we can't + * reliably kexec anyway, so BUG_ON is appropriate. + */ + BUG_ON(num_online_cpus() > 1); + + page_list = image->head & PAGE_MASK; + + reboot_code_buffer = page_address(image->control_code_page); + + /* copy our kernel relocation code to the control code page */ + reboot_entry = fncpy(reboot_code_buffer, + &relocate_new_kernel, + relocate_new_kernel_size); + + data = reboot_code_buffer + relocate_new_kernel_size; + data->kexec_start_address = image->start; + data->kexec_indirection_page = page_list; + data->kexec_mach_type = machine_arch_type; + data->kexec_r2 = image->arch.kernel_r2; + + /* get the identity mapping physical address for the reboot code */ + reboot_entry_phys = virt_to_idmap(reboot_entry); + + pr_info("Bye!\n"); + + if (kexec_reinit) + kexec_reinit(); + + soft_restart(reboot_entry_phys); +} + +void arch_crash_save_vmcoreinfo(void) +{ +#ifdef CONFIG_ARM_LPAE + VMCOREINFO_CONFIG(ARM_LPAE); +#endif +} |