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-rw-r--r--arch/loongarch/kernel/machine_kexec.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/machine_kexec.c
new file mode 100644
index 000000000..2dcb9e003
--- /dev/null
+++ b/arch/loongarch/kernel/machine_kexec.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * machine_kexec.c for kexec
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+#include <linux/compiler.h>
+#include <linux/cpu.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/libfdt.h>
+#include <linux/mm.h>
+#include <linux/of_fdt.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+
+#include <asm/bootinfo.h>
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+
+/* 0x100000 ~ 0x200000 is safe */
+#define KEXEC_CONTROL_CODE TO_CACHE(0x100000UL)
+#define KEXEC_CMDLINE_ADDR TO_CACHE(0x108000UL)
+
+static unsigned long reboot_code_buffer;
+static cpumask_t cpus_in_crash = CPU_MASK_NONE;
+
+#ifdef CONFIG_SMP
+static void (*relocated_kexec_smp_wait)(void *);
+atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
+#endif
+
+static unsigned long efi_boot;
+static unsigned long cmdline_ptr;
+static unsigned long systable_ptr;
+static unsigned long start_addr;
+static unsigned long first_ind_entry;
+
+static void kexec_image_info(const struct kimage *kimage)
+{
+ unsigned long i;
+
+ pr_debug("kexec kimage info:\n");
+ pr_debug("\ttype: %d\n", kimage->type);
+ pr_debug("\tstart: %lx\n", kimage->start);
+ pr_debug("\thead: %lx\n", kimage->head);
+ pr_debug("\tnr_segments: %lu\n", kimage->nr_segments);
+
+ for (i = 0; i < kimage->nr_segments; i++) {
+ pr_debug("\t segment[%lu]: %016lx - %016lx", i,
+ kimage->segment[i].mem,
+ kimage->segment[i].mem + kimage->segment[i].memsz);
+ pr_debug("\t\t0x%lx bytes, %lu pages\n",
+ (unsigned long)kimage->segment[i].memsz,
+ (unsigned long)kimage->segment[i].memsz / PAGE_SIZE);
+ }
+}
+
+int machine_kexec_prepare(struct kimage *kimage)
+{
+ int i;
+ char *bootloader = "kexec";
+ void *cmdline_ptr = (void *)KEXEC_CMDLINE_ADDR;
+
+ kexec_image_info(kimage);
+
+ kimage->arch.efi_boot = fw_arg0;
+ kimage->arch.systable_ptr = fw_arg2;
+
+ /* Find the command line */
+ for (i = 0; i < kimage->nr_segments; i++) {
+ if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(bootloader))) {
+ if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_SIZE))
+ kimage->arch.cmdline_ptr = (unsigned long)cmdline_ptr;
+ break;
+ }
+ }
+
+ if (!kimage->arch.cmdline_ptr) {
+ pr_err("Command line not included in the provided image\n");
+ return -EINVAL;
+ }
+
+ /* kexec/kdump need a safe page to save reboot_code_buffer */
+ kimage->control_code_page = virt_to_page((void *)KEXEC_CONTROL_CODE);
+
+ reboot_code_buffer = (unsigned long)page_address(kimage->control_code_page);
+ memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size);
+
+#ifdef CONFIG_SMP
+ /* All secondary cpus now may jump to kexec_smp_wait cycle */
+ relocated_kexec_smp_wait = reboot_code_buffer + (void *)(kexec_smp_wait - relocate_new_kernel);
+#endif
+
+ return 0;
+}
+
+void machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void kexec_reboot(void)
+{
+ do_kexec_t do_kexec = NULL;
+
+ /*
+ * We know we were online, and there will be no incoming IPIs at
+ * this point. Mark online again before rebooting so that the crash
+ * analysis tool will see us correctly.
+ */
+ set_cpu_online(smp_processor_id(), true);
+
+ /* Ensure remote CPUs observe that we're online before rebooting. */
+ smp_mb__after_atomic();
+
+ /*
+ * Make sure we get correct instructions written by the
+ * machine_kexec_prepare() CPU.
+ */
+ __asm__ __volatile__ ("\tibar 0\n"::);
+
+#ifdef CONFIG_SMP
+ /* All secondary cpus go to kexec_smp_wait */
+ if (smp_processor_id() > 0) {
+ relocated_kexec_smp_wait(NULL);
+ unreachable();
+ }
+#endif
+
+ do_kexec = (void *)reboot_code_buffer;
+ do_kexec(efi_boot, cmdline_ptr, systable_ptr, start_addr, first_ind_entry);
+
+ unreachable();
+}
+
+
+#ifdef CONFIG_SMP
+static void kexec_shutdown_secondary(void *regs)
+{
+ int cpu = smp_processor_id();
+
+ if (!cpu_online(cpu))
+ return;
+
+ /* We won't be sent IPIs any more. */
+ set_cpu_online(cpu, false);
+
+ local_irq_disable();
+ while (!atomic_read(&kexec_ready_to_reboot))
+ cpu_relax();
+
+ kexec_reboot();
+}
+
+static void crash_shutdown_secondary(void *passed_regs)
+{
+ int cpu = smp_processor_id();
+ struct pt_regs *regs = passed_regs;
+
+ /*
+ * If we are passed registers, use those. Otherwise get the
+ * regs from the last interrupt, which should be correct, as
+ * we are in an interrupt. But if the regs are not there,
+ * pull them from the top of the stack. They are probably
+ * wrong, but we need something to keep from crashing again.
+ */
+ if (!regs)
+ regs = get_irq_regs();
+ if (!regs)
+ regs = task_pt_regs(current);
+
+ if (!cpu_online(cpu))
+ return;
+
+ /* We won't be sent IPIs any more. */
+ set_cpu_online(cpu, false);
+
+ local_irq_disable();
+ if (!cpumask_test_cpu(cpu, &cpus_in_crash))
+ crash_save_cpu(regs, cpu);
+ cpumask_set_cpu(cpu, &cpus_in_crash);
+
+ while (!atomic_read(&kexec_ready_to_reboot))
+ cpu_relax();
+
+ kexec_reboot();
+}
+
+void crash_smp_send_stop(void)
+{
+ unsigned int ncpus;
+ unsigned long timeout;
+ static int cpus_stopped;
+
+ /*
+ * This function can be called twice in panic path, but obviously
+ * we should execute this only once.
+ */
+ if (cpus_stopped)
+ return;
+
+ cpus_stopped = 1;
+
+ /* Excluding the panic cpu */
+ ncpus = num_online_cpus() - 1;
+
+ smp_call_function(crash_shutdown_secondary, NULL, 0);
+ smp_wmb();
+
+ /*
+ * The crash CPU sends an IPI and wait for other CPUs to
+ * respond. Delay of at least 10 seconds.
+ */
+ timeout = MSEC_PER_SEC * 10;
+ pr_emerg("Sending IPI to other cpus...\n");
+ while ((cpumask_weight(&cpus_in_crash) < ncpus) && timeout--) {
+ mdelay(1);
+ cpu_relax();
+ }
+}
+#endif /* defined(CONFIG_SMP) */
+
+void machine_shutdown(void)
+{
+ int cpu;
+
+ /* All CPUs go to reboot_code_buffer */
+ for_each_possible_cpu(cpu)
+ if (!cpu_online(cpu))
+ cpu_device_up(get_cpu_device(cpu));
+
+#ifdef CONFIG_SMP
+ smp_call_function(kexec_shutdown_secondary, NULL, 0);
+#endif
+}
+
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+ int crashing_cpu;
+
+ local_irq_disable();
+
+ crashing_cpu = smp_processor_id();
+ crash_save_cpu(regs, crashing_cpu);
+
+#ifdef CONFIG_SMP
+ crash_smp_send_stop();
+#endif
+ cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
+
+ pr_info("Starting crashdump kernel...\n");
+}
+
+void machine_kexec(struct kimage *image)
+{
+ unsigned long entry, *ptr;
+ struct kimage_arch *internal = &image->arch;
+
+ efi_boot = internal->efi_boot;
+ cmdline_ptr = internal->cmdline_ptr;
+ systable_ptr = internal->systable_ptr;
+
+ start_addr = (unsigned long)phys_to_virt(image->start);
+
+ first_ind_entry = (image->type == KEXEC_TYPE_DEFAULT) ?
+ (unsigned long)phys_to_virt(image->head & PAGE_MASK) : 0;
+
+ /*
+ * The generic kexec code builds a page list with physical
+ * addresses. they are directly accessible through XKPRANGE
+ * hence the phys_to_virt() call.
+ */
+ for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
+ ptr = (entry & IND_INDIRECTION) ?
+ phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+ if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
+ *ptr & IND_DESTINATION)
+ *ptr = (unsigned long) phys_to_virt(*ptr);
+ }
+
+ /* Mark offline before disabling local irq. */
+ set_cpu_online(smp_processor_id(), false);
+
+ /* We do not want to be bothered. */
+ local_irq_disable();
+
+ pr_notice("EFI boot flag 0x%lx\n", efi_boot);
+ pr_notice("Command line at 0x%lx\n", cmdline_ptr);
+ pr_notice("System table at 0x%lx\n", systable_ptr);
+ pr_notice("We will call new kernel at 0x%lx\n", start_addr);
+ pr_notice("Bye ...\n");
+
+ /* Make reboot code buffer available to the boot CPU. */
+ flush_cache_all();
+
+#ifdef CONFIG_SMP
+ atomic_set(&kexec_ready_to_reboot, 1);
+#endif
+
+ kexec_reboot();
+}