v4.19.13 snapshot.
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
new file mode 100644
index 0000000..922add8
--- /dev/null
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -0,0 +1,360 @@
+/*
+ * kexec for arm64
+ *
+ * Copyright (C) Linaro.
+ * Copyright (C) Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/page-flags.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cpu_ops.h>
+#include <asm/daifflags.h>
+#include <asm/memory.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+#include <asm/page.h>
+
+#include "cpu-reset.h"
+
+/* Global variables for the arm64_relocate_new_kernel routine. */
+extern const unsigned char arm64_relocate_new_kernel[];
+extern const unsigned long arm64_relocate_new_kernel_size;
+
+/**
+ * kexec_image_info - For debugging output.
+ */
+#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
+static void _kexec_image_info(const char *func, int line,
+ const struct kimage *kimage)
+{
+ unsigned long i;
+
+ pr_debug("%s:%d:\n", func, line);
+ pr_debug(" kexec kimage info:\n");
+ pr_debug(" type: %d\n", kimage->type);
+ pr_debug(" start: %lx\n", kimage->start);
+ pr_debug(" head: %lx\n", kimage->head);
+ pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
+
+ for (i = 0; i < kimage->nr_segments; i++) {
+ pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
+ i,
+ kimage->segment[i].mem,
+ kimage->segment[i].mem + kimage->segment[i].memsz,
+ kimage->segment[i].memsz,
+ kimage->segment[i].memsz / PAGE_SIZE);
+ }
+}
+
+void machine_kexec_cleanup(struct kimage *kimage)
+{
+ /* Empty routine needed to avoid build errors. */
+}
+
+/**
+ * machine_kexec_prepare - Prepare for a kexec reboot.
+ *
+ * Called from the core kexec code when a kernel image is loaded.
+ * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
+ * are stuck in the kernel. This avoids a panic once we hit machine_kexec().
+ */
+int machine_kexec_prepare(struct kimage *kimage)
+{
+ kexec_image_info(kimage);
+
+ if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
+ pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+/**
+ * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
+ */
+static void kexec_list_flush(struct kimage *kimage)
+{
+ kimage_entry_t *entry;
+
+ for (entry = &kimage->head; ; entry++) {
+ unsigned int flag;
+ void *addr;
+
+ /* flush the list entries. */
+ __flush_dcache_area(entry, sizeof(kimage_entry_t));
+
+ flag = *entry & IND_FLAGS;
+ if (flag == IND_DONE)
+ break;
+
+ addr = phys_to_virt(*entry & PAGE_MASK);
+
+ switch (flag) {
+ case IND_INDIRECTION:
+ /* Set entry point just before the new list page. */
+ entry = (kimage_entry_t *)addr - 1;
+ break;
+ case IND_SOURCE:
+ /* flush the source pages. */
+ __flush_dcache_area(addr, PAGE_SIZE);
+ break;
+ case IND_DESTINATION:
+ break;
+ default:
+ BUG();
+ }
+ }
+}
+
+/**
+ * kexec_segment_flush - Helper to flush the kimage segments to PoC.
+ */
+static void kexec_segment_flush(const struct kimage *kimage)
+{
+ unsigned long i;
+
+ pr_debug("%s:\n", __func__);
+
+ for (i = 0; i < kimage->nr_segments; i++) {
+ pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
+ i,
+ kimage->segment[i].mem,
+ kimage->segment[i].mem + kimage->segment[i].memsz,
+ kimage->segment[i].memsz,
+ kimage->segment[i].memsz / PAGE_SIZE);
+
+ __flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
+ kimage->segment[i].memsz);
+ }
+}
+
+/**
+ * machine_kexec - Do the kexec reboot.
+ *
+ * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
+ */
+void machine_kexec(struct kimage *kimage)
+{
+ phys_addr_t reboot_code_buffer_phys;
+ void *reboot_code_buffer;
+ bool in_kexec_crash = (kimage == kexec_crash_image);
+ bool stuck_cpus = cpus_are_stuck_in_kernel();
+
+ /*
+ * New cpus may have become stuck_in_kernel after we loaded the image.
+ */
+ BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
+ WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
+ "Some CPUs may be stale, kdump will be unreliable.\n");
+
+ reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
+ reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
+
+ kexec_image_info(kimage);
+
+ pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__,
+ kimage->control_code_page);
+ pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__,
+ &reboot_code_buffer_phys);
+ pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__,
+ reboot_code_buffer);
+ pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__,
+ arm64_relocate_new_kernel);
+ pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
+ __func__, __LINE__, arm64_relocate_new_kernel_size,
+ arm64_relocate_new_kernel_size);
+
+ /*
+ * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
+ * after the kernel is shut down.
+ */
+ memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
+ arm64_relocate_new_kernel_size);
+
+ /* Flush the reboot_code_buffer in preparation for its execution. */
+ __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
+
+ /*
+ * Although we've killed off the secondary CPUs, we don't update
+ * the online mask if we're handling a crash kernel and consequently
+ * need to avoid flush_icache_range(), which will attempt to IPI
+ * the offline CPUs. Therefore, we must use the __* variant here.
+ */
+ __flush_icache_range((uintptr_t)reboot_code_buffer,
+ arm64_relocate_new_kernel_size);
+
+ /* Flush the kimage list and its buffers. */
+ kexec_list_flush(kimage);
+
+ /* Flush the new image if already in place. */
+ if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
+ kexec_segment_flush(kimage);
+
+ pr_info("Bye!\n");
+
+ local_daif_mask();
+
+ /*
+ * cpu_soft_restart will shutdown the MMU, disable data caches, then
+ * transfer control to the reboot_code_buffer which contains a copy of
+ * the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
+ * uses physical addressing to relocate the new image to its final
+ * position and transfers control to the image entry point when the
+ * relocation is complete.
+ */
+
+ cpu_soft_restart(reboot_code_buffer_phys, kimage->head, kimage->start, 0);
+
+ BUG(); /* Should never get here. */
+}
+
+static void machine_kexec_mask_interrupts(void)
+{
+ unsigned int i;
+ struct irq_desc *desc;
+
+ for_each_irq_desc(i, desc) {
+ struct irq_chip *chip;
+ int ret;
+
+ chip = irq_desc_get_chip(desc);
+ if (!chip)
+ continue;
+
+ /*
+ * First try to remove the active state. If this
+ * fails, try to EOI the interrupt.
+ */
+ ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
+
+ if (ret && irqd_irq_inprogress(&desc->irq_data) &&
+ chip->irq_eoi)
+ 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);
+ }
+}
+
+/**
+ * machine_crash_shutdown - shutdown non-crashing cpus and save registers
+ */
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+ local_irq_disable();
+
+ /* shutdown non-crashing cpus */
+ crash_smp_send_stop();
+
+ /* for crashing cpu */
+ crash_save_cpu(regs, smp_processor_id());
+ machine_kexec_mask_interrupts();
+
+ pr_info("Starting crashdump kernel...\n");
+}
+
+void arch_kexec_protect_crashkres(void)
+{
+ int i;
+
+ kexec_segment_flush(kexec_crash_image);
+
+ for (i = 0; i < kexec_crash_image->nr_segments; i++)
+ set_memory_valid(
+ __phys_to_virt(kexec_crash_image->segment[i].mem),
+ kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
+}
+
+void arch_kexec_unprotect_crashkres(void)
+{
+ int i;
+
+ for (i = 0; i < kexec_crash_image->nr_segments; i++)
+ set_memory_valid(
+ __phys_to_virt(kexec_crash_image->segment[i].mem),
+ kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
+}
+
+#ifdef CONFIG_HIBERNATION
+/*
+ * To preserve the crash dump kernel image, the relevant memory segments
+ * should be mapped again around the hibernation.
+ */
+void crash_prepare_suspend(void)
+{
+ if (kexec_crash_image)
+ arch_kexec_unprotect_crashkres();
+}
+
+void crash_post_resume(void)
+{
+ if (kexec_crash_image)
+ arch_kexec_protect_crashkres();
+}
+
+/*
+ * crash_is_nosave
+ *
+ * Return true only if a page is part of reserved memory for crash dump kernel,
+ * but does not hold any data of loaded kernel image.
+ *
+ * Note that all the pages in crash dump kernel memory have been initially
+ * marked as Reserved in kexec_reserve_crashkres_pages().
+ *
+ * In hibernation, the pages which are Reserved and yet "nosave" are excluded
+ * from the hibernation iamge. crash_is_nosave() does thich check for crash
+ * dump kernel and will reduce the total size of hibernation image.
+ */
+
+bool crash_is_nosave(unsigned long pfn)
+{
+ int i;
+ phys_addr_t addr;
+
+ if (!crashk_res.end)
+ return false;
+
+ /* in reserved memory? */
+ addr = __pfn_to_phys(pfn);
+ if ((addr < crashk_res.start) || (crashk_res.end < addr))
+ return false;
+
+ if (!kexec_crash_image)
+ return true;
+
+ /* not part of loaded kernel image? */
+ for (i = 0; i < kexec_crash_image->nr_segments; i++)
+ if (addr >= kexec_crash_image->segment[i].mem &&
+ addr < (kexec_crash_image->segment[i].mem +
+ kexec_crash_image->segment[i].memsz))
+ return false;
+
+ return true;
+}
+
+void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
+{
+ unsigned long addr;
+ struct page *page;
+
+ for (addr = begin; addr < end; addr += PAGE_SIZE) {
+ page = phys_to_page(addr);
+ ClearPageReserved(page);
+ free_reserved_page(page);
+ }
+}
+#endif /* CONFIG_HIBERNATION */