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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm64/kernel/machine_kexec.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kernel/machine_kexec.c')
-rw-r--r--arch/arm64/kernel/machine_kexec.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
new file mode 100644
index 000000000..ce3d40120
--- /dev/null
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kexec for arm64
+ *
+ * Copyright (C) Linaro.
+ * Copyright (C) Huawei Futurewei Technologies.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/page-flags.h>
+#include <linux/set_memory.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 <asm/sections.h>
+#include <asm/trans_pgd.h>
+
+/**
+ * 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);
+ pr_debug(" dtb_mem: %pa\n", &kimage->arch.dtb_mem);
+ pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc);
+ pr_debug(" el2_vectors: %pa\n", &kimage->arch.el2_vectors);
+
+ 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)
+{
+ 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_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);
+
+ dcache_clean_inval_poc(
+ (unsigned long)phys_to_virt(kimage->segment[i].mem),
+ (unsigned long)phys_to_virt(kimage->segment[i].mem) +
+ kimage->segment[i].memsz);
+ }
+}
+
+/* Allocates pages for kexec page table */
+static void *kexec_page_alloc(void *arg)
+{
+ struct kimage *kimage = (struct kimage *)arg;
+ struct page *page = kimage_alloc_control_pages(kimage, 0);
+ void *vaddr = NULL;
+
+ if (!page)
+ return NULL;
+
+ vaddr = page_address(page);
+ memset(vaddr, 0, PAGE_SIZE);
+
+ return vaddr;
+}
+
+int machine_kexec_post_load(struct kimage *kimage)
+{
+ int rc;
+ pgd_t *trans_pgd;
+ void *reloc_code = page_to_virt(kimage->control_code_page);
+ long reloc_size;
+ struct trans_pgd_info info = {
+ .trans_alloc_page = kexec_page_alloc,
+ .trans_alloc_arg = kimage,
+ };
+
+ /* If in place, relocation is not used, only flush next kernel */
+ if (kimage->head & IND_DONE) {
+ kexec_segment_flush(kimage);
+ kexec_image_info(kimage);
+ return 0;
+ }
+
+ kimage->arch.el2_vectors = 0;
+ if (is_hyp_nvhe()) {
+ rc = trans_pgd_copy_el2_vectors(&info,
+ &kimage->arch.el2_vectors);
+ if (rc)
+ return rc;
+ }
+
+ /* Create a copy of the linear map */
+ trans_pgd = kexec_page_alloc(kimage);
+ if (!trans_pgd)
+ return -ENOMEM;
+ rc = trans_pgd_create_copy(&info, &trans_pgd, PAGE_OFFSET, PAGE_END);
+ if (rc)
+ return rc;
+ kimage->arch.ttbr1 = __pa(trans_pgd);
+ kimage->arch.zero_page = __pa_symbol(empty_zero_page);
+
+ reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start;
+ memcpy(reloc_code, __relocate_new_kernel_start, reloc_size);
+ kimage->arch.kern_reloc = __pa(reloc_code);
+ rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0,
+ &kimage->arch.t0sz, reloc_code);
+ if (rc)
+ return rc;
+ kimage->arch.phys_offset = virt_to_phys(kimage) - (long)kimage;
+
+ /* Flush the reloc_code in preparation for its execution. */
+ dcache_clean_inval_poc((unsigned long)reloc_code,
+ (unsigned long)reloc_code + reloc_size);
+ icache_inval_pou((uintptr_t)reloc_code,
+ (uintptr_t)reloc_code + reloc_size);
+ kexec_image_info(kimage);
+
+ return 0;
+}
+
+/**
+ * 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)
+{
+ 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");
+
+ pr_info("Bye!\n");
+
+ local_daif_mask();
+
+ /*
+ * Both restart and kernel_reloc will shutdown the MMU, disable data
+ * caches. However, restart will start new kernel or purgatory directly,
+ * kernel_reloc contains the body of arm64_relocate_new_kernel
+ * In kexec case, kimage->start points to purgatory assuming that
+ * kernel entry and dtb address are embedded in purgatory by
+ * userspace (kexec-tools).
+ * In kexec_file case, the kernel starts directly without purgatory.
+ */
+ if (kimage->head & IND_DONE) {
+ typeof(cpu_soft_restart) *restart;
+
+ cpu_install_idmap();
+ restart = (void *)__pa_symbol(cpu_soft_restart);
+ restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem,
+ 0, 0);
+ } else {
+ void (*kernel_reloc)(struct kimage *kimage);
+
+ if (is_hyp_nvhe())
+ __hyp_set_vectors(kimage->arch.el2_vectors);
+ cpu_install_ttbr0(kimage->arch.ttbr0, kimage->arch.t0sz);
+ kernel_reloc = (void *)kimage->arch.kern_reloc;
+ kernel_reloc(kimage);
+ }
+
+ 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;
+
+ 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 as memory was allocated via memblock_reserve().
+ *
+ * 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)) {
+ if (!crashk_low_res.end)
+ return false;
+
+ if ((addr < crashk_low_res.start) || (crashk_low_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);
+ free_reserved_page(page);
+ }
+}
+#endif /* CONFIG_HIBERNATION */