1 files changed, 277 insertions, 0 deletions
diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
new file mode 100644
index 000000000..de64c7962
--- /dev/null
+++ b/arch/powerpc/kexec/core.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Code to handle transition of Linux booting another kernel.
+ *
+ * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ * Copyright (C) 2005 IBM Corporation.
+ */
+
+#include <linux/kexec.h>
+#include <linux/reboot.h>
+#include <linux/threads.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/irq.h>
+#include <linux/ftrace.h>
+
+#include <asm/kdump.h>
+#include <asm/machdep.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/firmware.h>
+
+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)
+{
+	default_machine_crash_shutdown(regs);
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+void arch_crash_save_vmcoreinfo(void)
+{
+
+#ifdef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(node_data);
+	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
+#endif
+#ifndef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(contig_page_data);
+#endif
+#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
+	VMCOREINFO_SYMBOL(vmemmap_list);
+	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
+	VMCOREINFO_SYMBOL(mmu_psize_defs);
+	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
+	VMCOREINFO_OFFSET(vmemmap_backing, list);
+	VMCOREINFO_OFFSET(vmemmap_backing, phys);
+	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
+	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
+	VMCOREINFO_OFFSET(mmu_psize_def, shift);
+#endif
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
+}
+
+/*
+ * Do not allocate memory (or fail in any way) in machine_kexec().
+ * We are past the point of no return, committed to rebooting now.
+ */
+void machine_kexec(struct kimage *image)
+{
+	int save_ftrace_enabled;
+
+	save_ftrace_enabled = __ftrace_enabled_save();
+	this_cpu_disable_ftrace();
+
+	if (ppc_md.machine_kexec)
+		ppc_md.machine_kexec(image);
+	else
+		default_machine_kexec(image);
+
+	this_cpu_enable_ftrace();
+	__ftrace_enabled_restore(save_ftrace_enabled);
+
+	/* Fall back to normal restart if we're still alive. */
+	machine_restart(NULL);
+	for(;;);
+}
+
+void __init reserve_crashkernel(void)
+{
+	unsigned long long crash_size, crash_base, total_mem_sz;
+	int ret;
+
+	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
+	/* use common parsing */
+	ret = parse_crashkernel(boot_command_line, total_mem_sz,
+			&crash_size, &crash_base);
+	if (ret == 0 && crash_size > 0) {
+		crashk_res.start = crash_base;
+		crashk_res.end = crash_base + crash_size - 1;
+	}
+
+	if (crashk_res.end == crashk_res.start) {
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
+
+	/* We might have got these values via the command line or the
+	 * device tree, either way sanitise them now. */
+
+	crash_size = resource_size(&crashk_res);
+
+#ifndef CONFIG_NONSTATIC_KERNEL
+	if (crashk_res.start != KDUMP_KERNELBASE)
+		printk("Crash kernel location must be 0x%x\n",
+				KDUMP_KERNELBASE);
+
+	crashk_res.start = KDUMP_KERNELBASE;
+#else
+	if (!crashk_res.start) {
+#ifdef CONFIG_PPC64
+		/*
+		 * On the LPAR platform place the crash kernel to mid of
+		 * RMA size (max. of 512MB) to ensure the crash kernel
+		 * gets enough space to place itself and some stack to be
+		 * in the first segment. At the same time normal kernel
+		 * also get enough space to allocate memory for essential
+		 * system resource in the first segment. Keep the crash
+		 * kernel starts at 128MB offset on other platforms.
+		 */
+		if (firmware_has_feature(FW_FEATURE_LPAR))
+			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M);
+		else
+			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M);
+#else
+		crashk_res.start = KDUMP_KERNELBASE;
+#endif
+	}
+
+	crash_base = PAGE_ALIGN(crashk_res.start);
+	if (crash_base != crashk_res.start) {
+		printk("Crash kernel base must be aligned to 0x%lx\n",
+				PAGE_SIZE);
+		crashk_res.start = crash_base;
+	}
+
+#endif
+	crash_size = PAGE_ALIGN(crash_size);
+	crashk_res.end = crashk_res.start + crash_size - 1;
+
+	/* The crash region must not overlap the current kernel */
+	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
+		printk(KERN_WARNING
+			"Crash kernel can not overlap current kernel\n");
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
+
+	/* Crash kernel trumps memory limit */
+	if (memory_limit && memory_limit <= crashk_res.end) {
+		memory_limit = crashk_res.end + 1;
+		total_mem_sz = memory_limit;
+		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
+		       memory_limit);
+	}
+
+	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+			"for crashkernel (System RAM: %ldMB)\n",
+			(unsigned long)(crash_size >> 20),
+			(unsigned long)(crashk_res.start >> 20),
+			(unsigned long)(total_mem_sz >> 20));
+
+	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
+	    memblock_reserve(crashk_res.start, crash_size)) {
+		pr_err("Failed to reserve memory for crashkernel!\n");
+		crashk_res.start = crashk_res.end = 0;
+		return;
+	}
+}
+
+int __init overlaps_crashkernel(unsigned long start, unsigned long size)
+{
+	return (start + size) > crashk_res.start && start <= crashk_res.end;
+}
+
+/* Values we need to export to the second kernel via the device tree. */
+static phys_addr_t kernel_end;
+static phys_addr_t crashk_base;
+static phys_addr_t crashk_size;
+static unsigned long long mem_limit;
+
+static struct property kernel_end_prop = {
+	.name = "linux,kernel-end",
+	.length = sizeof(phys_addr_t),
+	.value = &kernel_end,
+};
+
+static struct property crashk_base_prop = {
+	.name = "linux,crashkernel-base",
+	.length = sizeof(phys_addr_t),
+	.value = &crashk_base
+};
+
+static struct property crashk_size_prop = {
+	.name = "linux,crashkernel-size",
+	.length = sizeof(phys_addr_t),
+	.value = &crashk_size,
+};
+
+static struct property memory_limit_prop = {
+	.name = "linux,memory-limit",
+	.length = sizeof(unsigned long long),
+	.value = &mem_limit,
+};
+
+#define cpu_to_be_ulong	__PASTE(cpu_to_be, BITS_PER_LONG)
+
+static void __init export_crashk_values(struct device_node *node)
+{
+	/* There might be existing crash kernel properties, but we can't
+	 * be sure what's in them, so remove them. */
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-base", NULL));
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-size", NULL));
+
+	if (crashk_res.start != 0) {
+		crashk_base = cpu_to_be_ulong(crashk_res.start),
+		of_add_property(node, &crashk_base_prop);
+		crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
+		of_add_property(node, &crashk_size_prop);
+	}
+
+	/*
+	 * memory_limit is required by the kexec-tools to limit the
+	 * crash regions to the actual memory used.
+	 */
+	mem_limit = cpu_to_be_ulong(memory_limit);
+	of_update_property(node, &memory_limit_prop);
+}
+
+static int __init kexec_setup(void)
+{
+	struct device_node *node;
+
+	node = of_find_node_by_path("/chosen");
+	if (!node)
+		return -ENOENT;
+
+	/* remove any stale properties so ours can be found */
+	of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
+
+	/* information needed by userspace when using default_machine_kexec */
+	kernel_end = cpu_to_be_ulong(__pa(_end));
+	of_add_property(node, &kernel_end_prop);
+
+	export_crashk_values(node);
+
+	of_node_put(node);
+	return 0;
+}
+late_initcall(kexec_setup);