arch/powerpc/kexec/core.c - linux - Git at Google

 // 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/prom.h>
 #include <asm/sections.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);
 }

 /*
  * Do what every setup is needed on image and the
  * reboot code buffer to allow us to avoid allocations
  * later.
  */
 int machine_kexec_prepare(struct kimage *image)
 {
 	if (ppc_md.machine_kexec_prepare)
 		return ppc_md.machine_kexec_prepare(image);
 	else
 		return default_machine_kexec_prepare(image);
 }

 void machine_kexec_cleanup(struct kimage *image)
 {
 }

 void arch_crash_save_vmcoreinfo(void)
 {

 #ifdef CONFIG_NEED_MULTIPLE_NODES
 	VMCOREINFO_SYMBOL(node_data);
 	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
 #endif
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 	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;
 	int ret;

 	/* use common parsing */
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 			&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 64bit we split the RMO in half but cap it at half of
 		 * a small SLB (128MB) since the crash kernel needs to place
 		 * itself and some stacks to be in the first segment.
 		 */
 		crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 #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;
 		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)(memblock_phys_mem_size() >> 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 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);
	// 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/prom.h>
	#include <asm/sections.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);
	}

	/*
	* Do what every setup is needed on image and the
	* reboot code buffer to allow us to avoid allocations
	* later.
	*/
	int machine_kexec_prepare(struct kimage *image)
	{
	if (ppc_md.machine_kexec_prepare)
	return ppc_md.machine_kexec_prepare(image);
	else
	return default_machine_kexec_prepare(image);
	}

	void machine_kexec_cleanup(struct kimage *image)
	{
	}

	void arch_crash_save_vmcoreinfo(void)
	{

	#ifdef CONFIG_NEED_MULTIPLE_NODES
	VMCOREINFO_SYMBOL(node_data);
	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
	#endif
	#ifndef CONFIG_NEED_MULTIPLE_NODES
	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;
	int ret;

	/* use common parsing */
	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
	&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 64bit we split the RMO in half but cap it at half of
	* a small SLB (128MB) since the crash kernel needs to place
	* itself and some stacks to be in the first segment.
	*/
	crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
	#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;
	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)(memblock_phys_mem_size() >> 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 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);