1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Code to handle transition of Linux booting another kernel.
4 *
5 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
6 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
7 * Copyright (C) 2005 IBM Corporation.
8 */
9
10#include <linux/kexec.h>
11#include <linux/reboot.h>
12#include <linux/threads.h>
13#include <linux/memblock.h>
14#include <linux/of.h>
15#include <linux/irq.h>
16#include <linux/ftrace.h>
17
18#include <asm/kdump.h>
19#include <asm/machdep.h>
20#include <asm/pgalloc.h>
21#include <asm/prom.h>
22#include <asm/sections.h>
23
24void machine_kexec_mask_interrupts(void) {
25	unsigned int i;
26	struct irq_desc *desc;
27
28	for_each_irq_desc(i, desc) {
29		struct irq_chip *chip;
30
31		chip = irq_desc_get_chip(desc);
32		if (!chip)
33			continue;
34
35		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
36			chip->irq_eoi(&desc->irq_data);
37
38		if (chip->irq_mask)
39			chip->irq_mask(&desc->irq_data);
40
41		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
42			chip->irq_disable(&desc->irq_data);
43	}
44}
45
46void machine_crash_shutdown(struct pt_regs *regs)
47{
48	default_machine_crash_shutdown(regs);
49}
50
51/*
52 * Do what every setup is needed on image and the
53 * reboot code buffer to allow us to avoid allocations
54 * later.
55 */
56int machine_kexec_prepare(struct kimage *image)
57{
58	if (ppc_md.machine_kexec_prepare)
59		return ppc_md.machine_kexec_prepare(image);
60	else
61		return default_machine_kexec_prepare(image);
62}
63
64void machine_kexec_cleanup(struct kimage *image)
65{
66}
67
68void arch_crash_save_vmcoreinfo(void)
69{
70
71#ifdef CONFIG_NEED_MULTIPLE_NODES
72	VMCOREINFO_SYMBOL(node_data);
73	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
74#endif
75#ifndef CONFIG_NEED_MULTIPLE_NODES
76	VMCOREINFO_SYMBOL(contig_page_data);
77#endif
78#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
79	VMCOREINFO_SYMBOL(vmemmap_list);
80	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
81	VMCOREINFO_SYMBOL(mmu_psize_defs);
82	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
83	VMCOREINFO_OFFSET(vmemmap_backing, list);
84	VMCOREINFO_OFFSET(vmemmap_backing, phys);
85	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
86	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
87	VMCOREINFO_OFFSET(mmu_psize_def, shift);
88#endif
89	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
90}
91
92/*
93 * Do not allocate memory (or fail in any way) in machine_kexec().
94 * We are past the point of no return, committed to rebooting now.
95 */
96void machine_kexec(struct kimage *image)
97{
98	int save_ftrace_enabled;
99
100	save_ftrace_enabled = __ftrace_enabled_save();
101	this_cpu_disable_ftrace();
102
103	if (ppc_md.machine_kexec)
104		ppc_md.machine_kexec(image);
105	else
106		default_machine_kexec(image);
107
108	this_cpu_enable_ftrace();
109	__ftrace_enabled_restore(save_ftrace_enabled);
110
111	/* Fall back to normal restart if we're still alive. */
112	machine_restart(NULL);
113	for(;;);
114}
115
116void __init reserve_crashkernel(void)
117{
118	unsigned long long crash_size, crash_base, total_mem_sz;
119	int ret;
120
121	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
122	/* use common parsing */
123	ret = parse_crashkernel(boot_command_line, total_mem_sz,
124			&crash_size, &crash_base);
125	if (ret == 0 && crash_size > 0) {
126		crashk_res.start = crash_base;
127		crashk_res.end = crash_base + crash_size - 1;
128	}
129
130	if (crashk_res.end == crashk_res.start) {
131		crashk_res.start = crashk_res.end = 0;
132		return;
133	}
134
135	/* We might have got these values via the command line or the
136	 * device tree, either way sanitise them now. */
137
138	crash_size = resource_size(&crashk_res);
139
140#ifndef CONFIG_NONSTATIC_KERNEL
141	if (crashk_res.start != KDUMP_KERNELBASE)
142		printk("Crash kernel location must be 0x%x\n",
143				KDUMP_KERNELBASE);
144
145	crashk_res.start = KDUMP_KERNELBASE;
146#else
147	if (!crashk_res.start) {
148#ifdef CONFIG_PPC64
149		/*
150		 * On the LPAR platform place the crash kernel to mid of
151		 * RMA size (512MB or more) to ensure the crash kernel
152		 * gets enough space to place itself and some stack to be
153		 * in the first segment. At the same time normal kernel
154		 * also get enough space to allocate memory for essential
155		 * system resource in the first segment. Keep the crash
156		 * kernel starts at 128MB offset on other platforms.
157		 */
158		if (firmware_has_feature(FW_FEATURE_LPAR))
159			crashk_res.start = ppc64_rma_size / 2;
160		else
161			crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
162#else
163		crashk_res.start = KDUMP_KERNELBASE;
164#endif
165	}
166
167	crash_base = PAGE_ALIGN(crashk_res.start);
168	if (crash_base != crashk_res.start) {
169		printk("Crash kernel base must be aligned to 0x%lx\n",
170				PAGE_SIZE);
171		crashk_res.start = crash_base;
172	}
173
174#endif
175	crash_size = PAGE_ALIGN(crash_size);
176	crashk_res.end = crashk_res.start + crash_size - 1;
177
178	/* The crash region must not overlap the current kernel */
179	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
180		printk(KERN_WARNING
181			"Crash kernel can not overlap current kernel\n");
182		crashk_res.start = crashk_res.end = 0;
183		return;
184	}
185
186	/* Crash kernel trumps memory limit */
187	if (memory_limit && memory_limit <= crashk_res.end) {
188		memory_limit = crashk_res.end + 1;
189		total_mem_sz = memory_limit;
190		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
191		       memory_limit);
192	}
193
194	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
195			"for crashkernel (System RAM: %ldMB)\n",
196			(unsigned long)(crash_size >> 20),
197			(unsigned long)(crashk_res.start >> 20),
198			(unsigned long)(total_mem_sz >> 20));
199
200	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
201	    memblock_reserve(crashk_res.start, crash_size)) {
202		pr_err("Failed to reserve memory for crashkernel!\n");
203		crashk_res.start = crashk_res.end = 0;
204		return;
205	}
206}
207
208int overlaps_crashkernel(unsigned long start, unsigned long size)
209{
210	return (start + size) > crashk_res.start && start <= crashk_res.end;
211}
212
213/* Values we need to export to the second kernel via the device tree. */
214static phys_addr_t kernel_end;
215static phys_addr_t crashk_base;
216static phys_addr_t crashk_size;
217static unsigned long long mem_limit;
218
219static struct property kernel_end_prop = {
220	.name = "linux,kernel-end",
221	.length = sizeof(phys_addr_t),
222	.value = &kernel_end,
223};
224
225static struct property crashk_base_prop = {
226	.name = "linux,crashkernel-base",
227	.length = sizeof(phys_addr_t),
228	.value = &crashk_base
229};
230
231static struct property crashk_size_prop = {
232	.name = "linux,crashkernel-size",
233	.length = sizeof(phys_addr_t),
234	.value = &crashk_size,
235};
236
237static struct property memory_limit_prop = {
238	.name = "linux,memory-limit",
239	.length = sizeof(unsigned long long),
240	.value = &mem_limit,
241};
242
243#define cpu_to_be_ulong	__PASTE(cpu_to_be, BITS_PER_LONG)
244
245static void __init export_crashk_values(struct device_node *node)
246{
247	/* There might be existing crash kernel properties, but we can't
248	 * be sure what's in them, so remove them. */
249	of_remove_property(node, of_find_property(node,
250				"linux,crashkernel-base", NULL));
251	of_remove_property(node, of_find_property(node,
252				"linux,crashkernel-size", NULL));
253
254	if (crashk_res.start != 0) {
255		crashk_base = cpu_to_be_ulong(crashk_res.start),
256		of_add_property(node, &crashk_base_prop);
257		crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
258		of_add_property(node, &crashk_size_prop);
259	}
260
261	/*
262	 * memory_limit is required by the kexec-tools to limit the
263	 * crash regions to the actual memory used.
264	 */
265	mem_limit = cpu_to_be_ulong(memory_limit);
266	of_update_property(node, &memory_limit_prop);
267}
268
269static int __init kexec_setup(void)
270{
271	struct device_node *node;
272
273	node = of_find_node_by_path("/chosen");
274	if (!node)
275		return -ENOENT;
276
277	/* remove any stale properties so ours can be found */
278	of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
279
280	/* information needed by userspace when using default_machine_kexec */
281	kernel_end = cpu_to_be_ulong(__pa(_end));
282	of_add_property(node, &kernel_end_prop);
283
284	export_crashk_values(node);
285
286	of_node_put(node);
287	return 0;
288}
289late_initcall(kexec_setup);
290