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/sections.h>
22#include <asm/setup.h>
23#include <asm/firmware.h>
24
25void machine_kexec_mask_interrupts(void) {
26	unsigned int i;
27	struct irq_desc *desc;
28
29	for_each_irq_desc(i, desc) {
30		struct irq_chip *chip;
31
32		chip = irq_desc_get_chip(desc);
33		if (!chip)
34			continue;
35
36		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
37			chip->irq_eoi(&desc->irq_data);
38
39		if (chip->irq_mask)
40			chip->irq_mask(&desc->irq_data);
41
42		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
43			chip->irq_disable(&desc->irq_data);
44	}
45}
46
47#ifdef CONFIG_CRASH_DUMP
48void machine_crash_shutdown(struct pt_regs *regs)
49{
50	default_machine_crash_shutdown(regs);
51}
52#endif
53
54void machine_kexec_cleanup(struct kimage *image)
55{
56}
57
58/*
59 * Do not allocate memory (or fail in any way) in machine_kexec().
60 * We are past the point of no return, committed to rebooting now.
61 */
62void machine_kexec(struct kimage *image)
63{
64	int save_ftrace_enabled;
65
66	save_ftrace_enabled = __ftrace_enabled_save();
67	this_cpu_disable_ftrace();
68
69	if (ppc_md.machine_kexec)
70		ppc_md.machine_kexec(image);
71	else
72		default_machine_kexec(image);
73
74	this_cpu_enable_ftrace();
75	__ftrace_enabled_restore(save_ftrace_enabled);
76
77	/* Fall back to normal restart if we're still alive. */
78	machine_restart(NULL);
79	for(;;);
80}
81
82#ifdef CONFIG_CRASH_RESERVE
83void __init reserve_crashkernel(void)
84{
85	unsigned long long crash_size, crash_base, total_mem_sz;
86	int ret;
87
88	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
89	/* use common parsing */
90	ret = parse_crashkernel(boot_command_line, total_mem_sz,
91			&crash_size, &crash_base, NULL, NULL);
92	if (ret == 0 && crash_size > 0) {
93		crashk_res.start = crash_base;
94		crashk_res.end = crash_base + crash_size - 1;
95	}
96
97	if (crashk_res.end == crashk_res.start) {
98		crashk_res.start = crashk_res.end = 0;
99		return;
100	}
101
102	/* We might have got these values via the command line or the
103	 * device tree, either way sanitise them now. */
104
105	crash_size = resource_size(&crashk_res);
106
107#ifndef CONFIG_NONSTATIC_KERNEL
108	if (crashk_res.start != KDUMP_KERNELBASE)
109		printk("Crash kernel location must be 0x%x\n",
110				KDUMP_KERNELBASE);
111
112	crashk_res.start = KDUMP_KERNELBASE;
113#else
114	if (!crashk_res.start) {
115#ifdef CONFIG_PPC64
116		/*
117		 * On the LPAR platform place the crash kernel to mid of
118		 * RMA size (max. of 512MB) to ensure the crash kernel
119		 * gets enough space to place itself and some stack to be
120		 * in the first segment. At the same time normal kernel
121		 * also get enough space to allocate memory for essential
122		 * system resource in the first segment. Keep the crash
123		 * kernel starts at 128MB offset on other platforms.
124		 */
125		if (firmware_has_feature(FW_FEATURE_LPAR))
126			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M);
127		else
128			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M);
129#else
130		crashk_res.start = KDUMP_KERNELBASE;
131#endif
132	}
133
134	crash_base = PAGE_ALIGN(crashk_res.start);
135	if (crash_base != crashk_res.start) {
136		printk("Crash kernel base must be aligned to 0x%lx\n",
137				PAGE_SIZE);
138		crashk_res.start = crash_base;
139	}
140
141#endif
142	crash_size = PAGE_ALIGN(crash_size);
143	crashk_res.end = crashk_res.start + crash_size - 1;
144
145	/* The crash region must not overlap the current kernel */
146	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
147		printk(KERN_WARNING
148			"Crash kernel can not overlap current kernel\n");
149		crashk_res.start = crashk_res.end = 0;
150		return;
151	}
152
153	/* Crash kernel trumps memory limit */
154	if (memory_limit && memory_limit <= crashk_res.end) {
155		memory_limit = crashk_res.end + 1;
156		total_mem_sz = memory_limit;
157		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
158		       memory_limit);
159	}
160
161	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
162			"for crashkernel (System RAM: %ldMB)\n",
163			(unsigned long)(crash_size >> 20),
164			(unsigned long)(crashk_res.start >> 20),
165			(unsigned long)(total_mem_sz >> 20));
166
167	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
168	    memblock_reserve(crashk_res.start, crash_size)) {
169		pr_err("Failed to reserve memory for crashkernel!\n");
170		crashk_res.start = crashk_res.end = 0;
171		return;
172	}
173}
174
175int __init overlaps_crashkernel(unsigned long start, unsigned long size)
176{
177	return (start + size) > crashk_res.start && start <= crashk_res.end;
178}
179
180/* Values we need to export to the second kernel via the device tree. */
181static phys_addr_t kernel_end;
182static phys_addr_t crashk_base;
183static phys_addr_t crashk_size;
184static unsigned long long mem_limit;
185
186static struct property kernel_end_prop = {
187	.name = "linux,kernel-end",
188	.length = sizeof(phys_addr_t),
189	.value = &kernel_end,
190};
191
192static struct property crashk_base_prop = {
193	.name = "linux,crashkernel-base",
194	.length = sizeof(phys_addr_t),
195	.value = &crashk_base
196};
197
198static struct property crashk_size_prop = {
199	.name = "linux,crashkernel-size",
200	.length = sizeof(phys_addr_t),
201	.value = &crashk_size,
202};
203
204static struct property memory_limit_prop = {
205	.name = "linux,memory-limit",
206	.length = sizeof(unsigned long long),
207	.value = &mem_limit,
208};
209
210#define cpu_to_be_ulong	__PASTE(cpu_to_be, BITS_PER_LONG)
211
212static void __init export_crashk_values(struct device_node *node)
213{
214	/* There might be existing crash kernel properties, but we can't
215	 * be sure what's in them, so remove them. */
216	of_remove_property(node, of_find_property(node,
217				"linux,crashkernel-base", NULL));
218	of_remove_property(node, of_find_property(node,
219				"linux,crashkernel-size", NULL));
220
221	if (crashk_res.start != 0) {
222		crashk_base = cpu_to_be_ulong(crashk_res.start),
223		of_add_property(node, &crashk_base_prop);
224		crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
225		of_add_property(node, &crashk_size_prop);
226	}
227
228	/*
229	 * memory_limit is required by the kexec-tools to limit the
230	 * crash regions to the actual memory used.
231	 */
232	mem_limit = cpu_to_be_ulong(memory_limit);
233	of_update_property(node, &memory_limit_prop);
234}
235
236static int __init kexec_setup(void)
237{
238	struct device_node *node;
239
240	node = of_find_node_by_path("/chosen");
241	if (!node)
242		return -ENOENT;
243
244	/* remove any stale properties so ours can be found */
245	of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
246
247	/* information needed by userspace when using default_machine_kexec */
248	kernel_end = cpu_to_be_ulong(__pa(_end));
249	of_add_property(node, &kernel_end_prop);
250
251	export_crashk_values(node);
252
253	of_node_put(node);
254	return 0;
255}
256late_initcall(kexec_setup);
257#endif /* CONFIG_CRASH_RESERVE */
258