1/*
  2 * Code to handle transition of Linux booting another kernel.
  3 *
  4 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
  5 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
  6 * Copyright (C) 2005 IBM Corporation.
  7 *
  8 * This source code is licensed under the GNU General Public License,
  9 * Version 2.  See the file COPYING for more details.
 10 */
 11
 12#include <linux/kexec.h>
 13#include <linux/reboot.h>
 14#include <linux/threads.h>
 15#include <linux/memblock.h>
 16#include <linux/of.h>
 17#include <linux/irq.h>
 18#include <linux/ftrace.h>
 19
 20#include <asm/machdep.h>
 21#include <asm/pgalloc.h>
 22#include <asm/prom.h>
 23#include <asm/sections.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
 47void machine_crash_shutdown(struct pt_regs *regs)
 48{
 49	default_machine_crash_shutdown(regs);
 50}
 51
 52/*
 53 * Do what every setup is needed on image and the
 54 * reboot code buffer to allow us to avoid allocations
 55 * later.
 56 */
 57int machine_kexec_prepare(struct kimage *image)
 58{
 59	if (ppc_md.machine_kexec_prepare)
 60		return ppc_md.machine_kexec_prepare(image);
 61	else
 62		return default_machine_kexec_prepare(image);
 63}
 64
 65void machine_kexec_cleanup(struct kimage *image)
 66{
 67}
 68
 69void arch_crash_save_vmcoreinfo(void)
 70{
 71
 72#ifdef CONFIG_NEED_MULTIPLE_NODES
 73	VMCOREINFO_SYMBOL(node_data);
 74	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
 75#endif
 76#ifndef CONFIG_NEED_MULTIPLE_NODES
 77	VMCOREINFO_SYMBOL(contig_page_data);
 78#endif
 79#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
 80	VMCOREINFO_SYMBOL(vmemmap_list);
 81	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
 82	VMCOREINFO_SYMBOL(mmu_psize_defs);
 83	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
 84	VMCOREINFO_OFFSET(vmemmap_backing, list);
 85	VMCOREINFO_OFFSET(vmemmap_backing, phys);
 86	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
 87	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
 88	VMCOREINFO_OFFSET(mmu_psize_def, shift);
 89#endif
 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
102	if (ppc_md.machine_kexec)
103		ppc_md.machine_kexec(image);
104	else
105		default_machine_kexec(image);
106
107	__ftrace_enabled_restore(save_ftrace_enabled);
108
109	/* Fall back to normal restart if we're still alive. */
110	machine_restart(NULL);
111	for(;;);
112}
113
114void __init reserve_crashkernel(void)
115{
116	unsigned long long crash_size, crash_base;
117	int ret;
118
119	/* use common parsing */
120	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
121			&crash_size, &crash_base);
122	if (ret == 0 && crash_size > 0) {
123		crashk_res.start = crash_base;
124		crashk_res.end = crash_base + crash_size - 1;
125	}
126
127	if (crashk_res.end == crashk_res.start) {
128		crashk_res.start = crashk_res.end = 0;
129		return;
130	}
131
132	/* We might have got these values via the command line or the
133	 * device tree, either way sanitise them now. */
134
135	crash_size = resource_size(&crashk_res);
136
137#ifndef CONFIG_NONSTATIC_KERNEL
138	if (crashk_res.start != KDUMP_KERNELBASE)
139		printk("Crash kernel location must be 0x%x\n",
140				KDUMP_KERNELBASE);
141
142	crashk_res.start = KDUMP_KERNELBASE;
143#else
144	if (!crashk_res.start) {
145#ifdef CONFIG_PPC64
146		/*
147		 * On 64bit we split the RMO in half but cap it at half of
148		 * a small SLB (128MB) since the crash kernel needs to place
149		 * itself and some stacks to be in the first segment.
150		 */
151		crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
152#else
153		crashk_res.start = KDUMP_KERNELBASE;
154#endif
155	}
156
157	crash_base = PAGE_ALIGN(crashk_res.start);
158	if (crash_base != crashk_res.start) {
159		printk("Crash kernel base must be aligned to 0x%lx\n",
160				PAGE_SIZE);
161		crashk_res.start = crash_base;
162	}
163
164#endif
165	crash_size = PAGE_ALIGN(crash_size);
166	crashk_res.end = crashk_res.start + crash_size - 1;
167
168	/* The crash region must not overlap the current kernel */
169	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
170		printk(KERN_WARNING
171			"Crash kernel can not overlap current kernel\n");
172		crashk_res.start = crashk_res.end = 0;
173		return;
174	}
175
176	/* Crash kernel trumps memory limit */
177	if (memory_limit && memory_limit <= crashk_res.end) {
178		memory_limit = crashk_res.end + 1;
179		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
180		       memory_limit);
181	}
182
183	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
184			"for crashkernel (System RAM: %ldMB)\n",
185			(unsigned long)(crash_size >> 20),
186			(unsigned long)(crashk_res.start >> 20),
187			(unsigned long)(memblock_phys_mem_size() >> 20));
188
189	memblock_reserve(crashk_res.start, crash_size);
190}
191
192int overlaps_crashkernel(unsigned long start, unsigned long size)
193{
194	return (start + size) > crashk_res.start && start <= crashk_res.end;
195}
196
197/* Values we need to export to the second kernel via the device tree. */
198static phys_addr_t kernel_end;
199static phys_addr_t crashk_base;
200static phys_addr_t crashk_size;
201static unsigned long long mem_limit;
202
203static struct property kernel_end_prop = {
204	.name = "linux,kernel-end",
205	.length = sizeof(phys_addr_t),
206	.value = &kernel_end,
207};
208
209static struct property crashk_base_prop = {
210	.name = "linux,crashkernel-base",
211	.length = sizeof(phys_addr_t),
212	.value = &crashk_base
213};
214
215static struct property crashk_size_prop = {
216	.name = "linux,crashkernel-size",
217	.length = sizeof(phys_addr_t),
218	.value = &crashk_size,
219};
220
221static struct property memory_limit_prop = {
222	.name = "linux,memory-limit",
223	.length = sizeof(unsigned long long),
224	.value = &mem_limit,
225};
226
227#define cpu_to_be_ulong	__PASTE(cpu_to_be, BITS_PER_LONG)
228
229static void __init export_crashk_values(struct device_node *node)
230{
231	struct property *prop;
232
233	/* There might be existing crash kernel properties, but we can't
234	 * be sure what's in them, so remove them. */
235	prop = of_find_property(node, "linux,crashkernel-base", NULL);
236	if (prop)
237		of_remove_property(node, prop);
238
239	prop = of_find_property(node, "linux,crashkernel-size", NULL);
240	if (prop)
241		of_remove_property(node, prop);
242
243	if (crashk_res.start != 0) {
244		crashk_base = cpu_to_be_ulong(crashk_res.start),
245		of_add_property(node, &crashk_base_prop);
246		crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
247		of_add_property(node, &crashk_size_prop);
248	}
249
250	/*
251	 * memory_limit is required by the kexec-tools to limit the
252	 * crash regions to the actual memory used.
253	 */
254	mem_limit = cpu_to_be_ulong(memory_limit);
255	of_update_property(node, &memory_limit_prop);
256}
257
258static int __init kexec_setup(void)
259{
260	struct device_node *node;
261	struct property *prop;
262
263	node = of_find_node_by_path("/chosen");
264	if (!node)
265		return -ENOENT;
266
267	/* remove any stale properties so ours can be found */
268	prop = of_find_property(node, kernel_end_prop.name, NULL);
269	if (prop)
270		of_remove_property(node, prop);
271
272	/* information needed by userspace when using default_machine_kexec */
273	kernel_end = cpu_to_be_ulong(__pa(_end));
274	of_add_property(node, &kernel_end_prop);
275
276	export_crashk_values(node);
277
278	of_node_put(node);
279	return 0;
280}
281late_initcall(kexec_setup);