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/prom.h>
 22#include <asm/sections.h>
 23
 24void machine_kexec_mask_interrupts(void) {
 25	unsigned int i;
 26
 27	for_each_irq(i) {
 28		struct irq_desc *desc = irq_to_desc(i);
 29		struct irq_chip *chip;
 30
 31		if (!desc)
 32			continue;
 33
 34		chip = irq_desc_get_chip(desc);
 35		if (!chip)
 36			continue;
 37
 38		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
 39			chip->irq_eoi(&desc->irq_data);
 40
 41		if (chip->irq_mask)
 42			chip->irq_mask(&desc->irq_data);
 43
 44		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
 45			chip->irq_disable(&desc->irq_data);
 46	}
 47}
 48
 49void machine_crash_shutdown(struct pt_regs *regs)
 50{
 51	default_machine_crash_shutdown(regs);
 52}
 53
 54/*
 55 * Do what every setup is needed on image and the
 56 * reboot code buffer to allow us to avoid allocations
 57 * later.
 58 */
 59int machine_kexec_prepare(struct kimage *image)
 60{
 61	if (ppc_md.machine_kexec_prepare)
 62		return ppc_md.machine_kexec_prepare(image);
 63	else
 64		return default_machine_kexec_prepare(image);
 65}
 66
 67void machine_kexec_cleanup(struct kimage *image)
 68{
 69}
 70
 71void arch_crash_save_vmcoreinfo(void)
 72{
 73
 74#ifdef CONFIG_NEED_MULTIPLE_NODES
 75	VMCOREINFO_SYMBOL(node_data);
 76	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
 77#endif
 78#ifndef CONFIG_NEED_MULTIPLE_NODES
 79	VMCOREINFO_SYMBOL(contig_page_data);
 80#endif
 81}
 82
 83/*
 84 * Do not allocate memory (or fail in any way) in machine_kexec().
 85 * We are past the point of no return, committed to rebooting now.
 86 */
 87void machine_kexec(struct kimage *image)
 88{
 89	int save_ftrace_enabled;
 90
 91	save_ftrace_enabled = __ftrace_enabled_save();
 92
 93	if (ppc_md.machine_kexec)
 94		ppc_md.machine_kexec(image);
 95	else
 96		default_machine_kexec(image);
 97
 98	__ftrace_enabled_restore(save_ftrace_enabled);
 99
100	/* Fall back to normal restart if we're still alive. */
101	machine_restart(NULL);
102	for(;;);
103}
104
105void __init reserve_crashkernel(void)
106{
107	unsigned long long crash_size, crash_base;
108	int ret;
109
110	/* this is necessary because of memblock_phys_mem_size() */
111	memblock_analyze();
112
113	/* use common parsing */
114	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
115			&crash_size, &crash_base);
116	if (ret == 0 && crash_size > 0) {
117		crashk_res.start = crash_base;
118		crashk_res.end = crash_base + crash_size - 1;
119	}
120
121	if (crashk_res.end == crashk_res.start) {
122		crashk_res.start = crashk_res.end = 0;
123		return;
124	}
125
126	/* We might have got these values via the command line or the
127	 * device tree, either way sanitise them now. */
128
129	crash_size = resource_size(&crashk_res);
130
131#ifndef CONFIG_RELOCATABLE
132	if (crashk_res.start != KDUMP_KERNELBASE)
133		printk("Crash kernel location must be 0x%x\n",
134				KDUMP_KERNELBASE);
135
136	crashk_res.start = KDUMP_KERNELBASE;
137#else
138	if (!crashk_res.start) {
139#ifdef CONFIG_PPC64
140		/*
141		 * On 64bit we split the RMO in half but cap it at half of
142		 * a small SLB (128MB) since the crash kernel needs to place
143		 * itself and some stacks to be in the first segment.
144		 */
145		crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
146#else
147		crashk_res.start = KDUMP_KERNELBASE;
148#endif
149	}
150
151	crash_base = PAGE_ALIGN(crashk_res.start);
152	if (crash_base != crashk_res.start) {
153		printk("Crash kernel base must be aligned to 0x%lx\n",
154				PAGE_SIZE);
155		crashk_res.start = crash_base;
156	}
157
158#endif
159	crash_size = PAGE_ALIGN(crash_size);
160	crashk_res.end = crashk_res.start + crash_size - 1;
161
162	/* The crash region must not overlap the current kernel */
163	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
164		printk(KERN_WARNING
165			"Crash kernel can not overlap current kernel\n");
166		crashk_res.start = crashk_res.end = 0;
167		return;
168	}
169
170	/* Crash kernel trumps memory limit */
171	if (memory_limit && memory_limit <= crashk_res.end) {
172		memory_limit = crashk_res.end + 1;
173		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
174		       (unsigned long long)memory_limit);
175	}
176
177	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
178			"for crashkernel (System RAM: %ldMB)\n",
179			(unsigned long)(crash_size >> 20),
180			(unsigned long)(crashk_res.start >> 20),
181			(unsigned long)(memblock_phys_mem_size() >> 20));
182
183	memblock_reserve(crashk_res.start, crash_size);
184}
185
186int overlaps_crashkernel(unsigned long start, unsigned long size)
187{
188	return (start + size) > crashk_res.start && start <= crashk_res.end;
189}
190
191/* Values we need to export to the second kernel via the device tree. */
192static phys_addr_t kernel_end;
193static phys_addr_t crashk_size;
194
195static struct property kernel_end_prop = {
196	.name = "linux,kernel-end",
197	.length = sizeof(phys_addr_t),
198	.value = &kernel_end,
199};
200
201static struct property crashk_base_prop = {
202	.name = "linux,crashkernel-base",
203	.length = sizeof(phys_addr_t),
204	.value = &crashk_res.start,
205};
206
207static struct property crashk_size_prop = {
208	.name = "linux,crashkernel-size",
209	.length = sizeof(phys_addr_t),
210	.value = &crashk_size,
211};
212
213static void __init export_crashk_values(struct device_node *node)
214{
215	struct property *prop;
216
217	/* There might be existing crash kernel properties, but we can't
218	 * be sure what's in them, so remove them. */
219	prop = of_find_property(node, "linux,crashkernel-base", NULL);
220	if (prop)
221		prom_remove_property(node, prop);
222
223	prop = of_find_property(node, "linux,crashkernel-size", NULL);
224	if (prop)
225		prom_remove_property(node, prop);
226
227	if (crashk_res.start != 0) {
228		prom_add_property(node, &crashk_base_prop);
229		crashk_size = resource_size(&crashk_res);
230		prom_add_property(node, &crashk_size_prop);
231	}
232}
233
234static int __init kexec_setup(void)
235{
236	struct device_node *node;
237	struct property *prop;
238
239	node = of_find_node_by_path("/chosen");
240	if (!node)
241		return -ENOENT;
242
243	/* remove any stale properties so ours can be found */
244	prop = of_find_property(node, kernel_end_prop.name, NULL);
245	if (prop)
246		prom_remove_property(node, prop);
247
248	/* information needed by userspace when using default_machine_kexec */
249	kernel_end = __pa(_end);
250	prom_add_property(node, &kernel_end_prop);
251
252	export_crashk_values(node);
253
254	of_node_put(node);
255	return 0;
256}
257late_initcall(kexec_setup);