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	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}
 79
 80/*
 81 * Do not allocate memory (or fail in any way) in machine_kexec().
 82 * We are past the point of no return, committed to rebooting now.
 83 */
 84void machine_kexec(struct kimage *image)
 85{
 86	int save_ftrace_enabled;
 87
 88	save_ftrace_enabled = __ftrace_enabled_save();
 89
 90	if (ppc_md.machine_kexec)
 91		ppc_md.machine_kexec(image);
 92	else
 93		default_machine_kexec(image);
 94
 95	__ftrace_enabled_restore(save_ftrace_enabled);
 96
 97	/* Fall back to normal restart if we're still alive. */
 98	machine_restart(NULL);
 99	for(;;);
100}
101
102void __init reserve_crashkernel(void)
103{
104	unsigned long long crash_size, crash_base;
105	int ret;
106
107	/* use common parsing */
108	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
109			&crash_size, &crash_base);
110	if (ret == 0 && crash_size > 0) {
111		crashk_res.start = crash_base;
112		crashk_res.end = crash_base + crash_size - 1;
113	}
114
115	if (crashk_res.end == crashk_res.start) {
116		crashk_res.start = crashk_res.end = 0;
117		return;
118	}
119
120	/* We might have got these values via the command line or the
121	 * device tree, either way sanitise them now. */
122
123	crash_size = resource_size(&crashk_res);
124
125#ifndef CONFIG_NONSTATIC_KERNEL
126	if (crashk_res.start != KDUMP_KERNELBASE)
127		printk("Crash kernel location must be 0x%x\n",
128				KDUMP_KERNELBASE);
129
130	crashk_res.start = KDUMP_KERNELBASE;
131#else
132	if (!crashk_res.start) {
133#ifdef CONFIG_PPC64
134		/*
135		 * On 64bit we split the RMO in half but cap it at half of
136		 * a small SLB (128MB) since the crash kernel needs to place
137		 * itself and some stacks to be in the first segment.
138		 */
139		crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
140#else
141		crashk_res.start = KDUMP_KERNELBASE;
142#endif
143	}
144
145	crash_base = PAGE_ALIGN(crashk_res.start);
146	if (crash_base != crashk_res.start) {
147		printk("Crash kernel base must be aligned to 0x%lx\n",
148				PAGE_SIZE);
149		crashk_res.start = crash_base;
150	}
151
152#endif
153	crash_size = PAGE_ALIGN(crash_size);
154	crashk_res.end = crashk_res.start + crash_size - 1;
155
156	/* The crash region must not overlap the current kernel */
157	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
158		printk(KERN_WARNING
159			"Crash kernel can not overlap current kernel\n");
160		crashk_res.start = crashk_res.end = 0;
161		return;
162	}
163
164	/* Crash kernel trumps memory limit */
165	if (memory_limit && memory_limit <= crashk_res.end) {
166		memory_limit = crashk_res.end + 1;
167		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
168		       (unsigned long long)memory_limit);
169	}
170
171	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
172			"for crashkernel (System RAM: %ldMB)\n",
173			(unsigned long)(crash_size >> 20),
174			(unsigned long)(crashk_res.start >> 20),
175			(unsigned long)(memblock_phys_mem_size() >> 20));
176
177	memblock_reserve(crashk_res.start, crash_size);
178}
179
180int overlaps_crashkernel(unsigned long start, unsigned long size)
181{
182	return (start + size) > crashk_res.start && start <= crashk_res.end;
183}
184
185/* Values we need to export to the second kernel via the device tree. */
186static phys_addr_t kernel_end;
187static phys_addr_t crashk_size;
188
189static struct property kernel_end_prop = {
190	.name = "linux,kernel-end",
191	.length = sizeof(phys_addr_t),
192	.value = &kernel_end,
193};
194
195static struct property crashk_base_prop = {
196	.name = "linux,crashkernel-base",
197	.length = sizeof(phys_addr_t),
198	.value = &crashk_res.start,
199};
200
201static struct property crashk_size_prop = {
202	.name = "linux,crashkernel-size",
203	.length = sizeof(phys_addr_t),
204	.value = &crashk_size,
205};
206
207static void __init export_crashk_values(struct device_node *node)
208{
209	struct property *prop;
210
211	/* There might be existing crash kernel properties, but we can't
212	 * be sure what's in them, so remove them. */
213	prop = of_find_property(node, "linux,crashkernel-base", NULL);
214	if (prop)
215		prom_remove_property(node, prop);
216
217	prop = of_find_property(node, "linux,crashkernel-size", NULL);
218	if (prop)
219		prom_remove_property(node, prop);
220
221	if (crashk_res.start != 0) {
222		prom_add_property(node, &crashk_base_prop);
223		crashk_size = resource_size(&crashk_res);
224		prom_add_property(node, &crashk_size_prop);
225	}
226}
227
228static int __init kexec_setup(void)
229{
230	struct device_node *node;
231	struct property *prop;
232
233	node = of_find_node_by_path("/chosen");
234	if (!node)
235		return -ENOENT;
236
237	/* remove any stale properties so ours can be found */
238	prop = of_find_property(node, kernel_end_prop.name, NULL);
239	if (prop)
240		prom_remove_property(node, prop);
241
242	/* information needed by userspace when using default_machine_kexec */
243	kernel_end = __pa(_end);
244	prom_add_property(node, &kernel_end_prop);
245
246	export_crashk_values(node);
247
248	of_node_put(node);
249	return 0;
250}
251late_initcall(kexec_setup);