2 * Hypervisor-assisted dump
4 * Linas Vepstas, Manish Ahuja 2008
5 * Copyright 2008 IBM Corp.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
14 #include <linux/init.h>
15 #include <linux/kobject.h>
18 #include <linux/pfn.h>
19 #include <linux/swap.h>
20 #include <linux/sysfs.h>
23 #include <asm/phyp_dump.h>
24 #include <asm/machdep.h>
28 /* Variables, used to communicate data between early boot and late boot */
29 static struct phyp_dump phyp_dump_vars
;
30 struct phyp_dump
*phyp_dump_info
= &phyp_dump_vars
;
32 static int ibm_configure_kernel_dump
;
33 /* ------------------------------------------------- */
34 /* RTAS interfaces to declare the dump regions */
43 u64 destination_address
;
46 struct phyp_dump_header
{
51 u32 first_offset_section
;
52 u32 dump_disk_section
;
57 /* No dump disk path string used */
59 struct dump_section cpu_data
;
60 struct dump_section hpte_data
;
61 struct dump_section kernel_data
;
64 /* The dump header *must be* in low memory, so .bss it */
65 static struct phyp_dump_header phdr
;
67 #define NUM_DUMP_SECTIONS 3
68 #define DUMP_HEADER_VERSION 0x1
69 #define DUMP_REQUEST_FLAG 0x1
70 #define DUMP_SOURCE_CPU 0x0001
71 #define DUMP_SOURCE_HPTE 0x0002
72 #define DUMP_SOURCE_RMO 0x0011
75 * init_dump_header() - initialize the header declaring a dump
76 * Returns: length of dump save area.
78 * When the hypervisor saves crashed state, it needs to put
79 * it somewhere. The dump header tells the hypervisor where
80 * the data can be saved.
82 static unsigned long init_dump_header(struct phyp_dump_header
*ph
)
84 unsigned long addr_offset
= 0;
86 /* Set up the dump header */
87 ph
->version
= DUMP_HEADER_VERSION
;
88 ph
->num_of_sections
= NUM_DUMP_SECTIONS
;
91 ph
->first_offset_section
=
92 (u32
)offsetof(struct phyp_dump_header
, cpu_data
);
93 ph
->dump_disk_section
= 0;
95 ph
->num_of_blocks_dd
= 0;
98 ph
->maxtime_to_auto
= 0; /* disabled */
100 /* The first two sections are mandatory */
101 ph
->cpu_data
.dump_flags
= DUMP_REQUEST_FLAG
;
102 ph
->cpu_data
.source_type
= DUMP_SOURCE_CPU
;
103 ph
->cpu_data
.source_address
= 0;
104 ph
->cpu_data
.source_length
= phyp_dump_info
->cpu_state_size
;
105 ph
->cpu_data
.destination_address
= addr_offset
;
106 addr_offset
+= phyp_dump_info
->cpu_state_size
;
108 ph
->hpte_data
.dump_flags
= DUMP_REQUEST_FLAG
;
109 ph
->hpte_data
.source_type
= DUMP_SOURCE_HPTE
;
110 ph
->hpte_data
.source_address
= 0;
111 ph
->hpte_data
.source_length
= phyp_dump_info
->hpte_region_size
;
112 ph
->hpte_data
.destination_address
= addr_offset
;
113 addr_offset
+= phyp_dump_info
->hpte_region_size
;
115 /* This section describes the low kernel region */
116 ph
->kernel_data
.dump_flags
= DUMP_REQUEST_FLAG
;
117 ph
->kernel_data
.source_type
= DUMP_SOURCE_RMO
;
118 ph
->kernel_data
.source_address
= PHYP_DUMP_RMR_START
;
119 ph
->kernel_data
.source_length
= PHYP_DUMP_RMR_END
;
120 ph
->kernel_data
.destination_address
= addr_offset
;
121 addr_offset
+= ph
->kernel_data
.source_length
;
126 static void print_dump_header(const struct phyp_dump_header
*ph
)
129 printk(KERN_INFO
"dump header:\n");
130 /* setup some ph->sections required */
131 printk(KERN_INFO
"version = %d\n", ph
->version
);
132 printk(KERN_INFO
"Sections = %d\n", ph
->num_of_sections
);
133 printk(KERN_INFO
"Status = 0x%x\n", ph
->status
);
135 /* No ph->disk, so all should be set to 0 */
136 printk(KERN_INFO
"Offset to first section 0x%x\n",
137 ph
->first_offset_section
);
138 printk(KERN_INFO
"dump disk sections should be zero\n");
139 printk(KERN_INFO
"dump disk section = %d\n", ph
->dump_disk_section
);
140 printk(KERN_INFO
"block num = %ld\n", ph
->block_num_dd
);
141 printk(KERN_INFO
"number of blocks = %ld\n", ph
->num_of_blocks_dd
);
142 printk(KERN_INFO
"dump disk offset = %d\n", ph
->offset_dd
);
143 printk(KERN_INFO
"Max auto time= %d\n", ph
->maxtime_to_auto
);
145 /*set cpu state and hpte states as well scratch pad area */
146 printk(KERN_INFO
" CPU AREA \n");
147 printk(KERN_INFO
"cpu dump_flags =%d\n", ph
->cpu_data
.dump_flags
);
148 printk(KERN_INFO
"cpu source_type =%d\n", ph
->cpu_data
.source_type
);
149 printk(KERN_INFO
"cpu error_flags =%d\n", ph
->cpu_data
.error_flags
);
150 printk(KERN_INFO
"cpu source_address =%lx\n",
151 ph
->cpu_data
.source_address
);
152 printk(KERN_INFO
"cpu source_length =%lx\n",
153 ph
->cpu_data
.source_length
);
154 printk(KERN_INFO
"cpu length_copied =%lx\n",
155 ph
->cpu_data
.length_copied
);
157 printk(KERN_INFO
" HPTE AREA \n");
158 printk(KERN_INFO
"HPTE dump_flags =%d\n", ph
->hpte_data
.dump_flags
);
159 printk(KERN_INFO
"HPTE source_type =%d\n", ph
->hpte_data
.source_type
);
160 printk(KERN_INFO
"HPTE error_flags =%d\n", ph
->hpte_data
.error_flags
);
161 printk(KERN_INFO
"HPTE source_address =%lx\n",
162 ph
->hpte_data
.source_address
);
163 printk(KERN_INFO
"HPTE source_length =%lx\n",
164 ph
->hpte_data
.source_length
);
165 printk(KERN_INFO
"HPTE length_copied =%lx\n",
166 ph
->hpte_data
.length_copied
);
168 printk(KERN_INFO
" SRSD AREA \n");
169 printk(KERN_INFO
"SRSD dump_flags =%d\n", ph
->kernel_data
.dump_flags
);
170 printk(KERN_INFO
"SRSD source_type =%d\n", ph
->kernel_data
.source_type
);
171 printk(KERN_INFO
"SRSD error_flags =%d\n", ph
->kernel_data
.error_flags
);
172 printk(KERN_INFO
"SRSD source_address =%lx\n",
173 ph
->kernel_data
.source_address
);
174 printk(KERN_INFO
"SRSD source_length =%lx\n",
175 ph
->kernel_data
.source_length
);
176 printk(KERN_INFO
"SRSD length_copied =%lx\n",
177 ph
->kernel_data
.length_copied
);
181 static void register_dump_area(struct phyp_dump_header
*ph
, unsigned long addr
)
184 ph
->cpu_data
.destination_address
+= addr
;
185 ph
->hpte_data
.destination_address
+= addr
;
186 ph
->kernel_data
.destination_address
+= addr
;
189 rc
= rtas_call(ibm_configure_kernel_dump
, 3, 1, NULL
,
190 1, ph
, sizeof(struct phyp_dump_header
));
191 } while (rtas_busy_delay(rc
));
194 printk(KERN_ERR
"phyp-dump: unexpected error (%d) on "
196 print_dump_header(ph
);
200 /* ------------------------------------------------- */
202 * release_memory_range -- release memory previously lmb_reserved
203 * @start_pfn: starting physical frame number
204 * @nr_pages: number of pages to free.
206 * This routine will release memory that had been previously
207 * lmb_reserved in early boot. The released memory becomes
208 * available for genreal use.
211 release_memory_range(unsigned long start_pfn
, unsigned long nr_pages
)
214 unsigned long end_pfn
;
217 end_pfn
= start_pfn
+ nr_pages
;
219 for (i
= start_pfn
; i
<= end_pfn
; i
++) {
220 rpage
= pfn_to_page(i
);
221 if (PageReserved(rpage
)) {
222 ClearPageReserved(rpage
);
223 init_page_count(rpage
);
230 /* ------------------------------------------------- */
232 * sysfs_release_region -- sysfs interface to release memory range.
235 * "echo <start addr> <length> > /sys/kernel/release_region"
238 * "echo 0x40000000 0x10000000 > /sys/kernel/release_region"
240 * will release 256MB starting at 1GB.
242 static ssize_t
store_release_region(struct kobject
*kobj
,
243 struct kobj_attribute
*attr
,
244 const char *buf
, size_t count
)
246 unsigned long start_addr
, length
, end_addr
;
247 unsigned long start_pfn
, nr_pages
;
250 ret
= sscanf(buf
, "%lx %lx", &start_addr
, &length
);
254 /* Range-check - don't free any reserved memory that
255 * wasn't reserved for phyp-dump */
256 if (start_addr
< phyp_dump_info
->init_reserve_start
)
257 start_addr
= phyp_dump_info
->init_reserve_start
;
259 end_addr
= phyp_dump_info
->init_reserve_start
+
260 phyp_dump_info
->init_reserve_size
;
261 if (start_addr
+length
> end_addr
)
262 length
= end_addr
- start_addr
;
264 /* Release the region of memory assed in by user */
265 start_pfn
= PFN_DOWN(start_addr
);
266 nr_pages
= PFN_DOWN(length
);
267 release_memory_range(start_pfn
, nr_pages
);
272 static struct kobj_attribute rr
= __ATTR(release_region
, 0600,
273 NULL
, store_release_region
);
275 static int __init
phyp_dump_setup(void)
277 struct device_node
*rtas
;
278 const struct phyp_dump_header
*dump_header
= NULL
;
279 unsigned long dump_area_start
;
280 unsigned long dump_area_length
;
284 /* If no memory was reserved in early boot, there is nothing to do */
285 if (phyp_dump_info
->init_reserve_size
== 0)
288 /* Return if phyp dump not supported */
289 if (!phyp_dump_info
->phyp_dump_configured
)
292 /* Is there dump data waiting for us? If there isn't,
293 * then register a new dump area, and release all of
294 * the rest of the reserved ram.
296 * The /rtas/ibm,kernel-dump rtas node is present only
297 * if there is dump data waiting for us.
299 rtas
= of_find_node_by_path("/rtas");
301 dump_header
= of_get_property(rtas
, "ibm,kernel-dump",
306 print_dump_header(dump_header
);
307 dump_area_length
= init_dump_header(&phdr
);
309 dump_area_start
= phyp_dump_info
->init_reserve_start
& PAGE_MASK
;
311 if (dump_header
== NULL
) {
312 register_dump_area(&phdr
, dump_area_start
);
316 /* Should we create a dump_subsys, analogous to s390/ipl.c ? */
317 rc
= sysfs_create_file(kernel_kobj
, &rr
.attr
);
319 printk(KERN_ERR
"phyp-dump: unable to create sysfs file (%d)\n",
322 /* ToDo: re-register the dump area, for next time. */
325 machine_subsys_initcall(pseries
, phyp_dump_setup
);
327 int __init
early_init_dt_scan_phyp_dump(unsigned long node
,
328 const char *uname
, int depth
, void *data
)
330 const unsigned int *sizes
;
332 phyp_dump_info
->phyp_dump_configured
= 0;
333 phyp_dump_info
->phyp_dump_is_active
= 0;
335 if (depth
!= 1 || strcmp(uname
, "rtas") != 0)
338 if (of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump", NULL
))
339 phyp_dump_info
->phyp_dump_configured
++;
341 if (of_get_flat_dt_prop(node
, "ibm,dump-kernel", NULL
))
342 phyp_dump_info
->phyp_dump_is_active
++;
344 sizes
= of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump-sizes",
350 phyp_dump_info
->cpu_state_size
= *((unsigned long *)&sizes
[1]);
353 phyp_dump_info
->hpte_region_size
=
354 *((unsigned long *)&sizes
[4]);