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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * OS info memory interface
4 *
5 * Copyright IBM Corp. 2012
6 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
7 */
8
9#define KMSG_COMPONENT "os_info"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12#include <linux/crash_dump.h>
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <asm/checksum.h>
16#include <asm/abs_lowcore.h>
17#include <asm/os_info.h>
18#include <asm/maccess.h>
19#include <asm/asm-offsets.h>
20
21/*
22 * OS info structure has to be page aligned
23 */
24static struct os_info os_info __page_aligned_data;
25
26/*
27 * Compute checksum over OS info structure
28 */
29u32 os_info_csum(struct os_info *os_info)
30{
31 int size = sizeof(*os_info) - offsetof(struct os_info, version_major);
32 return (__force u32)csum_partial(&os_info->version_major, size, 0);
33}
34
35/*
36 * Add crashkernel info to OS info and update checksum
37 */
38void os_info_crashkernel_add(unsigned long base, unsigned long size)
39{
40 os_info.crashkernel_addr = (u64)(unsigned long)base;
41 os_info.crashkernel_size = (u64)(unsigned long)size;
42 os_info.csum = os_info_csum(&os_info);
43}
44
45/*
46 * Add OS info entry and update checksum
47 */
48void os_info_entry_add(int nr, void *ptr, u64 size)
49{
50 os_info.entry[nr].addr = __pa(ptr);
51 os_info.entry[nr].size = size;
52 os_info.entry[nr].csum = (__force u32)csum_partial(ptr, size, 0);
53 os_info.csum = os_info_csum(&os_info);
54}
55
56/*
57 * Initialize OS info structure and set lowcore pointer
58 */
59void __init os_info_init(void)
60{
61 struct lowcore *abs_lc;
62 unsigned long flags;
63
64 os_info.version_major = OS_INFO_VERSION_MAJOR;
65 os_info.version_minor = OS_INFO_VERSION_MINOR;
66 os_info.magic = OS_INFO_MAGIC;
67 os_info.csum = os_info_csum(&os_info);
68 abs_lc = get_abs_lowcore(&flags);
69 abs_lc->os_info = __pa(&os_info);
70 put_abs_lowcore(abs_lc, flags);
71}
72
73#ifdef CONFIG_CRASH_DUMP
74
75static struct os_info *os_info_old;
76
77/*
78 * Allocate and copy OS info entry from oldmem
79 */
80static void os_info_old_alloc(int nr, int align)
81{
82 unsigned long addr, size = 0;
83 char *buf, *buf_align, *msg;
84 u32 csum;
85
86 addr = os_info_old->entry[nr].addr;
87 if (!addr) {
88 msg = "not available";
89 goto fail;
90 }
91 size = os_info_old->entry[nr].size;
92 buf = kmalloc(size + align - 1, GFP_KERNEL);
93 if (!buf) {
94 msg = "alloc failed";
95 goto fail;
96 }
97 buf_align = PTR_ALIGN(buf, align);
98 if (copy_oldmem_kernel(buf_align, addr, size)) {
99 msg = "copy failed";
100 goto fail_free;
101 }
102 csum = (__force u32)csum_partial(buf_align, size, 0);
103 if (csum != os_info_old->entry[nr].csum) {
104 msg = "checksum failed";
105 goto fail_free;
106 }
107 os_info_old->entry[nr].addr = (u64)(unsigned long)buf_align;
108 msg = "copied";
109 goto out;
110fail_free:
111 kfree(buf);
112fail:
113 os_info_old->entry[nr].addr = 0;
114out:
115 pr_info("entry %i: %s (addr=0x%lx size=%lu)\n",
116 nr, msg, addr, size);
117}
118
119/*
120 * Initialize os info and os info entries from oldmem
121 */
122static void os_info_old_init(void)
123{
124 static int os_info_init;
125 unsigned long addr;
126
127 if (os_info_init)
128 return;
129 if (!oldmem_data.start)
130 goto fail;
131 if (copy_oldmem_kernel(&addr, __LC_OS_INFO, sizeof(addr)))
132 goto fail;
133 if (addr == 0 || addr % PAGE_SIZE)
134 goto fail;
135 os_info_old = kzalloc(sizeof(*os_info_old), GFP_KERNEL);
136 if (!os_info_old)
137 goto fail;
138 if (copy_oldmem_kernel(os_info_old, addr, sizeof(*os_info_old)))
139 goto fail_free;
140 if (os_info_old->magic != OS_INFO_MAGIC)
141 goto fail_free;
142 if (os_info_old->csum != os_info_csum(os_info_old))
143 goto fail_free;
144 if (os_info_old->version_major > OS_INFO_VERSION_MAJOR)
145 goto fail_free;
146 os_info_old_alloc(OS_INFO_VMCOREINFO, 1);
147 os_info_old_alloc(OS_INFO_REIPL_BLOCK, 1);
148 pr_info("crashkernel: addr=0x%lx size=%lu\n",
149 (unsigned long) os_info_old->crashkernel_addr,
150 (unsigned long) os_info_old->crashkernel_size);
151 os_info_init = 1;
152 return;
153fail_free:
154 kfree(os_info_old);
155fail:
156 os_info_init = 1;
157 os_info_old = NULL;
158}
159
160/*
161 * Return pointer to os infor entry and its size
162 */
163void *os_info_old_entry(int nr, unsigned long *size)
164{
165 os_info_old_init();
166
167 if (!os_info_old)
168 return NULL;
169 if (!os_info_old->entry[nr].addr)
170 return NULL;
171 *size = (unsigned long) os_info_old->entry[nr].size;
172 return (void *)(unsigned long)os_info_old->entry[nr].addr;
173}
174#endif
1/*
2 * OS info memory interface
3 *
4 * Copyright IBM Corp. 2012
5 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
6 */
7
8#define KMSG_COMPONENT "os_info"
9#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11#include <linux/crash_dump.h>
12#include <linux/kernel.h>
13#include <asm/checksum.h>
14#include <asm/lowcore.h>
15#include <asm/os_info.h>
16
17/*
18 * OS info structure has to be page aligned
19 */
20static struct os_info os_info __page_aligned_data;
21
22/*
23 * Compute checksum over OS info structure
24 */
25u32 os_info_csum(struct os_info *os_info)
26{
27 int size = sizeof(*os_info) - offsetof(struct os_info, version_major);
28 return csum_partial(&os_info->version_major, size, 0);
29}
30
31/*
32 * Add crashkernel info to OS info and update checksum
33 */
34void os_info_crashkernel_add(unsigned long base, unsigned long size)
35{
36 os_info.crashkernel_addr = (u64)(unsigned long)base;
37 os_info.crashkernel_size = (u64)(unsigned long)size;
38 os_info.csum = os_info_csum(&os_info);
39}
40
41/*
42 * Add OS info entry and update checksum
43 */
44void os_info_entry_add(int nr, void *ptr, u64 size)
45{
46 os_info.entry[nr].addr = (u64)(unsigned long)ptr;
47 os_info.entry[nr].size = size;
48 os_info.entry[nr].csum = csum_partial(ptr, size, 0);
49 os_info.csum = os_info_csum(&os_info);
50}
51
52/*
53 * Initialize OS info struture and set lowcore pointer
54 */
55void __init os_info_init(void)
56{
57 void *ptr = &os_info;
58
59 os_info.version_major = OS_INFO_VERSION_MAJOR;
60 os_info.version_minor = OS_INFO_VERSION_MINOR;
61 os_info.magic = OS_INFO_MAGIC;
62 os_info.csum = os_info_csum(&os_info);
63 memcpy_absolute(&S390_lowcore.os_info, &ptr, sizeof(ptr));
64}
65
66#ifdef CONFIG_CRASH_DUMP
67
68static struct os_info *os_info_old;
69
70/*
71 * Allocate and copy OS info entry from oldmem
72 */
73static void os_info_old_alloc(int nr, int align)
74{
75 unsigned long addr, size = 0;
76 char *buf, *buf_align, *msg;
77 u32 csum;
78
79 addr = os_info_old->entry[nr].addr;
80 if (!addr) {
81 msg = "not available";
82 goto fail;
83 }
84 size = os_info_old->entry[nr].size;
85 buf = kmalloc(size + align - 1, GFP_KERNEL);
86 if (!buf) {
87 msg = "alloc failed";
88 goto fail;
89 }
90 buf_align = PTR_ALIGN(buf, align);
91 if (copy_from_oldmem(buf_align, (void *) addr, size)) {
92 msg = "copy failed";
93 goto fail_free;
94 }
95 csum = csum_partial(buf_align, size, 0);
96 if (csum != os_info_old->entry[nr].csum) {
97 msg = "checksum failed";
98 goto fail_free;
99 }
100 os_info_old->entry[nr].addr = (u64)(unsigned long)buf_align;
101 msg = "copied";
102 goto out;
103fail_free:
104 kfree(buf);
105fail:
106 os_info_old->entry[nr].addr = 0;
107out:
108 pr_info("entry %i: %s (addr=0x%lx size=%lu)\n",
109 nr, msg, addr, size);
110}
111
112/*
113 * Initialize os info and os info entries from oldmem
114 */
115static void os_info_old_init(void)
116{
117 static int os_info_init;
118 unsigned long addr;
119
120 if (os_info_init)
121 return;
122 if (!OLDMEM_BASE)
123 goto fail;
124 if (copy_from_oldmem(&addr, &S390_lowcore.os_info, sizeof(addr)))
125 goto fail;
126 if (addr == 0 || addr % PAGE_SIZE)
127 goto fail;
128 os_info_old = kzalloc(sizeof(*os_info_old), GFP_KERNEL);
129 if (!os_info_old)
130 goto fail;
131 if (copy_from_oldmem(os_info_old, (void *) addr, sizeof(*os_info_old)))
132 goto fail_free;
133 if (os_info_old->magic != OS_INFO_MAGIC)
134 goto fail_free;
135 if (os_info_old->csum != os_info_csum(os_info_old))
136 goto fail_free;
137 if (os_info_old->version_major > OS_INFO_VERSION_MAJOR)
138 goto fail_free;
139 os_info_old_alloc(OS_INFO_VMCOREINFO, 1);
140 os_info_old_alloc(OS_INFO_REIPL_BLOCK, 1);
141 pr_info("crashkernel: addr=0x%lx size=%lu\n",
142 (unsigned long) os_info_old->crashkernel_addr,
143 (unsigned long) os_info_old->crashkernel_size);
144 os_info_init = 1;
145 return;
146fail_free:
147 kfree(os_info_old);
148fail:
149 os_info_init = 1;
150 os_info_old = NULL;
151}
152
153/*
154 * Return pointer to os infor entry and its size
155 */
156void *os_info_old_entry(int nr, unsigned long *size)
157{
158 os_info_old_init();
159
160 if (!os_info_old)
161 return NULL;
162 if (!os_info_old->entry[nr].addr)
163 return NULL;
164 *size = (unsigned long) os_info_old->entry[nr].size;
165 return (void *)(unsigned long)os_info_old->entry[nr].addr;
166}
167#endif