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