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9#include <linux/errno.h>
10#include <linux/crash_dump.h>
11#include <linux/uaccess.h>
12#include <linux/io.h>
13
14static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
15 unsigned long offset, int userbuf,
16 bool encrypted)
17{
18 void *vaddr;
19
20 if (!csize)
21 return 0;
22
23 if (encrypted)
24 vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
25 else
26 vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
27
28 if (!vaddr)
29 return -ENOMEM;
30
31 if (userbuf) {
32 if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
33 iounmap((void __iomem *)vaddr);
34 return -EFAULT;
35 }
36 } else
37 memcpy(buf, vaddr + offset, csize);
38
39 set_iounmap_nonlazy();
40 iounmap((void __iomem *)vaddr);
41 return csize;
42}
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56
57ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
58 unsigned long offset, int userbuf)
59{
60 return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
61}
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67
68ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
69 unsigned long offset, int userbuf)
70{
71 return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
72}
73
74ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
75{
76 return read_from_oldmem(buf, count, ppos, 0, sev_active());
77}
78