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77 lines
2.2 KiB
77 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Memory preserving reboot related code. |
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* |
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* Created by: Hariprasad Nellitheertha ([email protected]) |
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* Copyright (C) IBM Corporation, 2004. All rights reserved |
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*/ |
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#include <linux/errno.h> |
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#include <linux/crash_dump.h> |
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#include <linux/uaccess.h> |
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#include <linux/io.h> |
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static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, |
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unsigned long offset, int userbuf, |
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bool encrypted) |
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{ |
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void *vaddr; |
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if (!csize) |
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return 0; |
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if (encrypted) |
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vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE); |
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else |
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vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE); |
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if (!vaddr) |
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return -ENOMEM; |
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if (userbuf) { |
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if (copy_to_user((void __user *)buf, vaddr + offset, csize)) { |
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iounmap((void __iomem *)vaddr); |
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return -EFAULT; |
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} |
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} else |
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memcpy(buf, vaddr + offset, csize); |
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set_iounmap_nonlazy(); |
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iounmap((void __iomem *)vaddr); |
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return csize; |
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} |
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/** |
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* copy_oldmem_page - copy one page of memory |
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* @pfn: page frame number to be copied |
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* @buf: target memory address for the copy; this can be in kernel address |
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* space or user address space (see @userbuf) |
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* @csize: number of bytes to copy |
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* @offset: offset in bytes into the page (based on pfn) to begin the copy |
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* @userbuf: if set, @buf is in user address space, use copy_to_user(), |
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* otherwise @buf is in kernel address space, use memcpy(). |
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* |
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* Copy a page from the old kernel's memory. For this page, there is no pte |
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* mapped in the current kernel. We stitch up a pte, similar to kmap_atomic. |
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*/ |
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ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, |
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unsigned long offset, int userbuf) |
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{ |
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return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false); |
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} |
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/** |
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* copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the |
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* memory with the encryption mask set to accommodate kdump on SME-enabled |
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* machines. |
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*/ |
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ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, |
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unsigned long offset, int userbuf) |
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{ |
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return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); |
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} |
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ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) |
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{ |
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return read_from_oldmem(buf, count, ppos, 0, sev_active()); |
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}
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