de4eda9de2
READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
// 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 (hari@in.ibm.com)
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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/uio.h>
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#include <linux/io.h>
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#include <linux/cc_platform.h>
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static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
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size_t csize, unsigned long offset,
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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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csize = copy_to_iter(vaddr + offset, csize, iter);
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iounmap((void __iomem *)vaddr);
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return csize;
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}
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ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
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unsigned long offset)
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{
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return __copy_oldmem_page(iter, pfn, csize, offset, 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(struct iov_iter *iter, unsigned long pfn,
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size_t csize, unsigned long offset)
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{
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return __copy_oldmem_page(iter, pfn, csize, offset, 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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struct kvec kvec = { .iov_base = buf, .iov_len = count };
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struct iov_iter iter;
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iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
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return read_from_oldmem(&iter, count, ppos,
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cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));
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}
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