835c34a168
Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
75 lines
1.9 KiB
C
75 lines
1.9 KiB
C
/*
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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/highmem.h>
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#include <linux/crash_dump.h>
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#include <asm/uaccess.h>
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static void *kdump_buf_page;
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/**
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* copy_oldmem_page - copy one page from "oldmem"
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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 "oldmem". For this page, there is no pte mapped
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* in the current kernel. We stitch up a pte, similar to kmap_atomic.
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*
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* Calling copy_to_user() in atomic context is not desirable. Hence first
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* copying the data to a pre-allocated kernel page and then copying to user
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* space in non-atomic context.
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*/
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ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
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size_t csize, unsigned long offset, int userbuf)
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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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vaddr = kmap_atomic_pfn(pfn, KM_PTE0);
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if (!userbuf) {
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memcpy(buf, (vaddr + offset), csize);
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kunmap_atomic(vaddr, KM_PTE0);
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} else {
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if (!kdump_buf_page) {
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printk(KERN_WARNING "Kdump: Kdump buffer page not"
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" allocated\n");
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return -EFAULT;
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}
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copy_page(kdump_buf_page, vaddr);
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kunmap_atomic(vaddr, KM_PTE0);
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if (copy_to_user(buf, (kdump_buf_page + offset), csize))
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return -EFAULT;
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}
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return csize;
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}
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static int __init kdump_buf_page_init(void)
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{
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int ret = 0;
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kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
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if (!kdump_buf_page) {
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printk(KERN_WARNING "Kdump: Failed to allocate kdump buffer"
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" page\n");
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ret = -ENOMEM;
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}
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return ret;
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}
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arch_initcall(kdump_buf_page_init);
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