arch/riscv/kernel/crash_dump.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This code comes from arch/arm64/kernel/crash_dump.c
   4  * Created by: AKASHI Takahiro <takahiro.akashi@linaro.org>
   5  * Copyright (C) 2017 Linaro Limited
   6  */
   7
   8 #include <linux/crash_dump.h>
   9 #include <linux/io.h>
  10 #include <linux/uio.h>
  11
  12 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
  13                          size_t csize, unsigned long offset)
  14 {
  15         void *vaddr;
  16
  17         if (!csize)
  18                 return 0;
  19
  20         vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB);
  21         if (!vaddr)
  22                 return -ENOMEM;
  23
  24         csize = copy_to_iter(vaddr + offset, csize, iter);
  25
  26         memunmap(vaddr);
  27         return csize;
  28 }