// SPDX-License-Identifier: GPL-2.0 /* * This code comes from arch/arm64/kernel/crash_dump.c * Created by: AKASHI Takahiro <takahiro.akashi@linaro.org> * Copyright (C) 2017 Linaro Limited */ #include <linux/crash_dump.h> #include <linux/io.h> #include <linux/uio.h> ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, unsigned long offset) { void *vaddr; if (!csize) return 0; vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB); if (!vaddr) return -ENOMEM; csize = copy_to_iter(vaddr + offset, csize, iter); memunmap(vaddr); return csize; }