diff options
Diffstat (limited to 'arch/x86/kernel/crash_dump_64.c')
-rw-r--r-- | arch/x86/kernel/crash_dump_64.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c new file mode 100644 index 0000000000..32d710f7eb --- /dev/null +++ b/arch/x86/kernel/crash_dump_64.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Memory preserving reboot related code. + * + * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) + * Copyright (C) IBM Corporation, 2004. All rights reserved + */ + +#include <linux/errno.h> +#include <linux/crash_dump.h> +#include <linux/uio.h> +#include <linux/io.h> +#include <linux/cc_platform.h> + +static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset, + bool encrypted) +{ + void *vaddr; + + if (!csize) + return 0; + + if (encrypted) + vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE); + else + vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE); + + if (!vaddr) + return -ENOMEM; + + csize = copy_to_iter(vaddr + offset, csize, iter); + + iounmap((void __iomem *)vaddr); + return csize; +} + +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) +{ + return __copy_oldmem_page(iter, pfn, csize, offset, false); +} + +/* + * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the + * memory with the encryption mask set to accommodate kdump on SME-enabled + * machines. + */ +ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) +{ + return __copy_oldmem_page(iter, pfn, csize, offset, true); +} + +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) +{ + struct kvec kvec = { .iov_base = buf, .iov_len = count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)); +} |