From: Jiaqi Yan <jiaqiyan@google.com> mainline inclusion from mainline-v5.4-rc1 commit 6efc7afb5cc98488410d44695685d003d832534d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8K5CO Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Similar to how copy_mc_user_highpage is implemented for copy_user_highpage on #MC supported architecture, introduce the #MC handled version of copy_highpage. This helper has immediate usage when khugepaged wants to copy file-backed memory pages and tolerate #MC. Link: https://lkml.kernel.org/r/20230329151121.949896-3-jiaqiyan@google.com Signed-off-by: Jiaqi Yan <jiaqiyan@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: David Stevens <stevensd@chromium.org> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Tong Tiangen <tongtiangen@huawei.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> (wupeng: backport copy_mc_highpage for this patch) Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> --- include/linux/highmem.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index cc5fe6c620ad..366198ebba71 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -396,4 +396,32 @@ static inline void memcpy_to_page(struct page *page, size_t offset, kunmap_atomic(to); } +#ifdef copy_mc_to_kernel +/* + * If architecture supports machine check exception handling, define the + * #MC versions of copy_user_highpage and copy_highpage. They copy a memory + * page with #MC in source page (@from) handled, and return the number + * of bytes not copied if there was a #MC, otherwise 0 for success. + */ +static inline int copy_mc_highpage(struct page *to, struct page *from) +{ + char *vfrom, *vto; + int ret; + + vfrom = kmap_atomic(from); + vto = kmap_atomic(to); + ret = copy_mc_to_kernel(vto, vfrom, PAGE_SIZE); + kunmap_atomic(vto); + kunmap_atomic(vfrom); + + return ret; +} +#else +static inline int copy_mc_highpage(struct page *to, struct page *from) +{ + copy_highpage(to, from); + return 0; +} +#endif + #endif /* _LINUX_HIGHMEM_H */ -- 2.25.1