The Xen interface is always using 4KB page. This means that a Linux page may be split across multiple Xen page when the page granularity is not the same.
This helper will break down a Linux page into 4KB chunk and call the helper on each of them. Signed-off-by: Julien Grall <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: David Vrabel <[email protected]> --- Changes in v2: - Patch added --- include/xen/page.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/xen/page.h b/include/xen/page.h index 8ebd37b..b1f7722 100644 --- a/include/xen/page.h +++ b/include/xen/page.h @@ -39,4 +39,24 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS]; extern unsigned long xen_released_pages; +typedef int (*xen_pfn_fn_t)(struct page *page, unsigned long pfn, void *data); + +/* Break down the page in 4KB granularity and call fn foreach xen pfn */ +static inline int xen_apply_to_page(struct page *page, xen_pfn_fn_t fn, + void *data) +{ + unsigned long pfn = xen_page_to_pfn(page); + int i; + int ret; + + for (i = 0; i < XEN_PFN_PER_PAGE; i++, pfn++) { + ret = fn(page, pfn, data); + if (ret) + return ret; + } + + return ret; +} + + #endif /* _XEN_PAGE_H */ -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
