From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: [PATCH v2 02/20] xen: Introduce a function to split a Linux page into Xen page Date: Thu, 9 Jul 2015 21:42:14 +0100 Message-ID: <1436474552-31789-3-git-send-email-julien.grall@citrix.com> References: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZDIfa-0008DN-Jj for xen-devel@lists.xenproject.org; Thu, 09 Jul 2015 20:43:46 +0000 In-Reply-To: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, linux-kernel@vger.kernel.org, Julien Grall , David Vrabel , Boris Ostrovsky , linux-arm-kernel@lists.infradead.org List-Id: xen-devel@lists.xenproject.org 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 Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel --- 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