From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2 01/20] xen: Add Xen specific page definition Date: Thu, 16 Jul 2015 16:52:59 +0200 Message-ID: <55A7C54B.5030603__45485.8000427068$1437058463$gmane$org@citrix.com> References: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> <1436474552-31789-2-git-send-email-julien.grall@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZFkXC-0007Ib-I6 for xen-devel@lists.xenproject.org; Thu, 16 Jul 2015 14:53:14 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini Cc: ian.campbell@citrix.com, linux-kernel@vger.kernel.org, David Vrabel , xen-devel@lists.xenproject.org, Boris Ostrovsky , linux-arm-kernel@lists.infradead.org List-Id: xen-devel@lists.xenproject.org Hi Stefano, On 16/07/2015 16:19, Stefano Stabellini wrote: >> diff --git a/include/xen/page.h b/include/xen/page.h >> index c5ed20b..8ebd37b 100644 >> --- a/include/xen/page.h >> +++ b/include/xen/page.h >> @@ -1,11 +1,30 @@ >> #ifndef _XEN_PAGE_H >> #define _XEN_PAGE_H >> >> +#include >> + >> +/* The hypercall interface supports only 4KB page */ >> +#define XEN_PAGE_SHIFT 12 >> +#define XEN_PAGE_SIZE (_AC(1,UL) << XEN_PAGE_SHIFT) >> +#define XEN_PAGE_MASK (~(XEN_PAGE_SIZE-1)) >> +#define xen_offset_in_page(p) ((unsigned long)(p) & ~XEN_PAGE_MASK) >> +#define xen_pfn_to_page(pfn) \ > > I think it would be clearer if you called the parameter "xen_pfn" > instead of "pfn". Good idea, I will do it in the next version. > >> + ((pfn_to_page(((unsigned long)(pfn) << XEN_PAGE_SHIFT) >> PAGE_SHIFT))) >> +#define xen_page_to_pfn(page) \ >> + (((page_to_pfn(page)) << PAGE_SHIFT) >> XEN_PAGE_SHIFT) > > > It would be nice to have a comment: > > /* assume PAGE_SIZE is a multiple of XEN_PAGE_SIZE */ Ok. FWIW, there is already a BUILD_BUG_ON the privcmd driver to check this assumption (see patch #19). I could move the BUILD_BUG_ON in page.h. Maybe inside xen_page_to_pfn? > > >> +#define XEN_PFN_PER_PAGE (PAGE_SIZE / XEN_PAGE_SIZE) >> + >> +#define XEN_PFN_DOWN(x) ((x) >> XEN_PAGE_SHIFT) >> +#define XEN_PFN_UP(x) (((x) + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT) >> +#define XEN_PFN_PHYS(x) ((phys_addr_t)(x) << XEN_PAGE_SHIFT) >> + >> #include >> >> +/* Return the MFN associated to the first 4KB of the page */ >> static inline unsigned long page_to_mfn(struct page *page) >> { >> - return pfn_to_mfn(page_to_pfn(page)); >> + return pfn_to_mfn(xen_page_to_pfn(page)); >> } >> >> struct xen_memory_region { > > > Aside from the two minor suggestions: > > Reviewed-by: Stefano Stabellini Thank you, -- Julien Grall