From 3922f32c1e6db2e096ff095a5b8af0b940b97508 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Fri, 19 Jun 2015 18:05:06 +0100 Subject: [PATCH] xen/grant: Add helper gnttab_page_grant_foreign_access_ref_one Many PV drivers contain the idiom: pfn = page_to_gfn(...) /* Or similar */ gnttab_grant_foreign_access_ref Replace it by a new helper. Note that when Linux is using a different page granularity than Xen, the helper only gives access to the first 4KB grant. This is useful where drivers are allocating a full Linux page for each grant. Also include xen/interface/grant_table.h rather than xen/grant_table.h in asm/page.h for x86 to fix a compilation issue [1]. Only the former is useful in order to get the structure definition. [1] Interdependency between asm/page.h and xen/grant_table.h which result to page_mfn not being defined when necessary. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel --- include/xen/grant_table.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 05b5b08c2afc..e17a4b381a16 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -131,6 +131,15 @@ void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, unsigned long frame, int readonly); +/* Give access to the first 4K of the page */ +static inline void gnttab_page_grant_foreign_access_ref_one( + grant_ref_t ref, domid_t domid, + struct page *page, int readonly) +{ + gnttab_grant_foreign_access_ref(ref, domid, xen_page_to_gfn(page), + readonly); +} + void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, unsigned long pfn); -- GitLab