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Commit 3922f32c authored by Julien Grall's avatar Julien Grall Committed by David Vrabel
Browse files

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: default avatarJulien Grall <julien.grall@citrix.com>
Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
parent 008c320a

include/xen/grant_table.h

+9 −0
Original line number Diff line number Diff line
@@ -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);