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Commit b1e495b2 authored by Annie Li's avatar Annie Li Committed by Konrad Rzeszutek Wilk
Browse files

xen/granttable: Refactor some code 



Acked-by: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarAnnie Li <annie.li@oracle.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 0f9f5a95

drivers/xen/grant-table.c

+10 −5
Original line number Diff line number Diff line
@@ -257,15 +257,17 @@ EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); 
static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly)

{

	u16 flags, nflags;

	u16 *pflags;



	nflags = gnttab_shared.v1[ref].flags;

	pflags = &gnttab_shared.v1[ref].flags;

	nflags = *pflags;

	do {

		flags = nflags;

		if (flags & (GTF_reading|GTF_writing)) {

			printk(KERN_ALERT "WARNING: g.e. still in use!\n");

			return 0;

		}

	} while ((nflags = sync_cmpxchg(&gnttab_shared.v1[ref].flags, flags, 0)) != flags);

	} while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags);



	return 1;

}
@@ -316,20 +318,23 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) 
{

	unsigned long frame;

	u16           flags;

	u16          *pflags;



	pflags = &gnttab_shared.v1[ref].flags;



	/*

	 * If a transfer is not even yet started, try to reclaim the grant

	 * reference and return failure (== 0).

	 */

	while (!((flags = gnttab_shared.v1[ref].flags) & GTF_transfer_committed)) {

		if (sync_cmpxchg(&gnttab_shared.v1[ref].flags, flags, 0) == flags)

	while (!((flags = *pflags) & GTF_transfer_committed)) {

		if (sync_cmpxchg(pflags, flags, 0) == flags)

			return 0;

		cpu_relax();

	}



	/* If a transfer is in progress then wait until it is completed. */

	while (!(flags & GTF_transfer_completed)) {

		flags = gnttab_shared.v1[ref].flags;

		flags = *pflags;

		cpu_relax();

	}