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authorWei Liu <wei.liu2@citrix.com>2015-04-03 14:44:59 +0800
committerDavid Vrabel <david.vrabel@citrix.com>2015-04-15 10:56:47 +0100
commitccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d (patch)
tree2a147c10a289a3f4283d6008708297f07df052a6 /drivers/char
parent278edfc07875779a69277f6c5773ec9318a994ee (diff)
downloadlinux-ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d.tar.gz
xenbus_client: Extend interface to support multi-page ring
Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/xen-tpmfront.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
index c3b4f5a5ac10..3111f2778079 100644
--- a/drivers/char/tpm/xen-tpmfront.c
+++ b/drivers/char/tpm/xen-tpmfront.c
@@ -193,6 +193,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv)
 	struct xenbus_transaction xbt;
 	const char *message = NULL;
 	int rv;
+	grant_ref_t gref;
 
 	priv->shr = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
 	if (!priv->shr) {
@@ -200,11 +201,11 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv)
 		return -ENOMEM;
 	}
 
-	rv = xenbus_grant_ring(dev, virt_to_mfn(priv->shr));
+	rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref);
 	if (rv < 0)
 		return rv;
 
-	priv->ring_ref = rv;
+	priv->ring_ref = gref;
 
 	rv = xenbus_alloc_evtchn(dev, &priv->evtchn);
 	if (rv)