Merge tag '9p-for-5.8' of git://github.com/martinetd/linux

Pull 9p update from Dominique Martinet:
 "Another very quiet cycle... Only one commit: increase the size of the
  ring used for xen transport"

* tag '9p-for-5.8' of git://github.com/martinetd/linux:
  9p/xen: increase XEN_9PFS_RING_ORDER

Author: torvalds

net/9p/trans_xen.c

@@ -43,8 +43,8 @@
 #include <net/9p/transport.h>
 
 #define XEN_9PFS_NUM_RINGS 2
-#define XEN_9PFS_RING_ORDER 6
-#define XEN_9PFS_RING_SIZE  XEN_FLEX_RING_SIZE(XEN_9PFS_RING_ORDER)
+#define XEN_9PFS_RING_ORDER 9
+#define XEN_9PFS_RING_SIZE(ring)  XEN_FLEX_RING_SIZE(ring->intf->ring_order)
 
 struct xen_9pfs_header {
 	uint32_t size;
@@ -132,8 +132,8 @@ static bool p9_xen_write_todo(struct xen_9pfs_dataring *ring, RING_IDX size)
 	prod = ring->intf->out_prod;
 	virt_mb();
 
-	return XEN_9PFS_RING_SIZE -
-		xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE) >= size;
+	return XEN_9PFS_RING_SIZE(ring) -
+		xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) >= size;
 }
 
 static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
@@ -167,17 +167,18 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
 	prod = ring->intf->out_prod;
 	virt_mb();
 
-	if (XEN_9PFS_RING_SIZE - xen_9pfs_queued(prod, cons,
-						 XEN_9PFS_RING_SIZE) < size) {
+	if (XEN_9PFS_RING_SIZE(ring) -
+	    xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < size) {
 		spin_unlock_irqrestore(&ring->lock, flags);
 		goto again;
 	}
 
-	masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE);
-	masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);
+	masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring));
+	masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
 
 	xen_9pfs_write_packet(ring->data.out, p9_req->tc.sdata, size,
-			      &masked_prod, masked_cons, XEN_9PFS_RING_SIZE);
+			      &masked_prod, masked_cons,
+			      XEN_9PFS_RING_SIZE(ring));
 
 	p9_req->status = REQ_STATUS_SENT;
 	virt_wmb();			/* write ring before updating pointer */
@@ -207,19 +208,19 @@ static void p9_xen_response(struct work_struct *work)
 		prod = ring->intf->in_prod;
 		virt_rmb();
 
-		if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE) <
+		if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) <
 		    sizeof(h)) {
 			notify_remote_via_irq(ring->irq);
 			return;
 		}
 
-		masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE);
-		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);
+		masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring));
+		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
 
 		/* First, read just the header */
 		xen_9pfs_read_packet(&h, ring->data.in, sizeof(h),
 				     masked_prod, &masked_cons,
-				     XEN_9PFS_RING_SIZE);
+				     XEN_9PFS_RING_SIZE(ring));
 
 		req = p9_tag_lookup(priv->client, h.tag);
 		if (!req || req->status != REQ_STATUS_SENT) {
@@ -233,11 +234,11 @@ static void p9_xen_response(struct work_struct *work)
 		memcpy(&req->rc, &h, sizeof(h));
 		req->rc.offset = 0;
 
-		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);
+		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
 		/* Then, read the whole packet (including the header) */
 		xen_9pfs_read_packet(req->rc.sdata, ring->data.in, h.size,
 				     masked_prod, &masked_cons,
-				     XEN_9PFS_RING_SIZE);
+				     XEN_9PFS_RING_SIZE(ring));
 
 		virt_mb();
 		cons += h.size;
@@ -267,7 +268,7 @@ static irqreturn_t xen_9pfs_front_event_handler(int irq, void *r)
 
 static struct p9_trans_module p9_xen_trans = {
 	.name = "xen",
-	.maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT),
+	.maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2),
 	.def = 1,
 	.create = p9_xen_create,
 	.close = p9_xen_close,
@@ -295,14 +296,16 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
 		if (priv->rings[i].irq > 0)
 			unbind_from_irqhandler(priv->rings[i].irq, priv->dev);
 		if (priv->rings[i].data.in) {
-			for (j = 0; j < (1 << XEN_9PFS_RING_ORDER); j++) {
+			for (j = 0;
+			     j < (1 << priv->rings[i].intf->ring_order);
+			     j++) {
 				grant_ref_t ref;
 
 				ref = priv->rings[i].intf->ref[j];
 				gnttab_end_foreign_access(ref, 0, 0);
 			}
 			free_pages((unsigned long)priv->rings[i].data.in,
-				   XEN_9PFS_RING_ORDER -
+				   priv->rings[i].intf->ring_order -
 				   (PAGE_SHIFT - XEN_PAGE_SHIFT));
 		}
 		gnttab_end_foreign_access(priv->rings[i].ref, 0, 0);
@@ -323,7 +326,8 @@ static int xen_9pfs_front_remove(struct xenbus_device *dev)
 }
 
 static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
-					 struct xen_9pfs_dataring *ring)
+					 struct xen_9pfs_dataring *ring,
+					 unsigned int order)
 {
 	int i = 0;
 	int ret = -ENOMEM;
@@ -342,21 +346,21 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
 		goto out;
 	ring->ref = ret;
 	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-			XEN_9PFS_RING_ORDER - (PAGE_SHIFT - XEN_PAGE_SHIFT));
+			order - (PAGE_SHIFT - XEN_PAGE_SHIFT));
 	if (!bytes) {
 		ret = -ENOMEM;
 		goto out;
 	}
-	for (; i < (1 << XEN_9PFS_RING_ORDER); i++) {
+	for (; i < (1 << order); i++) {
 		ret = gnttab_grant_foreign_access(
 				dev->otherend_id, virt_to_gfn(bytes) + i, 0);
 		if (ret < 0)
 			goto out;
 		ring->intf->ref[i] = ret;
 	}
-	ring->intf->ring_order = XEN_9PFS_RING_ORDER;
+	ring->intf->ring_order = order;
 	ring->data.in = bytes;
-	ring->data.out = bytes + XEN_9PFS_RING_SIZE;
+	ring->data.out = bytes + XEN_FLEX_RING_SIZE(order);
 
 	ret = xenbus_alloc_evtchn(dev, &ring->evtchn);
 	if (ret)
@@ -374,7 +378,7 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
 		for (i--; i >= 0; i--)
 			gnttab_end_foreign_access(ring->intf->ref[i], 0, 0);
 		free_pages((unsigned long)bytes,
-			   XEN_9PFS_RING_ORDER -
+			   ring->intf->ring_order -
 			   (PAGE_SHIFT - XEN_PAGE_SHIFT));
 	}
 	gnttab_end_foreign_access(ring->ref, 0, 0);
@@ -404,8 +408,10 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
 		return -EINVAL;
 	max_ring_order = xenbus_read_unsigned(dev->otherend,
 					      "max-ring-page-order", 0);
-	if (max_ring_order < XEN_9PFS_RING_ORDER)
-		return -EINVAL;
+	if (max_ring_order > XEN_9PFS_RING_ORDER)
+		max_ring_order = XEN_9PFS_RING_ORDER;
+	if (p9_xen_trans.maxsize > XEN_FLEX_RING_SIZE(max_ring_order))
+		p9_xen_trans.maxsize = XEN_FLEX_RING_SIZE(max_ring_order) / 2;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -422,7 +428,8 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
 
 	for (i = 0; i < priv->num_rings; i++) {
 		priv->rings[i].priv = priv;
-		ret = xen_9pfs_front_alloc_dataring(dev, &priv->rings[i]);
+		ret = xen_9pfs_front_alloc_dataring(dev, &priv->rings[i],
+						    max_ring_order);
 		if (ret < 0)
 			goto error;
 	}