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Diffstat (limited to 'net/9p/trans_xen.c')
-rw-r--r--net/9p/trans_xen.c121
1 files changed, 53 insertions, 68 deletions
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 3963eb11c3fb..b15c64128c3e 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -1,33 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/9p/trans_xen
*
* Xen transport layer.
*
* Copyright (C) 2017 by Stefano Stabellini <stefano@aporeto.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation; or, when distributed
- * separately from the Linux kernel or incorporated into other
- * software packages, subject to the following license:
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this source file (the "Software"), to deal in the Software without
- * restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software,
- * and to permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
*/
#include <xen/events.h>
@@ -43,8 +20,8 @@
#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;
@@ -132,13 +109,13 @@ 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)
{
- struct xen_9pfs_front_priv *priv = NULL;
+ struct xen_9pfs_front_priv *priv;
RING_IDX cons, prod, masked_cons, masked_prod;
unsigned long flags;
u32 size = p9_req->tc.size;
@@ -151,7 +128,7 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
break;
}
read_unlock(&xen_9pfs_lock);
- if (!priv || priv->client != client)
+ if (list_entry_is_head(priv, &xen_9pfs_devs, list))
return -EINVAL;
num = p9_req->tc.tag % priv->num_rings;
@@ -167,17 +144,18 @@ again:
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 */
@@ -185,7 +163,7 @@ again:
ring->intf->out_prod = prod;
spin_unlock_irqrestore(&ring->lock, flags);
notify_remote_via_irq(ring->irq);
- p9_req_put(p9_req);
+ p9_req_put(client, p9_req);
return 0;
}
@@ -207,19 +185,19 @@ 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 +211,11 @@ 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 +245,8 @@ 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),
+ .pooled_rbuffers = false,
.def = 1,
.create = p9_xen_create,
.close = p9_xen_close,
@@ -295,17 +274,19 @@ 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);
+ gnttab_end_foreign_access(ref, NULL);
}
- free_pages((unsigned long)priv->rings[i].data.in,
- XEN_9PFS_RING_ORDER -
- (PAGE_SHIFT - XEN_PAGE_SHIFT));
+ free_pages_exact(priv->rings[i].data.in,
+ 1UL << (priv->rings[i].intf->ring_order +
+ XEN_PAGE_SHIFT));
}
- gnttab_end_foreign_access(priv->rings[i].ref, 0, 0);
+ gnttab_end_foreign_access(priv->rings[i].ref, NULL);
free_page((unsigned long)priv->rings[i].intf);
}
kfree(priv->rings);
@@ -323,7 +304,8 @@ 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;
@@ -341,22 +323,22 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
if (ret < 0)
goto out;
ring->ref = ret;
- bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
- XEN_9PFS_RING_ORDER - (PAGE_SHIFT - XEN_PAGE_SHIFT));
+ bytes = alloc_pages_exact(1UL << (order + XEN_PAGE_SHIFT),
+ GFP_KERNEL | __GFP_ZERO);
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)
@@ -372,12 +354,10 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
out:
if (bytes) {
for (i--; i >= 0; i--)
- gnttab_end_foreign_access(ring->intf->ref[i], 0, 0);
- free_pages((unsigned long)bytes,
- XEN_9PFS_RING_ORDER -
- (PAGE_SHIFT - XEN_PAGE_SHIFT));
+ gnttab_end_foreign_access(ring->intf->ref[i], NULL);
+ free_pages_exact(bytes, 1UL << (order + XEN_PAGE_SHIFT));
}
- gnttab_end_foreign_access(ring->ref, 0, 0);
+ gnttab_end_foreign_access(ring->ref, NULL);
free_page((unsigned long)ring->intf);
return ret;
}
@@ -404,8 +384,10 @@ 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 +404,8 @@ 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;
}
@@ -444,13 +427,13 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
char str[16];
BUILD_BUG_ON(XEN_9PFS_NUM_RINGS > 9);
- sprintf(str, "ring-ref%u", i);
+ sprintf(str, "ring-ref%d", i);
ret = xenbus_printf(xbt, dev->nodename, str, "%d",
priv->rings[i].ref);
if (ret)
goto error_xenbus;
- sprintf(str, "event-channel-%u", i);
+ sprintf(str, "event-channel-%d", i);
ret = xenbus_printf(xbt, dev->nodename, str, "%u",
priv->rings[i].evtchn);
if (ret)
@@ -513,7 +496,7 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
case XenbusStateClosed:
if (dev->state == XenbusStateClosed)
break;
- /* fall through - Missed the backend's CLOSING state */
+ fallthrough; /* Missed the backend's CLOSING state */
case XenbusStateClosing:
xenbus_frontend_closed(dev);
break;
@@ -528,7 +511,7 @@ static struct xenbus_driver xen_9pfs_front_driver = {
.otherend_changed = xen_9pfs_front_changed,
};
-static int p9_trans_xen_init(void)
+static int __init p9_trans_xen_init(void)
{
int rc;
@@ -545,14 +528,16 @@ static int p9_trans_xen_init(void)
return rc;
}
module_init(p9_trans_xen_init);
+MODULE_ALIAS_9P("xen");
-static void p9_trans_xen_exit(void)
+static void __exit p9_trans_xen_exit(void)
{
v9fs_unregister_trans(&p9_xen_trans);
return xenbus_unregister_driver(&xen_9pfs_front_driver);
}
module_exit(p9_trans_xen_exit);
+MODULE_ALIAS("xen:9pfs");
MODULE_AUTHOR("Stefano Stabellini <stefano@aporeto.com>");
MODULE_DESCRIPTION("Xen Transport for 9P");
MODULE_LICENSE("GPL");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.