summaryrefslogtreecommitdiff
path: root/net/9p/trans_xen.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/9p/trans_xen.c')
-rw-r--r--net/9p/trans_xen.c224
1 files changed, 124 insertions, 100 deletions
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index e2fbf3677b9b..12f752a92332 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>
@@ -38,13 +15,14 @@
#include <linux/module.h>
#include <linux/spinlock.h>
+#include <linux/fs_context.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#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;
@@ -77,7 +55,6 @@ struct xen_9pfs_front_priv {
char *tag;
struct p9_client *client;
- int num_rings;
struct xen_9pfs_dataring *rings;
};
@@ -90,8 +67,9 @@ static int p9_xen_cancel(struct p9_client *client, struct p9_req_t *req)
return 1;
}
-static int p9_xen_create(struct p9_client *client, const char *addr, char *args)
+static int p9_xen_create(struct p9_client *client, struct fs_context *fc)
{
+ const char *addr = fc->source;
struct xen_9pfs_front_priv *priv;
if (addr == NULL)
@@ -132,13 +110,13 @@ 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;
@@ -151,10 +129,10 @@ 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;
+ num = p9_req->tc.tag % XEN_9PFS_NUM_RINGS;
ring = &priv->rings[num];
again:
@@ -167,25 +145,26 @@ 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;
+ WRITE_ONCE(p9_req->status, REQ_STATUS_SENT);
virt_wmb(); /* write ring before updating pointer */
prod += size;
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 +186,19 @@ 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) {
@@ -230,15 +209,26 @@ static void p9_xen_response(struct work_struct *work)
continue;
}
- memcpy(&req->rc, &h, sizeof(h));
+ if (h.size > req->rc.capacity) {
+ dev_warn(&priv->dev->dev,
+ "requested packet size too big: %d for tag %d with capacity %zd\n",
+ h.size, h.tag, req->rc.capacity);
+ WRITE_ONCE(req->status, REQ_STATUS_ERROR);
+ goto recv_error;
+ }
+
+ req->rc.size = h.size;
+ req->rc.id = h.id;
+ req->rc.tag = h.tag;
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));
+recv_error:
virt_mb();
cons += h.size;
ring->intf->in_cons = cons;
@@ -267,8 +257,10 @@ 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),
- .def = 1,
+ .maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2),
+ .pooled_rbuffers = false,
+ .def = true,
+ .supports_vmalloc = false,
.create = p9_xen_create,
.close = p9_xen_close,
.request = p9_xen_request,
@@ -289,23 +281,29 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
list_del(&priv->list);
write_unlock(&xen_9pfs_lock);
- for (i = 0; i < priv->num_rings; i++) {
+ for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) {
+ struct xen_9pfs_dataring *ring = &priv->rings[i];
+
+ cancel_work_sync(&ring->work);
+
if (!priv->rings[i].intf)
break;
if (priv->rings[i].irq > 0)
- unbind_from_irqhandler(priv->rings[i].irq, priv->dev);
+ unbind_from_irqhandler(priv->rings[i].irq, ring);
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);
@@ -313,17 +311,17 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
kfree(priv);
}
-static int xen_9pfs_front_remove(struct xenbus_device *dev)
+static void xen_9pfs_front_remove(struct xenbus_device *dev)
{
struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev);
dev_set_drvdata(&dev->dev, NULL);
xen_9pfs_front_free(priv);
- return 0;
}
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 +339,22 @@ 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)
@@ -372,29 +370,32 @@ 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;
}
-static int xen_9pfs_front_probe(struct xenbus_device *dev,
- const struct xenbus_device_id *id)
+static int xen_9pfs_front_init(struct xenbus_device *dev)
{
int ret, i;
struct xenbus_transaction xbt;
- struct xen_9pfs_front_priv *priv = NULL;
- char *versions;
+ struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev);
+ char *versions, *v;
unsigned int max_rings, max_ring_order, len = 0;
versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
if (IS_ERR(versions))
return PTR_ERR(versions);
- if (strcmp(versions, "1")) {
+ for (v = versions; *v; v++) {
+ if (simple_strtoul(v, &v, 10) == 1) {
+ v = NULL;
+ break;
+ }
+ }
+ if (v) {
kfree(versions);
return -EINVAL;
}
@@ -404,25 +405,22 @@ 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)
- return -ENOMEM;
-
- priv->dev = dev;
- priv->num_rings = XEN_9PFS_NUM_RINGS;
- priv->rings = kcalloc(priv->num_rings, sizeof(*priv->rings),
+ priv->rings = kcalloc(XEN_9PFS_NUM_RINGS, sizeof(*priv->rings),
GFP_KERNEL);
if (!priv->rings) {
kfree(priv);
return -ENOMEM;
}
- for (i = 0; i < priv->num_rings; i++) {
+ for (i = 0; i < XEN_9PFS_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;
}
@@ -437,20 +435,21 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "num-rings", "%u",
- priv->num_rings);
+ XEN_9PFS_NUM_RINGS);
if (ret)
goto error_xenbus;
- for (i = 0; i < priv->num_rings; i++) {
+
+ for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) {
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)
@@ -469,23 +468,36 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
goto error;
}
- write_lock(&xen_9pfs_lock);
- list_add_tail(&priv->list, &xen_9pfs_devs);
- write_unlock(&xen_9pfs_lock);
- dev_set_drvdata(&dev->dev, priv);
xenbus_switch_state(dev, XenbusStateInitialised);
-
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
error:
- dev_set_drvdata(&dev->dev, NULL);
xen_9pfs_front_free(priv);
return ret;
}
+static int xen_9pfs_front_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ struct xen_9pfs_front_priv *priv = NULL;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+ dev_set_drvdata(&dev->dev, priv);
+
+ write_lock(&xen_9pfs_lock);
+ list_add_tail(&priv->list, &xen_9pfs_devs);
+ write_unlock(&xen_9pfs_lock);
+
+ return 0;
+}
+
static int xen_9pfs_front_resume(struct xenbus_device *dev)
{
dev_warn(&dev->dev, "suspend/resume unsupported\n");
@@ -504,6 +516,10 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
break;
case XenbusStateInitWait:
+ if (dev->state != XenbusStateInitialising)
+ break;
+
+ xen_9pfs_front_init(dev);
break;
case XenbusStateConnected:
@@ -513,7 +529,7 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
case XenbusStateClosed:
if (dev->state == XenbusStateClosed)
break;
- /* Missed the backend's CLOSING state -- fallthrough */
+ fallthrough; /* Missed the backend's CLOSING state */
case XenbusStateClosing:
xenbus_frontend_closed(dev);
break;
@@ -528,25 +544,33 @@ 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;
+
if (!xen_domain())
return -ENODEV;
pr_info("Initialising Xen transport for 9pfs\n");
v9fs_register_trans(&p9_xen_trans);
- return xenbus_register_frontend(&xen_9pfs_front_driver);
+ rc = xenbus_register_frontend(&xen_9pfs_front_driver);
+ if (rc)
+ v9fs_unregister_trans(&p9_xen_trans);
+
+ 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");
generated by cgit (git 2.34.1) at 2025-12-25 02:47:55 +0000