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path: root/drivers/usb/usbip/stub_main.c
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Diffstat (limited to 'drivers/usb/usbip/stub_main.c')
-rw-r--r--drivers/usb/usbip/stub_main.c105
1 files changed, 92 insertions, 13 deletions
diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index d41d0cdeec0f..bf8a5feb0ee9 100644
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -14,6 +14,7 @@
#define DRIVER_DESC "USB/IP Host Driver"
struct kmem_cache *stub_priv_cache;
+
/*
* busid_tables defines matching busids that usbip can grab. A user can change
* dynamically what device is locally used and what device is exported to a
@@ -25,6 +26,8 @@ static spinlock_t busid_table_lock;
static void init_busid_table(void)
{
+ int i;
+
/*
* This also sets the bus_table[i].status to
* STUB_BUSID_OTHER, which is 0.
@@ -32,6 +35,9 @@ static void init_busid_table(void)
memset(busid_table, 0, sizeof(busid_table));
spin_lock_init(&busid_table_lock);
+
+ for (i = 0; i < MAX_BUSID; i++)
+ spin_lock_init(&busid_table[i].busid_lock);
}
/*
@@ -43,15 +49,20 @@ static int get_busid_idx(const char *busid)
int i;
int idx = -1;
- for (i = 0; i < MAX_BUSID; i++)
+ for (i = 0; i < MAX_BUSID; i++) {
+ spin_lock(&busid_table[i].busid_lock);
if (busid_table[i].name[0])
if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
idx = i;
+ spin_unlock(&busid_table[i].busid_lock);
break;
}
+ spin_unlock(&busid_table[i].busid_lock);
+ }
return idx;
}
+/* Returns holding busid_lock. Should call put_busid_priv() to unlock */
struct bus_id_priv *get_busid_priv(const char *busid)
{
int idx;
@@ -59,13 +70,22 @@ struct bus_id_priv *get_busid_priv(const char *busid)
spin_lock(&busid_table_lock);
idx = get_busid_idx(busid);
- if (idx >= 0)
+ if (idx >= 0) {
bid = &(busid_table[idx]);
+ /* get busid_lock before returning */
+ spin_lock(&bid->busid_lock);
+ }
spin_unlock(&busid_table_lock);
return bid;
}
+void put_busid_priv(struct bus_id_priv *bid)
+{
+ if (bid)
+ spin_unlock(&bid->busid_lock);
+}
+
static int add_match_busid(char *busid)
{
int i;
@@ -78,15 +98,19 @@ static int add_match_busid(char *busid)
goto out;
}
- for (i = 0; i < MAX_BUSID; i++)
+ for (i = 0; i < MAX_BUSID; i++) {
+ spin_lock(&busid_table[i].busid_lock);
if (!busid_table[i].name[0]) {
strlcpy(busid_table[i].name, busid, BUSID_SIZE);
if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
(busid_table[i].status != STUB_BUSID_REMOV))
busid_table[i].status = STUB_BUSID_ADDED;
ret = 0;
+ spin_unlock(&busid_table[i].busid_lock);
break;
}
+ spin_unlock(&busid_table[i].busid_lock);
+ }
out:
spin_unlock(&busid_table_lock);
@@ -107,6 +131,8 @@ int del_match_busid(char *busid)
/* found */
ret = 0;
+ spin_lock(&busid_table[idx].busid_lock);
+
if (busid_table[idx].status == STUB_BUSID_OTHER)
memset(busid_table[idx].name, 0, BUSID_SIZE);
@@ -114,6 +140,7 @@ int del_match_busid(char *busid)
(busid_table[idx].status != STUB_BUSID_ADDED))
busid_table[idx].status = STUB_BUSID_REMOV;
+ spin_unlock(&busid_table[idx].busid_lock);
out:
spin_unlock(&busid_table_lock);
@@ -126,9 +153,12 @@ static ssize_t match_busid_show(struct device_driver *drv, char *buf)
char *out = buf;
spin_lock(&busid_table_lock);
- for (i = 0; i < MAX_BUSID; i++)
+ for (i = 0; i < MAX_BUSID; i++) {
+ spin_lock(&busid_table[i].busid_lock);
if (busid_table[i].name[0])
out += sprintf(out, "%s ", busid_table[i].name);
+ spin_unlock(&busid_table[i].busid_lock);
+ }
spin_unlock(&busid_table_lock);
out += sprintf(out, "\n");
@@ -169,6 +199,51 @@ static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
}
static DRIVER_ATTR_RW(match_busid);
+static int do_rebind(char *busid, struct bus_id_priv *busid_priv)
+{
+ int ret;
+
+ /* device_attach() callers should hold parent lock for USB */
+ if (busid_priv->udev->dev.parent)
+ device_lock(busid_priv->udev->dev.parent);
+ ret = device_attach(&busid_priv->udev->dev);
+ if (busid_priv->udev->dev.parent)
+ device_unlock(busid_priv->udev->dev.parent);
+ if (ret < 0) {
+ dev_err(&busid_priv->udev->dev, "rebind failed\n");
+ return ret;
+ }
+ return 0;
+}
+
+static void stub_device_rebind(void)
+{
+#if IS_MODULE(CONFIG_USBIP_HOST)
+ struct bus_id_priv *busid_priv;
+ int i;
+
+ /* update status to STUB_BUSID_OTHER so probe ignores the device */
+ spin_lock(&busid_table_lock);
+ for (i = 0; i < MAX_BUSID; i++) {
+ if (busid_table[i].name[0] &&
+ busid_table[i].shutdown_busid) {
+ busid_priv = &(busid_table[i]);
+ busid_priv->status = STUB_BUSID_OTHER;
+ }
+ }
+ spin_unlock(&busid_table_lock);
+
+ /* now run rebind - no need to hold locks. driver files are removed */
+ for (i = 0; i < MAX_BUSID; i++) {
+ if (busid_table[i].name[0] &&
+ busid_table[i].shutdown_busid) {
+ busid_priv = &(busid_table[i]);
+ do_rebind(busid_table[i].name, busid_priv);
+ }
+ }
+#endif
+}
+
static ssize_t rebind_store(struct device_driver *dev, const char *buf,
size_t count)
{
@@ -186,16 +261,17 @@ static ssize_t rebind_store(struct device_driver *dev, const char *buf,
if (!bid)
return -ENODEV;
- /* device_attach() callers should hold parent lock for USB */
- if (bid->udev->dev.parent)
- device_lock(bid->udev->dev.parent);
- ret = device_attach(&bid->udev->dev);
- if (bid->udev->dev.parent)
- device_unlock(bid->udev->dev.parent);
- if (ret < 0) {
- dev_err(&bid->udev->dev, "rebind failed\n");
+ /* mark the device for deletion so probe ignores it during rescan */
+ bid->status = STUB_BUSID_OTHER;
+ /* release the busid lock */
+ put_busid_priv(bid);
+
+ ret = do_rebind((char *) buf, bid);
+ if (ret < 0)
return ret;
- }
+
+ /* delete device from busid_table */
+ del_match_busid((char *) buf);
return count;
}
@@ -317,6 +393,9 @@ static void __exit usbip_host_exit(void)
*/
usb_deregister_device_driver(&stub_driver);
+ /* initiate scan to attach devices */
+ stub_device_rebind();
+
kmem_cache_destroy(stub_priv_cache);
}