ACPI identifies peer ports by setting their 'group_token' and
'group_position' _PLD data to the same value. If a platform has tier
mismatch [1] , ACPI can override the default, USB3 defined, peer port
association for internal hubs. External hubs follow the default peer
association scheme.
Location data is cached as an opaque cookie in usb_port_location data.
Note that we only consider the group_token and group_position attributes
from the _PLD data as ACPI specifies that group_token is a unique
identifier.
[1]: xhci 1.1 appendix D figure 131
[2]: acpi 5 section 6.1.8
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/hub.h | 6 +++
drivers/usb/core/port.c | 96 +++++++++++++++++++++++++++++++++++++++++++
drivers/usb/core/usb-acpi.c | 35 +++++++++++++---
drivers/usb/core/usb.h | 2 +
4 files changed, 131 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 975a0ad3a348..5ba1bc16d4b7 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -76,6 +76,10 @@ struct usb_hub {
struct usb_port **ports;
};
+struct usb_port_location {
+ u32 cookie;
+};
+
/**
* struct usb port - kernel's representation of a usb port
* @child: usb device attached to the port
@@ -83,6 +87,7 @@ struct usb_hub {
* @port_owner: port's owner
* @peer: related usb2 and usb3 ports (share the same connector)
* @connect_type: port's connect type
+ * @location: opaque representation of platform connector location
* @portnum: port index num based one
* @power_is_on: port's power state
* @did_runtime_put: port has done pm_runtime_put().
@@ -93,6 +98,7 @@ struct usb_port {
struct dev_state *port_owner;
struct usb_port *peer;
enum usb_port_connect_type connect_type;
+ struct usb_port_location location;
u8 portnum;
unsigned power_is_on:1;
unsigned did_runtime_put:1;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 7fd22020d7ee..8fae3cd03305 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -149,11 +149,14 @@ struct device_type usb_port_device_type = {
static struct usb_port *find_peer_port(struct usb_hub *hub, int port1)
{
- struct usb_device *hdev = hub->hdev;
+ struct usb_device *hdev = hub ? hub->hdev : NULL;
struct usb_device *peer_hdev;
struct usb_port *peer = NULL;
struct usb_hub *peer_hub;
+ if (!hub)
+ return NULL;
+
/* set the default peer port for root hubs. Platform firmware
* can later fix this up if tier-mismatch is present. Assumes
* the primary_hcd is usb2.0 and registered first
@@ -193,6 +196,97 @@ static struct usb_port *find_peer_port(struct usb_hub *hub, int port1)
return peer;
}
+static void reset_peer(struct usb_port *port_dev, struct usb_port *peer)
+{
+ if (!peer)
+ return;
+
+ spin_lock(&peer_lock);
+ if (port_dev->peer)
+ put_device(&port_dev->peer->dev);
+ if (peer->peer)
+ put_device(&peer->peer->dev);
+ port_dev->peer = peer;
+ peer->peer = port_dev;
+ get_device(&peer->dev);
+ get_device(&port_dev->dev);
+ spin_unlock(&peer_lock);
+}
+
+/* assumes that location data is only set for external connectors and that
+ * external hubs never have tier mismatch
+ */
+static int redo_find_peer_port(struct device *dev, void *data)
+{
+ struct usb_port *port_dev = to_usb_port(dev);
+
+ if (is_usb_port(dev)) {
+ struct usb_device *hdev = to_usb_device(dev->parent->parent);
+ struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+ int port1 = port_dev->portnum;
+ struct usb_port *peer;
+
+ peer = find_peer_port(hub, port1);
+ reset_peer(port_dev, peer);
+ }
+
+ return device_for_each_child(dev, NULL, redo_find_peer_port);
+}
+
+static int pair_port(struct device *dev, void *data)
+{
+ struct usb_port *peer = data;
+ struct usb_port *port_dev = to_usb_port(dev);
+
+ if (!is_usb_port(dev)
+ || port_dev->location.cookie != peer->location.cookie)
+ return device_for_each_child(dev, peer, pair_port);
+
+ dev_dbg(dev->parent->parent, "port%d peer = %s port%d (by location)\n",
+ port_dev->portnum, dev_name(peer->dev.parent->parent),
+ peer->portnum);
+ if (port_dev->peer != peer) {
+ /* Sigh, tier mismatch has invalidated our ancestry.
+ * This should not be too onerous even in deep hub
+ * topologies as we will discover tier mismatch early
+ * (after platform internal hubs have been enumerated),
+ * before external hubs are probed.
+ */
+ reset_peer(port_dev, peer);
+ device_for_each_child(dev, NULL, redo_find_peer_port);
+ }
+
+ return true;
+}
+
+void usb_set_hub_port_location(struct usb_device *hdev, int port1,
+ u32 cookie)
+{
+ struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+ struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
+ struct usb_hcd *peer_hcd = hcd->shared_hcd;
+ struct usb_device *peer_hdev;
+ struct usb_port *port_dev;
+
+ if (cookie == 0)
+ return;
+
+ if (!hub)
+ return;
+
+ port_dev = hub->ports[port1 - 1];
+ port_dev->location.cookie = cookie;
+
+ /* see if a port with the same location data exists in a peer
+ * usb domain
+ */
+ if (!peer_hcd)
+ return;
+
+ peer_hdev = peer_hcd->self.root_hub;
+ device_for_each_child(&peer_hdev->dev, port_dev, pair_port);
+}
+
int usb_hub_create_port_device(struct usb_hub *hub, int port1)
{
struct usb_port *port_dev, *peer;
diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index d7cb822d6eab..8a466438bff7 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -18,7 +18,7 @@
#include <linux/usb/hcd.h>
#include <acpi/acpi_bus.h>
-#include "usb.h"
+#include "hub.h"
/**
* usb_acpi_power_manageable - check whether usb port has
@@ -42,6 +42,19 @@ bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
}
EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
+static void usb_acpi_check_port_peer(struct usb_device *hdev,
+ acpi_handle *handle, int port1,
+ struct acpi_pld_info *pld)
+{
+ if (!pld)
+ return;
+
+ #define USB_ACPI_LOCATION_VALID (1 << 31)
+ usb_set_hub_port_location(hdev, port1, USB_ACPI_LOCATION_VALID
+ | pld->group_token << 8
+ | pld->group_position);
+}
+
/**
* usb_acpi_set_power_state - control usb port's power via acpi power
* resource
@@ -83,12 +96,11 @@ int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
- acpi_handle handle, int port1)
+ acpi_handle handle, int port1, struct acpi_pld_info *pld)
{
acpi_status status;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *upc;
- struct acpi_pld_info *pld;
int ret = 0;
/*
@@ -99,8 +111,7 @@ static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
* a usb device is directly hard-wired to the port. If no visible and
* no connectable, the port would be not used.
*/
- status = acpi_get_physical_device_location(handle, &pld);
- if (ACPI_FAILURE(status))
+ if (!pld)
return -ENODEV;
status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
@@ -122,7 +133,6 @@ static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
usb_set_hub_port_connect_type(hdev, port1, USB_PORT_NOT_USED);
out:
- ACPI_FREE(pld);
kfree(upc);
return ret;
}
@@ -179,6 +189,9 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
return -ENODEV;
return 0;
} else if (is_usb_port(dev)) {
+ struct acpi_pld_info *pld;
+ acpi_status status;
+
sscanf(dev_name(dev), "port%d", &port_num);
/* Get the struct usb_device point of port's hub */
udev = to_usb_device(dev->parent->parent);
@@ -209,7 +222,15 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
if (!*handle)
return -ENODEV;
}
- usb_acpi_check_port_connect_type(udev, *handle, port_num);
+
+ status = acpi_get_physical_device_location(*handle, &pld);
+ if (ACPI_FAILURE(status))
+ pld = NULL;
+
+ usb_acpi_check_port_connect_type(udev, *handle, port_num, pld);
+ usb_acpi_check_port_peer(udev, *handle, port_num, pld);
+
+ ACPI_FREE(pld);
} else
return -ENODEV;
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index c49383669cd8..b80785106b27 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -184,6 +184,8 @@ extern enum usb_port_connect_type
usb_get_hub_port_connect_type(struct usb_device *hdev, int port1);
extern void usb_set_hub_port_connect_type(struct usb_device *hdev, int port1,
enum usb_port_connect_type type);
+extern void usb_set_hub_port_location(struct usb_device *hdev, int port1,
+ u32 cookie);
extern void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
struct usb_hub_descriptor *desc);
--
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