firewire: cdev: add PHY packet reception
Add an FW_CDEV_IOC_RECEIVE_PHY_PACKETS ioctl() and
FW_CDEV_EVENT_PHY_PACKET_RECEIVED poll()/read() event for /dev/fw*.
This can be used to get information from remote PHYs by remote access
PHY packets.
This is also the 2nd half of the functionality (the receive part) to
support a userspace implementation of a VersaPHY transaction layer.
Safety considerations:
- PHY packets are generally broadcasts, hence some kind of elevated
privileges should be required of a process to be able to listen in
on PHY packets. This implementation assumes that a process that is
allowed to open the /dev/fw* of a local node does have this
privilege.
There was an inconclusive discussion about introducing POSIX
capabilities as a means to check for user privileges for these
kinds of operations.
Other limitations:
- PHY packet reception may be switched on by ioctl() but cannot be
switched off again. It would be trivial to provide an off switch,
but this is not worth the code. The client should simply close()
the fd then, or just ignore further events.
- For sake of simplicity of API and kernel-side implementation, no
filter per packet content is provided.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 0c312c4..6d1cfae 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -500,6 +500,7 @@
kref_init(&card->kref);
init_completion(&card->done);
INIT_LIST_HEAD(&card->transaction_list);
+ INIT_LIST_HEAD(&card->phy_receiver_list);
spin_lock_init(&card->lock);
card->local_node = NULL;
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index f957199..0425dd5 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -69,6 +69,9 @@
struct fw_iso_buffer buffer;
unsigned long vm_start;
+ struct list_head phy_receiver_link;
+ u64 phy_receiver_closure;
+
struct list_head link;
struct kref kref;
};
@@ -201,6 +204,11 @@
struct fw_cdev_event_phy_packet phy_packet;
};
+struct inbound_phy_packet_event {
+ struct event event;
+ struct fw_cdev_event_phy_packet phy_packet;
+};
+
static inline void __user *u64_to_uptr(__u64 value)
{
return (void __user *)(unsigned long)value;
@@ -236,6 +244,7 @@
idr_init(&client->resource_idr);
INIT_LIST_HEAD(&client->event_list);
init_waitqueue_head(&client->wait);
+ INIT_LIST_HEAD(&client->phy_receiver_link);
kref_init(&client->kref);
file->private_data = client;
@@ -357,7 +366,7 @@
e = kzalloc(sizeof(*e), GFP_KERNEL);
if (e == NULL) {
- fw_notify("Out of memory when allocating bus reset event\n");
+ fw_notify("Out of memory when allocating event\n");
return;
}
@@ -404,6 +413,7 @@
struct fw_cdev_send_stream_packet send_stream_packet;
struct fw_cdev_get_cycle_timer2 get_cycle_timer2;
struct fw_cdev_send_phy_packet send_phy_packet;
+ struct fw_cdev_receive_phy_packets receive_phy_packets;
};
static int ioctl_get_info(struct client *client, union ioctl_arg *arg)
@@ -671,9 +681,10 @@
r = kmalloc(sizeof(*r), GFP_ATOMIC);
e = kmalloc(sizeof(*e), GFP_ATOMIC);
- if (r == NULL || e == NULL)
+ if (r == NULL || e == NULL) {
+ fw_notify("Out of memory when allocating event\n");
goto failed;
-
+ }
r->card = card;
r->request = request;
r->data = payload;
@@ -902,9 +913,10 @@
struct iso_interrupt_event *e;
e = kmalloc(sizeof(*e) + header_length, GFP_ATOMIC);
- if (e == NULL)
+ if (e == NULL) {
+ fw_notify("Out of memory when allocating event\n");
return;
-
+ }
e->interrupt.type = FW_CDEV_EVENT_ISO_INTERRUPT;
e->interrupt.closure = client->iso_closure;
e->interrupt.cycle = cycle;
@@ -1447,6 +1459,52 @@
return 0;
}
+static int ioctl_receive_phy_packets(struct client *client, union ioctl_arg *arg)
+{
+ struct fw_cdev_receive_phy_packets *a = &arg->receive_phy_packets;
+ struct fw_card *card = client->device->card;
+
+ /* Access policy: Allow this ioctl only on local nodes' device files. */
+ if (!client->device->is_local)
+ return -ENOSYS;
+
+ spin_lock_irq(&card->lock);
+
+ list_move_tail(&client->phy_receiver_link, &card->phy_receiver_list);
+ client->phy_receiver_closure = a->closure;
+
+ spin_unlock_irq(&card->lock);
+
+ return 0;
+}
+
+void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p)
+{
+ struct client *client;
+ struct inbound_phy_packet_event *e;
+ unsigned long flags;
+
+ spin_lock_irqsave(&card->lock, flags);
+
+ list_for_each_entry(client, &card->phy_receiver_list, phy_receiver_link) {
+ e = kmalloc(sizeof(*e) + 8, GFP_ATOMIC);
+ if (e == NULL) {
+ fw_notify("Out of memory when allocating event\n");
+ break;
+ }
+ e->phy_packet.closure = client->phy_receiver_closure;
+ e->phy_packet.type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED;
+ e->phy_packet.rcode = RCODE_COMPLETE;
+ e->phy_packet.length = 8;
+ e->phy_packet.data[0] = p->header[1];
+ e->phy_packet.data[1] = p->header[2];
+ queue_event(client, &e->event,
+ &e->phy_packet, sizeof(e->phy_packet) + 8, NULL, 0);
+ }
+
+ spin_unlock_irqrestore(&card->lock, flags);
+}
+
static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = {
[0x00] = ioctl_get_info,
[0x01] = ioctl_send_request,
@@ -1470,6 +1528,7 @@
[0x13] = ioctl_send_stream_packet,
[0x14] = ioctl_get_cycle_timer2,
[0x15] = ioctl_send_phy_packet,
+ [0x16] = ioctl_receive_phy_packets,
};
static int dispatch_ioctl(struct client *client,
@@ -1577,6 +1636,10 @@
struct client *client = file->private_data;
struct event *event, *next_event;
+ spin_lock_irq(&client->device->card->lock);
+ list_del(&client->phy_receiver_link);
+ spin_unlock_irq(&client->device->card->lock);
+
mutex_lock(&client->device->client_list_mutex);
list_del(&client->link);
mutex_unlock(&client->device->client_list_mutex);
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index e2e4dc62..6f225ca 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -883,6 +883,11 @@
if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
return;
+ if (TCODE_IS_LINK_INTERNAL(HEADER_GET_TCODE(p->header[0]))) {
+ fw_cdev_handle_phy_packet(card, p);
+ return;
+ }
+
request = allocate_request(card, p);
if (request == NULL) {
/* FIXME: send statically allocated busy packet. */
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index ff6c909..3102b6b 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -128,6 +128,7 @@
void fw_device_cdev_update(struct fw_device *device);
void fw_device_cdev_remove(struct fw_device *device);
+void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p);
/* -device */
@@ -214,6 +215,7 @@
#define TCODE_IS_READ_REQUEST(tcode) (((tcode) & ~1) == 4)
#define TCODE_IS_BLOCK_PACKET(tcode) (((tcode) & 1) != 0)
+#define TCODE_IS_LINK_INTERNAL(tcode) ((tcode) == 0xe)
#define TCODE_IS_REQUEST(tcode) (((tcode) & 2) == 0)
#define TCODE_IS_RESPONSE(tcode) (((tcode) & 2) != 0)
#define TCODE_HAS_REQUEST_DATA(tcode) (((tcode) & 12) != 4)
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index bb6a92b..08afccc 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1759,10 +1759,9 @@
OHCI1394_HCControl_noByteSwapData);
reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
- reg_write(ohci, OHCI1394_LinkControlClear,
- OHCI1394_LinkControl_rcvPhyPkt);
reg_write(ohci, OHCI1394_LinkControlSet,
OHCI1394_LinkControl_rcvSelfID |
+ OHCI1394_LinkControl_rcvPhyPkt |
OHCI1394_LinkControl_cycleTimerEnable |
OHCI1394_LinkControl_cycleMaster);