firewire: implement asynchronous stream transmission

Allow userspace and other firewire drivers (fw-ipv4 I'm looking at
you!) to send Asynchronous Transmit Streams as described in 7.8.3 of
release 1.1 of the 1394 Open Host Controller Interface Specification.

Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (tweaks)

5 files changed, 108 insertions, 2 deletions

diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 214e534efee5..539dae5eb5b2 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -1242,6 +1242,38 @@ static int ioctl_send_broadcast_request(struct client *client, void *buffer)
         return init_request(client, request, LOCAL_BUS | 0x3f, SCODE_100);
 }
 
+struct stream_packet {
+        struct fw_packet packet;
+        u8 data[0];
+};
+
+static void send_stream_packet_done(struct fw_packet *packet,
+                                    struct fw_card *card, int status)
+{
+        kfree(container_of(packet, struct stream_packet, packet));
+}
+
+static int ioctl_send_stream_packet(struct client *client, void *buffer)
+{
+        struct fw_cdev_send_stream_packet *request = buffer;
+        struct stream_packet *p;
+
+        p = kmalloc(sizeof(*p) + request->size, GFP_KERNEL);
+        if (p == NULL)
+                return -ENOMEM;
+
+        if (request->data &&
+            copy_from_user(p->data, u64_to_uptr(request->data), request->size)) {
+                kfree(p);
+                return -EFAULT;
+        }
+        fw_send_stream_packet(client->device->card, &p->packet,
+                              request->generation, request->speed,
+                              request->channel, request->sy, request->tag,
+                              p->data, request->size, send_stream_packet_done);
+        return 0;
+}
+
 static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
         ioctl_get_info,
         ioctl_send_request,
@@ -1262,6 +1294,7 @@ static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
         ioctl_deallocate_iso_resource_once,
         ioctl_get_speed,
         ioctl_send_broadcast_request,
+        ioctl_send_stream_packet,
 };
 
 static int dispatch_ioctl(struct client *client,
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index c92278374658..1180d0be0bb4 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -936,7 +936,9 @@ static int at_context_queue_packet(struct context *ctx,
          */
 
         header = (__le32 *) &d[1];
-        if (packet->header_length > 8) {
+        switch (packet->header_length) {
+        case 16:
+        case 12:
                 header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
                                         (packet->speed << 16));
                 header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
@@ -950,12 +952,27 @@ static int at_context_queue_packet(struct context *ctx,
                         header[3] = (__force __le32) packet->header[3];
 
                 d[0].req_count = cpu_to_le16(packet->header_length);
-        } else {
+                break;
+
+        case 8:
                 header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
                                         (packet->speed << 16));
                 header[1] = cpu_to_le32(packet->header[0]);
                 header[2] = cpu_to_le32(packet->header[1]);
                 d[0].req_count = cpu_to_le16(12);
+                break;
+
+        case 4:
+                header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
+                                        (packet->speed << 16));
+                header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
+                d[0].req_count = cpu_to_le16(8);
+                break;
+
+        default:
+                /* BUG(); */
+                packet->ack = RCODE_SEND_ERROR;
+                return -1;
         }
 
         driver_data = (struct driver_data *) &d[3];
diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 76938fe432a0..e3da58991960 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -37,6 +37,10 @@
 #include "fw-topology.h"
 #include "fw-device.h"
 
+#define HEADER_TAG(tag)                 ((tag) << 14)
+#define HEADER_CHANNEL(ch)              ((ch) << 8)
+#define HEADER_SY(sy)                   ((sy) << 0)
+
 #define HEADER_PRI(pri)                 ((pri) << 0)
 #define HEADER_TCODE(tcode)             ((tcode) << 4)
 #define HEADER_RETRY(retry)             ((retry) << 8)
@@ -293,6 +297,27 @@ void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
 }
 EXPORT_SYMBOL(fw_send_request);
 
+void fw_send_stream_packet(struct fw_card *card, struct fw_packet *p,
+                int generation, int speed, int channel, int sy, int tag,
+                void *payload, size_t length, fw_packet_callback_t callback)
+{
+        p->callback = callback;
+        p->header[0] =
+                  HEADER_DATA_LENGTH(length)
+                | HEADER_TAG(tag)
+                | HEADER_CHANNEL(channel)
+                | HEADER_TCODE(TCODE_STREAM_DATA)
+                | HEADER_SY(sy);
+        p->header_length = 4;
+        p->payload = payload;
+        p->payload_length = length;
+        p->speed = speed;
+        p->generation = generation;
+        p->ack = 0;
+
+        card->driver->send_request(card, p);
+}
+
 struct transaction_callback_data {
         struct completion done;
         void *payload;
diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h
index 35d0a4bb6d5c..eed2e295eb3c 100644
--- a/drivers/firewire/fw-transaction.h
+++ b/drivers/firewire/fw-transaction.h
@@ -407,6 +407,10 @@ void fw_send_request(struct fw_card *card, struct fw_transaction *t,
                 int tcode, int destination_id, int generation, int speed,
                 unsigned long long offset, void *payload, size_t length,
                 fw_transaction_callback_t callback, void *callback_data);
+void fw_send_stream_packet(struct fw_card *card, struct fw_packet *p,
+                int generation, int speed, int channel, int sy, int tag,
+                void *payload, size_t length, fw_packet_callback_t callback);
+
 int fw_cancel_transaction(struct fw_card *card,
                           struct fw_transaction *transaction);
 void fw_flush_transactions(struct fw_card *card);
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 2e35379bf96c..4dfc84d0ac76 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -246,6 +246,7 @@ union fw_cdev_event {
 #define FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE_ONCE _IOW('#', 0x10, struct fw_cdev_allocate_iso_resource)
 #define FW_CDEV_IOC_GET_SPEED                    _IOR('#', 0x11, struct fw_cdev_get_speed)
 #define FW_CDEV_IOC_SEND_BROADCAST_REQUEST       _IOW('#', 0x12, struct fw_cdev_send_request)
+#define FW_CDEV_IOC_SEND_STREAM_PACKET           _IOW('#', 0x13, struct fw_cdev_send_stream_packet)
 
 /*
  * FW_CDEV_VERSION History
@@ -609,4 +610,30 @@ struct fw_cdev_get_speed {
         __u32 max_speed;
 };
 
+/**
+ * struct fw_cdev_send_stream_packet - send an asynchronous stream packet
+ * @generation:   Bus generation where the packet is valid
+ * @speed:        Speed code to send the packet at
+ * @channel:      Channel to send the packet on
+ * @sy:           Four-bit sy code for the packet
+ * @tag:          Two-bit tag field to use for the packet
+ * @size:         Size of the packet's data payload
+ * @data:         Userspace pointer to the payload
+ *
+ * The %FW_CDEV_IOC_SEND_STREAM_PACKET ioctl sends an asynchronous stream packet
+ * to every device (that is listening to the specified channel) on the
+ * firewire bus.  It is the applications's job to ensure
+ * that the intended device(s) will be able to receive the packet at the chosen
+ * transmit speed.
+ */
+struct fw_cdev_send_stream_packet {
+        __u32 generation;
+        __u32 speed;
+        __u32 channel;
+        __u32 sy;
+        __u32 tag;
+        __u32 size;
+        __u64 data;
+};
+
 #endif /* _LINUX_FIREWIRE_CDEV_H */