[PATCH 14/24] thunderbolt: Let the connection manager handle all notifications

[Mika Westerberg]

Currently the control channel (ctl.c) handles the one supported
notification (PLUG_EVENT) and sends back ACK accordingly. However, we
are going to add support for the internal connection manager (ICM) that
needs to handle a different notifications. So instead of dealing
everything in the control channel, we change the callback to take an
arbitrary thunderbolt packet and convert the native connection manager
to handle the event itself.

In addition we only push replies we know of to the response FIFO.
Everything else is treated as notification (or request) and is expected
to be dealt by the connection manager implementation.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@xxxxxxxxx>
Reviewed-by: Michael Jamet <michael.jamet@xxxxxxxxx>
---
 drivers/thunderbolt/ctl.c    | 86 ++++++++++++++++++++++++++++++--------------
 drivers/thunderbolt/ctl.h    |  5 +--
 drivers/thunderbolt/domain.c | 15 +++++++-
 drivers/thunderbolt/tb.c     | 30 ++++++++++++----
 drivers/thunderbolt/tb.h     |  5 +--
 5 files changed, 103 insertions(+), 38 deletions(-)

diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
index 87880dc53199..b3ee755fdb37 100644
--- a/drivers/thunderbolt/ctl.c
+++ b/drivers/thunderbolt/ctl.c
@@ -35,7 +35,7 @@ struct tb_ctl {
 	DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16);
 	struct completion response_ready;
 
-	hotplug_cb callback;
+	event_cb callback;
 	void *callback_data;
 };
 
@@ -52,6 +52,9 @@ struct tb_ctl {
 #define tb_ctl_info(ctl, format, arg...) \
 	dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
 
+#define tb_ctl_dbg(ctl, format, arg...) \
+	dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg)
+
 /* utility functions */
 
 static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type,
@@ -272,24 +275,12 @@ static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
 }
 
 /**
- * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback
+ * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback
  */
-static void tb_ctl_handle_plug_event(struct tb_ctl *ctl,
-				     struct ctl_pkg *response)
+static void tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,
+				struct ctl_pkg *pkg, size_t size)
 {
-	struct cfg_event_pkg *pkg = response->buffer;
-	u64 route = tb_cfg_get_route(&pkg->header);
-
-	if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) {
-		tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n");
-		return;
-	}
-
-	if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT))
-		tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n",
-			    route, pkg->port);
-	WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero);
-	ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug);
+	ctl->callback(ctl->callback_data, type, pkg->buffer, size);
 }
 
 static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
@@ -302,10 +293,29 @@ static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
 					     */
 }
 
+static int tb_async_error(const struct ctl_pkg *pkg)
+{
+	const struct cfg_error_pkg *error = (const struct cfg_error_pkg *)pkg;
+
+	if (pkg->frame.eof != TB_CFG_PKG_ERROR)
+		return false;
+
+	switch (error->error) {
+	case TB_CFG_ERROR_LINK_ERROR:
+	case TB_CFG_ERROR_HEC_ERROR_DETECTED:
+	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
 static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
 			       bool canceled)
 {
 	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
+	__be32 crc32;
 
 	if (canceled)
 		return; /*
@@ -320,18 +330,42 @@ static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
 	}
 
 	frame->size -= 4; /* remove checksum */
-	if (*(__be32 *) (pkg->buffer + frame->size)
-			!= tb_crc(pkg->buffer, frame->size)) {
-		tb_ctl_err(pkg->ctl,
-			   "RX: checksum mismatch, dropping packet\n");
-		goto rx;
-	}
+	crc32 = tb_crc(pkg->buffer, frame->size);
 	be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
 
-	if (frame->eof == TB_CFG_PKG_EVENT) {
-		tb_ctl_handle_plug_event(pkg->ctl, pkg);
+	switch (frame->eof) {
+	case TB_CFG_PKG_READ:
+	case TB_CFG_PKG_WRITE:
+	case TB_CFG_PKG_ERROR:
+	case TB_CFG_PKG_OVERRIDE:
+	case TB_CFG_PKG_RESET:
+		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
+			tb_ctl_err(pkg->ctl,
+				   "RX: checksum mismatch, dropping packet\n");
+			goto rx;
+		}
+		if (tb_async_error(pkg)) {
+			tb_ctl_handle_event(pkg->ctl, frame->eof,
+					    pkg, frame->size);
+			goto rx;
+		}
+		break;
+
+	case TB_CFG_PKG_EVENT:
+		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
+			tb_ctl_err(pkg->ctl,
+				   "RX: checksum mismatch, dropping packet\n");
+			goto rx;
+		}
+		tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size);
+		goto rx;
+
+	default:
+		tb_ctl_dbg(pkg->ctl, "RX: unknown package %#x, dropping\n",
+			   frame->eof);
 		goto rx;
 	}
+
 	if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) {
 		tb_ctl_err(pkg->ctl, "RX: fifo is full\n");
 		goto rx;
@@ -379,7 +413,7 @@ static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer,
  *
  * Return: Returns a pointer on success or NULL on failure.
  */
-struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data)
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, event_cb cb, void *cb_data)
 {
 	int i;
 	struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
diff --git a/drivers/thunderbolt/ctl.h b/drivers/thunderbolt/ctl.h
index 914da86ec77d..2b23e030a85b 100644
--- a/drivers/thunderbolt/ctl.h
+++ b/drivers/thunderbolt/ctl.h
@@ -13,9 +13,10 @@
 /* control channel */
 struct tb_ctl;
 
-typedef void (*hotplug_cb)(void *data, u64 route, u8 port, bool unplug);
+typedef void (*event_cb)(void *data, enum tb_cfg_pkg_type type,
+			 const void *buf, size_t size);
 
-struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data);
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, event_cb cb, void *cb_data);
 void tb_ctl_start(struct tb_ctl *ctl);
 void tb_ctl_stop(struct tb_ctl *ctl);
 void tb_ctl_free(struct tb_ctl *ctl);
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index b5bfca95415d..99fe34d16b18 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -96,6 +96,19 @@ struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
 	return NULL;
 }
 
+static void tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
+			       const void *buf, size_t size)
+{
+	struct tb *tb = data;
+
+	if (!tb->cm_ops->handle_event) {
+		tb_warn(tb, "domain does not have event handler\n");
+		return;
+	}
+
+	tb->cm_ops->handle_event(tb, type, buf, size);
+}
+
 /**
  * tb_domain_add() - Add domain to the system
  * @tb: Domain to add
@@ -116,7 +129,7 @@ int tb_domain_add(struct tb *tb)
 
 	mutex_lock(&tb->lock);
 
-	tb->ctl = tb_ctl_alloc(tb->nhi, tb->cm_ops->hotplug, tb);
+	tb->ctl = tb_ctl_alloc(tb->nhi, tb_domain_event_cb, tb);
 	if (!tb->ctl) {
 		ret = -ENOMEM;
 		goto err_unlock;
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 94ecac012428..ea9de49b5e10 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -311,18 +311,34 @@ static void tb_handle_hotplug(struct work_struct *work)
  *
  * Delegates to tb_handle_hotplug.
  */
-static void tb_schedule_hotplug_handler(void *data, u64 route, u8 port,
-					bool unplug)
+static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
+			    const void *buf, size_t size)
 {
-	struct tb *tb = data;
-	struct tb_hotplug_event *ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+	const struct cfg_event_pkg *pkg = buf;
+	struct tb_hotplug_event *ev;
+	u64 route;
+
+	if (type != TB_CFG_PKG_EVENT) {
+		tb_warn(tb, "unexpected event %#x, ignoring\n", type);
+		return;
+	}
+
+	route = tb_cfg_get_route(&pkg->header);
+
+	if (tb_cfg_error(tb->ctl, route, pkg->port,
+			 TB_CFG_ERROR_ACK_PLUG_EVENT)) {
+		tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
+			pkg->port);
+	}
+
+	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
 	if (!ev)
 		return;
 	INIT_WORK(&ev->work, tb_handle_hotplug);
 	ev->tb = tb;
 	ev->route = route;
-	ev->port = port;
-	ev->unplug = unplug;
+	ev->port = pkg->port;
+	ev->unplug = pkg->unplug;
 	queue_work(tb->wq, &ev->work);
 }
 
@@ -419,7 +435,7 @@ static const struct tb_cm_ops tb_cm_ops = {
 	.stop = tb_stop,
 	.suspend_noirq = tb_suspend_noirq,
 	.resume_noirq = tb_resume_noirq,
-	.hotplug = tb_schedule_hotplug_handler,
+	.handle_event = tb_handle_event,
 };
 
 struct tb *tb_probe(struct tb_nhi *nhi)
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 5e66dce53c65..73db614fa913 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -118,14 +118,15 @@ struct tb_path {
  * @stop: Stops the domain
  * @suspend_noirq: Connection manager specific suspend_noirq
  * @resume_noirq: Connection manager specific resume_noirq
- * @hotplug: Handle hotplug event
+ * @handle_event: Handle thunderbolt event
  */
 struct tb_cm_ops {
 	int (*start)(struct tb *tb);
 	void (*stop)(struct tb *tb);
 	int (*suspend_noirq)(struct tb *tb);
 	int (*resume_noirq)(struct tb *tb);
-	hotplug_cb hotplug;
+	void (*handle_event)(struct tb *tb, enum tb_cfg_pkg_type,
+			     const void *buf, size_t size);
 };
 
 /**
-- 
2.11.0