rapidio: add global inbound port write interfaces

Add new Port Write handler registration interfaces that attach PW
handlers to local mport device objects.  This is different from old
interface that attaches PW callback to individual RapidIO device.  The
new interfaces are intended for use for common event handling (e.g.
hot-plug notifications) while the old interface is available for
individual device drivers.

This patch is based on patch proposed by Andre van Herk but preserves
existing per-device interface and adds lock protection for list
handling.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 122 insertions, 44 deletions

diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index db95d71..5e1d526 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -36,8 +36,6 @@
 
 #include "tsi721.h"
 
-#define DEBUG_PW	/* Inbound Port-Write debugging */
-
 static void tsi721_omsg_handler(struct tsi721_device *priv, int ch);
 static void tsi721_imsg_handler(struct tsi721_device *priv, int ch);
 
@@ -282,30 +280,15 @@ static void tsi721_pw_dpc(struct work_struct *work)
 {
 	struct tsi721_device *priv = container_of(work, struct tsi721_device,
 						    pw_work);
-	u32 msg_buffer[RIO_PW_MSG_SIZE/sizeof(u32)]; /* Use full size PW message
-							buffer for RIO layer */
+	union rio_pw_msg pwmsg;
 
 	/*
 	 * Process port-write messages
 	 */
-	while (kfifo_out_spinlocked(&priv->pw_fifo, (unsigned char *)msg_buffer,
+	while (kfifo_out_spinlocked(&priv->pw_fifo, (unsigned char *)&pwmsg,
 			 TSI721_RIO_PW_MSG_SIZE, &priv->pw_fifo_lock)) {
-		/* Process one message */
-#ifdef DEBUG_PW
-		{
-		u32 i;
-		pr_debug("%s : Port-Write Message:", __func__);
-		for (i = 0; i < RIO_PW_MSG_SIZE/sizeof(u32); ) {
-			pr_debug("0x%02x: %08x %08x %08x %08x", i*4,
-				msg_buffer[i], msg_buffer[i + 1],
-				msg_buffer[i + 2], msg_buffer[i + 3]);
-			i += 4;
-		}
-		pr_debug("\n");
-		}
-#endif
 		/* Pass the port-write message to RIO core for processing */
-		rio_inb_pwrite_handler((union rio_pw_msg *)msg_buffer);
+		rio_inb_pwrite_handler(&priv->mport, &pwmsg);
 	}
 }
 
@@ -2702,6 +2685,7 @@ static void tsi721_remove(struct pci_dev *pdev)
 
 	tsi721_disable_ints(priv);
 	tsi721_free_irq(priv);
+	flush_scheduled_work();
 	rio_unregister_mport(&priv->mport);
 
 	tsi721_unregister_dma(priv);
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 673774b..17973d3 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -30,6 +30,20 @@
 
 #include "rio.h"
 
+/*
+ * struct rio_pwrite - RIO portwrite event
+ * @node:    Node in list of doorbell events
+ * @pwcback: Doorbell event callback
+ * @context: Handler specific context to pass on event
+ */
+struct rio_pwrite {
+	struct list_head node;
+
+	int (*pwcback)(struct rio_mport *mport, void *context,
+		       union rio_pw_msg *msg, int step);
+	void *context;
+};
+
 MODULE_DESCRIPTION("RapidIO Subsystem Core");
 MODULE_AUTHOR("Matt Porter <mporter@kernel.crashing.org>");
 MODULE_AUTHOR("Alexandre Bounine <alexandre.bounine@idt.com>");
@@ -514,7 +528,71 @@ int rio_release_outb_dbell(struct rio_dev *rdev, struct resource *res)
 }
 
 /**
- * rio_request_inb_pwrite - request inbound port-write message service
+ * rio_add_mport_pw_handler - add port-write message handler into the list
+ *                            of mport specific pw handlers
+ * @mport:   RIO master port to bind the portwrite callback
+ * @context: Handler specific context to pass on event
+ * @pwcback: Callback to execute when portwrite is received
+ *
+ * Returns 0 if the request has been satisfied.
+ */
+int rio_add_mport_pw_handler(struct rio_mport *mport, void *context,
+			     int (*pwcback)(struct rio_mport *mport,
+			     void *context, union rio_pw_msg *msg, int step))
+{
+	int rc = 0;
+	struct rio_pwrite *pwrite;
+
+	pwrite = kzalloc(sizeof(struct rio_pwrite), GFP_KERNEL);
+	if (!pwrite) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	pwrite->pwcback = pwcback;
+	pwrite->context = context;
+	mutex_lock(&mport->lock);
+	list_add_tail(&pwrite->node, &mport->pwrites);
+	mutex_unlock(&mport->lock);
+out:
+	return rc;
+}
+EXPORT_SYMBOL_GPL(rio_add_mport_pw_handler);
+
+/**
+ * rio_del_mport_pw_handler - remove port-write message handler from the list
+ *                            of mport specific pw handlers
+ * @mport:   RIO master port to bind the portwrite callback
+ * @context: Registered handler specific context to pass on event
+ * @pwcback: Registered callback function
+ *
+ * Returns 0 if the request has been satisfied.
+ */
+int rio_del_mport_pw_handler(struct rio_mport *mport, void *context,
+			     int (*pwcback)(struct rio_mport *mport,
+			     void *context, union rio_pw_msg *msg, int step))
+{
+	int rc = -EINVAL;
+	struct rio_pwrite *pwrite;
+
+	mutex_lock(&mport->lock);
+	list_for_each_entry(pwrite, &mport->pwrites, node) {
+		if (pwrite->pwcback == pwcback && pwrite->context == context) {
+			list_del(&pwrite->node);
+			kfree(pwrite);
+			rc = 0;
+			break;
+		}
+	}
+	mutex_unlock(&mport->lock);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(rio_del_mport_pw_handler);
+
+/**
+ * rio_request_inb_pwrite - request inbound port-write message service for
+ *                          specific RapidIO device
  * @rdev: RIO device to which register inbound port-write callback routine
  * @pwcback: Callback routine to execute when port-write is received
  *
@@ -539,6 +617,7 @@ EXPORT_SYMBOL_GPL(rio_request_inb_pwrite);
 
 /**
  * rio_release_inb_pwrite - release inbound port-write message service
+ *                          associated with specific RapidIO device
  * @rdev: RIO device which registered for inbound port-write callback
  *
  * Removes callback from the rio_dev structure. Returns 0 if the request
@@ -1002,52 +1081,66 @@ rd_err:
 }
 
 /**
- * rio_inb_pwrite_handler - process inbound port-write message
+ * rio_inb_pwrite_handler - inbound port-write message handler
+ * @mport:  mport device associated with port-write
  * @pw_msg: pointer to inbound port-write message
  *
  * Processes an inbound port-write message. Returns 0 if the request
  * has been satisfied.
  */
-int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg)
+int rio_inb_pwrite_handler(struct rio_mport *mport, union rio_pw_msg *pw_msg)
 {
 	struct rio_dev *rdev;
 	u32 err_status, em_perrdet, em_ltlerrdet;
 	int rc, portnum;
-
-	rdev = rio_get_comptag((pw_msg->em.comptag & RIO_CTAG_UDEVID), NULL);
-	if (rdev == NULL) {
-		/* Device removed or enumeration error */
-		pr_debug("RIO: %s No matching device for CTag 0x%08x\n",
-			__func__, pw_msg->em.comptag);
-		return -EIO;
-	}
-
-	pr_debug("RIO: Port-Write message from %s\n", rio_name(rdev));
+	struct rio_pwrite *pwrite;
 
 #ifdef DEBUG_PW
 	{
-	u32 i;
-	for (i = 0; i < RIO_PW_MSG_SIZE/sizeof(u32);) {
+		u32 i;
+
+		pr_debug("%s: PW to mport_%d:\n", __func__, mport->id);
+		for (i = 0; i < RIO_PW_MSG_SIZE / sizeof(u32); i = i + 4) {
 			pr_debug("0x%02x: %08x %08x %08x %08x\n",
-				 i*4, pw_msg->raw[i], pw_msg->raw[i + 1],
-				 pw_msg->raw[i + 2], pw_msg->raw[i + 3]);
-			i += 4;
-	}
+				i * 4, pw_msg->raw[i], pw_msg->raw[i + 1],
+				pw_msg->raw[i + 2], pw_msg->raw[i + 3]);
+		}
 	}
 #endif
 
-	/* Call an external service function (if such is registered
-	 * for this device). This may be the service for endpoints that send
-	 * device-specific port-write messages. End-point messages expected
-	 * to be handled completely by EP specific device driver.
+	rdev = rio_get_comptag((pw_msg->em.comptag & RIO_CTAG_UDEVID), NULL);
+	if (rdev) {
+		pr_debug("RIO: Port-Write message from %s\n", rio_name(rdev));
+	} else {
+		pr_debug("RIO: %s No matching device for CTag 0x%08x\n",
+			__func__, pw_msg->em.comptag);
+	}
+
+	/* Call a device-specific handler (if it is registered for the device).
+	 * This may be the service for endpoints that send device-specific
+	 * port-write messages. End-point messages expected to be handled
+	 * completely by EP specific device driver.
 	 * For switches rc==0 signals that no standard processing required.
 	 */
-	if (rdev->pwcback != NULL) {
+	if (rdev && rdev->pwcback) {
 		rc = rdev->pwcback(rdev, pw_msg, 0);
 		if (rc == 0)
 			return 0;
 	}
 
+	mutex_lock(&mport->lock);
+	list_for_each_entry(pwrite, &mport->pwrites, node)
+		pwrite->pwcback(mport, pwrite->context, pw_msg, 0);
+	mutex_unlock(&mport->lock);
+
+	if (!rdev)
+		return 0;
+
+	/*
+	 * FIXME: The code below stays as it was before for now until we decide
+	 * how to do default PW handling in combination with per-mport callbacks
+	 */
+
 	portnum = pw_msg->em.is_port & 0xFF;
 
 	/* Check if device and route to it are functional:
@@ -2060,6 +2153,7 @@ int rio_mport_initialize(struct rio_mport *mport)
 	mport->nscan = NULL;
 	mutex_init(&mport->lock);
 	mport->pwe_refcnt = 0;
+	INIT_LIST_HEAD(&mport->pwrites);
 
 	return 0;
 }