SYSLINK: IPC - changes for messageQ unblock

Added a new command in messageq to unblock. A new variable
is also added to the messageq object to unblock the messageq.
The purpose of unblock is to unblock the messageq_get() when
it is pending for a new message with MessageQ_FOREVER timeout. The
messageq_unblock is intended for use before deletion of messageq
and it unblocks messageq_get() with MessageQ_FOREVER timeout value
for termination.

Signed-off-by: Shahid Akhtar <[email protected]>

Author: Shahid Akhtar

arch/arm/plat-omap/include/syslink/ipc_ioctl.h

@@ -34,7 +34,7 @@ enum ipc_command_count {
 	SHAREDREGION_CMD_NOS = 13,
 	GATEMP_CMD_NOS = 13,
 	LISTMP_CMD_NOS = 19,
-	MESSAGEQ_CMD_NOS = 18,
+	MESSAGEQ_CMD_NOS = 19,
 	IPC_CMD_NOS = 5,
 	SYSMEMMGR_CMD_NOS = 6,
 	HEAPMEMMP_CMD_NOS = 15,

arch/arm/plat-omap/include/syslink/messageq.h

@@ -166,6 +166,11 @@
  *  @brief  Operation is successful.
  */
 #define MESSAGEQ_E_CANNOTFREESTATICMSG		-18
+/*!
+ *  @def    MESSAGEQ_E_UNBLOCKED
+ *  @brief  The resource is now unblocked
+ */
+#define MESSAGEQ_E_UNBLOCKED			-20
 
 
 /* =============================================================================
@@ -436,5 +441,7 @@ int messageq_register_transport(void *imessageq_transport_handle,
 /* Unregister a transport with MessageQ */
 void messageq_unregister_transport(u16 proc_id, u32 priority);
 
+/* Unblock messageq to prevent waiting forever */
+int messageq_unblock(void *messageq_handle);
 
 #endif /* _MESSAGEQ_H_ */

arch/arm/plat-omap/include/syslink/messageq_ioctl.h

@@ -50,7 +50,8 @@ enum messageq_drv_cmd {
 	MESSAGEQ_ATTACH,
 	MESSAGEQ_DETACH,
 	MESSAGEQ_GET,
-	MESSAGEQ_SHAREDMEMREQ
+	MESSAGEQ_SHAREDMEMREQ,
+	MESSAGEQ_UNBLOCK
 };
 
 /*  ----------------------------------------------------------------------------
@@ -120,6 +121,11 @@ enum messageq_drv_cmd {
 			_IOWR(MESSAGEQ_IOC_MAGIC, MESSAGEQ_PUT, \
 			struct messageq_cmd_args)
 
+/* Command for messageq_unblock */
+#define CMD_MESSAGEQ_UNBLOCK \
+			_IOWR(MESSAGEQ_IOC_MAGIC, MESSAGEQ_UNBLOCK, \
+			struct messageq_cmd_args)
+
 /* Command for messageq_register_heap */
 #define CMD_MESSAGEQ_REGISTERHEAP \
 			_IOWR(MESSAGEQ_IOC_MAGIC, MESSAGEQ_REGISTERHEAP, \
@@ -237,6 +243,11 @@ struct messageq_cmd_args {
 		struct {
 			u16 remote_proc_id;
 		} detach;
+
+		struct {
+			void *messageq_handle;
+		} unblock;
+
 	} args;
 
 	int api_status;

drivers/dsp/syslink/multicore_ipc/messageq.c

@@ -179,6 +179,8 @@ struct messageq_object {
 	/* NameServer key */
 	struct semaphore *synchronizer;
 	/* Semaphore used for synchronizing message events */
+	bool unblocked;
+	/* Whether MessageQ is unblocked */
 };
 
 
@@ -573,6 +575,9 @@ void *messageq_create(char *name, const struct messageq_params *params)
 		}
 	}
 
+	/* Whether messageq is blocked */
+	obj->unblocked = false;
+
 exit:
 	if (unlikely(status < 0)) {
 		messageq_delete((void **)&obj);
@@ -814,6 +819,12 @@ int messageq_get(void *messageq_handle, messageq_msg *msg,
 					*msg = NULL;
 					break;
 				}
+				if (obj->unblocked) {
+					*msg = NULL;
+					status = MESSAGEQ_E_UNBLOCKED;
+					obj->unblocked = false;
+					break;
+				}
 			}
 			status = mutex_lock_interruptible(
 					messageq_module->gate_handle);
@@ -1196,6 +1207,36 @@ int messageq_unregister_heap(u16 heap_id)
 }
 EXPORT_SYMBOL(messageq_unregister_heap);
 
+/* Unblock messageq to prevent waiting forever */
+int messageq_unblock(void *messageq_handle)
+{
+	int status = 0;
+	struct messageq_object *obj = (struct messageq_object *)messageq_handle;
+
+	if (WARN_ON(unlikely(atomic_cmpmask_and_lt(
+				&(messageq_module->ref_count),
+				MESSAGEQ_MAKE_MAGICSTAMP(0),
+				MESSAGEQ_MAKE_MAGICSTAMP(1)) == true))) {
+		status = -ENODEV;
+		goto exit;
+	}
+	if (WARN_ON(unlikely(obj == NULL)) || (WARN_ON(unlikely(
+				obj->synchronizer == NULL)))) {
+		status = -EINVAL;
+		goto exit;
+	}
+	/* Set instance to 'unblocked' state */
+	obj->unblocked = true;
+	up(obj->synchronizer);
+
+exit:
+	if (status < 0) {
+		pr_err("messageq_unblock failed! status = 0x%x\n",
+			status);
+	}
+	return status;
+}
+
 /* Register a transport */
 int messageq_register_transport(void *messageq_transportshm_handle,
 				 u16 proc_id, u32 priority)

drivers/dsp/syslink/multicore_ipc/messageq_ioctl.c

@@ -393,6 +393,18 @@ static inline int messageq_ioctl_get_config(struct messageq_cmd_args *cargs)
 	return retval;
 }
 
+/*
+ * ======== messageq_ioctl_unblock ========
+ *  Purpose:
+ *  This ioctl interface to messageq_unblock function
+ */
+static inline int messageq_ioctl_unblock(struct messageq_cmd_args *cargs)
+{
+	cargs->api_status = messageq_unblock(cargs->args.unblock.messageq_handle);
+
+	return 0;
+}
+
 /*
  * ======== messageq_ioctl_setup ========
  *  Purpose:
@@ -631,6 +643,10 @@ int messageq_ioctl(struct inode *inode, struct file *filp,
 		status = messageq_ioctl_get_config(&cargs);
 		break;
 
+	case CMD_MESSAGEQ_UNBLOCK:
+		status = messageq_ioctl_unblock(&cargs);
+		break;
+
 	case CMD_MESSAGEQ_SETUP:
 		status = messageq_ioctl_setup(&cargs);
 		if (status >= 0)