SYSLINK Notify - Adds IPC migrations to the Notify driver module.

This patch supports pid to be passed from the notify use side
module to provide callback to registered events.
Attach and detach functions added. exit function removed.
Signed-off-by: C A Subramaniam <subramaniam.ca@ti.com>

drivers/dsp/syslink/omap_notify/drv_notify.c

@@ -64,6 +64,7 @@ static struct class *ipcnotify_class;
 /*Structure of Event Packet read from notify kernel-side..*/
 struct notify_drv_event_packet {
 	struct list_head element;
+	u32 pid;
 	u32 proc_id;
 	u32 event_no;
 	u32 data;
@@ -119,9 +120,6 @@ int major = 232;
 
 static void notify_drv_setup(void);
 
-/* exit function */
-static int notify_drv_exit(void);
-
 static int notify_drv_add_buf_by_pid(u16 procId, u32 pid,
 		u32 eventNo, u32 data, notify_callback_fxn cbFxn, void *param);
 
@@ -154,6 +152,13 @@ static int notify_drv_register_driver(void);
 
 static int notify_drv_unregister_driver(void);
 
+/* Attach a process to notify user support framework. */
+static int notify_drv_attach(u32 pid);
+
+/* Detach a process from notify user support framework. */
+static int notify_drv_detach(u32 pid);
+
+
 /* Function to invoke the APIs through ioctl.*/
 static const struct file_operations driver_ops = {
 	.open = notify_drv_open,
@@ -201,66 +206,7 @@ func_end:
  */
 static int notify_drv_open(struct inode *inode, struct file *filp)
 {
-	u32 status = NOTIFY_SUCCESS;
-	short int flag = false ;
-	u32 pid = (u32) current->mm ;
-	u32 i;
-	bool isinit = false;
-	struct semaphore *sem_handle;
-	struct semaphore *ter_sem_handle;
-	int ret_val = 0;
-
-	notifydrv_state.open_refcount += 2;
-	if (notifydrv_state.open_refcount == 2) {
-		WARN_ON(mutex_lock_interruptible(notifydrv_state.gatehandle));
-		for (i = 0 ; (i < MAX_PROCESSES) ; i++) {
-			if (notifydrv_state.event_state[i].pid == pid) {
-				notifydrv_state.event_state[i].ref_count++;
-				isinit = true;
-				break;
-			}
-		}
-		mutex_unlock(notifydrv_state.gatehandle);
-		if (isinit == true)
-			goto func_end;
-		sem_handle = kmalloc(sizeof(struct semaphore), GFP_ATOMIC);
-		ter_sem_handle = kmalloc(sizeof(struct semaphore), GFP_ATOMIC);
-		sema_init(sem_handle, 0);
-		/* Create the termination semaphore */
-		sema_init(ter_sem_handle, 0);
-		WARN_ON(mutex_lock_interruptible(notifydrv_state.gatehandle));
-		/* Search for an available slot for user process. */
-		for (i = 0 ; i < MAX_PROCESSES ; i++) {
-			if (notifydrv_state.event_state[i].pid == -1) {
-				notifydrv_state.event_state[i].semhandle =
-							sem_handle;
-				notifydrv_state.event_state[i].tersemhandle =
-							ter_sem_handle;
-				notifydrv_state.event_state[i].pid = pid;
-				notifydrv_state.event_state[i].ref_count
-								= 1;
-				INIT_LIST_HEAD(&(notifydrv_state.event_state[i].
-								buf_list));
-				flag = true;
-				break;
-			}
-		}
-		mutex_unlock(notifydrv_state.gatehandle);
-		/* No free slots found. Let this check remain at
-		* run-time, since it is dependent on user environment.
-		*/
-		if (WARN_ON(flag != true)) {
-			/*! @retval -1 Maximum number of supported user
-			clients have already been registered. */
-			status = NOTIFY_E_MAXCLIENTS;
-		}
-	}
-		if (status == NOTIFY_SUCCESS)
-			ret_val = 0;
-		else
-			ret_val = -EINVAL;
-func_end:
-	return ret_val;
+	return 0;
 }
 
 /*
@@ -268,7 +214,6 @@ func_end:
  */
 static int notify_drv_close(struct inode *inode, struct file *filp)
 {
-	notifydrv_state.open_refcount--;
 	return 0 ;
 }
 
@@ -281,18 +226,24 @@ static int notify_drv_read(struct file *filp, char *dst, size_t size,
 
 	bool flag = false;
 	struct notify_drv_event_packet *u_buf = NULL;
-	u32 pid = (u32) current->mm;
 	int ret_val = 0;
 	u32 i;
 	struct list_head *elem;
+	struct notify_drv_event_packet t_buf;
 
 	if (WARN_ON(notifydrv_state.is_setup == false)) {
 		ret_val = -EFAULT;
 		goto func_end;
 	}
 
+	ret_val = copy_from_user((void *)&t_buf,
+				(void *)dst,
+				sizeof(struct notify_drv_event_packet));
+	WARN_ON(ret_val != 0);
+
+
 	for (i = 0 ; i < MAX_PROCESSES ; i++) {
-		if (notifydrv_state.event_state[i].pid == pid) {
+		if (notifydrv_state.event_state[i].pid == t_buf.pid) {
 			flag = true;
 			break;
 		}
@@ -412,7 +363,7 @@ static int notify_drv_ioctl(struct inode *inode, struct file *filp, u32 cmd,
 		cbck->proc_id = src_args.procId;
 		cbck->func = src_args.fnNotifyCbck;
 		cbck->param = src_args.cbckArg;
-		cbck->pid = (u32) current->mm;
+		cbck->pid = src_args.pid;
 		status = notify_register_event(src_args.handle, src_args.procId,
 			src_args.eventNo, notify_drv_cbck, (void *)cbck);
 		if (status < 0) {
@@ -434,7 +385,7 @@ static int notify_drv_ioctl(struct inode *inode, struct file *filp, u32 cmd,
 	case CMD_NOTIFY_UNREGISTEREVENT:
 	{
 		bool found = false;
-		u32 pid = (u32) current->mm;
+		u32 pid;
 		struct notify_drv_event_cbck *cbck = NULL;
 		struct list_head *entry = NULL;
 		struct notify_cmd_args_unregister_event src_args;
@@ -445,6 +396,8 @@ static int notify_drv_ioctl(struct inode *inode, struct file *filp, u32 cmd,
 
 		if (WARN_ON(retval != 0))
 			goto func_end;
+
+		pid = src_args.pid;
 		WARN_ON(mutex_lock_interruptible(notifydrv_state.gatehandle));
 		list_for_each(entry,
 			(struct list_head *)&(notifydrv_state.evt_cbck_list)) {
@@ -583,12 +536,25 @@ static int notify_drv_ioctl(struct inode *inode, struct file *filp, u32 cmd,
 	}
 	break;
 
-	case CMD_NOTIFY_EXIT:
+	case CMD_NOTIFY_ATTACH:
+	{
+		/* FIXME: User copy_from_user */
+		u32 pid = *((u32 *)args);
+		status = notify_drv_attach(pid);
+
+		if (status < 0)
+			printk(KERN_ERR "NOTIFY_ATTACH FAILED\n");
+	}
+	break;
+
+	case CMD_NOTIFY_DETACH:
 	{
-		/* No args to be copied from user-side. */
-		status = notify_drv_exit();
+		/* FIXME: User copy_from_user */
+		u32 pid = *((u32 *)args);
+		status = notify_drv_detach(pid);
+
 		if (status < 0)
-			printk(KERN_ERR "notify_driver_exit FAILED\n");
+			printk(KERN_ERR "NOTIFY_DETACH FAILED\n");
 	}
 	break;
 
@@ -668,37 +634,161 @@ func_end:
 }
 
 /*
- * notify_drv_exit
+ * Module setup function.
  *
  */
-int notify_drv_exit(void)
+static void notify_drv_setup(void)
+{
+	int i;
+
+	INIT_LIST_HEAD((struct list_head *)&(notifydrv_state.evt_cbck_list));
+	notifydrv_state.gatehandle = kmalloc(sizeof(struct mutex),
+						GFP_KERNEL);
+	mutex_init(notifydrv_state.gatehandle);
+	for (i = 0; i < MAX_PROCESSES ; i++) {
+		notifydrv_state.event_state[i].pid = -1;
+		notifydrv_state.event_state[i].ref_count = 0;
+		INIT_LIST_HEAD((struct list_head *)
+			&(notifydrv_state.event_state[i].buf_list));
+	}
+	notifydrv_state.is_setup = true;
+}
+
+
+/*
+* brief Module destroy function.
+*/
+static void notify_drv_destroy(void)
 {
-	int status = NOTIFY_SUCCESS;
-	bool flag = false;
-	u32 pid = (u32) current->mm;
 	int i;
+	struct notify_drv_event_packet *packet;
+	struct list_head *entry;
+	struct notify_drv_event_cbck *cbck;
+
+	for (i = 0; i < MAX_PROCESSES ; i++) {
+		list_for_each(entry, (struct list_head *)
+				&(notifydrv_state.event_state[i].buf_list)) {
+			packet = (struct notify_drv_event_packet *)entry;
+			if (packet != NULL)
+				kfree(packet);
+		}
+		INIT_LIST_HEAD(&notifydrv_state.event_state[i].buf_list);
+	}
+	list_for_each(entry,
+			(struct list_head *)&(notifydrv_state.evt_cbck_list)) {
+		cbck = (struct notify_drv_event_cbck *)(entry);
+		if (cbck != NULL)
+			kfree(cbck) ;
+	}
+	INIT_LIST_HEAD(&notifydrv_state.evt_cbck_list);
+	mutex_destroy(notifydrv_state.gatehandle);
+	kfree(notifydrv_state.gatehandle);
+	notifydrv_state.is_setup = false;
+	return;
+}
+
+
+
+
+/*
+ *  brief      Attach a process to notify user support framework.
+ */
+static int notify_drv_attach(u32 pid)
+{
+	s32 status = NOTIFY_SUCCESS;
+	bool flag = false;
+	bool is_init = false;
+	u32 i;
 	struct semaphore *sem_handle;
 	struct semaphore *ter_sem_handle;
+	int ret_val = 0;
 
-	notifydrv_state.open_refcount--;
-	/* Last dummy close will make the ref_count 0. */
-	if (notifydrv_state.open_refcount != 1) {
+	if (notifydrv_state.is_setup == false) {
 		status = NOTIFY_E_FAIL;
+	} else {
+		WARN_ON(mutex_lock_interruptible(notifydrv_state.gatehandle));
+
+		for (i = 0 ; (i < MAX_PROCESSES) ; i++) {
+			if (notifydrv_state.event_state[i].pid == pid) {
+				notifydrv_state.event_state[i].ref_count++;
+				is_init = true;
+				break;
+			}
+		}
+		mutex_unlock(notifydrv_state.gatehandle);
+
+		if (is_init == true)
 			goto func_end;
+
+		sem_handle = kmalloc(sizeof(struct semaphore), GFP_ATOMIC);
+		ter_sem_handle = kmalloc(sizeof(struct semaphore), GFP_ATOMIC);
+
+		sema_init(sem_handle, 0);
+		/* Create the termination semaphore */
+		sema_init(ter_sem_handle, 0);
+
+		WARN_ON(mutex_lock_interruptible(notifydrv_state.gatehandle));
+		/* Search for an available slot for user process. */
+		for (i = 0 ; i < MAX_PROCESSES ; i++) {
+			if (notifydrv_state.event_state[i].pid == -1) {
+				notifydrv_state.event_state[i].semhandle =
+							sem_handle;
+				notifydrv_state.event_state[i].tersemhandle =
+							ter_sem_handle;
+				notifydrv_state.event_state[i].pid = pid;
+				notifydrv_state.event_state[i].ref_count
+								= 1;
+				INIT_LIST_HEAD(&(notifydrv_state.event_state[i].
+								buf_list));
+				flag = true;
+				break;
 			}
-	if (WARN_ON(notifydrv_state.is_setup == false)) {
-		/* The Notify OS driver was not setup */
-		status = NOTIFY_E_SETUP;
+		}
+		mutex_unlock(notifydrv_state.gatehandle);
+
+		if (WARN_ON(flag != true)) {
+			/* Max users have registered. No more clients
+			 * can be supported */
+			status = NOTIFY_E_MAXCLIENTS;
+		}
+
+		if (status == NOTIFY_SUCCESS)
+			ret_val = 0;
+		else {
+			kfree(ter_sem_handle);
+			kfree(sem_handle);
+			ret_val = -EINVAL;
+		}
+
+	}
+func_end:
+    return ret_val;
+}
+
+
+/*
+ *  brief      Detach a process from notify user support framework.
+ */
+static int notify_drv_detach(u32 pid)
+{
+	s32 status = NOTIFY_SUCCESS;
+	bool flag = false;
+	u32 i;
+	struct semaphore *sem_handle;
+	struct semaphore *ter_sem_handle;
+
+	if (notifydrv_state.is_setup == false) {
+		status = NOTIFY_E_FAIL;
 		goto func_end;
 	}
+
 	/* Send the termination packet to notify thread */
-	status = notify_drv_add_buf_by_pid(0, /* Ignored. */
-			(u32) current->mm, (u32) -1, (u32)0, NULL, NULL);
-	if (status < 0) {
-		printk(KERN_ERR "notify_drv_exit failed to send"
-			"termination packet\n.");
+	status = notify_drv_add_buf_by_pid(0, pid, (u32)-1, (u32)0,
+					NULL, NULL);
+
+	if (status < 0)
 		goto func_end;
-	}
+
 	if (mutex_lock_interruptible(notifydrv_state.gatehandle)) {
 		status = NOTIFY_E_OSFAILURE;
 		goto func_end;
@@ -730,7 +820,7 @@ int notify_drv_exit(void)
 
 	if ((flag == false) && (i == MAX_PROCESSES)) {
 		/*retval NOTIFY_E_NOTFOUND The specified user process was
-			 not found registered with Notify Driver module. */
+		 * not found registered with Notify Driver module. */
 	    status = NOTIFY_E_NOTFOUND;
 	} else {
 	    kfree(sem_handle);
@@ -738,60 +828,9 @@ int notify_drv_exit(void)
 	}
 func_end:
 	    return status;
-}
-
-/*
- * Module setup function.
- *
- */
-static void notify_drv_setup(void)
-{
-	int i;
-
-	INIT_LIST_HEAD((struct list_head *)&(notifydrv_state.evt_cbck_list));
-	notifydrv_state.gatehandle = kmalloc(sizeof(struct mutex),
-						GFP_KERNEL);
-	mutex_init(notifydrv_state.gatehandle);
-	for (i = 0; i < MAX_PROCESSES ; i++) {
-		notifydrv_state.event_state[i].pid = -1;
-		notifydrv_state.event_state[i].ref_count = 0;
-		INIT_LIST_HEAD((struct list_head *)
-			&(notifydrv_state.event_state[i].buf_list));
-	}
-	notifydrv_state.is_setup = true;
-}
-
 
-/*
-* brief Module destroy function.
-*/
-static void notify_drv_destroy(void)
-{
-	int i;
-	struct notify_drv_event_packet *packet;
-	struct list_head *entry;
-	struct notify_drv_event_cbck *cbck;
-
-	for (i = 0; i < MAX_PROCESSES ; i++) {
-		list_for_each(entry, (struct list_head *)
-				&(notifydrv_state.event_state[i].buf_list)) {
-			packet = (struct notify_drv_event_packet *)entry;
-			if (packet != NULL)
-				kfree(packet);
-		}
-		INIT_LIST_HEAD(&notifydrv_state.event_state[i].buf_list);
-	}
-	list_for_each(entry,
-			(struct list_head *)&(notifydrv_state.evt_cbck_list)) {
-		cbck = (struct notify_drv_event_cbck *)(entry);
-		if (cbck != NULL)
-			kfree(cbck) ;
-	}
-	INIT_LIST_HEAD(&notifydrv_state.evt_cbck_list);
-	mutex_destroy(notifydrv_state.gatehandle);
-	kfree(notifydrv_state.gatehandle);
-	notifydrv_state.is_setup = false;
-	return;
+    /*! @retval NOTIFY_SUCCESS Operation successfully completed */
+    return status;
 }