SYSLINK Notify-Ducati Adds syslink specific atomic functions to check and set driver state.

Uses syslink atomic calls to maintain driver state in the
notify ducati driver module.
Signed-off-by: C A Subramaniam <subramaniam.ca@ti.com>

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

@@ -164,7 +164,7 @@ struct notify_ducatidrv_params {
  */
 
 struct notify_ducatidrv_config {
-	void *gate_handle;
+	u32 reserved;
 };
 
 /* Function to get the default configuration for the Notify module. */

drivers/dsp/syslink/notify_ducatidriver/notify_ducati.c

@@ -29,6 +29,7 @@
 #include <syslink/notify_ducatidriver.h>
 #include <syslink/notify_dispatcher.h>
 #include <syslink/multiproc.h>
+#include <syslink/atomic_linux.h>
 
 
 
@@ -62,6 +63,13 @@
 #define PROCAPPM3	3
 #define MAX_SUBPROC_EVENTS	15
 
+/*FIXME MOVE THIS TO  A SUITABLE HEADER */
+#define NOTIFYDRIVERSHM_MODULEID           (u32) 0xb9d4
+
+/* Macro to make a correct module magic number with refCount */
+#define NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(x) \
+				((NOTIFYDRIVERSHM_MODULEID << 12u) | (x))
+
 static void notify_ducatidrv_isr(void *ref_data);
 
 
@@ -72,7 +80,7 @@ struct notify_ducatidrv_object {
 	struct notify_ducatidrv_params params;
 	short int  proc_id;
 	struct notify_drv_eventlist *event_list;
-	struct notify_shmdrv_ctrl *ctrl_ptr;
+	volatile struct notify_shmdrv_ctrl *ctrl_ptr;
 	struct notify_shmdrv_eventreg *reg_chart;
 	struct notify_driver_object *drv_handle;
 	short int  self_id;
@@ -85,18 +93,16 @@ struct notify_ducatidrv_object {
  * 		the module specific information.
  */
 struct notify_ducatidrv_module {
+	atomic_t ref_count;
 	struct notify_ducatidrv_config cfg;
 	struct notify_ducatidrv_config def_cfg;
 	struct notify_ducatidrv_params def_inst_params;
-	bool is_setup;
 	struct mutex *gate_handle;
 } ;
 
 
 static struct notify_ducatidrv_module notify_ducatidriver_state = {
-	.is_setup = false,
 	.gate_handle = NULL,
-	.def_cfg.gate_handle = NULL,
 	.def_inst_params.shared_addr = 0x0,
 	.def_inst_params.shared_addr_size = 0x0,
 	.def_inst_params.num_events = NOTIFYSHMDRV_MAX_EVENTS,
@@ -129,9 +135,17 @@ void notify_ducatidrv_getconfig(struct notify_ducatidrv_config *cfg)
 {
 	BUG_ON(cfg == NULL);
 
-	memcpy(cfg,
-		&(notify_ducatidriver_state.def_cfg),
-		sizeof(struct notify_ducatidrv_config));
+	if (atomic_cmpmask_and_lt(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1))
+					== true)
+		memcpy(cfg,
+			&(notify_ducatidriver_state.def_cfg),
+			sizeof(struct notify_ducatidrv_config));
+	else
+		memcpy(cfg,
+			&(notify_ducatidriver_state.cfg),
+			sizeof(struct notify_ducatidrv_config));
 }
 EXPORT_SYMBOL(notify_ducatidrv_getconfig);
 
@@ -189,6 +203,15 @@ void notify_ducatidrv_params_init(struct notify_driver_object *handle,
 {
 	struct notify_ducatidrv_object *driver_obj;
 	BUG_ON(params == NULL);
+
+	if (atomic_cmpmask_and_lt(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1))
+								== true) {
+		/*FIXME not intialized to be returned */
+		BUG_ON(1);
+	}
+
 	if (handle == NULL) {
 		memcpy(params,
 		&(notify_ducatidriver_state.def_inst_params),
@@ -217,7 +240,7 @@ struct notify_driver_object *notify_ducatidrv_create(char *driver_name,
 	struct notify_ducatidrv_object *driver_obj = NULL;
 	struct notify_driver_object *drv_handle = NULL;
 	struct notify_drv_eventlist *event_list = NULL;
-	struct notify_shmdrv_proc_ctrl *ctrl_ptr = NULL;
+	volatile struct notify_shmdrv_proc_ctrl *ctrl_ptr = NULL;
 	struct notify_driver_attrs drv_attrs;
 	struct notify_interface fxn_table;
 	int proc_id;
@@ -231,7 +254,14 @@ struct notify_driver_object *notify_ducatidrv_create(char *driver_name,
 
 	BUG_ON(driver_name == NULL);
 	BUG_ON(params == NULL);
-	BUG_ON(notify_ducatidriver_state.is_setup == false);
+
+	if (atomic_cmpmask_and_lt(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1))
+					== true) {
+		goto func_end;
+	}
+
 
 	WARN_ON(mutex_lock_interruptible(notify_ducatidriver_state.
 				gate_handle) != 0);
@@ -466,6 +496,14 @@ int notify_ducatidrv_delete(struct notify_driver_object **handle_ptr)
 	int interrupt_no;
 	int mbx_ret_val = 0;
 
+	if (atomic_cmpmask_and_lt(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1))
+					== true) {
+		/*FIXME not intialized to be returned */
+		return -1;
+	}
+
 	WARN_ON(handle_ptr == NULL);
 	if (handle_ptr == NULL)
 		return -1;
@@ -546,14 +584,30 @@ EXPORT_SYMBOL(notify_ducatidrv_delete);
 int notify_ducatidrv_destroy(void)
 {
 	int status = 0;
-	WARN_ON(notify_ducatidriver_state.is_setup != true);
 
-	/* Check if the gate_handle was created internally. */
-	if (notify_ducatidriver_state.cfg.gate_handle == NULL) {
+	if (atomic_cmpmask_and_lt(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1))
+								== true)
+		/* FIXME Invalid state to be reuurned. */
+		return -1;
+
+	if (atomic_dec_return(&(notify_ducatidriver_state.ref_count)) ==
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0)) {
+
+		/* Check if the gate_handle was created internally. */
+
 		if (notify_ducatidriver_state.gate_handle != NULL)
 			kfree(notify_ducatidriver_state.gate_handle);
+
+		/* FIXME- Why do we need to reset this if we already
+		 *	decremented it to 0 */
+		atomic_set(&(notify_ducatidriver_state.ref_count),
+			NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0));
+
 	}
-	notify_ducatidriver_state.is_setup = false;
+
+
 	return status;
 }
 EXPORT_SYMBOL(notify_ducatidrv_destroy);
@@ -585,23 +639,33 @@ int notify_ducatidrv_setup(struct notify_ducatidrv_config *cfg)
 		cfg = &tmp_cfg;
 	}
 
-	if (cfg->gate_handle != NULL)
-		notify_ducatidriver_state.gate_handle = cfg->gate_handle;
-	else {
-		notify_ducatidriver_state.gate_handle =
-			kmalloc(sizeof(struct mutex), GFP_KERNEL);
-		mutex_init(notify_ducatidriver_state.gate_handle);
+	/* Init the ref_count to 0 */
+	atomic_cmpmask_and_set(&(notify_ducatidriver_state.ref_count),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0),
+					NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0));
+
+	if (atomic_inc_return(&(notify_ducatidriver_state.ref_count)) !=
+		NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(1u)) {
+		/* FIXME Already exists status to be returned. */
+		return -1;
 	}
 
+
+	/* Create a default gate handle here */
+	notify_ducatidriver_state.gate_handle =
+			kmalloc(sizeof(struct mutex), GFP_KERNEL);
+			mutex_init(notify_ducatidriver_state.gate_handle);
+
 	if (notify_ducatidriver_state.gate_handle == NULL) {
+		atomic_set(&(notify_ducatidriver_state.ref_count),
+				NOTIFYDRIVERSHM_MAKE_MAGICSTAMP(0));
 		status = -ENOMEM;
 	} else {
 		memcpy(&notify_ducatidriver_state.cfg,
 		cfg, sizeof(struct notify_ducatidrv_config));
-		notify_ducatidriver_state.is_setup = true;
-
 	}
 
+
 	return status;
 }
 EXPORT_SYMBOL(notify_ducatidrv_setup);
@@ -625,8 +689,8 @@ int notify_ducatidrv_register_event(
 	struct notify_drv_eventlist *event_list;
 	struct notify_ducatidrv_object *driver_object;
 	struct notify_shmdrv_eventreg *reg_chart;
-	struct notify_shmdrv_ctrl *ctrl_ptr;
-	struct notify_shmdrv_event_entry *self_event_chart;
+	volatile struct notify_shmdrv_ctrl *ctrl_ptr;
+	volatile struct notify_shmdrv_event_entry *self_event_chart;
 	int i;
 	int j;
 	BUG_ON(handle == NULL);
@@ -741,9 +805,9 @@ int notify_ducatidrv_unregister_event(
 	struct notify_ducatidrv_object *driver_object;
 	struct notify_drv_eventlist *event_list;
 	struct notify_shmdrv_eventreg *reg_chart;
-	struct notify_shmdrv_ctrl *ctrl_ptr = NULL;
+	volatile struct notify_shmdrv_ctrl *ctrl_ptr = NULL;
 	struct notify_drv_eventlistner   unreg_info;
-	struct notify_shmdrv_event_entry *self_event_chart;
+	volatile struct notify_shmdrv_event_entry *self_event_chart;
 	int i;
 	int j;
 
@@ -830,9 +894,9 @@ int notify_ducatidrv_sendevent(struct notify_driver_object *handle,
 {
 	int status = 0;
 	struct notify_ducatidrv_object *driver_object;
-	struct notify_shmdrv_ctrl *ctrl_ptr;
+	volatile struct notify_shmdrv_ctrl *ctrl_ptr;
 	int max_poll_count;
-	struct notify_shmdrv_event_entry *other_event_chart;
+	volatile struct notify_shmdrv_event_entry *other_event_chart;
 	struct mbox_config *mbox_hw_config;
 	int mbox_module_no;
 	int mbx_ret_val = 0;
@@ -1042,10 +1106,10 @@ static void notify_ducatidrv_isr(void *ref_data)
 	int i = 0;
 	struct list_head *temp;
 	int j = 0;
-	struct notify_shmdrv_event_entry  *self_event_chart;
+	volatile struct notify_shmdrv_event_entry  *self_event_chart;
 	struct notify_ducatidrv_object *driver_obj;
 	struct notify_shmdrv_eventreg *reg_chart;
-	struct notify_shmdrv_proc_ctrl *proc_ctrl_ptr;
+	volatile struct notify_shmdrv_proc_ctrl *proc_ctrl_ptr;
 	struct mbox_config *mbox_hw_config = ntfy_disp_get_config();
 	unsigned long int mbox_module_no = mbox_hw_config->mbox_modules;
 	int event_no;