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 <sakhtar@ti.com>

2 files changed, 57 insertions, 0 deletions

diff --git a/drivers/dsp/syslink/multicore_ipc/messageq.c b/drivers/dsp/syslink/multicore_ipc/messageq.c
index 04f14a335b0..332288c8142 100644
--- a/drivers/dsp/syslink/multicore_ipc/messageq.c
+++ b/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 @@ exit:
 }
 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)
diff --git a/drivers/dsp/syslink/multicore_ipc/messageq_ioctl.c b/drivers/dsp/syslink/multicore_ipc/messageq_ioctl.c
index 0da59a3b9b0..5a16d2c7d1f 100644
--- a/drivers/dsp/syslink/multicore_ipc/messageq_ioctl.c
+++ b/drivers/dsp/syslink/multicore_ipc/messageq_ioctl.c
@@ -394,6 +394,18 @@ exit:
 }
 
 /*
+ * ======== 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:
  *  This ioctl interface to messageq_setup function
@@ -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)