Changeset 207 for soft/giet_vm/libs

Timestamp:

Aug 16, 2012, 6:36:16 PM (12 years ago)

Author:

alain

Message:

Several bugs have been fixed to support TSAR multi-cluster architecture
such as the "tsarv4-generic_mmu" platform.

File:

• soft/giet_vm/libs/mwmr_channel.c (modified) (4 diffs)

soft/giet_vm/libs/mwmr_channel.c

@@ -62 +62 @@
             :"$2", "$3", "$4");
 } 
+//////////////////////////////////////////////////////////////////////////////
+//         nb_mwmr_write()
+// This is a non-blocking function.
+// The nitems parameter is the number of items to be transfered.
+// The requested transfer is therefore (nitems * width) words.
+// It takes the lock for exclusive access before testing the channel state.
+// If there is not enough data in mwmr channel to read nitems,
+// it reads as many items as possible, releases the lock, and returns 
+// the number of read items (it can be 0).
+//////////////////////////////////////////////////////////////////////////////
+unsigned int nb_mwmr_write( mwmr_channel_t*     mwmr, 
+                            unsigned int*               buffer,
+                            unsigned int                nitems )
+{
+    unsigned int        x;
+    unsigned int        spaces;         // number of empty slots (in words)
+    unsigned int        nwords;         // requested transfer length (in words)
+    unsigned int    depth;              // channel depth (in words)
+    unsigned int    width;              // channel width (in words)
+    unsigned int    sts;        // channel sts
+    unsigned int    ptw;        // channel ptw
+
+    if(nitems == 0) return 0;
+
+    // get the lock
+    mwmr_lock_acquire( &mwmr->lock );
+
+    // access fifo status
+    depth  = mwmr->depth;
+    width  = mwmr->width;
+    sts    = mwmr->sts;
+    ptw    = mwmr->ptw;
+    spaces = depth - sts;
+    nwords = width * nitems;
+
+    if( spaces >= nwords )      // transfer nitems, release lock and return 
+    {
+        for ( x = 0 ; x < nwords ; x++ )  
+        {
+            mwmr->data[ptw] = buffer[x];
+            if ( (ptw + 1) == depth ) ptw = 0;
+            else                      ptw = ptw + 1;
+        }
+        mwmr->sts  = mwmr->sts + nwords;
+        mwmr->ptw  = ptw;
+        mwmr->lock = 0;
+        return nitems;
+    }
+   
+    else if ( spaces < width )  // release lock and return 
+    {
+        mwmr->lock = 0;
+        return 0;
+    }
+    else        // transfer as many items as possible, release lock and return 
+    {
+        nwords = (spaces/width) * width;        // integer number of items
+        for ( x = 0 ; x < nwords ; x++ )  
+        {
+            mwmr->data[ptw] = buffer[x];
+            if ( (ptw + 1) == depth ) ptw = 0;
+            else                      ptw = ptw + 1;
+        }
+        mwmr->sts  = sts + nwords;
+        mwmr->ptw  = ptw;
+        mwmr->lock = 0;
+        return (nwords/width);
+    }
+} // end nb_mwmr_write()
 
 //////////////////////////////////////////////////////////////////////////////
@@ -136 +205 @@
         for ( x = giet_rand()>>6 ; x > 0 ; x-- ) asm volatile ( "nop" );
     }
-} 
+} // end mwmr_write()
+
+//////////////////////////////////////////////////////////////////////////////
+//         nb_mwmr_read()
+// This is a non-blocking function.
+// The nitems parameter is the number of items to be transfered.
+// The requested transfer is therefore (nitems * width) words.
+// It takes the lock for exclusive access before testing the channel state.
+// If there is not enough data in mwmr channel to read nitems,
+// it reads as many items as possible, releases the lock, and returns 
+// the number of read items (it can be 0).
+//////////////////////////////////////////////////////////////////////////////
+unsigned int nb_mwmr_read( mwmr_channel_t*      mwmr, 
+                           unsigned int*                buffer,
+                           unsigned int                 nitems )
+{
+    unsigned int        x;
+    unsigned int        nwords;         // requested transfer length (in words)
+    unsigned int    depth;              // channel depth (in words)
+    unsigned int    width;              // channel width (in words)
+    unsigned int    sts;        // channel sts
+    unsigned int    ptr;        // channel ptr
+
+    if(nitems == 0) return 0;
+
+    // get the lock
+    mwmr_lock_acquire( &mwmr->lock );
+
+    // access fifo status
+    depth  = mwmr->depth;
+    width  = mwmr->width;
+    sts    = mwmr->sts;
+    ptr    = mwmr->ptr;
+    nwords = width * nitems;
+
+    if( sts >= nwords )         // transfer nitems, release lock and return 
+    {
+        for ( x = 0 ; x < nwords ; x++ )  
+        {
+            buffer[x] = mwmr->data[ptr];
+            if ( (ptr + 1) == depth ) ptr = 0;
+            else                      ptr = ptr + 1;
+        }
+        mwmr->sts  = mwmr->sts - nwords;
+        mwmr->ptr  = ptr;
+        mwmr->lock = 0;
+        return nitems;
+    }
+   
+    else if ( sts < width )     // release lock and return 
+    {
+        mwmr->lock = 0;
+        return 0;
+    }
+    else        // transfer as many items as possible, release lock and return 
+    {
+        nwords = (sts/width) * width;   // integer number of items
+        for ( x = 0 ; x < nwords ; x++ )  
+        {
+            buffer[x] = mwmr->data[ptr];
+            if ( (ptr + 1) == depth ) ptr = 0;
+            else                      ptr = ptr + 1;
+        }
+        mwmr->sts  = sts - nwords;
+        mwmr->ptr  = ptr;
+        mwmr->lock = 0;
+        return (nwords/width);
+    }
+} // nb_mwmr_read() 
 
 //////////////////////////////////////////////////////////////////////////////
@@ -157 +294 @@
     unsigned int    width;              // channel width (in words)
     unsigned int    sts;        // channel sts
-    unsigned int    ptr;        // channel ptw
+    unsigned int    ptr;        // channel ptr
 
     if(nitems == 0) return;
@@ -209 +346 @@
         for ( x = giet_rand()>>6 ; x > 0 ; x-- ) asm volatile ( "nop" );
     }
-} 
-
+} // end mwmr_read() 
+
+