Added optional debug printk tracking of IO to the WB bridge

Fixed bugs in kernel etherbone:
  record_len was shadowed by redeclation
  wrote maximum of possible bytes instead of minimum
  added non-blocking IO support

driver/pcie_wb.c

@@ -110,9 +110,18 @@ void wb_write(struct wishbone* wb, wb_addr_t addr, wb_data_t data)
 	}
 	
 	switch (dev->width) {
-	case 4:	iowrite32(data, window + (addr & WINDOW_LOW)); break;
-	case 2: iowrite16(data >> dev->shift, window + (addr & WINDOW_LOW) + dev->low_addr); break;
-	case 1: iowrite8 (data >> dev->shift, window + (addr & WINDOW_LOW) + dev->low_addr); break;
+	case 4:	
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": iowrite32(0x%x, 0x%x)\n", data, addr);
+		iowrite32(data, window + (addr & WINDOW_LOW)); 
+		break;
+	case 2: 
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": iowrite16(0x%x, 0x%x)\n", data >> dev->shift, addr + dev->low_addr);
+		iowrite16(data >> dev->shift, window + (addr & WINDOW_LOW) + dev->low_addr); 
+		break;
+	case 1: 
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": iowrite8(0x%x, 0x%x)\n", data >> dev->shift, addr + dev->low_addr);
+		iowrite8 (data >> dev->shift, window + (addr & WINDOW_LOW) + dev->low_addr); 
+		break;
 	}
 }
 
@@ -136,9 +145,15 @@ wb_data_t wb_read(struct wishbone* wb, wb_addr_t addr)
 	rmb();	// has to be executed before reading
 	
 	switch (dev->width) {
-	case 4:	return ((wb_data_t)ioread32(window + (addr & WINDOW_LOW)));
-	case 2: return ((wb_data_t)ioread16(window + (addr & WINDOW_LOW) + dev->low_addr)) << dev->shift;
-	case 1: return ((wb_data_t)ioread8 (window + (addr & WINDOW_LOW) + dev->low_addr)) << dev->shift;
+	case 4:	
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": ioread32(0x%x)\n", addr);
+		return ((wb_data_t)ioread32(window + (addr & WINDOW_LOW)));
+	case 2: 
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": ioread32(0x%x)\n", addr + dev->low_addr);
+		return ((wb_data_t)ioread16(window + (addr & WINDOW_LOW) + dev->low_addr)) << dev->shift;
+	case 1: 
+		if (unlikely(debug)) printk(KERN_ALERT PCIE_WB ": ioread32(0x%x)\n", addr + dev->low_addr);
+		return ((wb_data_t)ioread8 (window + (addr & WINDOW_LOW) + dev->low_addr)) << dev->shift;
 	}
 	return 0;
 }

driver/wishbone.c

@@ -51,7 +51,7 @@ static void etherbone_process(struct etherbone_context* context)
 {
 	struct wishbone *wb;
 	const struct wishbone_operations *wops;
-	unsigned int size, left, i, record_len = 0;
+	unsigned int size, left, i, record_len;
 	unsigned char *buf;
 	
 	if (context->state == header) {
@@ -77,7 +77,6 @@ static void etherbone_process(struct etherbone_context* context)
 	size = RING_PROC_LEN(context);
 	
 	for (left = size; left >= 4; left -= record_len) {
-		unsigned int record_len;
 		unsigned char flags, be, wcount, rcount;
 		
 		/* Determine record size */
@@ -191,7 +190,7 @@ static ssize_t char_aio_read(struct kiocb *iocb, const struct iovec *iov, unsign
 	mutex_lock(&context->mutex);
 	
 	ring_len = RING_READ_LEN(context);
-	len = max_t(unsigned int, ring_len, iov_len);
+	len = min_t(unsigned int, ring_len, iov_len);
 	
 	/* How far till we must wrap?  */
 	buf_len = sizeof(context->buf) - context->sent;
@@ -210,6 +209,9 @@ static ssize_t char_aio_read(struct kiocb *iocb, const struct iovec *iov, unsign
 	
 	mutex_unlock(&context->mutex);
 	
+	if (len == 0 && (filep->f_flags & O_NONBLOCK) != 0)
+		return -EAGAIN;
+	
 	return len;
 }
 
@@ -224,7 +226,7 @@ static ssize_t char_aio_write(struct kiocb *iocb, const struct iovec *iov, unsig
 	mutex_lock(&context->mutex);
 	
 	ring_len = RING_WRITE_LEN(context);
-	len = max_t(unsigned int, ring_len, iov_len);
+	len = min_t(unsigned int, ring_len, iov_len);
 	
 	/* How far till we must wrap?  */
 	buf_len = sizeof(context->buf) - context->received;
@@ -246,6 +248,9 @@ static ssize_t char_aio_write(struct kiocb *iocb, const struct iovec *iov, unsig
 	
 	mutex_unlock(&context->mutex);
 	
+	if (len == 0 && (filep->f_flags & O_NONBLOCK) != 0)
+		return -EAGAIN;
+	
 	return len;
 }