firewire: core: fix DMA mapping direction

@@ -22,6 +22,7 @@
 #include <linux/compat.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
 #include <linux/errno.h>
 #include <linux/firewire.h>
 #include <linux/firewire-cdev.h>

@@ -71,6 +72,7 @@ struct client {
 	u64 iso_closure;
 	struct fw_iso_buffer buffer;
 	unsigned long vm_start;
+	bool buffer_is_mapped;
 
 	struct list_head phy_receiver_link;
 	u64 phy_receiver_closure;

@@ -960,11 +962,20 @@ static void iso_mc_callback(struct fw_is
 		    sizeof(e->interrupt), NULL, 0);
 }
 
+static enum dma_data_direction iso_dma_direction(struct fw_iso_context *context)
+{
+		if (context->type == FW_ISO_CONTEXT_TRANSMIT)
+			return DMA_TO_DEVICE;
+		else
+			return DMA_FROM_DEVICE;
+}
+
 static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
 {
 	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
 	struct fw_iso_context *context;
 	fw_iso_callback_t cb;
+	int ret;
 
 	BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
 		     FW_CDEV_ISO_CONTEXT_RECEIVE  != FW_ISO_CONTEXT_RECEIVE  ||

@@ -1005,8 +1016,21 @@ static int ioctl_create_iso_context(stru
 	if (client->iso_context != NULL) {
 		spin_unlock_irq(&client->lock);
 		fw_iso_context_destroy(context);
+
 		return -EBUSY;
 	}
+	if (!client->buffer_is_mapped) {
+		ret = fw_iso_buffer_map_dma(&client->buffer,
+					    client->device->card,
+					    iso_dma_direction(context));
+		if (ret < 0) {
+			spin_unlock_irq(&client->lock);
+			fw_iso_context_destroy(context);
+
+			return ret;
+		}
+		client->buffer_is_mapped = true;
+	}
 	client->iso_closure = a->closure;
 	client->iso_context = context;
 	spin_unlock_irq(&client->lock);

@@ -1652,7 +1676,6 @@ static long fw_device_op_compat_ioctl(st
 static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct client *client = file->private_data;
-	enum dma_data_direction direction;
 	unsigned long size;
 	int page_count, ret;
 

@@ -1675,20 +1698,28 @@ static int fw_device_op_mmap(struct file
 	if (size & ~PAGE_MASK)
 		return -EINVAL;
 
-	if (vma->vm_flags & VM_WRITE)
-		direction = DMA_TO_DEVICE;
-	else
-		direction = DMA_FROM_DEVICE;
-
-	ret = fw_iso_buffer_init(&client->buffer, client->device->card,
-				 page_count, direction);
+	ret = fw_iso_buffer_alloc(&client->buffer, page_count);
 	if (ret < 0)
 		return ret;
 
-	ret = fw_iso_buffer_map(&client->buffer, vma);
+	spin_lock_irq(&client->lock);
+	if (client->iso_context) {
+		ret = fw_iso_buffer_map_dma(&client->buffer,
+				client->device->card,
+				iso_dma_direction(client->iso_context));
+		client->buffer_is_mapped = (ret == 0);
+	}
+	spin_unlock_irq(&client->lock);
 	if (ret < 0)
-		fw_iso_buffer_destroy(&client->buffer, client->device->card);
+		goto fail;
 
+	ret = fw_iso_buffer_map_vma(&client->buffer, vma);
+	if (ret < 0)
+		goto fail;
+
+	return 0;
+ fail:
+	fw_iso_buffer_destroy(&client->buffer, client->device->card);
 	return ret;
 }
 

119 lines not on this page · raw message

@@ -3,6 +3,7 @@
 
 #include <linux/compiler.h>
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
 #include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/idr.h>

@@ -169,7 +170,11 @@ void fw_node_event(struct fw_card *card,
 
 /* -iso */
 
-int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma);
+int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count);
+int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
+			  enum dma_data_direction direction);
+int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
+			  struct vm_area_struct *vma);
 
 
 /* -topology */

@@ -391,6 +391,7 @@ struct fw_iso_buffer {
 	enum dma_data_direction direction;
 	struct page **pages;
 	int page_count;
+	int page_count_mapped;
 };
 
 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,