3 files changed, 99 insertions, 39 deletions

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 2e6b24547e2a..2783f69dada6 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -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>
@@ -70,6 +71,7 @@ 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;
@@ -959,11 +961,20 @@ static void iso_mc_callback(struct fw_iso_context *context,
                     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  ||
@@ -1004,8 +1015,21 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
         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);
@@ -1651,7 +1675,6 @@ static long fw_device_op_compat_ioctl(struct file *file,
 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;
 
@@ -1674,20 +1697,28 @@ static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
         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;
 }
 
diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
index d1565828ae2c..8382e27e9a27 100644
--- a/drivers/firewire/core-iso.c
+++ b/drivers/firewire/core-iso.c
@@ -39,52 +39,73 @@
  * Isochronous DMA context management
  */
 
-int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
-                       int page_count, enum dma_data_direction direction)
+int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count)
 {
-        int i, j;
-        dma_addr_t address;
-
-        buffer->page_count = page_count;
-        buffer->direction = direction;
+        int i;
 
+        buffer->page_count = 0;
+        buffer->page_count_mapped = 0;
         buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
                                 GFP_KERNEL);
         if (buffer->pages == NULL)
-                goto out;
+                return -ENOMEM;
 
-        for (i = 0; i < buffer->page_count; i++) {
+        for (i = 0; i < page_count; i++) {
                 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
                 if (buffer->pages[i] == NULL)
-                        goto out_pages;
+                        break;
+        }
+        buffer->page_count = i;
+        if (i < page_count) {
+                fw_iso_buffer_destroy(buffer, NULL);
+                return -ENOMEM;
+        }
 
+        return 0;
+}
+
+int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
+                          enum dma_data_direction direction)
+{
+        dma_addr_t address;
+        int i;
+
+        buffer->direction = direction;
+
+        for (i = 0; i < buffer->page_count; i++) {
                 address = dma_map_page(card->device, buffer->pages[i],
                                        0, PAGE_SIZE, direction);
-                if (dma_mapping_error(card->device, address)) {
-                        __free_page(buffer->pages[i]);
-                        goto out_pages;
-                }
+                if (dma_mapping_error(card->device, address))
+                        break;
+
                 set_page_private(buffer->pages[i], address);
         }
+        buffer->page_count_mapped = i;
+        if (i < buffer->page_count)
+                return -ENOMEM;
 
         return 0;
+}
 
- out_pages:
-        for (j = 0; j < i; j++) {
-                address = page_private(buffer->pages[j]);
-                dma_unmap_page(card->device, address,
-                               PAGE_SIZE, direction);
-                __free_page(buffer->pages[j]);
-        }
-        kfree(buffer->pages);
- out:
-        buffer->pages = NULL;
+int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
+                       int page_count, enum dma_data_direction direction)
+{
+        int ret;
+
+        ret = fw_iso_buffer_alloc(buffer, page_count);
+        if (ret < 0)
+                return ret;
+
+        ret = fw_iso_buffer_map_dma(buffer, card, direction);
+        if (ret < 0)
+                fw_iso_buffer_destroy(buffer, card);
 
-        return -ENOMEM;
+        return ret;
 }
 EXPORT_SYMBOL(fw_iso_buffer_init);
 
-int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
+int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
+                          struct vm_area_struct *vma)
 {
         unsigned long uaddr;
         int i, err;
@@ -107,15 +128,18 @@ void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
         int i;
         dma_addr_t address;
 
-        for (i = 0; i < buffer->page_count; i++) {
+        for (i = 0; i < buffer->page_count_mapped; i++) {
                 address = page_private(buffer->pages[i]);
                 dma_unmap_page(card->device, address,
                                PAGE_SIZE, buffer->direction);
-                __free_page(buffer->pages[i]);
         }
+        for (i = 0; i < buffer->page_count; i++)
+                __free_page(buffer->pages[i]);
 
         kfree(buffer->pages);
         buffer->pages = NULL;
+        buffer->page_count = 0;
+        buffer->page_count_mapped = 0;
 }
 EXPORT_SYMBOL(fw_iso_buffer_destroy);
 
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 9047f5547d98..94257aecd054 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -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, struct fw_node *node, int event);
 
 /* -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 */