Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[sfrench/cifs-2.6.git] / drivers / usb / dwc2 / hcd.c

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index b1104be3429c2285677d2101004080e9a30af769..6e2cdd7b93d46cf839fe2c515e88028dec22bb2e 100644 (file)
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -2665,34 +2665,35 @@ static int dwc2_alloc_split_dma_aligned_buf(struct dwc2_hsotg *hsotg,
 
 #define DWC2_USB_DMA_ALIGN 4
 
-struct dma_aligned_buffer {
-       void *kmalloc_ptr;
-       void *old_xfer_buffer;
-       u8 data[0];
-};
-
 static void dwc2_free_dma_aligned_buffer(struct urb *urb)
 {
-       struct dma_aligned_buffer *temp;
+       void *stored_xfer_buffer;
+       size_t length;
 
        if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
                return;
 
-       temp = container_of(urb->transfer_buffer,
-                           struct dma_aligned_buffer, data);
+       /* Restore urb->transfer_buffer from the end of the allocated area */
+       memcpy(&stored_xfer_buffer, urb->transfer_buffer +
+              urb->transfer_buffer_length, sizeof(urb->transfer_buffer));
 
-       if (usb_urb_dir_in(urb))
-               memcpy(temp->old_xfer_buffer, temp->data,
-                      urb->transfer_buffer_length);
-       urb->transfer_buffer = temp->old_xfer_buffer;
-       kfree(temp->kmalloc_ptr);
+       if (usb_urb_dir_in(urb)) {
+               if (usb_pipeisoc(urb->pipe))
+                       length = urb->transfer_buffer_length;
+               else
+                       length = urb->actual_length;
+
+               memcpy(stored_xfer_buffer, urb->transfer_buffer, length);
+       }
+       kfree(urb->transfer_buffer);
+       urb->transfer_buffer = stored_xfer_buffer;
 
        urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
 }
 
 static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
 {
-       struct dma_aligned_buffer *temp, *kmalloc_ptr;
+       void *kmalloc_ptr;
        size_t kmalloc_size;
 
        if (urb->num_sgs || urb->sg ||
@@ -2700,22 +2701,29 @@ static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
            !((uintptr_t)urb->transfer_buffer & (DWC2_USB_DMA_ALIGN - 1)))
                return 0;
 
-       /* Allocate a buffer with enough padding for alignment */
+       /*
+        * Allocate a buffer with enough padding for original transfer_buffer
+        * pointer. This allocation is guaranteed to be aligned properly for
+        * DMA
+        */
        kmalloc_size = urb->transfer_buffer_length +
-               sizeof(struct dma_aligned_buffer) + DWC2_USB_DMA_ALIGN - 1;
+               sizeof(urb->transfer_buffer);
 
        kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
        if (!kmalloc_ptr)
                return -ENOMEM;
 
-       /* Position our struct dma_aligned_buffer such that data is aligned */
-       temp = PTR_ALIGN(kmalloc_ptr + 1, DWC2_USB_DMA_ALIGN) - 1;
-       temp->kmalloc_ptr = kmalloc_ptr;
-       temp->old_xfer_buffer = urb->transfer_buffer;
+       /*
+        * Position value of original urb->transfer_buffer pointer to the end
+        * of allocation for later referencing
+        */
+       memcpy(kmalloc_ptr + urb->transfer_buffer_length,
+              &urb->transfer_buffer, sizeof(urb->transfer_buffer));
+
        if (usb_urb_dir_out(urb))
-               memcpy(temp->data, urb->transfer_buffer,
+               memcpy(kmalloc_ptr, urb->transfer_buffer,
                       urb->transfer_buffer_length);
-       urb->transfer_buffer = temp->data;
+       urb->transfer_buffer = kmalloc_ptr;
 
        urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;