Revert "kernel: usb: dwc2 DMA alignment fixes"

This reverts commit 1e5bd42d63e508358c703be550590d3ff72dc6e0.

this has already treacled down with the latest kernel bump

Signed-off-by: John Crispin <john@phrozen.org>

2 files changed, 0 insertions, 176 deletions

diff --git a/target/linux/generic/pending-4.14/170-usb-dwc2-Fix-DMA-alignment-to-start-at-allocated-boun.patch b/target/linux/generic/pending-4.14/170-usb-dwc2-Fix-DMA-alignment-to-start-at-allocated-boun.patch
deleted file mode 100644
index 49b33d514f..0000000000
--- a/target/linux/generic/pending-4.14/170-usb-dwc2-Fix-DMA-alignment-to-start-at-allocated-boun.patch
+++ /dev/null
@@ -1,126 +0,0 @@
-From 028c9191bdf88f120f65626920a6a679170fcc3e Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Antti=20Sepp=C3=A4l=C3=A4?= <a.seppala@gmail.com>
-Date: Thu, 5 Jul 2018 11:37:03 +0300
-Subject: [PATCH 1/2] usb: dwc2: Fix DMA alignment to start at allocated
- boundary
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-The commit 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more
-supported way") introduced a common way to align DMA allocations.
-The code in the commit aligns the struct dma_aligned_buffer but the
-actual DMA address pointed by data[0] gets aligned to an offset from
-the allocated boundary by the kmalloc_ptr and the old_xfer_buffer
-pointers.
-
-This is against the recommendation in Documentation/DMA-API.txt which
-states:
-
-  Therefore, it is recommended that driver writers who don't take
-  special care to determine the cache line size at run time only map
-  virtual regions that begin and end on page boundaries (which are
-  guaranteed also to be cache line boundaries).
-
-The effect of this is that architectures with non-coherent DMA caches
-may run into memory corruption or kernel crashes with Unhandled
-kernel unaligned accesses exceptions.
-
-Fix the alignment by positioning the DMA area in front of the allocation
-and use memory at the end of the area for storing the orginal
-transfer_buffer pointer. This may have the added benefit of increased
-performance as the DMA area is now fully aligned on all architectures.
-
-Tested with Lantiq xRX200 (MIPS) and RPi Model B Rev 2 (ARM).
-
-Fixes: 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more
-supported way")
-
-Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
----
- drivers/usb/dwc2/hcd.c | 44 +++++++++++++++++++++++---------------------
- 1 file changed, 23 insertions(+), 21 deletions(-)
-
---- a/drivers/usb/dwc2/hcd.c
-+++ b/drivers/usb/dwc2/hcd.c
-@@ -2628,34 +2628,29 @@ static void dwc2_hc_init_xfer(struct dwc
- 
- #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;
- 
- 	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,
-+		memcpy(stored_xfer_buffer, urb->transfer_buffer,
- 		       urb->transfer_buffer_length);
--	urb->transfer_buffer = temp->old_xfer_buffer;
--	kfree(temp->kmalloc_ptr);
-+	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 ||
-@@ -2663,22 +2658,29 @@ static int dwc2_alloc_dma_aligned_buffer
- 	    !((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;
- 
diff --git a/target/linux/generic/pending-4.14/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch b/target/linux/generic/pending-4.14/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch
deleted file mode 100644
index 78e6a7ef87..0000000000
--- a/target/linux/generic/pending-4.14/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch
+++ /dev/null
@@ -1,50 +0,0 @@
-From 81da1738eee68f1961e03bdeb2d60cf0eb4dd713 Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Antti=20Sepp=C3=A4l=C3=A4?= <a.seppala@gmail.com>
-Date: Thu, 5 Jul 2018 12:06:18 +0300
-Subject: [PATCH 2/2] usb: dwc2: Fix inefficient copy of unaligned buffers
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Make sure only to copy any actual data rather than the whole buffer,
-when releasing the temporary buffer used for unaligned non-isochronous
-transfers.
-
-Taken directly from commit 0efd937e27d5e ("USB: ehci-tegra: fix inefficient
-copy of unaligned buffers")
-
-Tested with Lantiq xRX200 (MIPS) and RPi Model B Rev 2 (ARM)
-
-Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
----
- drivers/usb/dwc2/hcd.c | 12 +++++++++---
- 1 file changed, 9 insertions(+), 3 deletions(-)
-
---- a/drivers/usb/dwc2/hcd.c
-+++ b/drivers/usb/dwc2/hcd.c
-@@ -2631,6 +2631,7 @@ static void dwc2_hc_init_xfer(struct dwc
- static void dwc2_free_dma_aligned_buffer(struct urb *urb)
- {
- 	void *stored_xfer_buffer;
-+	size_t length;
- 
- 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
- 		return;
-@@ -2639,9 +2640,14 @@ static void dwc2_free_dma_aligned_buffer
- 	memcpy(&stored_xfer_buffer, urb->transfer_buffer +
- 	       urb->transfer_buffer_length, sizeof(urb->transfer_buffer));
- 
--	if (usb_urb_dir_in(urb))
--		memcpy(stored_xfer_buffer, urb->transfer_buffer,
--		       urb->transfer_buffer_length);
-+	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;
-