Revert "kernel: usb: dwc2 DMA alignment fixes"
authorJohn Crispin <john@phrozen.org>
Wed, 8 Aug 2018 14:31:14 +0000 (16:31 +0200)
committerJohn Crispin <john@phrozen.org>
Wed, 8 Aug 2018 14:31:14 +0000 (16:31 +0200)
This reverts commit 1e5bd42d63e508358c703be550590d3ff72dc6e0.

this has already treacled down with the latest kernel bump

Signed-off-by: John Crispin <john@phrozen.org>
target/linux/generic/pending-4.14/170-usb-dwc2-Fix-DMA-alignment-to-start-at-allocated-boun.patch [deleted file]
target/linux/generic/pending-4.14/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch [deleted file]

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 (file)
index 49b33d5..0000000
+++ /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 (file)
index 78e6a7e..0000000
+++ /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;