This is a note to let you know that I've just added the patch titled
usb: chipidea: Simplify Tegra DMA alignment code
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-chipidea-simplify-tegra-dma-alignment-code.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9ca01556ce2d705ad00276e8a5dcbcdb70b431e0
Author: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Date: Thu Sep 28 23:06:03 2023 +0200
usb: chipidea: Simplify Tegra DMA alignment code
[ Upstream commit 2ae61a2562c0d1720545b0845829a65fb6a9c2c6 ]
The USB host on Tegra3 works with 32-bit alignment. Previous code tried
to align the buffer, but it did align the wrapper struct instead, so
the buffer was at a constant offset of 8 bytes (two pointers) from
expected alignment. Since kmalloc() guarantees at least 8-byte
alignment already, the alignment-extending is removed.
Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/a0d917d492b1f91ee0019e68b8e8bca9c585393f.1695934946.git.mirq-linux@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index abddd39d1ff1e..0cce192083701 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -30,8 +30,7 @@ struct ehci_ci_priv {
};
struct ci_hdrc_dma_aligned_buffer {
- void *kmalloc_ptr;
- void *old_xfer_buffer;
+ void *original_buffer;
u8 data[];
};
@@ -380,60 +379,52 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
return 0;
}
-static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
+static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb, bool copy_back)
{
struct ci_hdrc_dma_aligned_buffer *temp;
- size_t length;
if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
return;
+ urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
temp = container_of(urb->transfer_buffer,
struct ci_hdrc_dma_aligned_buffer, data);
+ urb->transfer_buffer = temp->original_buffer;
+
+ if (copy_back && usb_urb_dir_in(urb)) {
+ size_t length;
- if (usb_urb_dir_in(urb)) {
if (usb_pipeisoc(urb->pipe))
length = urb->transfer_buffer_length;
else
length = urb->actual_length;
- memcpy(temp->old_xfer_buffer, temp->data, length);
+ memcpy(temp->original_buffer, temp->data, length);
}
- urb->transfer_buffer = temp->old_xfer_buffer;
- kfree(temp->kmalloc_ptr);
- urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
+ kfree(temp);
}
static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
{
- struct ci_hdrc_dma_aligned_buffer *temp, *kmalloc_ptr;
- const unsigned int ci_hdrc_usb_dma_align = 32;
- size_t kmalloc_size;
+ struct ci_hdrc_dma_aligned_buffer *temp;
if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0)
return 0;
- if (!((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)) && !(urb->transfer_buffer_length & 3))
+ if (IS_ALIGNED((uintptr_t)urb->transfer_buffer, 4)
+ && IS_ALIGNED(urb->transfer_buffer_length, 4))
return 0;
- /* Allocate a buffer with enough padding for alignment */
- kmalloc_size = ALIGN(urb->transfer_buffer_length, 4) +
- sizeof(struct ci_hdrc_dma_aligned_buffer) +
- ci_hdrc_usb_dma_align - 1;
-
- kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
- if (!kmalloc_ptr)
+ temp = kmalloc(sizeof(*temp) + ALIGN(urb->transfer_buffer_length, 4), mem_flags);
+ if (!temp)
return -ENOMEM;
- /* Position our struct dma_aligned_buffer such that data is aligned */
- temp = PTR_ALIGN(kmalloc_ptr + 1, ci_hdrc_usb_dma_align) - 1;
- temp->kmalloc_ptr = kmalloc_ptr;
- temp->old_xfer_buffer = urb->transfer_buffer;
if (usb_urb_dir_out(urb))
memcpy(temp->data, urb->transfer_buffer,
urb->transfer_buffer_length);
- urb->transfer_buffer = temp->data;
+ temp->original_buffer = urb->transfer_buffer;
+ urb->transfer_buffer = temp->data;
urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
return 0;
@@ -450,7 +441,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
if (ret)
- ci_hdrc_free_dma_aligned_buffer(urb);
+ ci_hdrc_free_dma_aligned_buffer(urb, false);
return ret;
}
@@ -458,7 +449,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
static void ci_hdrc_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
usb_hcd_unmap_urb_for_dma(hcd, urb);
- ci_hdrc_free_dma_aligned_buffer(urb);
+ ci_hdrc_free_dma_aligned_buffer(urb, true);
}
#ifdef CONFIG_PM_SLEEP
