mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-28 21:33:52 +00:00
Code Issues Releases Wiki Activity

usb: chipidea: Simplify Tegra DMA alignment code

Browse source 
[ Upstream commit 2ae61a2562 ]

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: fc53d52790 ("usb: chipidea: tegra: Support host mode")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/a0d917d492b1f91ee0019e68b8e8bca9c585393f.1695934946.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Michał Mirosław 2023-09-28 23:06:03 +02:00 committed by Greg Kroah-Hartman
parent 58e8316b20
commit 2941a29fe9
1 changed files with 18 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

45
drivers/usb/chipidea/host.c
View file

@ -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[];
};
@ -372,60 +371,52 @@ 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;
@ -442,7 +433,7 @@ 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;
}
@ -450,7 +441,7 @@ 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);
}
int ci_hdrc_host_init(struct ci_hdrc *ci)