The netif_rx() function frees the skb so we can't dereference it to
save the skb->len.

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Link: https://lore.kernel.org/r/tencent_3B3D24B66ED66A6BB73CC0E63C6A14E45109@qq.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The flag of GFP_ATOMIC is given to the call of kmalloc when building node
tree, but the call is not atomic context. The call of
fw_core_handle_bus_reset() and fw_core_remove_card() builds the tree,
while they are done in specific workqueue or pci remove callback.

This commit obsolete the usage of GFP_ATOMIC.

Link: https://lore.kernel.org/r/20230604070255.172700-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver allocates several non-coherent DMA buffers for AR
request and response contexts. The buffers are mapped to kernel virtual
address (VMA) so that the first page locates after the last page. Even
when large payload of packet is handled crossing the boundary of buffers,
the driver operates continuously on VMA.

No kernel API is provided for this kind of mapping, while it is possible
to release the buffer when PCI device is going to be released.

This commit moves the call of release helper function to the callback
function of release resources.

Link: https://lore.kernel.org/r/20230604054451.161076-10-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver allocates DMA coherent buffer to transfer content
of configuration ROM.

This commit utilizes managed device resource to maintain the lifetime of
buffer.

Link: https://lore.kernel.org/r/20230604054451.161076-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver allocates DMA coherent buffer for descriptors of IT,
IR, AT receive, and AT request contexts by the same way.

This commit utilizes managed device resource to maintain the lifetime of
buffers.

Link: https://lore.kernel.org/r/20230604054451.161076-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver allocates the list of isochronous contexts as much
as the hardware supports.

This commit utilizes managed device resource to maintain the lifetime of
list.

Link: https://lore.kernel.org/r/20230604054451.161076-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI controller register handler to single interrupt number.

This commit uses managed device resource to maintain the lifetime of
requested IRQ.

Link: https://lore.kernel.org/r/20230604054451.161076-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver allocates a DMA coherent buffer for multi-purposes.
The buffer is split into three region for specific purposes; i.e. 1/4 for
context descriptors of AR request and response as well as 1/2 for self
ID handling.

This commit uses managed device resource to maintain the lifetime of
buffer.

Link: https://lore.kernel.org/r/20230604054451.161076-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The PCI framework has the convenient helper function to check and map MMIO
region with managed device resource.

This commit elaborates 1394 OHCI driver to use the function.

Link: https://lore.kernel.org/r/20230604054451.161076-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The PCI framework supports managed device resource to maintain the
lifetime of PCI specific resources.

This commit allows 1394 OHCI driver to utilize it.

Link: https://lore.kernel.org/r/20230604054451.161076-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>