lwn.git/drivers/firewire/ohci.c, branch docs-6.8-2

firewire: ohci: release buffer for AR req/resp contexts when managed resource is released

2023-06-05T22:54:24+00:00

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

firewire: ohci: use devres for content of configuration ROM

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for IT, IR, AT/receive, and AT/request contexts

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for list of isochronous contexts

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for requested IRQ

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for misc DMA buffer

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for MMIO region mapping

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for PCI-related resources

2023-06-05T22:54:23+00:00

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

firewire: ohci: use devres for memory object of ohci structure

2023-06-05T22:54:23+00:00

The managed device resource (devres) framework is convenient to maintain lifetime of allocated memory object for device. This commit utilizes the framework for the object of ohci structure. The extra operation for power management is required in Apple PowerMac based machines, thus release callback is assigned to the object to call the operation. Link: https://lore.kernel.org/r/20230604054451.161076-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto

firewire: core: use union for callback of transaction completion

2023-05-29T23:12:40+00:00

In 1394 OHCI, the OUTPUT_LAST descriptor of Asynchronous Transmit (AT) request context has timeStamp field, in which 1394 OHCI controller record the isochronous cycle when the packet was sent for the request subaction. Additionally, for the case of split transaction in IEEE 1394, Asynchronous Receive (AT) request context is used for response subaction to finish the transaction. The trailer quadlet of descriptor in the context has timeStamp field, in which 1394 OHCI controller records the isochronous cycle when the packet arrived. Current implementation of 1394 OHCI controller driver stores values of both fields to internal structure as time stamp, while Linux FireWire subsystem provides no way to access to it. When using asynchronous transaction service provided by the subsystem, callback function is passed to kernel API. The prototype of callback function has the lack of argument for the values. This commit adds a new callback function for the purpose. It has an additional argument to point to the constant array with two elements. For backward compatibility to kernel space, a new union is also adds to wrap two different prototype of callback function. The fw_transaction structure has the union as a member and a boolean flag to express which function callback is available. The core function is changed to handle the two cases; with or without time stamp. For the error path to process transaction, the isochronous cycle is computed by current value of CYCLE_TIMER register in 1394 OHCI controller. Especially for the case of timeout of split transaction, the expected isochronous cycle is computed. Link: https://lore.kernel.org/r/20230529113406.986289-6-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto