687a28590c
========
- Added alignment check for event ring read pointer to avoid the potential
buffer corruption issue.
- Added support for SDX75 modem which takes longer time to enter READY state.
- Added spinlock to protect concurrent access while queuing transfer ring
elements.
- Dropped the read channel lock before invoking the client callback as the
client can potentially queue buffers thus ending up wtih soft lockup.
MHI Endpoint
============
- Used kzalloc() to allocate event ring elements instead of allocating the
elements on the stack, as the endpoint controller trying to queue them may not
be able to use vmalloc memory (using DMA).
- Used slab allocator for allocting the memory for objects used frequently and
are of fixed size.
- Added support for interrupt moderation timer feature which is used by the host
to limit the number of interrupts raised by the device for an event ring.
- Added async read/write DMA support for transferring data between host and the
endpoint. So far MHI EP stack assumed that the data will be transferred
synchronously (i.e., it sends completion once the transfer APIs are returned).
But this impacts the throughput if the controller is using DMA to do the
transfer.
So to add async suport, existing sync transfer APIs are renamed to
{read/write}_sync and also introduced two new APIs {read/write}_async for
carrying out the async transfer.
Controllers implementing the async APIs should queue the buffers and return
immediately without waiting for transfer completion. Once the transfer
completion happens later, they should invoke the completion callback so that
the MHI EP stack can send the completion event to the host.
The controller driver patches (PCI EPF) for this async support are also merged
to the MHI tree with Acks from PCI maintainers.
- Fixed the DMA channel direction in error path of the PCI EPF driver.
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Merge tag 'mhi-for-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi into char-misc-next
Manivannan writes:
MHI Host
========
- Added alignment check for event ring read pointer to avoid the potential
buffer corruption issue.
- Added support for SDX75 modem which takes longer time to enter READY state.
- Added spinlock to protect concurrent access while queuing transfer ring
elements.
- Dropped the read channel lock before invoking the client callback as the
client can potentially queue buffers thus ending up wtih soft lockup.
MHI Endpoint
============
- Used kzalloc() to allocate event ring elements instead of allocating the
elements on the stack, as the endpoint controller trying to queue them may not
be able to use vmalloc memory (using DMA).
- Used slab allocator for allocting the memory for objects used frequently and
are of fixed size.
- Added support for interrupt moderation timer feature which is used by the host
to limit the number of interrupts raised by the device for an event ring.
- Added async read/write DMA support for transferring data between host and the
endpoint. So far MHI EP stack assumed that the data will be transferred
synchronously (i.e., it sends completion once the transfer APIs are returned).
But this impacts the throughput if the controller is using DMA to do the
transfer.
So to add async suport, existing sync transfer APIs are renamed to
{read/write}_sync and also introduced two new APIs {read/write}_async for
carrying out the async transfer.
Controllers implementing the async APIs should queue the buffers and return
immediately without waiting for transfer completion. Once the transfer
completion happens later, they should invoke the completion callback so that
the MHI EP stack can send the completion event to the host.
The controller driver patches (PCI EPF) for this async support are also merged
to the MHI tree with Acks from PCI maintainers.
- Fixed the DMA channel direction in error path of the PCI EPF driver.
* tag 'mhi-for-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi:
bus: mhi: host: Drop chan lock before queuing buffers
bus: mhi: host: Add spinlock to protect WP access when queueing TREs
PCI: epf-mhi: Fix the DMA data direction of dma_unmap_single()
bus: mhi: ep: Add checks for read/write callbacks while registering controllers
bus: mhi: ep: Add support for async DMA read operation
bus: mhi: ep: Add support for async DMA write operation
PCI: epf-mhi: Enable MHI async read/write support
PCI: epf-mhi: Add support for DMA async read/write operation
PCI: epf-mhi: Simulate async read/write using iATU
bus: mhi: ep: Introduce async read/write callbacks
bus: mhi: ep: Rename read_from_host() and write_to_host() APIs
bus: mhi: ep: Pass mhi_ep_buf_info struct to read/write APIs
bus: mhi: ep: Add support for interrupt moderation timer
bus: mhi: ep: Use slab allocator where applicable
bus: mhi: host: Add alignment check for event ring read pointer
bus: mhi: host: pci_generic: Add SDX75 based modem support
bus: mhi: host: Add a separate timeout parameter for waiting ready
bus: mhi: ep: Do not allocate event ring element on stack
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.