v4.2-rc1 enabled huge page support for ioremap(..).
Calling vmalloc_to_page after v4.2-rc1 results in the
crash shown below on the host upon booting X100 coprocessors:
BUG: unable to handle kernel paging request at ffffc47c00000000
IP: [<ffffffff811a2c0c>] vmalloc_to_page+0x6c/0xb0
This patch fixes this crash by obtaining the fake struct page
pointer which is required to be passed into dma_map_sg(..)
by calling pfn_to_page(..) instead of vmalloc_to_page(..).
Link: https://lkml.org/lkml/2015/7/18/110
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Suggested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Delete unnecessary prints resulting in an "spdev could be null"
warning from a static checker in scif_peer_remove(..).
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This issue was reported @ https://lkml.org/lkml/2015/6/9/731
Reported-by: Jim Davis <jim.epost@gmail.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF messaging APIs which allow sending messages between the SCIF
endpoints via a byte stream based ring buffer which has been
optimized to avoid reads across PCIe. The SCIF messaging APIs
are typically used for short < 1024 byte messages for best
performance while the RDMA APIs which will be submitted in a future
patch series is recommended for larger transfers. The node
enumeration API enables a user to query for the number of nodes
online in the SCIF network and their node ids.
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF connection APIs which establish a SCIF connection between
a pair of SCIF endpoints. A SCIF connection consists of a
dedicated queue-pair between the endpoints. Client messages are
sent over the queue-pair whereas the signaling associated with the
message is multiplexed over the node queue-pair. Similarly other
control messages such as exposing registered memory are also sent
over the node queue-pair. The SCIF endpoints must be in connected
state to exchange messages, register memory, map remote memory and
trigger DMA transfers. SCIF connections can be set up
asynchronously or synchronously.
Thanks to Johnnie S Peters for authoring parts of this patch during
early bring up of the SCIF driver.
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF character device file operations and kernel APIs for opening and
closing a user and kernel mode SCIF endpoint. This patch also enables
binding to a SCIF port and listening for incoming SCIF connections.
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF node queue pair setup creates the SCIF driver kernel
mode private node queue pairs between all the nodes to enable
internal control message communication once SCIF gets probed
by the SCIF hardware bus. Peer to peer communication between
MIC Coprocessor nodes is supported.
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF module initialization, DMA mapping, ioremap wrapper APIs
and debugfs hooks. SCIF gets probed by the SCIF hardware bus
if SCIF devices were registered by base drivers. A MISC device
is registered to provide the SCIF character device interface.
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SCIF peer bus is used to register and unregister SCIF peer devices
internally by the SCIF driver to signify the addition and removal of
peer nodes respectively from the SCIF network. This simplifies remote node
handling within SCIF and will also be used to support device probe/remove
for SCIF client drivers (e.g. netdev over SCIF)
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF ring buffer is a single producer, single consumer byte stream
ring buffer optimized for avoiding reads across the PCIe bus while
adding the required barriers and hardware workarounds for the MIC
Coprocessor. The ring buffer is used to implement a receive queue for
SCIF driver messaging between two nodes and for byte stream messaging
between SCIF endpoints. The existing in-kernel ring buffer was not
reused since it has not been designed for our use across the PCIe bus
where each node runs an independent OS. Each SCIF node has a receive
queue for every other SCIF node, and each connected endpoint has a
receive queue for messages from its peer. This pair of receive
queues is referred to as a SCIF queue pair.
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sudeep Dutt