kernel/linux.git/drivers/misc/mic/scif, branch v4.4.89

misc: mic/scif: fix wrap around tests

2016-05-04T21:48:51+00:00

commit 7b64dbf849abdd7e769820e25120758f956a7f13 upstream. Signed integer overflow is undefined. Also I added a check for "(offset < 0)" in scif_unregister() because that makes it match the other conditions and because I didn't want to subtract a negative. Fixes: ba612aa8b487 ('misc: mic: SCIF memory registration and unregistration') Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman

misc: mic/scif: fix error code in scif_create_remote_lookup()

2015-10-18T04:49:48+00:00

We should be returning -ENOMEM here instead of success. Fixes: ba612aa8b487 ('misc: mic: SCIF memory registration and unregistration') Signed-off-by: Dan Carpenter Reviewed-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic/scif: re-take a lock on error path

2015-10-18T04:49:48+00:00

The caller expects that we take this lock again before returning otherwise it you get double unlocks and races. Fixes: ba612aa8b487 ('misc: mic: SCIF memory registration and unregistration') Signed-off-by: Dan Carpenter Reviewed-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: fix memory leak

2015-10-18T04:42:29+00:00

In scif_node_connect() we were returning if the initialization of p2p_ji fails. But at that time p2p_ij has already been initialized and resources allocated for it. And since p2p_ij is not added to the list till now so we will have a leak. Lets deinitialize and release the resources connected to p2p_ij. Signed-off-by: Sudip Mukherjee Reviewed-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF RMA nodeqp and minor miscellaneous changes

2015-10-04T11:54:54+00:00

This patch adds the SCIF kernel node QP control messages required to enable SCIF RMAs. Examples of such node QP control messages include registration, unregistration, remote memory allocation requests, remote memory unmap and SCIF remote fence requests. The patch also updates the SCIF driver with minor changes required to enable SCIF RMAs by adding the new files to the build, initializing RMA specific information during SCIF endpoint creation, reserving SCIF DMA channels, initializing SCIF RMA specific global data structures, adding the IOCTL hooks required for SCIF RMAs and updating RMA specific debugfs hooks. Reviewed-by: Ashutosh Dixit Reviewed-by: Nikhil Rao Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF fence

2015-10-04T11:54:54+00:00

This patch implements the fence APIs required to synchronize DMAs. SCIF provides an interface to return a "mark" for all DMAs programmed at the instant the API was called. Users can then "wait" on the mark provided previously by blocking inside the kernel. Upon receipt of a DMA completion interrupt the waiting thread is woken up. There is also an interface to signal DMA completion by polling for a location to be updated via a "signal" cookie to avoid the interrupt overhead in the mark/wait interface. SCIF allows programming fences on both the local and the remote node for both the mark/wait or the fence signal APIs. Reviewed-by: Ashutosh Dixit Reviewed-by: Nikhil Rao Signed-off-by: Jacek Lawrynowicz Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF DMA and CPU copy interface

2015-10-04T11:54:54+00:00

SCIF allows users to read from or write to registered remote memory via CPU copies or DMA. The API verifies that both local and remote windows are valid before initiating the CPU or DMA transfers. SCIF has optimized algorithms for handling byte aligned as well as cache line aligned DMA engines. A registration cache is maintained to avoid the overhead of pinning pages repeatedly if buffers are reused. The registration cache is invalidated upon receipt of MMU notifier callbacks. SCIF windows are destroyed and the pages are unpinned only once all prior DMAs initiated using that window are drained. Users can request synchronous DMA operations as well as tail byte ordering if required. CPU copies are always performed synchronously. Reviewed-by: Ashutosh Dixit Reviewed-by: Nikhil Rao Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF remote memory map/unmap interface

2015-10-04T11:54:54+00:00

This patch implements the SCIF mmap/munmap interface. A similar capability is provided to kernel clients via the scif_get_pages()/scif_put_pages() APIs. The SCIF mmap interface queries to check if a window is valid and then remaps the local virtual address to the remote physical pages. These mappings are subsequently destroyed upon receipt of the VMA close operation or scif_get_pages(). This functionality allows SCIF users to directly access remote memory without any driver interaction once the mappings are created thereby providing bare-metal PCIe latency. These mappings are zapped to avoid RMA accesses from user space, if a Coprocessor is reset. Reviewed-by: Ashutosh Dixit Reviewed-by: Nikhil Rao Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF RMA list operations

2015-10-04T11:54:54+00:00

This patch adds the implementation for operations performed on the list of SCIF windows. Examples of such operations includes adding the windows to the list of registered (or cached) windows, querying the list of self or remote windows and unregistering windows. The query operation is used by SCIF APIs which initiate DMAs, CPU copies or fences to ensure that a window remains valid during a transfer. Reviewed-by: Ashutosh Dixit Signed-off-by: Nikhil Rao Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman

misc: mic: SCIF memory registration and unregistration

2015-10-04T11:54:54+00:00

This patch implements the SCIF APIs required to pin and unpin pages. SCIF registration locks down the pages. It then sends a remote window allocation request to the peer. Once the peer has allocated memory, the local SCIF endpoint copies the pinned page information to the peer and notifies the peer once the copy has complete. The peer upon receipt of the registration notification adds the new remote window to its list. At this point the window page information is available on both self and remote nodes so that they can start performing SCIF DMAs, CPU copies and fences. The unregistration API tears down the registration at both self and remote nodes. Reviewed-by: Nikhil Rao Reviewed-by: Ashutosh Dixit Signed-off-by: Sudeep Dutt Signed-off-by: Greg Kroah-Hartman