ntb: Fixes and enhancements to ntb tools

Hi,

I've been working on developing an experimental NTB driver for some custom hardware and I've found the need to make some minor enhancements to the NTB layer.

1) I've modified ntb_perf to take an option similar to ntb_transport which limits the memory window size. This was useful seeing the mws I'm dealing with are much larger than the available coherent memory I can allocate.

2) I've added code to ntb_perf and ntb_transport to check that there are enough scratchpad registers. (As I was hit by a problem where my hardware did not have enough for ntb_transport, and I would have liked better information on the cause of the issue.)

3) Added support to debug and test memory windows to ntb_tool. A coherent buffer is added when the link comes up, and then a debugfs file for each mw and peer mw is added which allows reading and writing the buffer. This was useful for me to debug window alignment issues I was having.

I'm happy to make any revisions to these patches if anyone finds any issues.

Thanks,

Logan

Logan Gunthorpe (3):
ntb_perf: Allow limiting the size of the memory windows
ntb_transport: Check the number of spads the hardware supports
ntb_tool: Add memory window debug support

 drivers/ntb/ntb_transport.c |   9 +-
 drivers/ntb/test/ntb_perf.c |  16 ++-
 drivers/ntb/test/ntb_tool.c | 258 +++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 278 insertions(+), 5 deletions(-)

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2.1.4