[PATCH v2 00/16] Switchtec NTB Support

Logan Gunthorpe
2017-07-18T16:07:22Z

Changes since v1:

- Rebased onto latest ntb-next branch (with v4.13-rc1)
- Reworked ntb_mw_count() function so that it can be called all the
time (per discussion with Allen)
- Various spelling and formatting cleanups from Bjorn
- Added request_module() call such that the NTB module is automatically
loaded when appropriate hardware exists.

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Changes since the rfc:

- Rebased on ntb-next
- Switched ntb_part_op to use sleep instead of delay
- Dropped a number of useless dbg __func__ prints
- Went back to the dynamic instead of the static class
- Swapped the notifier block for a simple callback
- Modified the new ntb api so that a couple functions with pidx
now must be called after link up. Per our discussion on the list.

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This patchset implements Non-Transparent Bridge (NTB) support for the
Microsemi Switchtec series of switches. We're looking for some
review from the community at this point but hope to get it upstreamed
for v4.14.

Switchtec NTB support is configured over the same function and bar
as the management endpoint. Thus, the new driver hooks into the
management driver which we had merged in v4.12. We use the class
interface API to register an NTB device for every switchtec device
which supports NTB (not all do).

The Switchtec hardware supports doorbells, memory windows and messages.
Seeing there is no native scratchpad support, 128 spads are emulated
through the use of a pre-setup memory window. The switch has 64
doorbells which are shared between the two partitions and a
configurable set of memory windows. While the hardware supports more
than 2 partitions, this driver only supports the first two seeing
the current NTB API only supports two hosts.

The driver has been tested with ntb_netdev and fully passes the
ntb_test script.

This patchset is based off of ntb-next and can be found in this
git repo:

https://github.com/sbates130272/linux-p2pmem.git switchtec_ntb_v2

Logan Gunthorpe (16):
switchtec: move structure definitions into a common header
switchtec: export class symbol for use in upper layer driver
switchtec: add NTB hardware register definitions
switchtec: add link event notifier callback
ntb: ensure ntb_mw_get_align() is only called when the link is up
ntb: add check and comment for link up to mw_count() and
mw_get_align()
ntb: ntb_test: ensure the link is up before trying to configure the
mws
switchtec_ntb: introduce initial NTB driver
switchtec_ntb: initialize hardware for memory windows
switchtec_ntb: initialize hardware for doorbells and messages
switchtec_ntb: add skeleton NTB driver
switchtec_ntb: add link management
switchtec_ntb: implement doorbell registers
switchtec_ntb: implement scratchpad registers
switchtec_ntb: add memory window support
switchtec_ntb: update switchtec documentation with notes for NTB

Documentation/switchtec.txt | 12 +
MAINTAINERS | 2 +
drivers/ntb/hw/Kconfig | 1 +
drivers/ntb/hw/Makefile | 1 +
drivers/ntb/hw/mscc/Kconfig | 9 +
drivers/ntb/hw/mscc/Makefile | 1 +
drivers/ntb/hw/mscc/switchtec_ntb.c | 1213 +++++++++++++++++++++++++++++++
drivers/ntb/ntb_transport.c | 20 +-
drivers/ntb/test/ntb_perf.c | 18 +-
drivers/ntb/test/ntb_tool.c | 6 +-
drivers/pci/switch/switchtec.c | 316 ++------
include/linux/ntb.h | 11 +-
include/linux/switchtec.h | 373 ++++++++++
tools/testing/selftests/ntb/ntb_test.sh | 4 +
14 files changed, 1704 insertions(+), 283 deletions(-)
create mode 100644 drivers/ntb/hw/mscc/Kconfig
create mode 100644 drivers/ntb/hw/mscc/Makefile
create mode 100644 drivers/ntb/hw/mscc/switchtec_ntb.c
create mode 100644 include/linux/switchtec.h

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2.11.0