[PATCH v4 0/2] dmaengine: avalon: Intel Avalon-MM DMA Interface for PCIe

[Alexander Gordeev <a.gordeev.box@gmail.com>]

This series is against v5.4-rc5

Patch 1. Introduces "avalon-dma" driver that conforms to the standard
"dmaengine" model;

Patch 2. The existing "dmatest" is not meant for DMA_SLAVE type of
transfers needed by "avalon-dma" driver. Instead, custom "avalon-test"
was used to debug and stress "avalon-dma". In fact, the methology used
for testing is pretty much generic:

  - DMA to/from the remote device (memory) - oneshot or multiple times;
  - continuously run cuncurrent threads DMAing to/from the remote device;
  - using IOCTL to DMA data to/from user level;

Such functionality could be very useful for bringing up custom embedded
devices, i.e sensors, displays etc.

With some effort "avalon-test" could even be merged into the existing
"dmatest" or turned into a tool for testing any "dmaengine" compatible
driver that does not need any custom hardware specifics to initiate DMA
transfers.

I am not certain that "avalon-test" in its current form is the best way
to proceed and thus marking patch 2 as RFC. It depends on "avalon-dma",
but the two drivers are not needed to be accepted together.


Changes since v3 ("avalon-test" only):
- BUG_ONs, WARN_ONs, dev_dbgs removed goto labels renamed;
- kernel configuration options removed in favour of module parameters;
- fail paths reworked to avoid resource leaks uninitialized data crashes;
- invalid parameter checks reworked;

Changes since v2 ("avalon-dma" only):
- avalon_dma_register() return value bug fixed;
- device_prep_slave_sg() does not crash dmaengine_prep_slave_single();
- kernel configuration options removed in favour of module parameters;
- BUG_ONs, WARN_ONs, dev_dbgs removed goto labels renamed;
- polling loop in interrupt handler commented;
- cpu_relax() added to polling loop in interrupt handler;

Changes since v1:
- "avalon-dma" converted to "dmaengine" model;
- "avalon-drv" renamed to "avalon-test";

The Avalon-MM DMA Interface for PCIe is a design used in hard IPs for
Intel Arria, Cyclone or Stratix FPGAs. It transfers data between on-chip
memory and system memory.

Testing was done using a custom FPGA build with Arria 10 FPGA streaming
data to target device RAM:

  +----------+    +----------+    +----------+        +----------+
  | NIOS CPU |<-->|   RAM    |<-->|  Avalon  |<-PCIe->| Host CPU |
  +----------+    +----------+    +----------+        +----------+

The data integrity was ensured by examining target device RAM contents
(a) from host CPU (indirectly - checking data DMAed to/from the system)
and (b) from NIOS CPU that has direct access to the device RAM.

A companion tool using "avalon-test" IOCTL commands was used to DMA files:
https://github.com/a-gordeev/avalon-tool.git


CC: dmaengine@vger.kernel.org

Alexander Gordeev (2):
  dmaengine: avalon: Intel Avalon-MM DMA Interface for PCIe
  dmaengine: avalon-test: Intel Avalon-MM DMA Interface for PCIe test

 drivers/dma/Kconfig                     |   3 +
 drivers/dma/Makefile                    |   2 +
 drivers/dma/avalon-test/Kconfig         |  12 +
 drivers/dma/avalon-test/Makefile        |  14 +
 drivers/dma/avalon-test/avalon-dev.c    | 108 +++++
 drivers/dma/avalon-test/avalon-dev.h    |  33 ++
 drivers/dma/avalon-test/avalon-ioctl.c  | 100 +++++
 drivers/dma/avalon-test/avalon-ioctl.h  |  13 +
 drivers/dma/avalon-test/avalon-mmap.c   |  75 ++++
 drivers/dma/avalon-test/avalon-mmap.h   |  13 +
 drivers/dma/avalon-test/avalon-sg-buf.c | 131 ++++++
 drivers/dma/avalon-test/avalon-sg-buf.h |  27 ++
 drivers/dma/avalon-test/avalon-xfer.c   | 559 ++++++++++++++++++++++++
 drivers/dma/avalon-test/avalon-xfer.h   |  29 ++
 drivers/dma/avalon/Kconfig              |  15 +
 drivers/dma/avalon/Makefile             |  12 +
 drivers/dma/avalon/avalon-core.c        | 477 ++++++++++++++++++++
 drivers/dma/avalon/avalon-core.h        |  93 ++++
 drivers/dma/avalon/avalon-hw.c          | 187 ++++++++
 drivers/dma/avalon/avalon-hw.h          |  86 ++++
 drivers/dma/avalon/avalon-pci.c         | 145 ++++++
 include/uapi/linux/avalon-ioctl.h       |  32 ++
 22 files changed, 2166 insertions(+)
 create mode 100644 drivers/dma/avalon-test/Kconfig
 create mode 100644 drivers/dma/avalon-test/Makefile
 create mode 100644 drivers/dma/avalon-test/avalon-dev.c
 create mode 100644 drivers/dma/avalon-test/avalon-dev.h
 create mode 100644 drivers/dma/avalon-test/avalon-ioctl.c
 create mode 100644 drivers/dma/avalon-test/avalon-ioctl.h
 create mode 100644 drivers/dma/avalon-test/avalon-mmap.c
 create mode 100644 drivers/dma/avalon-test/avalon-mmap.h
 create mode 100644 drivers/dma/avalon-test/avalon-sg-buf.c
 create mode 100644 drivers/dma/avalon-test/avalon-sg-buf.h
 create mode 100644 drivers/dma/avalon-test/avalon-xfer.c
 create mode 100644 drivers/dma/avalon-test/avalon-xfer.h
 create mode 100644 drivers/dma/avalon/Kconfig
 create mode 100644 drivers/dma/avalon/Makefile
 create mode 100644 drivers/dma/avalon/avalon-core.c
 create mode 100644 drivers/dma/avalon/avalon-core.h
 create mode 100644 drivers/dma/avalon/avalon-hw.c
 create mode 100644 drivers/dma/avalon/avalon-hw.h
 create mode 100644 drivers/dma/avalon/avalon-pci.c
 create mode 100644 include/uapi/linux/avalon-ioctl.h

-- 
2.23.0