[PATCH 0/4] dma: catch mistakes with CONFIG_DMA_API_DEBUG

[Ahmad Fatoum]

Cache invalidation issues around DMA accesses can be difficult to debug.
Motivated by recent fixes to the macb driver[1], let's add some optional
sanity checking to the DMA API inspired by the Linux CONFIG_DMA_API_DEBUG
option.

This would have caught the issue fixed by [1] in the macb driver and it
already caught a misuse of the API on the STM32MP system I tested it on.

Usage is simple: just enable it and ensure no warnings are printed.
All warnings are printed alongside the extents of the DMA buffer in
question and a stack trace at the time the check failed.

[1]: https://lore.barebox.org/barebox/20231128-v2023-08-0-topic-macb-v1-0-9faff73bc990@pengutronix.de/T/#t

Ahmad Fatoum (4):
  dma: factor out dma map generic implementations into file
  dma: add DMA API debugging support
  mci: core: remove broken, unneeded write bounce buffer
  mci: stm32_sdmmc2: correct usage of DMA API

 common/Kconfig             |  14 +++
 drivers/dma/Makefile       |   2 +
 drivers/dma/debug.c        | 183 +++++++++++++++++++++++++++++++++++++
 drivers/dma/debug.h        |  56 ++++++++++++
 drivers/dma/map.c          |  43 +++++++++
 drivers/mci/mci-core.c     |  10 +-
 drivers/mci/stm32_sdmmc2.c |  41 +++++----
 include/dma.h              |  61 ++++---------
 8 files changed, 340 insertions(+), 70 deletions(-)
 create mode 100644 drivers/dma/debug.c
 create mode 100644 drivers/dma/debug.h
 create mode 100644 drivers/dma/map.c

-- 
2.39.2