[PATCH v2 0/3] swiotlb: Add swiotlb=noforce debug option

[Geert Uytterhoeven]

	Hi Konrad,

This patch series adds a kernel command line option to aid debugging
when developing support for DMA to memory outside the 32-bit address
space.  If specified, trying to map memory that cannot be used with DMA
will fail, and a warning will be printed.  This has been used
succesfully to find drivers and DMA engines that do not support 64-bit
memory.

Changes compared to v1:
  - Dropp patch "swiotlb: Rate-limit printing when running out of
    SW-IOMMU space", which has been picked up,
  - Add cleanup patch 1/3,
  - Add patch 2/3, to convert the flag swiotlb_force from an int to an
    enum,
  - Change the kernel parameter "swiotlb=nobounce" to "swiotlb=noforce"
    (requested by Konrad Wilk),
  - Extend swiotlb_force enum instead of adding an swiotlb_nobounce
    variable (requested by Konrad Wilk).

This has been tested on ra7796/salvator-x, and compile-tested on x86.

Thanks!

Geert Uytterhoeven (3):
  x86, swiotlb: Simplify pci_swiotlb_detect_override()
  swiotlb: Convert swiotlb_force from int to enum
  swiotlb: Add swiotlb=noforce debug option

 Documentation/admin-guide/kernel-parameters.txt |  3 ++-
 arch/arm64/mm/dma-mapping.c                     |  3 ++-
 arch/arm64/mm/init.c                            |  3 ++-
 arch/x86/kernel/pci-swiotlb.c                   |  6 ++----
 arch/x86/xen/pci-swiotlb-xen.c                  |  2 +-
 drivers/xen/swiotlb-xen.c                       |  4 ++--
 include/linux/swiotlb.h                         |  8 +++++++-
 include/trace/events/swiotlb.h                  | 17 +++++++++-------
 lib/swiotlb.c                                   | 26 +++++++++++++++++++------
 9 files changed, 48 insertions(+), 24 deletions(-)

-- 
1.9.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds