On Fri, Dec 16, 2016 at 02:28:39PM +0100, Geert Uytterhoeven wrote:
> Hi Konrad,
Heya!
>
> 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.
Let me run it on various combinations of x86 and if all is good
will ask Linus to pick it up for rc1.
Thanks!
>
> 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
