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| author |   Geert Uytterhoeven <geert+renesas@glider.be> | 2016-12-16 14:28:42 +0100 |
|---|---|---|
| committer |   Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2016-12-19 09:05:20 -0500 |
| commit | fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 (patch) | |
| tree | 0b9748236ea4580bc44f9a24ec27c215cb46ed9b /include/linux/swiotlb.h | |
| parent | swiotlb: Convert swiotlb_force from int to enum (diff) | |
| download | wireguard-linux-fff5d99225107f5f13fe4a9805adc2a1c4b5fb00.tar.xz wireguard-linux-fff5d99225107f5f13fe4a9805adc2a1c4b5fb00.zip | |
swiotlb: Add swiotlb=noforce debug option
On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.
To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.
Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/linux/swiotlb.h')
| -rw-r--r-- | include/linux/swiotlb.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 71d104e4c849..d9c84a9cde3d 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -12,6 +12,7 @@ struct scatterlist; enum swiotlb_force { SWIOTLB_NORMAL, /* Default - depending on HW DMA mask etc. */ SWIOTLB_FORCE, /* swiotlb=force */ + SWIOTLB_NO_FORCE, /* swiotlb=noforce */ }; extern enum swiotlb_force swiotlb_force; |