diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2016-12-16 14:28:42 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-26 08:24:44 +0100 |
| commit | 41c6b3e8989e79772a50429d92cf91959bcce96d (patch) | |
| tree | e1098b8fb35ab3f524703d89c01d885c6ed76d54 /include/trace | |
| parent | 1fd1e6cd63143cf5d198a536d875dfc88ce179bc (diff) | |
swiotlb: Add swiotlb=noforce debug option
commit fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/swiotlb.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/trace/events/swiotlb.h b/include/trace/events/swiotlb.h index 5e2e30a7efce..288c0c54a2b4 100644 --- a/include/trace/events/swiotlb.h +++ b/include/trace/events/swiotlb.h @@ -39,7 +39,8 @@ TRACE_EVENT(swiotlb_bounced, __entry->size, __print_symbolic(__entry->swiotlb_force, { SWIOTLB_NORMAL, "NORMAL" }, - { SWIOTLB_FORCE, "FORCE" })) + { SWIOTLB_FORCE, "FORCE" }, + { SWIOTLB_NO_FORCE, "NO_FORCE" })) ); #endif /* _TRACE_SWIOTLB_H */ |