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authorGeert Uytterhoeven <geert+renesas@glider.be>2016-12-16 14:28:42 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2016-12-19 09:05:20 -0500
commitfff5d99225107f5f13fe4a9805adc2a1c4b5fb00 (patch)
tree0b9748236ea4580bc44f9a24ec27c215cb46ed9b /include
parentae7871be189cb41184f1e05742b4a99e2c59774d (diff)
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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')
-rw-r--r--include/linux/swiotlb.h1
-rw-r--r--include/trace/events/swiotlb.h3
2 files changed, 3 insertions, 1 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;
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 */