From fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 16 Dec 2016 14:28:42 +0100 Subject: 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 Signed-off-by: Konrad Rzeszutek Wilk --- include/trace/events/swiotlb.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/trace') diff --git a/include/trace/events/swiotlb.h b/include/trace/events/swiotlb.h index 5e2e30a..288c0c5 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 */ -- cgit v1.1