diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | include/linux/swiotlb.h | 1 | ||||
| -rw-r--r-- | include/trace/events/swiotlb.h | 3 | ||||
| -rw-r--r-- | lib/swiotlb.c | 18 |
4 files changed, 21 insertions, 4 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 37babf91f2cb..922dec8fa07e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3998,10 +3998,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. it if 0 is given (See Documentation/cgroup-v1/memory.txt) swiotlb= [ARM,IA-64,PPC,MIPS,X86] - Format: { <int> | force } + Format: { <int> | force | noforce } <int> -- Number of I/O TLB slabs force -- force using of bounce buffers even if they wouldn't be automatically used by the kernel + noforce -- Never use bounce buffers (for debugging) switches= [HW,M68k] diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 746ecebbd4ca..d2613536fd03 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 */ diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 68e8f49c7e06..ad1d2962d129 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -106,8 +106,12 @@ setup_io_tlb_npages(char *str) } if (*str == ',') ++str; - if (!strcmp(str, "force")) + if (!strcmp(str, "force")) { swiotlb_force = SWIOTLB_FORCE; + } else if (!strcmp(str, "noforce")) { + swiotlb_force = SWIOTLB_NO_FORCE; + io_tlb_nslabs = 1; + } return 0; } @@ -541,8 +545,15 @@ static phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size, enum dma_data_direction dir) { - dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); + dma_addr_t start_dma_addr; + + if (swiotlb_force == SWIOTLB_NO_FORCE) { + dev_warn_ratelimited(hwdev, "Cannot do DMA to address %pa\n", + &phys); + return SWIOTLB_MAP_ERROR; + } + start_dma_addr = phys_to_dma(hwdev, io_tlb_start); return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir); } @@ -707,6 +718,9 @@ static void swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir, int do_panic) { + if (swiotlb_force == SWIOTLB_NO_FORCE) + return; + /* * Ran out of IOMMU space for this operation. This is very bad. * Unfortunately the drivers cannot handle this operation properly. |