From 68b6dbf1f441c4eba3b8511728a41cf9b01dca35 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Fri, 18 Oct 2024 11:00:37 -0400 Subject: [PATCH] dma-mapping: trace more error paths It can be surprising to the user if DMA functions are only traced on success. On failure, it can be unclear what the source of the problem is. Fix this by tracing all functions even when they fail. Cases where we BUG/WARN are skipped, since those should be sufficiently noisy already. Signed-off-by: Sean Anderson Reviewed-by: Steven Rostedt (Google) Signed-off-by: Christoph Hellwig --- include/trace/events/dma.h | 36 ++++++++++++++++++++++++++++++++++++ kernel/dma/mapping.c | 25 ++++++++++++++++++------- 2 files changed, 54 insertions(+), 7 deletions(-) diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h index 7a9606b8934e7..d8ddc27b6a7c8 100644 --- a/include/trace/events/dma.h +++ b/include/trace/events/dma.h @@ -156,6 +156,7 @@ DEFINE_EVENT(dma_alloc_class, name, \ DEFINE_ALLOC_EVENT(dma_alloc); DEFINE_ALLOC_EVENT(dma_alloc_pages); +DEFINE_ALLOC_EVENT(dma_alloc_sgt_err); TRACE_EVENT(dma_alloc_sgt, TP_PROTO(struct device *dev, struct sg_table *sgt, size_t size, @@ -320,6 +321,41 @@ TRACE_EVENT(dma_map_sg, decode_dma_attrs(__entry->attrs)) ); +TRACE_EVENT(dma_map_sg_err, + TP_PROTO(struct device *dev, struct scatterlist *sgl, int nents, + int err, enum dma_data_direction dir, unsigned long attrs), + TP_ARGS(dev, sgl, nents, err, dir, attrs), + + TP_STRUCT__entry( + __string(device, dev_name(dev)) + __dynamic_array(u64, phys_addrs, nents) + __field(int, err) + __field(enum dma_data_direction, dir) + __field(unsigned long, attrs) + ), + + TP_fast_assign( + struct scatterlist *sg; + int i; + + __assign_str(device); + for_each_sg(sgl, sg, nents, i) + ((u64 *)__get_dynamic_array(phys_addrs))[i] = sg_phys(sg); + __entry->err = err; + __entry->dir = dir; + __entry->attrs = attrs; + ), + + TP_printk("%s dir=%s dma_addrs=%s err=%d attrs=%s", + __get_str(device), + decode_dma_data_direction(__entry->dir), + __print_array(__get_dynamic_array(phys_addrs), + __get_dynamic_array_len(phys_addrs) / + sizeof(u64), sizeof(u64)), + __entry->err, + decode_dma_attrs(__entry->attrs)) +); + TRACE_EVENT(dma_unmap_sg, TP_PROTO(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction dir, unsigned long attrs), diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b8a6bc492fae4..636dbb0629a4b 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -223,6 +223,7 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, debug_dma_map_sg(dev, sg, nents, ents, dir, attrs); } else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM && ents != -EIO && ents != -EREMOTEIO)) { + trace_dma_map_sg_err(dev, sg, nents, ents, dir, attrs); return -EIO; } @@ -604,20 +605,26 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, if (WARN_ON_ONCE(flag & __GFP_COMP)) return NULL; - if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) + if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) { + trace_dma_alloc(dev, cpu_addr, *dma_handle, size, + DMA_BIDIRECTIONAL, flag, attrs); return cpu_addr; + } /* let the implementation decide on the zone to allocate from: */ flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM); - if (dma_alloc_direct(dev, ops)) + if (dma_alloc_direct(dev, ops)) { cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs); - else if (use_dma_iommu(dev)) + } else if (use_dma_iommu(dev)) { cpu_addr = iommu_dma_alloc(dev, size, dma_handle, flag, attrs); - else if (ops->alloc) + } else if (ops->alloc) { cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); - else + } else { + trace_dma_alloc(dev, NULL, 0, size, DMA_BIDIRECTIONAL, flag, + attrs); return NULL; + } trace_dma_alloc(dev, cpu_addr, *dma_handle, size, DMA_BIDIRECTIONAL, flag, attrs); @@ -642,11 +649,11 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, */ WARN_ON(irqs_disabled()); + trace_dma_free(dev, cpu_addr, dma_handle, size, DMA_BIDIRECTIONAL, + attrs); if (!cpu_addr) return; - trace_dma_free(dev, cpu_addr, dma_handle, size, DMA_BIDIRECTIONAL, - attrs); debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); if (dma_alloc_direct(dev, ops)) dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); @@ -688,6 +695,8 @@ struct page *dma_alloc_pages(struct device *dev, size_t size, trace_dma_alloc_pages(dev, page_to_virt(page), *dma_handle, size, dir, gfp, 0); debug_dma_map_page(dev, page, 0, size, dir, *dma_handle, 0); + } else { + trace_dma_alloc_pages(dev, NULL, 0, size, dir, gfp, 0); } return page; } @@ -772,6 +781,8 @@ struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size, sgt->nents = 1; trace_dma_alloc_sgt(dev, sgt, size, dir, gfp, attrs); debug_dma_map_sg(dev, sgt->sgl, sgt->orig_nents, 1, dir, attrs); + } else { + trace_dma_alloc_sgt_err(dev, NULL, 0, size, gfp, dir, attrs); } return sgt; } -- 2.49.0