From nobody Sun Feb 8 11:45:05 2026 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 493C318B47C for ; Mon, 12 Aug 2024 20:44:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723495452; cv=none; b=mHfELd7iU0gLEHcNZu0+AyVqkjMPv/K1JqhgE6UD5yY7T4b+f4Ca0NYMzImpU3pY7ZznIrQH2pRQw1qqI8VVtAOvKpdcy6feX0T1Hp5hIgg88NyGFnGRf1Mz7VCj6nwBN2GWy+pQ89XLrzY4gkUbTJQJPGetysmWgihclTSrMxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723495452; c=relaxed/simple; bh=z9r1E1n1MkfQblbK869WFtMCFJHi5kCmMD8SiA+v0As=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=X6PY0D4BmpFfRD6aOIkbQtnBNvVmDmDrGtl07dgUiVoNRpACoUQ8AkePjUtJ/bk+XAQqe94Rw/TcFA+YfLHXx3s6GdBa8LGwnsXT0iGQ9V55MVxSBjwhKlytVqAW4yrAQJVHi5LwKqTS/5qbEPEITPqJZAf+VPz/t9Uu4srgwf0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ACWXkZtd; arc=none smtp.client-ip=91.218.175.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ACWXkZtd" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1723495448; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JUGlscjZ9It4yeML5SBXjbq8uMlJLcwt2MQT8BsMieE=; b=ACWXkZtdgHhhKdSYegvJHQyXY5IwIYQFkzV7UIe5Ht+kq31wKayOJ9wOH+Ay/+HCi+RmGe njHNJjEVBCaARwmv8YdpUEKdRk/6f3tB2dxou2XrUB17FVipKmgUKzH2CPauXI/D7xiRPu OtjHqSMqSgkB3AqDHAoP0CH0TtlG2DQ= From: Sean Anderson To: Christoph Hellwig , Marek Szyprowski , Robin Murphy , iommu@lists.linux.dev Cc: linux-kernel@vger.kernel.org, Sean Anderson Subject: [PATCH] dma: Trace dma_map/unmap_page Date: Mon, 12 Aug 2024 16:43:57 -0400 Message-Id: <20240812204358.3587730-1-sean.anderson@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" When debugging drivers, it can often be useful to trace when memory gets (un)mapped for DMA (and can be accessed by the device). Add some tracepoints for this purpose. While there are many other interesting DMA functions, this is a useful start for simpler drivers. Signed-off-by: Sean Anderson --- include/trace/events/dma.h | 103 +++++++++++++++++++++++++++++++++++++ kernel/dma/mapping.c | 5 ++ 2 files changed, 108 insertions(+) create mode 100644 include/trace/events/dma.h diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h new file mode 100644 index 000000000000..bc32e4302fde --- /dev/null +++ b/include/trace/events/dma.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dma + +#if !defined(_TRACE_DMA_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_DMA_H + +#include +#include +#include + +TRACE_DEFINE_ENUM(DMA_BIDIRECTIONAL); +TRACE_DEFINE_ENUM(DMA_TO_DEVICE); +TRACE_DEFINE_ENUM(DMA_FROM_DEVICE); +TRACE_DEFINE_ENUM(DMA_NONE); + +#define decode_dma_data_direction(dir) \ + __print_symbolic(dir, \ + { DMA_BIDIRECTIONAL, "BIDIRECTIONAL" }, \ + { DMA_TO_DEVICE, "TO_DEVICE" }, \ + { DMA_FROM_DEVICE, "FROM_DEVICE" }, \ + { DMA_NONE, "NONE" }) + +#define decode_dma_attrs(attrs) \ + __print_flags(attrs, "|", \ + { DMA_ATTR_WEAK_ORDERING, "WEAK_ORDERING" }, \ + { DMA_ATTR_WRITE_COMBINE, "WRITE_COMBINE" }, \ + { DMA_ATTR_NO_KERNEL_MAPPING, "NO_KERNEL_MAPPING" }, \ + { DMA_ATTR_SKIP_CPU_SYNC, "SKIP_CPU_SYNC" }, \ + { DMA_ATTR_FORCE_CONTIGUOUS, "FORCE_CONTIGUOUS" }, \ + { DMA_ATTR_ALLOC_SINGLE_PAGES, "ALLOC_SINGLE_PAGES" }, \ + { DMA_ATTR_NO_WARN, "NO_WARN" }, \ + { DMA_ATTR_PRIVILEGED, "PRIVILEGED" }) + +TRACE_EVENT(dma_map_page, + TP_PROTO(struct device *dev, const struct page *page, size_t offset, + size_t size, enum dma_data_direction dir, dma_addr_t addr, + unsigned long attrs), + TP_ARGS(dev, page, offset, size, dir, addr, attrs), + + TP_STRUCT__entry( + __string(device, dev_name(dev)) + __field(const struct page *, page) + __field(size_t, offset) + __field(size_t, size) + __field(enum dma_data_direction, dir) + __field(dma_addr_t, addr) + __field(unsigned long, attrs) + ), + + TP_fast_assign( + __assign_str(device); + __entry->page =3D page; + __entry->offset =3D offset; + __entry->size =3D size; + __entry->dir =3D dir; + __entry->addr =3D addr; + __entry->attrs =3D attrs; + ), + + TP_printk("%s page=3D%p offset=3D%zu size=3D%zu dir=3D%s addr=3D%llx attr= s=3D%s", + __get_str(device), + __entry->page, + __entry->offset, + __entry->size, + decode_dma_data_direction(__entry->dir), + (unsigned long long)__entry->addr, + decode_dma_attrs(__entry->attrs)) +); + +TRACE_EVENT(dma_unmap_page, + TP_PROTO(struct device *dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir, unsigned long attrs), + TP_ARGS(dev, addr, size, dir, attrs), + + TP_STRUCT__entry( + __string(device, dev_name(dev)) + __field(dma_addr_t, addr) + __field(size_t, size) + __field(enum dma_data_direction, dir) + __field(unsigned long, attrs) + ), + + TP_fast_assign( + __assign_str(device); + __entry->addr =3D addr; + __entry->size =3D size; + __entry->dir =3D dir; + __entry->attrs =3D attrs; + ), + + TP_printk("%s addr=3D%llx size=3D%zu dir=3D%s attrs=3D%s", + __get_str(device), + (unsigned long long)__entry->addr, + __entry->size, + decode_dma_data_direction(__entry->dir), + decode_dma_attrs(__entry->attrs)) +); + +#endif /* _TRACE_DMA_H */ + +/* This part must be outside protection */ +#include diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b1c18058d55f..fb4c77f6f7cc 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -17,6 +17,9 @@ #include "debug.h" #include "direct.h" =20 +#define CREATE_TRACE_POINTS +#include + #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) @@ -162,6 +165,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struc= t page *page, else addr =3D ops->map_page(dev, page, offset, size, dir, attrs); kmsan_handle_dma(page, offset, size, dir); + trace_dma_map_page(dev, page, offset, size, dir, addr, attrs); debug_dma_map_page(dev, page, offset, size, dir, addr, attrs); =20 return addr; @@ -179,6 +183,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_= t addr, size_t size, dma_direct_unmap_page(dev, addr, size, dir, attrs); else if (ops->unmap_page) ops->unmap_page(dev, addr, size, dir, attrs); + trace_dma_unmap_page(dev, addr, size, dir, attrs); debug_dma_unmap_page(dev, addr, size, dir); } EXPORT_SYMBOL(dma_unmap_page_attrs); --=20 2.35.1.1320.gc452695387.dirty