linux/kernel/dma/debug.c, branch v5.4

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333

2019-06-05T15:37:06Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 136 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de Signed-off-by: Greg Kroah-Hartman

dma/debug: Simplify stracktrace retrieval

2019-04-29T10:37:50Z

Replace the indirection through struct stack_trace with an invocation of the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Christoph Hellwig Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.248658135@linutronix.de

dma-debug: only skip one stackframe entry

2019-04-11T17:29:50Z

With skip set to 1, I get a traceback like this: [ 106.867637] DMA-API: Mapped at: [ 106.870784] afu_dma_map_region+0x2cd/0x4f0 [dfl_afu] [ 106.875839] afu_ioctl+0x258/0x380 [dfl_afu] [ 106.880108] do_vfs_ioctl+0xa9/0x720 [ 106.883688] ksys_ioctl+0x60/0x90 [ 106.887007] __x64_sys_ioctl+0x16/0x20 With the previous value of 2, afu_dma_map_region was being omitted. I suspect that the code paths have simply changed since the value of 2 was chosen a decade ago, but it's also possible that it varies based on which mapping function was used, compiler inlining choices, etc. In any case, it's best to err on the side of skipping less. Signed-off-by: Scott Wood Signed-off-by: Christoph Hellwig

dma-debug: add dumping facility via debugfs

2019-02-01T09:06:44Z

While debugging a DMA mapping leak, I needed to access debug_dma_dump_mappings() but easily from user space. This patch adds a /sys/kernel/debug/dma-api/dump file which contain all current DMA mapping. Signed-off-by: Corentin Labbe Signed-off-by: Christoph Hellwig

dma: debug: no need to check return value of debugfs_create functions

2019-02-01T09:02:32Z

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Also delete the variables for the file dentries for the debugfs entries as they are never used at all once they are created. Signed-off-by: Greg Kroah-Hartman Reviewed-by: Robin Murphy [hch: moved dma_debug_dent to function scope and renamed it] Signed-off-by: Christoph Hellwig

dma-mapping: remove a few unused exports

2019-01-04T08:03:17Z

Now that the slow path DMA API calls are implemented out of line a few helpers only used by them don't need to be exported anymore. Signed-off-by: Christoph Hellwig

dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs

2019-01-04T08:02:17Z

And also switch the way we implement the unmap side around to stay consistent. This ensures dma-debug works again because it records which function we used for mapping to ensure it is also used for unmapping, and also reduces further code duplication. Last but not least this also officially allows calling dma_sync_single_* for mappings created using dma_map_page, which is perfectly fine given that the sync calls only take a dma_addr_t, but not a virtual address or struct page. Fixes: 7f0fee242e ("dma-mapping: merge dma_unmap_page_attrs and dma_unmap_single_attrs") Signed-off-by: Christoph Hellwig Tested-by: LABBE Corentin

dma-mapping: simplify the dma_sync_single_range_for_{cpu,device} implementation

2018-12-13T20:06:08Z

We can just call the regular calls after adding offset the the address instead of reimplementing them. Signed-off-by: Christoph Hellwig Acked-by: Jesper Dangaard Brouer Tested-by: Jesper Dangaard Brouer Tested-by: Tony Luck

dma-debug: Batch dma_debug_entry allocation

2018-12-11T13:32:13Z

DMA debug entries are one of those things which aren't that useful individually - we will always want some larger quantity of them - and which we don't really need to manage the exact number of - we only care about having 'enough'. In that regard, the current behaviour of creating them one-by-one leads to a lot of unwarranted function call overhead and memory wasted on alignment padding. Now that we don't have to worry about freeing anything via dma_debug_resize_entries(), we can optimise the allocation behaviour by grabbing whole pages at once, which will save considerably on the aforementioned overheads, and probably offer a little more cache/TLB locality benefit for traversing the lists under normal operation. This should also give even less reason for an architecture-level override of the preallocation size, so make the definition unconditional - if there is still any desire to change the compile-time value for some platforms it would be better off as a Kconfig option anyway. Since freeing a whole page of entries at once becomes enough of a challenge that it's not really worth complicating dma_debug_init(), we may as well tweak the preallocation behaviour such that as long as we manage to allocate *some* pages, we can leave debugging enabled on a best-effort basis rather than otherwise wasting them. Signed-off-by: Robin Murphy Tested-by: Qian Cai Signed-off-by: Christoph Hellwig

dma/debug: Remove dma_debug_resize_entries()

2018-12-11T13:32:13Z

With the only caller now gone, we can clean up this part of dma-debug's exposed internals and make way to tweak the allocation behaviour. Signed-off-by: Robin Murphy Tested-by: Qian Cai Signed-off-by: Christoph Hellwig