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2019-03-06swiotlb: Introduce swiotlb_max_mapping_size()Joerg Roedel1-0/+5
The function returns the maximum size that can be remapped by the SWIOTLB implementation. This function will be later exposed to users through the DMA-API. Cc: stable@vger.kernel.org Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-02-20dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flagChristoph Hellwig1-18/+7
All users of dma_declare_coherent want their allocations to be exclusive, so default to exclusive allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20dma-mapping: remove dma_mark_declared_memory_occupiedChristoph Hellwig1-23/+0
This API is not used anywhere, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-20dma-mapping: move CONFIG_DMA_CMA to kernel/dma/KconfigChristoph Hellwig1-0/+77
This is where all the related code already lives. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20dma-mapping: improve selection of dma_declare_coherent availabilityChristoph Hellwig2-2/+2
This API is primarily used through DT entries, but two architectures and two drivers call it directly. So instead of selecting the config symbol for random architectures pull it in implicitly for the actual users. Also rename the Kconfig option to describe the feature better. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18swiotlb: remove swiotlb_dma_supportedChristoph Hellwig1-12/+0
The only user left is powerpc, but even there the generic dma-direct version works just as well, given that we guarantee that the swiotlb buffer must always be addressable. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18dma-mapping, powerpc: simplify the arch dma_set_mask overrideChristoph Hellwig2-2/+10
Instead of letting the architecture supply all of dma_set_mask just give it an additional hook selected by Kconfig. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: stop overriding dma_get_required_maskChristoph Hellwig1-2/+0
The ppc_md and pci_controller_ops methods are unused now and can be removed. The dma_nommu implementation is generic to the generic one except for using max_pfn instead of calling into the memblock API, and all other dma_map_ops instances implement a method of their own. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18dma-direct: we might need GFP_DMA for 32-bit dma masksChristoph Hellwig1-2/+1
If there is no ZONE_DMA32 we might need GFP_DMA to be able to allocate memory that satisfies a 32-bit DMA mask. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-16swiotlb: drop pointless static qualifier in swiotlb_create_debugfs()YueHaibing1-1/+1
There is no need to have the 'struct dentry *d_swiotlb_usage' variable static since new value always be assigned before use it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-02-13dma-mapping: remove an incorrect __iommem annotationChristoph Hellwig1-1/+1
memmap return a regular void pointer, not and __iomem one. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-13dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availabilityChristoph Hellwig1-0/+3
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-02-13dma-mapping: add a kconfig symbol for arch_setup_dma_ops availabilityChristoph Hellwig1-0/+3
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-02-13dma-mapping: move debug configuration options to kernel/dmaAndy Shevchenko1-0/+36
This is a follow up to the commit cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") which moved source code of DMA API to kernel/dma folder. Since there is no file left in the lib that require DMA API debugging options move the latter to kernel/dma as well. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-12swiotlb: checking whether swiotlb buffer is full with io_tlb_usedDongli Zhang1-0/+4
This patch uses io_tlb_used to help check whether swiotlb buffer is full. io_tlb_used is no longer used for only debugfs. It is also used to help optimize swiotlb_tbl_map_single(). Suggested-by: Joe Jin <joe.jin@oracle.com> Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-02-12swiotlb: add debugfs to track swiotlb buffer usageDongli Zhang1-0/+44
The device driver will not be able to do dma operations once swiotlb buffer is full, either because the driver is using so many IO TLB blocks inflight, or because there is memory leak issue in device driver. To export the swiotlb buffer usage via debugfs would help the user estimate the size of swiotlb buffer to pre-allocate or analyze device driver memory leak issue. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-02-12swiotlb: fix comment on swiotlb_bounce()Dongli Zhang1-1/+1
Fix the comment as swiotlb_bounce() is used to copy from original dma location to swiotlb buffer during swiotlb_tbl_map_single(), while to copy from swiotlb buffer to original dma location during swiotlb_tbl_unmap_single(). Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-02-01dma-debug: add dumping facility via debugfsCorentin Labbe1-0/+28
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 <clabbe@baylibre.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-01dma: debug: no need to check return value of debugfs_create functionsGreg Kroah-Hartman1-76/+12
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 <gregkh@linuxfoundation.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> [hch: moved dma_debug_dent to function scope and renamed it] Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-01dma-mapping: remove the default map_resource implementationChristoph Hellwig1-0/+14
Instead provide a proper implementation in the direct mapping code, and also wire it up for arm and powerpc, leaving an error return for all the IOMMU or virtual mapping instances for which we'd have to wire up an actual implementation Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
2019-01-16swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exitChristoph Hellwig1-0/+2
Otherwise is_swiotlb_buffer will return false positives when we first initialize a swiotlb buffer, but then free it because we have an IOMMU available. Fixes: 55897af63091 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code") Reported-by: Sibren Vasse <sibren@sibrenvasse.nl> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Sibren Vasse <sibren@sibrenvasse.nl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2019-01-05dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocationsChristoph Hellwig1-6/+7
We need to return a dma_addr_t even if we don't have a kernel mapping. Do so by consolidating the phys_to_dma call in a single place and jump to it from all the branches that return successfully. Fixes: bfd56cd60521 ("dma-mapping: support highmem in the generic remap allocator") Reported-by: Liviu Dudau <liviu@dudau.co.uk Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Liviu Dudau <liviu@dudau.co.uk>
2019-01-04dma-mapping: remove a few unused exportsChristoph Hellwig2-4/+0
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 <hch@lst.de>
2019-01-04dma-mapping: remove dmam_{declare,release}_coherent_memoryChristoph Hellwig1-55/+0
These functions have never been used. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-01-04dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrsChristoph Hellwig1-39/+0
dmam_alloc_coherent is just the default no-flags case of dmam_alloc_attrs, so take advantage of this similar to the non-managed version. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-01-04dma-mapping: implement dma_map_single_attrs using dma_map_page_attrsChristoph Hellwig1-13/+4
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 <hch@lst.de> Tested-by: LABBE Corentin <clabbe.montjoie@gmail.com>
2018-12-28Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds9-565/+708
Pull DMA mapping updates from Christoph Hellwig: "A huge update this time, but a lot of that is just consolidating or removing code: - provide a common DMA_MAPPING_ERROR definition and avoid indirect calls for dma_map_* error checking - use direct calls for the DMA direct mapping case, avoiding huge retpoline overhead for high performance workloads - merge the swiotlb dma_map_ops into dma-direct - provide a generic remapping DMA consistent allocator for architectures that have devices that perform DMA that is not cache coherent. Based on the existing arm64 implementation and also used for csky now. - improve the dma-debug infrastructure, including dynamic allocation of entries (Robin Murphy) - default to providing chaining scatterlist everywhere, with opt-outs for the few architectures (alpha, parisc, most arm32 variants) that can't cope with it - misc sparc32 dma-related cleanups - remove the dma_mark_clean arch hook used by swiotlb on ia64 and replace it with the generic noncoherent infrastructure - fix the return type of dma_set_max_seg_size (Niklas Söderlund) - move the dummy dma ops for not DMA capable devices from arm64 to common code (Robin Murphy) - ensure dma_alloc_coherent returns zeroed memory to avoid kernel data leaks through userspace. We already did this for most common architectures, but this ensures we do it everywhere. dma_zalloc_coherent has been deprecated and can hopefully be removed after -rc1 with a coccinelle script" * tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping: (73 commits) dma-mapping: fix inverted logic in dma_supported dma-mapping: deprecate dma_zalloc_coherent dma-mapping: zero memory returned from dma_alloc_* sparc/iommu: fix ->map_sg return value sparc/io-unit: fix ->map_sg return value arm64: default to the direct mapping in get_arch_dma_ops PCI: Remove unused attr variable in pci_dma_configure ia64: only select ARCH_HAS_DMA_COHERENT_TO_PFN if swiotlb is enabled dma-mapping: bypass indirect calls for dma-direct vmd: use the proper dma_* APIs instead of direct methods calls dma-direct: merge swiotlb_dma_ops into the dma_direct code dma-direct: use dma_direct_map_page to implement dma_direct_map_sg dma-direct: improve addressability error reporting swiotlb: remove dma_mark_clean swiotlb: remove SWIOTLB_MAP_ERROR ACPI / scan: Refactor _CCA enforcement dma-mapping: factor out dummy DMA ops dma-mapping: always build the direct mapping code dma-mapping: move dma_cache_sync out of line dma-mapping: move various slow path functions out of line ...
2018-12-20dma-mapping: fix inverted logic in dma_supportedThierry Reding1-1/+1
The cleanup in commit 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct") accidentally inverted the logic in the check for the presence of a ->dma_supported() callback. Switch this back to the way it was to prevent a crash on boot. Fixes: 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct") Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-20dma-mapping: zero memory returned from dma_alloc_*Christoph Hellwig1-1/+1
If we want to map memory from the DMA allocator to userspace it must be zeroed at allocation time to prevent stale data leaks. We already do this on most common architectures, but some architectures don't do this yet, fix them up, either by passing GFP_ZERO when we use the normal page allocator or doing a manual memset otherwise. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Sam Ravnborg <sam@ravnborg.org> [sparc]
2018-12-17dma-direct: do not include SME mask in the DMA supported checkLendacky, Thomas1-1/+6
The dma_direct_supported() function intends to check the DMA mask against specific values. However, the phys_to_dma() function includes the SME encryption mask, which defeats the intended purpose of the check. This results in drivers that support less than 48-bit DMA (SME encryption mask is bit 47) from being able to set the DMA mask successfully when SME is active, which results in the driver failing to initialize. Change the function used to check the mask from phys_to_dma() to __phys_to_dma() so that the SME encryption mask is not part of the check. Fixes: c1d0af1a1d5d ("kernel/dma/direct: take DMA offset into account in dma_direct_supported") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-13dma-mapping: bypass indirect calls for dma-directChristoph Hellwig2-44/+33
Avoid expensive indirect calls in the fast path DMA mapping operations by directly calling the dma_direct_* ops if we are using the directly mapped DMA operations. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-direct: merge swiotlb_dma_ops into the dma_direct codeChristoph Hellwig2-251/+94
While the dma-direct code is (relatively) clean and simple we actually have to use the swiotlb ops for the mapping on many architectures due to devices with addressing limits. Instead of keeping two implementations around this commit allows the dma-direct implementation to call the swiotlb bounce buffering functions and thus share the guts of the mapping implementation. This also simplified the dma-mapping setup on a few architectures where we don't have to differenciate which implementation to use. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-direct: use dma_direct_map_page to implement dma_direct_map_sgChristoph Hellwig1-9/+5
No need to duplicate the mapping logic. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-direct: improve addressability error reportingChristoph Hellwig1-21/+15
Only report report a DMA addressability report once to avoid spewing the kernel log with repeated message. Also provide a stack trace to make it easy to find the actual caller that caused the problem. Last but not least move the actual check into the fast path and only leave the error reporting in a helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13swiotlb: remove dma_mark_cleanChristoph Hellwig1-17/+1
Instead of providing a special dma_mark_clean hook just for ia64, switch ia64 to use the normal arch_sync_dma_for_cpu hooks instead. This means that we now also set the PG_arch_1 bit for pages in the swiotlb buffer, which isn't stricly needed as we will never execute code out of the swiotlb buffer, but otherwise harmless. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13swiotlb: remove SWIOTLB_MAP_ERRORChristoph Hellwig1-2/+2
We can use DMA_MAPPING_ERROR instead, which already maps to the same value. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: factor out dummy DMA opsRobin Murphy2-1/+40
The dummy DMA ops are currently used by arm64 for any device which has an invalid ACPI description and is thus barred from using DMA due to not knowing whether is is cache-coherent or not. Factor these out into general dma-mapping code so that they can be referenced from other common code paths. In the process, we can prune all the optional callbacks which just do the same thing as the default behaviour, and fill in .map_resource for completeness. Signed-off-by: Robin Murphy <robin.murphy@arm.com> [hch: moved to a separate source file] Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-13dma-mapping: always build the direct mapping codeChristoph Hellwig2-9/+1
All architectures except for sparc64 use the dma-direct code in some form, and even for sparc64 we had the discussion of a direct mapping mode a while ago. In preparation for directly calling the direct mapping code don't bother having it optionally but always build the code in. This is a minor hardship for some powerpc and arm configs that don't pull it in yet (although they should in a relase ot two), and sparc64 which currently doesn't need it at all, but it will reduce the ifdef mess we'd otherwise need significantly. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: move dma_cache_sync out of lineChristoph Hellwig1-0/+11
This isn't exactly a slow path routine, but it is not super critical either, and moving it out of line will help to keep the include chain clean for the following DMA indirection bypass work. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: move various slow path functions out of lineChristoph Hellwig1-2/+138
There is no need to have all setup and coherent allocation / freeing routines inline. Move them out of line to keep the implemeation nicely encapsulated and save some kernel text size. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: move dma_get_required_mask to kernel/dmaChristoph Hellwig1-1/+33
dma_get_required_mask should really be with the rest of the DMA mapping implementation instead of in drivers/base as a lone outlier. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: simplify the dma_sync_single_range_for_{cpu,device} implementationChristoph Hellwig1-42/+0
We can just call the regular calls after adding offset the the address instead of reimplementing them. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com>
2018-12-13dma-mapping: remove a pointless memset in dma_atomic_pool_initChristoph Hellwig1-1/+0
We already zero the memory after allocating it from the pool that this function fills, and having the memset here in this form means we can't support CMA highmem allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Russell King - ARM Linux <linux@armlinux.org.uk>
2018-12-11dma-debug: Batch dma_debug_entry allocationRobin Murphy1-29/+21
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 <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-11dma/debug: Remove dma_debug_resize_entries()Robin Murphy1-46/+0
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 <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-11dma-debug: Make leak-like behaviour apparentRobin Murphy1-0/+13
Now that we can dynamically allocate DMA debug entries to cope with drivers maintaining excessively large numbers of live mappings, a driver which *does* actually have a bug leaking mappings (and is not unloaded) will no longer trigger the "DMA-API: debugging out of memory - disabling" message until it gets to actual kernel OOM conditions, which means it could go unnoticed for a while. To that end, let's inform the user each time the pool has grown to a multiple of its initial size, which should make it apparent that they either have a leak or might want to increase the preallocation size. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-11dma-debug: Dynamically expand the dma_debug_entry poolRobin Murphy1-38/+41
Certain drivers such as large multi-queue network adapters can use pools of mapped DMA buffers larger than the default dma_debug_entry pool of 65536 entries, with the result that merely probing such a device can cause DMA debug to disable itself during boot unless explicitly given an appropriate "dma_debug_entries=..." option. Developers trying to debug some other driver on such a system may not be immediately aware of this, and at worst it can hide bugs if they fail to realise that dma-debug has already disabled itself unexpectedly by the time their code of interest gets to run. Even once they do realise, it can be a bit of a pain to emprirically determine a suitable number of preallocated entries to configure, short of massively over-allocating. There's really no need for such a static limit, though, since we can quite easily expand the pool at runtime in those rare cases that the preallocated entries are insufficient, which is arguably the least surprising and most useful behaviour. To that end, refactor the prealloc_memory() logic a little bit to generalise it for runtime reallocations as well. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-11dma-debug: Use pr_fmt()Robin Murphy1-36/+38
Use pr_fmt() to generate the "DMA-API: " prefix consistently. This results in it being added to a couple of pr_*() messages which were missing it before, and for the err_printk() calls moves it to the actual start of the message instead of somewhere in the middle. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-11dma-debug: Expose nr_total_entries in debugfsRobin Murphy1-0/+7
Expose nr_total_entries in debugfs, so that {num,min}_free_entries become even more meaningful to users interested in current/maximum utilisation. This becomes even more relevant once nr_total_entries may change at runtime beyond just the existing AMD GART debug code. Suggested-by: John Garry <john.garry@huawei.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-06dma-direct: remove the mapping_error dma_map_ops methodChristoph Hellwig2-13/+6
The dma-direct code already returns (~(dma_addr_t)0x0) on mapping failures, so we can switch over to returning DMA_MAPPING_ERROR and let the core dma-mapping code handle the rest. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
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