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2024-04-10dma-mapping: add dma_opt_mapping_size()John Garry
[ Upstream commit a229cc14f3395311b899e5e582b71efa8dd01df0 ] Streaming DMA mapping involving an IOMMU may be much slower for larger total mapping size. This is because every IOMMU DMA mapping requires an IOVA to be allocated and freed. IOVA sizes above a certain limit are not cached, which can have a big impact on DMA mapping performance. Provide an API for device drivers to know this "optimal" limit, such that they may try to produce mapping which don't exceed it. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Stable-dep-of: afc5aa46ed56 ("iommu/dma: Force swiotlb_max_mapping_size on an untrusted device") Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""Linus Torvalds
commit 901c7280ca0d5e2b4a8929fbe0bfb007ac2a6544 upstream. Halil Pasic points out [1] that the full revert of that commit (revert in bddac7c1e02b), and that a partial revert that only reverts the problematic case, but still keeps some of the cleanups is probably better.  And that partial revert [2] had already been verified by Oleksandr Natalenko to also fix the issue, I had just missed that in the long discussion. So let's reinstate the cleanups from commit aa6f8dcbab47 ("swiotlb: rework "fix info leak with DMA_FROM_DEVICE""), and effectively only revert the part that caused problems. Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1] Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2] Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3] Suggested-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""Linus Torvalds
commit bddac7c1e02ba47f0570e494c9289acea3062cc1 upstream. This reverts commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13. It turns out this breaks at least the ath9k wireless driver, and possibly others. What the ath9k driver does on packet receive is to set up the DMA transfer with: int ath_rx_init(..) .. bf->bf_buf_addr = dma_map_single(sc->dev, skb->data, common->rx_bufsize, DMA_FROM_DEVICE); and then the receive logic (through ath_rx_tasklet()) will fetch incoming packets static bool ath_edma_get_buffers(..) .. dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr, common->rx_bufsize, DMA_FROM_DEVICE); ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data); if (ret == -EINPROGRESS) { /*let device gain the buffer again*/ dma_sync_single_for_device(sc->dev, bf->bf_buf_addr, common->rx_bufsize, DMA_FROM_DEVICE); return false; } and it's worth noting how that first DMA sync: dma_sync_single_for_cpu(..DMA_FROM_DEVICE); is there to make sure the CPU can read the DMA buffer (possibly by copying it from the bounce buffer area, or by doing some cache flush). The iommu correctly turns that into a "copy from bounce bufer" so that the driver can look at the state of the packets. In the meantime, the device may continue to write to the DMA buffer, but we at least have a snapshot of the state due to that first DMA sync. But that _second_ DMA sync: dma_sync_single_for_device(..DMA_FROM_DEVICE); is telling the DMA mapping that the CPU wasn't interested in the area because the packet wasn't there. In the case of a DMA bounce buffer, that is a no-op. Note how it's not a sync for the CPU (the "for_device()" part), and it's not a sync for data written by the CPU (the "DMA_FROM_DEVICE" part). Or rather, it _should_ be a no-op. That's what commit aa6f8dcbab47 broke: it made the code bounce the buffer unconditionally, and changed the DMA_FROM_DEVICE to just unconditionally and illogically be DMA_TO_DEVICE. [ Side note: purely within the confines of the swiotlb driver it wasn't entirely illogical: The reason it did that odd DMA_FROM_DEVICE -> DMA_TO_DEVICE conversion thing is because inside the swiotlb driver, it uses just a swiotlb_bounce() helper that doesn't care about the whole distinction of who the sync is for - only which direction to bounce. So it took the "sync for device" to mean that the CPU must have been the one writing, and thought it meant DMA_TO_DEVICE. ] Also note how the commentary in that commit was wrong, probably due to that whole confusion, claiming that the commit makes the swiotlb code "bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer" which is nonsensical for two reasons: - that "also when dir == DMA_TO_DEVICE" is nonsensical, as that was exactly when it always did - and should do - the bounce. - since this is a sync for the device (not for the CPU), we're clearly fundamentally not coping back stale data from the bounce buffers at all, because we'd be copying *to* the bounce buffers. So that commit was just very confused. It confused the direction of the synchronization (to the device, not the cpu) with the direction of the DMA (from the device). Reported-and-bisected-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Olha Cherevyk <olha.cherevyk@gmail.com> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Kalle Valo <kvalo@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Toke Høiland-Jørgensen <toke@toke.dk> Cc: Maxime Bizon <mbizon@freebox.fr> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16swiotlb: rework "fix info leak with DMA_FROM_DEVICE"Halil Pasic
commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13 upstream. Unfortunately, we ended up merging an old version of the patch "fix info leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph (the swiotlb maintainer), he asked me to create an incremental fix (after I have pointed this out the mix up, and asked him for guidance). So here we go. The main differences between what we got and what was agreed are: * swiotlb_sync_single_for_device is also required to do an extra bounce * We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters * The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE must take precedence over DMA_ATTR_SKIP_CPU_SYNC Thus this patch removes DMA_ATTR_OVERWRITE, and makes swiotlb_sync_single_for_device() bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer. Let me note, that if the size used with dma_sync_* API is less than the size used with dma_[un]map_*, under certain circumstances we may still end up with swiotlb not being transparent. In that sense, this is no perfect fix either. To get this bullet proof, we would have to bounce the entire mapping/bounce buffer. For that we would have to figure out the starting address, and the size of the mapping in swiotlb_sync_single_for_device(). While this does seem possible, there seems to be no firm consensus on how things are supposed to work. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16swiotlb: fix info leak with DMA_FROM_DEVICEHalil Pasic
[ Upstream commit ddbd89deb7d32b1fbb879f48d68fda1a8ac58e8e ] The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-14dma-mapping: return an unsigned int from dma_map_sg{,_attrs}Christoph Hellwig
These can only return 0 for failure or the number of entries, so turn the return value into an unsigned int. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
2021-08-09dma-mapping: allow map_sg() ops to return negative error codesLogan Gunthorpe
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This will be required for returning appropriate error codes when mapping P2PDMA memory. Introduce __dma_map_sg_attrs() which will return the raw error code from the map_sg operation (whether it be negative or zero). Then add a dma_map_sg_attrs() wrapper to convert any negative errors to zero to satisfy the existing calling convention. dma_map_sgtable() defines three error codes that .map_sg implementations are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which is a generic return for cases that are passing DMA_MAPPING_ERROR through. dma_map_sgtable() will convert a zero error return for old map_sg() ops into a -EIO return and return any negative errors as reported. This allows map_sg implementations to start returning multiple negative error codes. Legacy map_sg implementations can continue to return zero until they are all converted. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-04-02dma-mapping: add unlikely hint to error path in dma_mapping_errorHeiner Kallweit
Zillions of drivers use the unlikely() hint when checking the result of dma_mapping_error(). This is an inline function anyway, so we can move the hint into the function and remove it from drivers over time. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-03-19dma-mapping: remove a pointless empty line in dma_alloc_coherentWang Qing
Signed-off-by: Wang Qing <wangqing@vivo.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-03-15dma-mapping: add a dma_alloc_noncontiguous APIChristoph Hellwig
Add a new API that returns a potentiall virtually non-contigous sg_table and a DMA address. This API is only properly implemented for dma-iommu and will simply return a contigious chunk as a fallback. The intent is that drivers can use this API if either: - no kernel mapping or only temporary kernel mappings are required. That is as a better replacement for DMA_ATTR_NO_KERNEL_MAPPING - a kernel mapping is required for cached and DMA mapped pages, but the driver also needs the pages to e.g. map them to userspace. In that sense it is a replacement for some aspects of the recently removed and never fully implemented DMA_ATTR_NON_CONSISTENT Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tomasz Figa <tfiga@chromium.org> Tested-by: Ricardo Ribalda <ribalda@chromium.org>
2021-03-15dma-mapping: add a dma_mmap_pages helperChristoph Hellwig
Add a helper to map memory allocated using dma_alloc_pages into a user address space, similar to the dma_alloc_attrs function for coherent allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tomasz Figa <tfiga@chromium.org> Tested-by: Ricardo Ribalda <ribalda@chromium.org>
2021-02-26Merge branch 'stable/for-linus-5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb updates from Konrad Rzeszutek Wilk: "Two memory encryption related patches (SWIOTLB is enabled by default for AMD-SEV): - Add support for alignment so that NVME can properly work - Keep track of requested DMA buffers length, as underlaying hardware devices can trip SWIOTLB to bounce too much and crash the kernel And a tiny fix to use proper APIs in drivers" * 'stable/for-linus-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: Validate bounce size in the sync/unmap path nvme-pci: set min_align_mask swiotlb: respect min_align_mask swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single swiotlb: refactor swiotlb_tbl_map_single swiotlb: clean up swiotlb_tbl_unmap_single swiotlb: factor out a nr_slots helper swiotlb: factor out an io_tlb_offset helper swiotlb: add a IO_TLB_SIZE define driver core: add a min_align_mask field to struct device_dma_parameters sdhci: stop poking into swiotlb internals
2021-02-20driver core: add a min_align_mask field to struct device_dma_parametersJianxiong Gao
Some devices rely on the address offset in a page to function correctly (NVMe driver as an example). These devices may use a different page size than the Linux kernel. The address offset has to be preserved upon mapping, and in order to do so, we need to record the page_offset_mask first. Signed-off-by: Jianxiong Gao <jxgao@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-02-09dma-mapping: remove the {alloc,free}_noncoherent methodsChristoph Hellwig
It turns out allowing non-contigous allocations here was a rather bad idea, as we'll now need to define ways to get the pages for mmaping or dma_buf sharing. Revert this change and stick to the original concept. A different API for the use case of non-contigous allocations will be added back later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tomasz Figa <tfiga@chromium.org> Tested-by: Ricardo Ribalda <ribalda@chromium.org>:wq
2020-12-16Merge tag 'arm-soc-drivers-5.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC driver updates from Arnd Bergmann: "There are a couple of subsystems maintained by other people that merge their drivers through the SoC tree, those changes include: - The SCMI firmware framework gains support for sensor notifications and for controlling voltage domains. - A large update for the Tegra memory controller driver, integrating it better with the interconnect framework - The memory controller subsystem gains support for Mediatek MT8192 - The reset controller framework gains support for sharing pulsed resets For Soc specific drivers in drivers/soc, the main changes are - The Allwinner/sunxi MBUS gets a rework for the way it handles dma_map_ops and offsets between physical and dma address spaces. - An errata fix plus some cleanups for Freescale Layerscape SoCs - A cleanup for renesas drivers regarding MMIO accesses. - New SoC specific drivers for Mediatek MT8192 and MT8183 power domains - New SoC specific drivers for Aspeed AST2600 LPC bus control and SoC identification. - Core Power Domain support for Qualcomm MSM8916, MSM8939, SDM660 and SDX55. - A rework of the TI AM33xx 'genpd' power domain support to use information from DT instead of platform data - Support for TI AM64x SoCs - Allow building some Amlogic drivers as modules instead of built-in Finally, there are numerous cleanups and smaller bug fixes for Mediatek, Tegra, Samsung, Qualcomm, TI OMAP, Amlogic, Rockchips, Renesas, and Xilinx SoCs" * tag 'arm-soc-drivers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (222 commits) soc: mediatek: mmsys: Specify HAS_IOMEM dependency for MTK_MMSYS firmware: xilinx: Properly align function parameter firmware: xilinx: Add a blank line after function declaration firmware: xilinx: Remove additional newline firmware: xilinx: Fix kernel-doc warnings firmware: xlnx-zynqmp: fix compilation warning soc: xilinx: vcu: add missing register NUM_CORE soc: xilinx: vcu: use vcu-settings syscon registers dt-bindings: soc: xlnx: extract xlnx, vcu-settings to separate binding soc: xilinx: vcu: drop useless success message clk: samsung: mark PM functions as __maybe_unused soc: samsung: exynos-chipid: initialize later - with arch_initcall soc: samsung: exynos-chipid: order list of SoCs by name memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe() memory: ti-emif-sram: only build for ARMv7 memory: tegra30: Support interconnect framework memory: tegra20: Support hardware versioning and clean up OPP table initialization dt-bindings: memory: tegra20-emc: Document opp-supported-hw property soc: rockchip: io-domain: Fix error return code in rockchip_iodomain_probe() reset-controller: ti: force the write operation when assert or deassert ...
2020-11-18dma-mapping: remove the dma_direct_set_offset exportChristoph Hellwig
Drop the dma_direct_set_offset export and move the declaration to dma-map-ops.h now that the Allwinner drivers have stopped calling it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
2020-11-17dma-mapping: remove dma_virt_opsChristoph Hellwig
Now that the RDMA core deals with devices that only do DMA mapping in lower layers properly, there is no user for dma_virt_ops and it can be removed. Link: https://lore.kernel.org/r/20201106181941.1878556-11-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-10-20dma-mapping: move more functions to dma-map-ops.hChristoph Hellwig
Due to a mismerge a bunch of prototypes that should have moved to dma-map-ops.h are still in dma-mapping.h, fix that up. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-06dma-mapping: move dma-debug.h to kernel/dma/Christoph Hellwig
Most of dma-debug.h is not required by anything outside of kernel/dma. Move the four declarations needed by dma-mappin.h or dma-ops providers into dma-mapping.h and dma-map-ops.h, and move the remainder of the file to kernel/dma/debug.h. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-06dma-mapping: split <linux/dma-mapping.h>Christoph Hellwig
Split out all the bits that are purely for dma_map_ops implementations and related code into a new <linux/dma-map-ops.h> header so that they don't get pulled into all the drivers. That also means the architecture specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h> any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methodsChristoph Hellwig
This will allow IOMMU drivers to allocate non-contigous memory and return a vmapped virtual address. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: add a new dma_alloc_pages APIChristoph Hellwig
This API is the equivalent of alloc_pages, except that the returned memory is guaranteed to be DMA addressable by the passed in device. The implementation will also be used to provide a more sensible replacement for DMA_ATTR_NON_CONSISTENT flag. Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages as its backend. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
2020-09-25dma-mapping: remove dma_cache_syncChristoph Hellwig
All users are gone now, remove the API. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
2020-09-25dma-mapping: add a new dma_alloc_noncoherent APIChristoph Hellwig
Add a new API to allocate and free memory that is guaranteed to be addressable by a device, but which potentially is not cache coherent for DMA. To transfer ownership to and from the device, the existing streaming DMA API calls dma_sync_single_for_device and dma_sync_single_for_cpu must be used. For now the new calls are implemented on top of dma_alloc_attrs just like the old-noncoherent API, but once all drivers are switched to the new API it will be replaced with a better working implementation that is available on all architectures. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: better document dma_addr_t and DMA_MAPPING_ERRORChristoph Hellwig
Move the comment documenting dma_addr_t away from the dma_map_ops definition which isn't very related to it, and toward DMA_MAPPING_ERROR, which is somewhat related. Add a little blurb about DMA_MAPPING_ERROR as well. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: move valid_dma_direction to dma-direction.hChristoph Hellwig
Move the valid_dma_direction helper to a more suitable header, and clean it up to use the proper enum as well as removing pointless braces. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: remove DMA_MASK_NONEChristoph Hellwig
This value is only used by a PCMCIA driver and not very useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Dominik Brodowski <linux@dominikbrodwski.net>
2020-09-17dma-mapping: introduce DMA range map, supplanting dma_pfn_offsetJim Quinlan
The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> [hch: various interface cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-09-03dma-mapping: set default segment_boundary_mask to ULONG_MAXNicolin Chen
The default segment_boundary_mask was set to DMA_BIT_MAKS(32) a decade ago by referencing SCSI/block subsystem, as a 32-bit mask was good enough for most of the devices. Now more and more drivers set dma_masks above DMA_BIT_MAKS(32) while only a handful of them call dma_set_seg_boundary(). This means that most drivers have a 4GB segmention boundary because DMA API returns a 32-bit default value, though they might not really have such a limit. The default segment_boundary_mask should mean "no limit" since the device doesn't explicitly set the mask. But a 32-bit mask certainly limits those devices capable of 32+ bits addressing. So this patch sets default segment_boundary_mask to ULONG_MAX. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-03dma-mapping: introduce dma_get_seg_boundary_nr_pages()Nicolin Chen
We found that callers of dma_get_seg_boundary mostly do an ALIGN with page mask and then do a page shift to get number of pages: ALIGN(boundary + 1, 1 << shift) >> shift However, the boundary might be as large as ULONG_MAX, which means that a device has no specific boundary limit. So either "+ 1" or passing it to ALIGN() would potentially overflow. According to kernel defines: #define ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) #define ALIGN(x, a) ALIGN_MASK(x, (typeof(x))(a) - 1) We can simplify the logic here into a helper function doing: ALIGN(boundary + 1, 1 << shift) >> shift = ALIGN_MASK(b + 1, (1 << s) - 1) >> s = {[b + 1 + (1 << s) - 1] & ~[(1 << s) - 1]} >> s = [b + 1 + (1 << s) - 1] >> s = [b + (1 << s)] >> s = (b >> s) + 1 This patch introduces and applies dma_get_seg_boundary_nr_pages() as an overflow-free helper for the dma_get_seg_boundary() callers to get numbers of pages. It also takes care of the NULL dev case for non-DMA API callers. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-14dma-pool: fix coherent pool allocations for IOMMU mappingsChristoph Hellwig
When allocating coherent pool memory for an IOMMU mapping we don't care about the DMA mask. Move the guess for the initial GFP mask into the dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer argument so that it doesn't get applied to the IOMMU case. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Amit Pundir <amit.pundir@linaro.org>
2020-08-04Merge tag 'docs-5.9' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It's been a busy cycle for documentation - hopefully the busiest for a while to come. Changes include: - Some new Chinese translations - Progress on the battle against double words words and non-HTTPS URLs - Some block-mq documentation - More RST conversions from Mauro. At this point, that task is essentially complete, so we shouldn't see this kind of churn again for a while. Unless we decide to switch to asciidoc or something...:) - Lots of typo fixes, warning fixes, and more" * tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits) scripts/kernel-doc: optionally treat warnings as errors docs: ia64: correct typo mailmap: add entry for <alobakin@marvell.com> doc/zh_CN: add cpu-load Chinese version Documentation/admin-guide: tainted-kernels: fix spelling mistake MAINTAINERS: adjust kprobes.rst entry to new location devices.txt: document rfkill allocation PCI: correct flag name docs: filesystems: vfs: correct flag name docs: filesystems: vfs: correct sync_mode flag names docs: path-lookup: markup fixes for emphasis docs: path-lookup: more markup fixes docs: path-lookup: fix HTML entity mojibake CREDITS: Replace HTTP links with HTTPS ones docs: process: Add an example for creating a fixes tag doc/zh_CN: add Chinese translation prefer section doc/zh_CN: add clearing-warn-once Chinese version doc/zh_CN: add admin-guide index doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label futex: MAINTAINERS: Re-add selftests directory ...
2020-07-19dma-mapping: make support for dma ops optionalChristoph Hellwig
Avoid the overhead of the dma ops support for tiny builds that only use the direct mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-16dma-mapping: move the remaining DMA API calls out of lineChristoph Hellwig
For a long time the DMA API has been implemented inline in dma-mapping.h, but the function bodies can be quite large. Move them all out of line. This also removes all the dma_direct_* exports as those are just implementation details and should never be used by drivers directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-06-30dma-mapping: Add a new dma_need_sync APIChristoph Hellwig
Add a new API to check if calls to dma_sync_single_for_{device,cpu} are required for a given DMA streaming mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200629130359.2690853-2-hch@lst.de
2020-06-26docs: fix references for DMA*.txt filesMauro Carvalho Chehab
As we moved those files to core-api, fix references to point to their newer locations. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/37b2fd159fbc7655dbf33b3eb1215396a25f6344.1592895969.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-06Merge tag 'dma-mapping-5.8-2' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping helpers from Christoph Hellwig: "These were in a separate stable branch so that various media and drm trees could pull the in for bug fixes, but looking at linux-next that hasn't actually happened yet. Still sending the APIs to you in the hope that these bug fixes get picked up for 5.8 in one way or another. Summary: - add DMA mapping helpers for struct sg_table (Marek Szyprowski)" * tag 'dma-mapping-5.8-2' of git://git.infradead.org/users/hch/dma-mapping: iommu: add generic helper for mapping sgtable objects scatterlist: add generic wrappers for iterating over sgtable objects dma-mapping: add generic helpers for mapping sgtable objects
2020-05-13dma-mapping: add generic helpers for mapping sgtable objectsMarek Szyprowski
struct sg_table is a common structure used for describing a memory buffer. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg function. To avoid such issues, let's introduce a common wrappers operating directly on the struct sg_table objects, which take care of the proper use of the nents and orig_nents entries. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-04-20dma-pool: add additional coherent pools to map to gfp maskDavid Rientjes
The single atomic pool is allocated from the lowest zone possible since it is guaranteed to be applicable for any DMA allocation. Devices may allocate through the DMA API but not have a strict reliance on GFP_DMA memory. Since the atomic pool will be used for all non-blockable allocations, returning all memory from ZONE_DMA may unnecessarily deplete the zone. Provision for multiple atomic pools that will map to the optimal gfp mask of the device. When allocating non-blockable memory, determine the optimal gfp mask of the device and use the appropriate atomic pool. The coherent DMA mask will remain the same between allocation and free and, thus, memory will be freed to the same atomic pool it was allocated from. __dma_atomic_pool_init() will be changed to return struct gen_pool * later once dynamic expansion is added. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-11-28Merge branch 'master' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux; tag 'dma-mapping-5.5' of git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping updates from Christoph Hellwig: - improve dma-debug scalability (Eric Dumazet) - tiny dma-debug cleanup (Dan Carpenter) - check for vmap memory in dma_map_single (Kees Cook) - check for dma_addr_t overflows in dma-direct when using DMA offsets (Nicolas Saenz Julienne) - switch the x86 sta2x11 SOC to use more generic DMA code (Nicolas Saenz Julienne) - fix arm-nommu dma-ranges handling (Vladimir Murzin) - use __initdata in CMA (Shyam Saini) - replace the bus dma mask with a limit (Nicolas Saenz Julienne) - merge the remapping helpers into the main dma-direct flow (me) - switch xtensa to the generic dma remap handling (me) - various cleanups around dma_capable (me) - remove unused dev arguments to various dma-noncoherent helpers (me) * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux: * tag 'dma-mapping-5.5' of git://git.infradead.org/users/hch/dma-mapping: (22 commits) dma-mapping: treat dev->bus_dma_mask as a DMA limit dma-direct: exclude dma_direct_map_resource from the min_low_pfn check dma-direct: don't check swiotlb=force in dma_direct_map_resource dma-debug: clean up put_hash_bucket() powerpc: remove support for NULL dev in __phys_to_dma / __dma_to_phys dma-direct: avoid a forward declaration for phys_to_dma dma-direct: unify the dma_capable definitions dma-mapping: drop the dev argument to arch_sync_dma_for_* x86/PCI: sta2x11: use default DMA address translation dma-direct: check for overflows on 32 bit DMA addresses dma-debug: increase HASH_SIZE dma-debug: reorder struct dma_debug_entry fields xtensa: use the generic uncached segment support dma-mapping: merge the generic remapping helpers into dma-direct dma-direct: provide mmap and get_sgtable method overrides dma-direct: remove the dma_handle argument to __dma_direct_alloc_pages dma-direct: remove __dma_direct_free_pages usb: core: Remove redundant vmap checks kernel: dma-contiguous: mark CMA parameters __initdata/__initconst dma-debug: add a schedule point in debug_dma_dump_mappings() ...
2019-11-21dma-mapping: treat dev->bus_dma_mask as a DMA limitNicolas Saenz Julienne
Using a mask to represent bus DMA constraints has a set of limitations. The biggest one being it can only hold a power of two (minus one). The DMA mapping code is already aware of this and treats dev->bus_dma_mask as a limit. This quirk is already used by some architectures although still rare. With the introduction of the Raspberry Pi 4 we've found a new contender for the use of bus DMA limits, as its PCIe bus can only address the lower 3GB of memory (of a total of 4GB). This is impossible to represent with a mask. To make things worse the device-tree code rounds non power of two bus DMA limits to the next power of two, which is unacceptable in this case. In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all over the tree and treat it as such. Note that dev->bus_dma_limit should contain the higher accessible DMA address. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-11-14dma-mapping: remove the DMA_ATTR_WRITE_BARRIER flagChristoph Hellwig
This flag is not implemented by any backend and only set by the ib_umem module in a single instance. Link: https://lore.kernel.org/r/20191113073214.9514-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-30dma-mapping: Add vmap checks to dma_map_single()Kees Cook
As we've seen from USB and other areas[1], we need to always do runtime checks for DMA operating on memory regions that might be remapped. This adds vmap checks (similar to those already in USB but missing in other places) into dma_map_single() so all callers benefit from the checking. [1] https://git.kernel.org/linus/3840c5b78803b2b6cc1ff820100a74a092c40cbb Suggested-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> [hch: fixed the printk message] Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-10-30dma-mapping: fix handling of dma-ranges for reserved memory (again)Vladimir Murzin
Daniele reported that issue previously fixed in c41f9ea998f3 ("drivers: dma-coherent: Account dma_pfn_offset when used with device tree") reappear shortly after 43fc509c3efb ("dma-coherent: introduce interface for default DMA pool") where fix was accidentally dropped. Lets put fix back in place and respect dma-ranges for reserved memory. Fixes: 43fc509c3efb ("dma-coherent: introduce interface for default DMA pool") Reported-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Tested-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Tested-by: Alexandre Torgue <alexandre.torgue@st.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-19Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping updates from Christoph Hellwig: - add dma-mapping and block layer helpers to take care of IOMMU merging for mmc plus subsequent fixups (Yoshihiro Shimoda) - rework handling of the pgprot bits for remapping (me) - take care of the dma direct infrastructure for swiotlb-xen (me) - improve the dma noncoherent remapping infrastructure (me) - better defaults for ->mmap, ->get_sgtable and ->get_required_mask (me) - cleanup mmaping of coherent DMA allocations (me) - various misc cleanups (Andy Shevchenko, me) * tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits) mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE mmc: queue: Fix bigger segments usage arm64: use asm-generic/dma-mapping.h swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page swiotlb-xen: simplify cache maintainance swiotlb-xen: use the same foreign page check everywhere swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable xen: remove the exports for xen_{create,destroy}_contiguous_region xen/arm: remove xen_dma_ops xen/arm: simplify dma_cache_maint xen/arm: use dev_is_dma_coherent xen/arm: consolidate page-coherent.h xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance arm: remove wrappers for the generic dma remap helpers dma-mapping: introduce a dma_common_find_pages helper dma-mapping: always use VM_DMA_COHERENT for generic DMA remap vmalloc: lift the arm flag for coherent mappings to common code dma-mapping: provide a better default ->get_required_mask dma-mapping: remove the dma_declare_coherent_memory export remoteproc: don't allow modular build ...
2019-09-04dma-mapping: introduce a dma_common_find_pages helperChristoph Hellwig
A helper to find the backing page array based on a virtual address. This also ensures we do the same vm_flags check everywhere instead of slightly different or missing ones in a few places. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: always use VM_DMA_COHERENT for generic DMA remapChristoph Hellwig
Currently the generic dma remap allocator gets a vm_flags passed by the caller that is a little confusing. We just introduced a generic vmalloc-level flag to identify the dma coherent allocations, so use that everywhere and remove the now pointless argument. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: remove dma_release_declared_memoryChristoph Hellwig
This function is entirely unused given that declared memory is generally provided by platform setup code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: remove dma_{alloc,free,mmap}_writecombineChristoph Hellwig
We can already use DMA_ATTR_WRITE_COMBINE or the _wc prefixed version, so remove the third way of doing things. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2019-09-04dma-mapping: add a dma_can_mmap helperChristoph Hellwig
Add a helper to check if DMA allocations for a specific device can be mapped to userspace using dma_mmap_*. Signed-off-by: Christoph Hellwig <hch@lst.de>