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2019-06-20scsi: lib/sg_pool.c: improve APIs for allocating sg poolMing Lei1-4/+7
sg_alloc_table_chained() currently allows the caller to provide one preallocated SGL and returns if the requested number isn't bigger than size of that SGL. This is used to inline an SGL for an IO request. However, scattergather code only allows that size of the 1st preallocated SGL to be SG_CHUNK_SIZE(128). This means a substantial amount of memory (4KB) is claimed for the SGL for each IO request. If the I/O is small, it would be prudent to allocate a smaller SGL. Introduce an extra parameter to sg_alloc_table_chained() and sg_free_table_chained() for specifying size of the preallocated SGL. Both __sg_free_table() and __sg_alloc_table() assume that each SGL has the same size except for the last one. Change the code to allow both functions to accept a variable size for the 1st preallocated SGL. [mkp: attempted to clarify commit desc] Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Ewan D. Milne <emilne@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: netdev@vger.kernel.org Cc: linux-nvme@lists.infradead.org Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-05-07lib/scatterlist: Remove leftover from sg_page_iter commentGal Pressman1-5/+5
Commit d901b2760dc6 ("lib/scatterlist: Provide a DMA page iterator") added the sg DMA iterator but a leftover remained in the sg_page_iter documentation as you cannot get the page dma address (only the page itself), fix it. Signed-off-by: Gal Pressman <galpress@amazon.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-02-11lib/scatterlist: Provide a DMA page iteratorJason Gunthorpe1-9/+40
Commit 2db76d7c3c6d ("lib/scatterlist: sg_page_iter: support sg lists w/o backing pages") introduced the sg_page_iter_dma_address() function without providing a way to use it in the general case. If the sg_dma_len() is not equal to the sg length callers cannot safely use the for_each_sg_page/sg_page_iter_dma_address combination. Resolve this API mistake by providing a DMA specific iterator, for_each_sg_dma_page(), that uses the right length so sg_page_iter_dma_address() works as expected with all sglists. A new iterator type is introduced to provide compile-time safety against wrongly mixing accessors and iterators. Acked-by: Christoph Hellwig <hch@lst.de> (for scatterlist) Acked-by: Thomas Hellstrom <thellstrom@vmware.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> (ipu3-cio2) Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-12-06arch: switch the default on ARCH_HAS_SG_CHAINChristoph Hellwig1-3/+3
These days architectures are mostly out of the business of dealing with struct scatterlist at all, unless they have architecture specific iommu drivers. Replace the ARCH_HAS_SG_CHAIN symbol with a ARCH_NO_SG_CHAIN one only enabled for architectures with horrible legacy iommu drivers like alpha and parisc, and conditionally for arm which wants to keep it disable for legacy platforms. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-29sg: remove ->sg_magic memberJens Axboe1-18/+0
This was introduced more than a decade ago when sg chaining was added, but we never really caught anything with it. The scatterlist entry size can be critical, since drivers allocate it, so remove the magic member. Recently it's been triggering allocation stalls and failures in NVMe. Tested-by: Jordan Glover <Golden_Miller83@protonmail.ch> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-05Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-blockLinus Torvalds1-10/+13
Pull block layer updates from Jens Axboe: "It's a pretty quiet round this time, which is nice. This contains: - series from Bart, cleaning up the way we set/test/clear atomic queue flags. - series from Bart, fixing races between gendisk and queue registration and removal. - set of bcache fixes and improvements from various folks, by way of Michael Lyle. - set of lightnvm updates from Matias, most of it being the 1.2 to 2.0 transition. - removal of unused DIO flags from Nikolay. - blk-mq/sbitmap memory ordering fixes from Omar. - divide-by-zero fix for BFQ from Paolo. - minor documentation patches from Randy. - timeout fix from Tejun. - Alpha "can't write a char atomically" fix from Mikulas. - set of NVMe fixes by way of Keith. - bsg and bsg-lib improvements from Christoph. - a few sed-opal fixes from Jonas. - cdrom check-disk-change deadlock fix from Maurizio. - various little fixes, comment fixes, etc from various folks" * tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits) blk-mq: Directly schedule q->timeout_work when aborting a request blktrace: fix comment in blktrace_api.h lightnvm: remove function name in strings lightnvm: pblk: remove some unnecessary NULL checks lightnvm: pblk: don't recover unwritten lines lightnvm: pblk: implement 2.0 support lightnvm: pblk: implement get log report chunk lightnvm: pblk: rename ppaf* to addrf* lightnvm: pblk: check for supported version lightnvm: implement get log report chunk helpers lightnvm: make address conversions depend on generic device lightnvm: add support for 2.0 address format lightnvm: normalize geometry nomenclature lightnvm: complete geo structure with maxoc* lightnvm: add shorten OCSSD version in geo lightnvm: add minor version to generic geometry lightnvm: simplify geometry structure lightnvm: pblk: refactor init/exit sequences lightnvm: Avoid validation of default op value lightnvm: centralize permission check for lightnvm ioctl ...
2018-03-30lib/scatterlist: add sg_init_marker() helperPrashant Bhole1-0/+18
sg_init_marker initializes sg_magic in the sg table and calls sg_mark_end() on the last entry of the table. This can be useful to avoid memset in sg_init_table() when scatterlist is already zeroed out For example: when scatterlist is embedded inside other struct and that container struct is zeroed out Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-28lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodingsAnshuman Khandual1-10/+13
This replaces scatterlist->page_link LSB encodings with SG_CHAIN and SG_END definitions without any functional change. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-19lib/scatterlist: Fix chaining support in sgl_alloc_order()Bart Van Assche1-0/+1
This patch avoids that workloads with large block sizes (megabytes) can trigger the following call stack with the ib_srpt driver (that driver is the only driver that chains scatterlists allocated by sgl_alloc_order()): BUG: Bad page state in process kworker/0:1H pfn:2423a78 page:fffffb03d08e9e00 count:-3 mapcount:0 mapping: (null) index:0x0 flags: 0x57ffffc0000000() raw: 0057ffffc0000000 0000000000000000 0000000000000000 fffffffdffffffff raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000 page dumped because: nonzero _count CPU: 0 PID: 733 Comm: kworker/0:1H Tainted: G I 4.15.0-rc7.bart+ #1 Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015 Workqueue: ib-comp-wq ib_cq_poll_work [ib_core] Call Trace: dump_stack+0x5c/0x83 bad_page+0xf5/0x10f get_page_from_freelist+0xa46/0x11b0 __alloc_pages_nodemask+0x103/0x290 sgl_alloc_order+0x101/0x180 target_alloc_sgl+0x2c/0x40 [target_core_mod] srpt_alloc_rw_ctxs+0x173/0x2d0 [ib_srpt] srpt_handle_new_iu+0x61e/0x7f0 [ib_srpt] __ib_process_cq+0x55/0xa0 [ib_core] ib_cq_poll_work+0x1b/0x60 [ib_core] process_one_work+0x141/0x340 worker_thread+0x47/0x3e0 kthread+0xf5/0x130 ret_from_fork+0x1f/0x30 Fixes: e80a0af4759a ("lib/scatterlist: Introduce sgl_alloc() and sgl_free()") Reported-by: Laurence Oberman <loberman@redhat.com> Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Cc: Laurence Oberman <loberman@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06lib/scatterlist: Introduce sgl_alloc() and sgl_free()Bart Van Assche1-0/+10
Many kernel drivers contain code that allocates and frees both a scatterlist and the pages that populate that scatterlist. Introduce functions in lib/scatterlist.c that perform these tasks instead of duplicating this functionality in multiple drivers. Only include these functions in the build if CONFIG_SGL_ALLOC=y to avoid that the kernel size increases if this functionality is not used. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-15Merge tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds1-4/+13
Pull drm updates from Dave Airlie: "This is the main drm pull request for v4.15. Core: - Atomic object lifetime fixes - Atomic iterator improvements - Sparse/smatch fixes - Legacy kms ioctls to be interruptible - EDID override improvements - fb/gem helper cleanups - Simple outreachy patches - Documentation improvements - Fix dma-buf rcu races - DRM mode object leasing for improving VR use cases. - vgaarb improvements for non-x86 platforms. New driver: - tve200: Faraday Technology TVE200 block. This "TV Encoder" encodes a ITU-T BT.656 stream and can be found in the StorLink SL3516 (later Cortina Systems CS3516) as well as the Grain Media GM8180. New bridges: - SiI9234 support New panels: - S6E63J0X03, OTM8009A, Seiko 43WVF1G, 7" rpi touch panel, Toshiba LT089AC19000, Innolux AT043TN24 i915: - Remove Coffeelake from alpha support - Cannonlake workarounds - Infoframe refactoring for DisplayPort - VBT updates - DisplayPort vswing/emph/buffer translation refactoring - CCS fixes - Restore GPU clock boost on missed vblanks - Scatter list updates for userptr allocations - Gen9+ transition watermarks - Display IPC (Isochronous Priority Control) - Private PAT management - GVT: improved error handling and pci config sanitizing - Execlist refactoring - Transparent Huge Page support - User defined priorities support - HuC/GuC firmware refactoring - DP MST fixes - eDP power sequencing fixes - Use RCU instead of stop_machine - PSR state tracking support - Eviction fixes - BDW DP aux channel timeout fixes - LSPCON fixes - Cannonlake PLL fixes amdgpu: - Per VM BO support - Powerplay cleanups - CI powerplay support - PASID mgr for kfd - SR-IOV fixes - initial GPU reset for vega10 - Prime mmap support - TTM updates - Clock query interface for Raven - Fence to handle ioctl - UVD encode ring support on Polaris - Transparent huge page DMA support - Compute LRU pipe tweaks - BO flag to allow buffers to opt out of implicit sync - CTX priority setting API - VRAM lost infrastructure plumbing qxl: - fix flicker since atomic rework amdkfd: - Further improvements from internal AMD tree - Usermode events - Drop radeon support nouveau: - Pascal temperature sensor support - Improved BAR2 handling - MMU rework to support Pascal MMU exynos: - Improved HDMI/mixer support - HDMI audio interface support tegra: - Prep work for tegra186 - Cleanup/fixes msm: - Preemption support for a5xx - Display fixes for 8x96 (snapdragon 820) - Async cursor plane fixes - FW loading rework - GPU debugging improvements vc4: - Prep for DSI panels - fix T-format tiling scanout - New madvise ioctl Rockchip: - LVDS support omapdrm: - omap4 HDMI CEC support etnaviv: - GPU performance counters groundwork sun4i: - refactor driver load + TCON backend - HDMI improvements - A31 support - Misc fixes udl: - Probe/EDID read fixes. tilcdc: - Misc fixes. pl111: - Support more variants adv7511: - Improve EDID handling. - HDMI CEC support sii8620: - Add remote control support" * tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linux: (1480 commits) drm/rockchip: analogix_dp: Use mutex rather than spinlock drm/mode_object: fix documentation for object lookups. drm/i915: Reorder context-close to avoid calling i915_vma_close() under RCU drm/i915: Move init_clock_gating() back to where it was drm/i915: Prune the reservation shared fence array drm/i915: Idle the GPU before shinking everything drm/i915: Lock llist_del_first() vs llist_del_all() drm/i915: Calculate ironlake intermediate watermarks correctly, v2. drm/i915: Disable lazy PPGTT page table optimization for vGPU drm/i915/execlists: Remove the priority "optimisation" drm/i915: Filter out spurious execlists context-switch interrupts drm/amdgpu: use irq-safe lock for kiq->ring_lock drm/amdgpu: bypass lru touch for KIQ ring submission drm/amdgpu: Potential uninitialized variable in amdgpu_vm_update_directories() drm/amdgpu: potential uninitialized variable in amdgpu_vce_ring_parse_cs() drm/amd/powerplay: initialize a variable before using it drm/amd/powerplay: suppress KASAN out of bounds warning in vega10_populate_all_memory_levels drm/amd/amdgpu: fix evicted VRAM bo adjudgement condition drm/vblank: Tune drm_crtc_accurate_vblank_count() WARN down to a debug drm/rockchip: add CONFIG_OF dependency for lvds ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07lib/scatterlist: Introduce and export __sg_alloc_table_from_pagesTvrtko Ursulin1-4/+7
Drivers like i915 benefit from being able to control the maxium size of the sg coalesced segment while building the scatter- gather list. Introduce and export the __sg_alloc_table_from_pages function which will allow it that control. v2: Reorder parameters. (Chris Wilson) v3: Fix incomplete reordering in v2. v4: max_segment needs to be page aligned. v5: Rebase. v6: Rebase. v7: Fix spelling in commit and mention max segment size in __sg_alloc_table_from_pages kerneldoc. (Andrew Morton) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: linux-kernel@vger.kernel.org Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://patchwork.freedesktop.org/patch/msgid/20170803091351.23594-1-tvrtko.ursulin@linux.intel.com
2017-09-07lib/scatterlist: Avoid potential scatterlist entry overflowTvrtko Ursulin1-0/+6
Since the scatterlist length field is an unsigned int, make sure that sg_alloc_table_from_pages does not overflow it while coalescing pages to a single entry. v2: Drop reference to future use. Use UINT_MAX. v3: max_segment must be page aligned. v4: Do not rely on compiler to optimise out the rounddown. (Joonas Lahtinen) v5: Simplified loops and use post-increments rather than pre-increments. Use PAGE_MASK and fix comment typo. (Andy Shevchenko) v6: Commit spelling fix. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20170803091312.22875-1-tvrtko.ursulin@linux.intel.com
2017-09-07lib/scatterlist: Fix offset type in sg_alloc_table_from_pagesTvrtko Ursulin1-1/+1
Scatterlist entries have an unsigned int for the offset so correct the sg_alloc_table_from_pages function accordingly. Since these are offsets withing a page, unsigned int is wide enough. Also converts callers which were using unsigned long locally with the lower_32_bits annotation to make it explicitly clear what is happening. v2: Use offset_in_page. (Chris Wilson) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Pawel Osciak <pawel@osciak.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Tomasz Stanislawski <t.stanislaws@samsung.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alexandre.bounine@idt.com> Cc: linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> (v1) Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Link: https://patchwork.freedesktop.org/patch/msgid/20170731185512.20010-1-tvrtko.ursulin@linux.intel.com
2017-06-15scatterlist: add sg_zero_buffer() helperJohannes Thumshirn1-0/+2
The sg_zero_buffer() helper is used to zero fill an area in a SG list. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> [hch: renamed to sg_zero_buffer] Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-04-15lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.cMing Lin1-0/+25
Now it's ready to move the mempool based SG chained allocator code from SCSI driver to lib/sg_pool.c, which will be compiled only based on a Kconfig symbol CONFIG_SG_POOL. SCSI selects CONFIG_SG_POOL. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-08-24lib: scatterlist: add sg splitting functionRobert Jarzmik1-0/+5
Sometimes a scatter-gather has to be split into several chunks, or sub scatter lists. This happens for example if a scatter list will be handled by multiple DMA channels, each one filling a part of it. A concrete example comes with the media V4L2 API, where the scatter list is allocated from userspace to hold an image, regardless of the knowledge of how many DMAs will fill it : - in a simple RGB565 case, one DMA will pump data from the camera ISP to memory - in the trickier YUV422 case, 3 DMAs will pump data from the camera ISP pipes, one for pipe Y, one for pipe U and one for pipe V For these cases, it is necessary to split the original scatter list into multiple scatter lists, which is the purpose of this patch. The guarantees that are required for this patch are : - the intersection of spans of any couple of resulting scatter lists is empty. - the union of spans of all resulting scatter lists is a subrange of the span of the original scatter list. - streaming DMA API operations (mapping, unmapping) should not happen both on both the resulting and the original scatter list. It's either the first or the later ones. - the caller is reponsible to call kfree() on the resulting scatterlists. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17scatterlist: allow limited chaining without ARCH_HAS_SG_CHAINChristoph Hellwig1-4/+0
There are a couple of uses of struct scatterlist that never go to the dma_map_sg() helper and thus don't care about ARCH_HAS_SG_CHAIN which indicates that we can map chained S/G list. The most important one is the crypto code, which currently has to open code a few helpers to always allow chaining. This patch removes a few #ifdef ARCH_HAS_SG_CHAIN statements so that we can switch the crypto code to these common helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-30drivers/scsi/scsi_debug.c: resolve sg buffer const-ness issueDave Gordon1-0/+3
do_device_access() takes a separate parameter to indicate the direction of data transfer, which it used to use to select the appropriate function out of sg_pcopy_{to,from}_buffer(). However these two functions now have So this patch makes it bypass these wrappers and call the underlying function sg_copy_buffer() directly; this has the same calling style as do_device_access() i.e. a separate direction-of-transfer parameter and no pointers-to-const, so skipping the wrappers not only eliminates the warning, it also make the code simpler :) [akpm@linux-foundation.org: fix very broken build] Signed-off-by: Dave Gordon <david.s.gordon@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30lib/scatterlist: mark input buffer parameters as 'const'Dave Gordon1-2/+2
The 'buf' parameter of sg(p)copy_from_buffer() can and should be const-qualified, although because of the shared implementation of _to_buffer() and _from_buffer(), we have to cast this away internally. This means that callers who have a 'const' buffer containing the data to be copied to the sg-list no longer have to cast away the const-ness themselves. It also enables improved coverage by code analysis tools. Signed-off-by: Dave Gordon <david.s.gordon@intel.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-blockLinus Torvalds1-7/+32
Pull asm/scatterlist.h removal from Jens Axboe: "We don't have any specific arch scatterlist anymore, since parisc finally switched over. Kill the include" * 'for-4.2/sg' of git://git.kernel.dk/linux-block: remove scatterlist.h generation from arch Kbuild files remove <asm/scatterlist.h>
2015-06-03scatterlist: introduce sg_nents_for_lenTom Lendacky1-0/+1
When performing a dma_map_sg() call, the number of sg entries to map is required. Using sg_nents to retrieve the number of sg entries will return the total number of entries in the sg list up to the entry marked as the end. If there happen to be unused entries in the list, these will still be counted. Some dma_map_sg() implementations will not handle the unused entries correctly (lib/swiotlb.c) and execute a BUG_ON. The sg_nents_for_len() function will traverse the sg list and return the number of entries required to satisfy the supplied length argument. This can then be supplied to the dma_map_sg() call to successfully map the sg. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-05remove <asm/scatterlist.h>Christoph Hellwig1-7/+32
We don't have any arch specific scatterlist now that parisc switched over to the generic one. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-08lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual KconfigLaura Abbott1-1/+1
Rather than have architectures #define ARCH_HAS_SG_CHAIN in an architecture specific scatterlist.h, make it a proper Kconfig option and use that instead. At same time, remove the header files are are now mostly useless and just include asm-generic/scatterlist.h. [sfr@canb.auug.org.au: powerpc files now need asm/dma.h] Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-25scatterlist: allow chaining to preallocated chunksChristoph Hellwig1-3/+3
Blk-mq drivers usually preallocate their S/G list as part of the request, but if we want to support the very large S/G lists currently supported by the SCSI code that would tie up a lot of memory in the preallocated request pool. Add support to the scatterlist code so that it can initialize a S/G list that uses a preallocated first chunks and dynamically allocated additional chunks. That way the scsi-mq code can preallocate a first page worth of S/G entries as part of the request, and dynamically extend the S/G list when needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2013-12-08lib/scatterlist: export sg_miter_skip()Ming Lei1-0/+1
sg_copy_buffer() can't meet demand for some drrivers(such usb mass storage), so we have to use the sg_miter_* APIs to access sg buffer, then need export sg_miter_skip() for these drivers. The API is needed for converting to sg_miter_* APIs in USB storage driver for accessing sg buffer. Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <ming.lei@canonical.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-09lib/scatterlist: introduce sg_pcopy_from_buffer() and sg_pcopy_to_buffer()Akinobu Mita1-0/+5
The only difference between sg_pcopy_{from,to}_buffer() and sg_copy_{from,to}_buffer() is an additional argument that specifies the number of bytes to skip the SG list before copying. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Horia Geanta <horia.geanta@freescale.com> Cc: Imre Deak <imre.deak@intel.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-30scatterlist: sg_set_buf() argument must be in linear mappingRusty Russell1-0/+3
Add a check behind CONFIG_DEBUG_SG to verify this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-05-02Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds1-5/+23
Pull drm updates from Dave Airlie: "This is the main drm pull request for 3.10. Wierd bits: - OMAP drm changes required OMAP dss changes, in drivers/video, so I took them in here. - one more fbcon fix for font handover - VT switch avoidance in pm code - scatterlist helpers for gpu drivers - have acks from akpm Highlights: - qxl kms driver - driver for the spice qxl virtual GPU Nouveau: - fermi/kepler VRAM compression - GK110/nvf0 modesetting support. Tegra: - host1x core merged with 2D engine support i915: - vt switchless resume - more valleyview support - vblank fixes - modesetting pipe config rework radeon: - UVD engine support - SI chip tiling support - GPU registers initialisation from golden values. exynos: - device tree changes - fimc block support Otherwise: - bunches of fixes all over the place." * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (513 commits) qxl: update to new idr interfaces. drm/nouveau: fix build with nv50->nvc0 drm/radeon: fix handling of v6 power tables drm/radeon: clarify family checks in pm table parsing drm/radeon: consolidate UVD clock programming drm/radeon: fix UPLL_REF_DIV_MASK definition radeon: add bo tracking debugfs drm/radeon: add new richland pci ids drm/radeon: add some new SI PCI ids drm/radeon: fix scratch reg handling for UVD fence drm/radeon: allocate SA bo in the requested domain drm/radeon: fix possible segfault when parsing pm tables drm/radeon: fix endian bugs in atom_allocate_fb_scratch() OMAPDSS: TFP410: return EPROBE_DEFER if the i2c adapter not found OMAPDSS: VENC: Add error handling for venc_probe_pdata OMAPDSS: HDMI: Add error handling for hdmi_probe_pdata OMAPDSS: RFBI: Add error handling for rfbi_probe_pdata OMAPDSS: DSI: Add error handling for dsi_probe_pdata OMAPDSS: SDI: Add error handling for sdi_probe_pdata OMAPDSS: DPI: Add error handling for dpi_probe_pdata ...
2013-03-27lib/scatterlist: sg_page_iter: support sg lists w/o backing pagesImre Deak1-5/+23
The i915 driver uses sg lists for memory without backing 'struct page' pages, similarly to other IO memory regions, setting only the DMA address for these. It does this, so that it can program the HW MMU tables in a uniform way both for sg lists with and without backing pages. Without a valid page pointer we can't call nth_page to get the current page in __sg_page_iter_next, so add a helper that relevant users can call separately. Also add a helper to get the DMA address of the current page (idea from Daniel). Convert all places in i915, to use the new API. Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Damien Lespiau <damien.lespiau@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-03-20scatterlist: introduce sg_unmark_endPaolo Bonzini1-0/+16
This is useful in places that recycle the same scatterlist multiple times, and do not want to incur the cost of sg_init_table every time in hot paths. Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-02-27lib/scatterlist: use page iterator in the mapping iteratorImre Deak1-3/+3
For better code reuse use the newly added page iterator to iterate through the pages. The offset, length within the page is still calculated by the mapping iterator as well as the actual mapping. Idea from Tejun Heo. Signed-off-by: Imre Deak <imre.deak@intel.com> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: James Hogan <james.hogan@imgtec.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27lib/scatterlist: add simple page iteratorImre Deak1-0/+35
Add an iterator to walk through a scatter list a page at a time starting at a specific page offset. As opposed to the mapping iterator this is meant to be small, performing well even in simple loops like collecting all pages on the scatterlist into an array or setting up an iommu table based on the pages' DMA address. Signed-off-by: Imre Deak <imre.deak@intel.com> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-27scatterlist: add sg_nentsMaxim Levitsky1-0/+1
Useful helper to know the number of entries in scatterlist. Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Alex Dubov <oakad@yahoo.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-30scatterlist: add sg_alloc_table_from_pages functionTomasz Stanislawski1-0/+4
This patch adds a new constructor for an sg table. The table is constructed from an array of struct pages. All contiguous chunks of the pages are merged into a single sg nodes. A user may provide an offset and a size of a buffer if the buffer is not page-aligned. The function is dedicated for DMABUF exporters which often perform conversion from an page array to a scatterlist. Moreover the scatterlist should be squashed in order to save memory and to speed-up the process of DMA mapping using dma_map_sg. The code is based on the patch 'v4l: vb2-dma-contig: add support for scatterlist in userptr mode' and hints from Laurent Pinchart. Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> CC: Andrew Morton <akpm@linux-foundation.org>
2012-03-04BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker1-2/+4
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2009-07-31lib/scatterlist: add a flags to signalize mapping directionSebastian Andrzej Siewior1-0/+2
sg_miter_start() is currently unaware of the direction of the copy process (to or from the scatter list). It is important to know the direction because the page has to be flushed in case the data written is seen on a different mapping in user land on cache incoherent architectures. Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
2008-07-23sg: reimplement sg mapping iteratorTejun Heo1-0/+38
This is alternative implementation of sg content iterator introduced by commit 83e7d317... from Pierre Ossman in next-20080716. As there's already an sg iterator which iterates over sg entries themselves, name this sg_mapping_iterator. Slightly edited description from the original implementation follows. Iteration over a sg list is not that trivial when you take into account that memory pages might have to be mapped before being used. Unfortunately, that means that some parts of the kernel restrict themselves to directly accesible memory just to not have to deal with the mess. This patch adds a simple iterator system that allows any code to easily traverse an sg list and not have to deal with all the details. The user can decide to consume part of the iteration. Also, iteration can be stopped and resumed later if releasing the kmap between iteration steps is necessary. These features are useful to implement piecemeal sg copying for interrupt drive PIO for example. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-04-07[SCSI] block: add sg buffer copy helper functionsFUJITA Tomonori1-0/+5
This patch adds new three helper functions to copy data between an SG list and a linear buffer. - sg_copy_from_buffer copies data from linear buffer to an SG list - sg_copy_to_buffer copies data from an SG list to a linear buffer When the APIs copy data from a linear buffer to an SG list, flush_kernel_dcache_page is called. It's not necessary for everyone but it's a no-op on most architectures and in general the API is not used in performance critical path. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-28SG: work with the SCSI fixed maximum allocations.James Bottomley1-2/+3
SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS, currently 128) and this will cause a BUG_ON() in SCSI if something tries an allocation over it. This patch adds a size limit to the chaining allocator to allow the specification of the maximum allocation size for chaining, so we always chain in units of the maximum SCSI allocation size. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpersJens Axboe1-100/+25
Manually doing chained sg lists is not trivial, so add some helpers to make sure that drivers get it right. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-11Don't blatt first element of prv in sg_chain()Rusty Russell1-2/+2
I realize that sg chaining is a ploy to make the rest of the kernel devs feel the pain of the SCSI subsystem. But this was a little unsubtle. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-27scatterlist: add more safeguardsTejun Heo1-11/+26
Add more safeguards to protect against misinterpreting a chain entry as a normal scatterlist and vice-versa. * Make sure the entry isn't a chain when assigning and reading a normal sg. * Clear offset and length when chaining. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02[SG] Get rid of __sg_mark_end()Jens Axboe1-10/+12
sg_mark_end() overwrites the page_link information, but all users want __sg_mark_end() behaviour where we just set the end bit. That is the most natural way to use the sg list, since you'll fill it in and then mark the end point. So change sg_mark_end() to only set the termination bit. Add a sg_magic debug check as well, and clear a chain pointer if it is set. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02SG: Make sg_init_one() use general table init functionsJens Axboe1-22/+18
Don't open code sg_init_one(), make it reuse sg_init_table(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-29sg_init_table() should use unsigned loop index variableChuck Lever1-1/+1
Clean up: fix a mixed sign comparison in sg_init_table() accidentally introduced by commit d6ec0842. The sign of the loop index variable should match the sign of the "nents" argument. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2007-10-29sg_last() should use unsigned loop index variableChuck Lever1-1/+1
Clean up: fix a mixed sign comparison in sg_last() accidentally introduced by commit 70eb8040. The sign of the loop index variable should match the sign of the "nents" argument. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2007-10-29SG: clear termination bit in sg_chain()Jens Axboe1-1/+5
Since we are using the last entry in the list, clear any possible termination bit that may have already been set. Pointed out by Rusty. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-25fix sg_phys to use dma_addr_tHugh Dickins1-1/+2
x86_32 CONFIG_HIGHMEM64G with 5GB RAM hung when booting, after issuing some "request_module: runaway loop modprobe binfmt-0000" messages in trying to exec /sbin/init. The binprm buf doesn't see the right ".ELF" header because sg_phys() is providing the wrong physical addresses for high pages: a 32-bit unsigned long is too small in this case, we need to use dma_addr_t. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>