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[PATCHv20 00/15] Contiguous Memory Allocator

by Marek Szyprowski

Welcome everyone again! This is yet another quick update on Contiguous Memory Allocator patches. This version includes another set of code cleanups requested by Mel Gorman and a few minor bug fixes. I really hope that this version will be accepted for merging and future development will be handled by incremental patches. ARM integration code has not been changed since v16. It provides implementation of the ideas that has been discussed during Linaro Sprint meeting in Cambourne, August 2011. Here are the details: This version provides a solution for complete integration of CMA to DMA mapping subsystem on ARM architecture. The issue caused by double dma pages mapping and possible aliasing in coherent memory mapping has been finally resolved, both for GFP_ATOMIC case (allocations comes from coherent memory pool) and non-GFP_ATOMIC case (allocations comes from CMA managed areas). For coherent, nommu, ARMv4 and ARMv5 systems the current DMA-mapping implementation has been kept. For ARMv6+ systems, CMA has been enabled and a special pool of coherent memory for atomic allocations has been created. The size of this pool defaults to DEFAULT_CONSISTEN_DMA_SIZE/8, but can be changed with coherent_pool kernel parameter (if really required). All atomic allocations are served from this pool. I've did a little simplification here, because there is no separate pool for writecombine memory - such requests are also served from coherent pool. I don't think that such simplification is a problem here - I found no driver that use dma_alloc_writecombine with GFP_ATOMIC flags. All non-atomic allocation are served from CMA area. Kernel mappings are updated to reflect required memory attributes changes. This is possible because during early boot, all CMA area are remapped with 4KiB pages in kernel low-memory. This version have been tested on Samsung S5PC110 based Goni machine and Exynos4 UniversalC210 board with various V4L2 multimedia drivers. Coherent atomic allocations has been tested by manually enabling the dma bounce for the s3c-sdhci device. All patches are prepared on top of Linux Kernel v3.3-rc2. A few words for these who see CMA for the first time: The Contiguous Memory Allocator (CMA) makes it possible for device drivers to allocate big contiguous chunks of memory after the system has booted. The main difference from the similar frameworks is the fact that CMA allows to transparently reuse memory region reserved for the big chunk allocation as a system memory, so no memory is wasted when no big chunk is allocated. Once the alloc request is issued, the framework will migrate system pages to create a required big chunk of physically contiguous memory. For more information you can refer to nice LWN articles: http://lwn.net/Articles/447405/ and http://lwn.net/Articles/450286/ as well as links to previous versions of the CMA framework. The CMA framework has been initially developed by Michal Nazarewicz at Samsung Poland R&D Center. Since version 9, I've taken over the development, because Michal has left the company. Since version v17 Michal is working again on CMA patches and the current version is the result of our joint open-source effort. Best regards Marek Szyprowski Samsung Poland R&D Center Links to previous versions of the patchset: v19: <http://www.spinics.net/lists/linux-mm/msg29145.html> v18: <http://www.spinics.net/lists/linux-mm/msg28125.html> v17: <http://www.spinics.net/lists/arm-kernel/msg148499.html> v16: <http://www.spinics.net/lists/linux-mm/msg25066.html> v15: <http://www.spinics.net/lists/linux-mm/msg23365.html> v14: <http://www.spinics.net/lists/linux-media/msg36536.html> v13: (internal, intentionally not released) v12: <http://www.spinics.net/lists/linux-media/msg35674.html> v11: <http://www.spinics.net/lists/linux-mm/msg21868.html> v10: <http://www.spinics.net/lists/linux-mm/msg20761.html> v9: <http://article.gmane.org/gmane.linux.kernel.mm/60787> v8: <http://article.gmane.org/gmane.linux.kernel.mm/56855> v7: <http://article.gmane.org/gmane.linux.kernel.mm/55626> v6: <http://article.gmane.org/gmane.linux.kernel.mm/55626> v5: (intentionally left out as CMA v5 was identical to CMA v4) v4: <http://article.gmane.org/gmane.linux.kernel.mm/52010> v3: <http://article.gmane.org/gmane.linux.kernel.mm/51573> v2: <http://article.gmane.org/gmane.linux.kernel.mm/50986> v1: <http://article.gmane.org/gmane.linux.kernel.mm/50669> Changelog: v20: 1. Addressed even more comments from Mel Gorman and added his Acked-by tag on most of the core memory management patches. 2. Squashed a few minor fixes here and there (corrected alignment calculation for region limit, added adjusting low watermark level on reclaim, fixed return value of __alloc_contig_migrate_range function) 3. Removed problematic "mm: page_alloc: update migrate type of pages on pcp when isolating" patch and sligtly altered MIGRATE_CMA type handling what solved the problem 4. Rebased onto v3.3-rc2 v19: 1. Addressed another set of comments and suggestions from Mel Gorman, mainly related to breaking patches into smaller, single-feature related chunks and rewriting already existing functions in memory compaction code. 2. Reworked completely page reclaim code, removed it from split_free_page() and introduce direct call from alloc_contig_range(). 3. Merged a fix from Mans Rullgard for correct cma area limit alignment. 4. Replaced broken "mm: page_alloc: set_migratetype_isolate: drain PCP prior to isolating" patch with "mm: page_alloc: update migrate type of pages on pcp when isolating" which is another attempt to solve this issue without touching free_pcppages_bulk(). 5. Rebased onto v3.3-rc1 v18: 1. Addressed comments and suggestions from Mel Gorman related to changes in memory compaction code, most important points: - removed "mm: page_alloc: handle MIGRATE_ISOLATE in free_pcppages_bulk()" and moved all the logic to set_migratetype_isolate - see "mm: page_alloc: set_migratetype_isolate: drain PCP prior to isolating" patch - code in "mm: compaction: introduce isolate_{free,migrate}pages_range()" patch have been simplified and improved - removed "mm: mmzone: introduce zone_pfn_same_memmap()" patch 2. Fixed crash on initialization if HIGHMEM is available on ARM platforms 3. Fixed problems with allocation of contiguous memory if all free pages are occupied by page cache and reclaim is required. 4. Added a workaround for temporary migration failures (now CMA tries to allocate different memory block in such case), what heavily increased reliability of the CMA. 5. Minor cleanup here and there. 6. Rebased onto v3.2-rc7 kernel tree. v17: 1. Replaced whole CMA core memory migration code to the new one kindly provided by Michal Nazarewicz. The new code is based on memory compaction framework not the memory hotplug, like it was before. This change has been suggested by Mel Godman. 2. Addressed most of the comments from Andrew Morton and Mel Gorman in the rest of the CMA code. 3. Fixed broken initialization on ARM systems with DMA zone enabled. 4. Rebased onto v3.2-rc2 kernel. v16: 1. merged a fixup from Michal Nazarewicz to address comments from Dave Hansen about checking if pfns belong to the same memory zone 2. merged a fix from Michal Nazarewicz for incorrect handling of pages which belong to page block that is in MIGRATE_ISOLATE state, in very rare cases the migrate type of page block might have been changed from MIGRATE_CMA to MIGRATE_MOVABLE because of this bug 3. moved some common code to include/asm-generic 4. added support for x86 DMA-mapping framework for pci-dma hardware, CMA can be now even more widely tested on KVM/QEMU and a lot of common x86 boxes 5. rebased onto next-20111005 kernel tree, which includes changes in ARM DMA-mapping subsystem (CONSISTENT_DMA_SIZE removal) 6. removed patch for CMA s5p-fimc device private regions (served only as example) and provided the one that matches real life case - s5p-mfc device v15: 1. fixed calculation of the total memory after activating CMA area (was broken from v12) 2. more code cleanup in drivers/base/dma-contiguous.c 3. added address limit for default CMA area 4. rewrote ARM DMA integration: - removed "ARM: DMA: steal memory for DMA coherent mappings" patch - kept current DMA mapping implementation for coherent, nommu and ARMv4/ARMv5 systems - enabled CMA for all ARMv6+ systems - added separate, small pool for coherent atomic allocations, defaults to CONSISTENT_DMA_SIZE/8, but can be changed with kernel parameter coherent_pool=[size] v14: 1. Merged with "ARM: DMA: steal memory for DMA coherent mappings" patch, added support for GFP_ATOMIC allocations. 2. Added checks for NULL device pointer v13: (internal, intentionally not released) v12: 1. Fixed 2 nasty bugs in dma-contiguous allocator: - alignment argument was not passed correctly - range for dma_release_from_contiguous was not checked correctly 2. Added support for architecture specfic dma_contiguous_early_fixup() function 3. CMA and DMA-mapping integration for ARM architechture has been rewritten to take care of the memory aliasing issue that might happen for newer ARM CPUs (mapping of the same pages with different cache attributes is forbidden). TODO: add support for GFP_ATOMIC allocations basing on the "ARM: DMA: steal memory for DMA coherent mappings" patch and implement support for contiguous memory areas that are placed in HIGHMEM zone v11: 1. Removed genalloc usage and replaced it with direct calls to bitmap_* functions, dropped patches that are not needed anymore (genalloc extensions) 2. Moved all contiguous area management code from mm/cma.c to drivers/base/dma-contiguous.c 3. Renamed cm_alloc/free to dma_alloc/release_from_contiguous 4. Introduced global, system wide (default) contiguous area configured with kernel config and kernel cmdline parameters 5. Simplified initialization to just one function: dma_declare_contiguous() 6. Added example of device private memory contiguous area v10: 1. Rebased onto 3.0-rc2 and resolved all conflicts 2. Simplified CMA to be just a pure memory allocator, for use with platfrom/bus specific subsystems, like dma-mapping. Removed all device specific functions are calls. 3. Integrated with ARM DMA-mapping subsystem. 4. Code cleanup here and there. 5. Removed private context support. v9: 1. Rebased onto 2.6.39-rc1 and resolved all conflicts 2. Fixed a bunch of nasty bugs that happened when the allocation failed (mainly kernel oops due to NULL ptr dereference). 3. Introduced testing code: cma-regions compatibility layer and videobuf2-cma memory allocator module. v8: 1. The alloc_contig_range() function has now been separated from CMA and put in page_allocator.c. This function tries to migrate all LRU pages in specified range and then allocate the range using alloc_contig_freed_pages(). 2. Support for MIGRATE_CMA has been separated from the CMA code. I have not tested if CMA works with ZONE_MOVABLE but I see no reasons why it shouldn't. 3. I have added a @private argument when creating CMA contexts so that one can reserve memory and not share it with the rest of the system. This way, CMA acts only as allocation algorithm. v7: 1. A lot of functionality that handled driver->allocator_context mapping has been removed from the patchset. This is not to say that this code is not needed, it's just not worth posting everything in one patchset. Currently, CMA is "just" an allocator. It uses it's own migratetype (MIGRATE_CMA) for defining ranges of pageblokcs which behave just like ZONE_MOVABLE but dispite the latter can be put in arbitrary places. 2. The migration code that was introduced in the previous version actually started working. v6: 1. Most importantly, v6 introduces support for memory migration. The implementation is not yet complete though. Migration support means that when CMA is not using memory reserved for it, page allocator can allocate pages from it. When CMA wants to use the memory, the pages have to be moved and/or evicted as to make room for CMA. To make it possible it must be guaranteed that only movable and reclaimable pages are allocated in CMA controlled regions. This is done by introducing a MIGRATE_CMA migrate type that guarantees exactly that. Some of the migration code is "borrowed" from Kamezawa Hiroyuki's alloc_contig_pages() implementation. The main difference is that thanks to MIGRATE_CMA migrate type CMA assumes that memory controlled by CMA are is always movable or reclaimable so that it makes allocation decisions regardless of the whether some pages are actually allocated and migrates them if needed. The most interesting patches from the patchset that implement the functionality are: 09/13: mm: alloc_contig_free_pages() added 10/13: mm: MIGRATE_CMA migration type added 11/13: mm: MIGRATE_CMA isolation functions added 12/13: mm: cma: Migration support added [wip] Currently, kernel panics in some situations which I am trying to investigate. 2. cma_pin() and cma_unpin() functions has been added (after a conversation with Johan Mossberg). The idea is that whenever hardware does not use the memory (no transaction is on) the chunk can be moved around. This would allow defragmentation to be implemented if desired. No defragmentation algorithm is provided at this time. 3. Sysfs support has been replaced with debugfs. I always felt unsure about the sysfs interface and when Greg KH pointed it out I finally got to rewrite it to debugfs. v5: (intentionally left out as CMA v5 was identical to CMA v4) v4: 1. The "asterisk" flag has been removed in favour of requiring that platform will provide a "*=<regions>" rule in the map attribute. 2. The terminology has been changed slightly renaming "kind" to "type" of memory. In the previous revisions, the documentation indicated that device drivers define memory kinds and now, v3: 1. The command line parameters have been removed (and moved to a separate patch, the fourth one). As a consequence, the cma_set_defaults() function has been changed -- it no longer accepts a string with list of regions but an array of regions. 2. The "asterisk" attribute has been removed. Now, each region has an "asterisk" flag which lets one specify whether this region should by considered "asterisk" region. 3. SysFS support has been moved to a separate patch (the third one in the series) and now also includes list of regions. v2: 1. The "cma_map" command line have been removed. In exchange, a SysFS entry has been created under kernel/mm/contiguous. The intended way of specifying the attributes is a cma_set_defaults() function called by platform initialisation code. "regions" attribute (the string specified by "cma" command line parameter) can be overwritten with command line parameter; the other attributes can be changed during run-time using the SysFS entries. 2. The behaviour of the "map" attribute has been modified slightly. Currently, if no rule matches given device it is assigned regions specified by the "asterisk" attribute. It is by default built from the region names given in "regions" attribute. 3. Devices can register private regions as well as regions that can be shared but are not reserved using standard CMA mechanisms. A private region has no name and can be accessed only by devices that have the pointer to it. 4. The way allocators are registered has changed. Currently, a cma_allocator_register() function is used for that purpose. Moreover, allocators are attached to regions the first time memory is registered from the region or when allocator is registered which means that allocators can be dynamic modules that are loaded after the kernel booted (of course, it won't be possible to allocate a chunk of memory from a region if allocator is not loaded). 5. Index of new functions: +static inline dma_addr_t __must_check +cma_alloc_from(const char *regions, size_t size, + dma_addr_t alignment) +static inline int +cma_info_about(struct cma_info *info, const const char *regions) +int __must_check cma_region_register(struct cma_region *reg); +dma_addr_t __must_check +cma_alloc_from_region(struct cma_region *reg, + size_t size, dma_addr_t alignment); +static inline dma_addr_t __must_check +cma_alloc_from(const char *regions, + size_t size, dma_addr_t alignment); +int cma_allocator_register(struct cma_allocator *alloc); Patches in this patchset: Marek Szyprowski (6): mm: extract reclaim code from __alloc_pages_direct_reclaim() mm: trigger page reclaim in alloc_contig_range() to stabilize watermarks drivers: add Contiguous Memory Allocator X86: integrate CMA with DMA-mapping subsystem ARM: integrate CMA with DMA-mapping subsystem ARM: Samsung: use CMA for 2 memory banks for s5p-mfc device Michal Nazarewicz (9): mm: page_alloc: remove trailing whitespace mm: compaction: introduce isolate_migratepages_range(). mm: compaction: introduce map_pages() mm: compaction: introduce isolate_freepages_range() mm: compaction: export some of the functions mm: page_alloc: introduce alloc_contig_range() mm: page_alloc: change fallbacks array handling mm: mmzone: MIGRATE_CMA migration type added mm: page_isolation: MIGRATE_CMA isolation functions added Documentation/kernel-parameters.txt | 9 + arch/Kconfig | 3 + arch/arm/Kconfig | 2 + arch/arm/include/asm/dma-contiguous.h | 16 ++ arch/arm/include/asm/mach/map.h | 1 + arch/arm/kernel/setup.c | 9 +- arch/arm/mm/dma-mapping.c | 368 ++++++++++++++++++++++++------ arch/arm/mm/init.c | 22 ++- arch/arm/mm/mm.h | 3 + arch/arm/mm/mmu.c | 31 ++- arch/arm/plat-s5p/dev-mfc.c | 51 +---- arch/x86/Kconfig | 1 + arch/x86/include/asm/dma-contiguous.h | 13 + arch/x86/include/asm/dma-mapping.h | 4 + arch/x86/kernel/pci-dma.c | 18 ++- arch/x86/kernel/pci-nommu.c | 8 +- arch/x86/kernel/setup.c | 2 + drivers/base/Kconfig | 89 +++++++ drivers/base/Makefile | 1 + drivers/base/dma-contiguous.c | 405 ++++++++++++++++++++++++++++++++ include/asm-generic/dma-contiguous.h | 27 ++ include/linux/device.h | 4 + include/linux/dma-contiguous.h | 110 +++++++++ include/linux/gfp.h | 12 + include/linux/mmzone.h | 38 +++- include/linux/page-isolation.h | 18 +- mm/Kconfig | 2 +- mm/Makefile | 3 +- mm/compaction.c | 418 +++++++++++++++++++++------------ mm/internal.h | 33 +++ mm/memory-failure.c | 2 +- mm/memory_hotplug.c | 6 +- mm/page_alloc.c | 377 ++++++++++++++++++++++++++--- mm/page_isolation.c | 15 +- mm/vmstat.c | 3 + 35 files changed, 1757 insertions(+), 367 deletions(-) create mode 100644 arch/arm/include/asm/dma-contiguous.h create mode 100644 arch/x86/include/asm/dma-contiguous.h create mode 100644 drivers/base/dma-contiguous.c create mode 100644 include/asm-generic/dma-contiguous.h create mode 100644 include/linux/dma-contiguous.h -- 1.7.1.569.g6f426

13 years, 3 months

[RFC][PATCH 1/1] gpu: ion: Add IOMMU heap allocator with IOMMU API

by Hiroshi Doyu

Hi, Recently we've implemented IOMMU heap as an attachment which is one of the ION memory manager(*1) heap/backend. This implementation is completely independent of any SoC, and this can be used for other SoC as well. If our implementation is not totally wrong, it would be nice to share some experience/code here since Ion is still not so clear to me yet. I found that Linaro also seems to have started some ION work(*2). I think that some of Ion feature could be supported/replaced with Linaro UMM. For example, presently "ion_iommu_heap" is implemented with the standard IOMMU API, but it could be also implemented with the coming DMA API? Also DMABUF can be used in Ion core part as well, I guess. Currently there's no Ion memmgr code in the upstream "drivers/staging/android"(*3). Is there any plan to support this? Or is this something considered as a completely _temporary_ solution, and never going to be added? It would be nice if we can share some of our effort here since not small Android users need Ion, even temporary. Any comment would be really appreciated. Hiroshi DOYU *1: https://android.googlesource.com/kernel/common.git $ git clone https://android.googlesource.com/kernel/common.git $ cd common $ git checkout -b android origin/android-3.0 $ git grep -e "<linux/ion.h>" drivers/ drivers/gpu/ion/ion.c:#include <linux/ion.h> drivers/gpu/ion/ion_carveout_heap.c:#include <linux/ion.h> drivers/gpu/ion/ion_heap.c:#include <linux/ion.h> drivers/gpu/ion/ion_priv.h:#include <linux/ion.h> drivers/gpu/ion/ion_system_heap.c:#include <linux/ion.h> drivers/gpu/ion/ion_system_mapper.c:#include <linux/ion.h> drivers/gpu/ion/tegra/tegra_ion.c:#include <linux/ion.h> *2: https://blueprints.launchpad.net/linaro-mm-sig/+spec/linaro-mmwg-cma-ion *3: http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=tree;f=driv…

13 years, 3 months

dma_buf presentation at fosdem in brussel

by Daniel Vetter

Hi all, Just a quick heads up for those who're interested, phoronix recorded my dma_buf talk at fosdem. It starts with a quick recap about what v1 is, but it's mostly about what's still missing and what we still need to solve imo: http://www.phoronix.com/scan.php?page=news_item&px=MTA1NDE Slides are on my fdo account: http://people.freedesktop.org/~danvet/presentations/fosdem2012-dma_buf.odp Cheers, Daniel -- Daniel Vetter Mail: daniel(a)ffwll.ch Mobile: +41 (0)79 365 57 48

13 years, 3 months

[RFCv1 0/4] v4l: DMA buffer sharing support as a user

by Sumit Semwal

Hello Everyone, A very happy new year 2012! :) This patchset is an RFC for the way videobuf2 can be adapted to add support for DMA buffer sharing framework[1]. The original patch-set for the idea, and PoC of buffer sharing was by Tomasz Stanislawski <t.stanislaws(a)samsung.com>, who demonstrated buffer sharing between two v4l2 devices[2]. This RFC is needed to adapt these patches to the changes that have happened in the DMA buffer sharing framework over past few months. To begin with, I have tried to adapt only the dma-contig allocator, and only as a user of dma-buf buffer. I am currently working on the v4l2-as-an-exporter changes, and will share as soon as I get it in some shape. As with the PoC [2], the handle for sharing buffers is a file-descriptor (fd). The usage documentation is also a part of [1]. So, the current RFC has the following limitations: - Only buffer sharing as a buffer user, - doesn't handle cases where even for a contiguous buffer, the sg_table can have more than one scatterlist entry. Thanks and best regards, ~Sumit. [1]: dma-buf patchset at: https://lkml.org/lkml/2011/12/26/29 [2]: http://lwn.net/Articles/454389 Sumit Semwal (4): v4l: Add DMABUF as a memory type v4l:vb2: add support for shared buffer (dma_buf) v4l:vb: remove warnings about MEMORY_DMABUF v4l:vb2: Add dma-contig allocator as dma_buf user drivers/media/video/videobuf-core.c | 4 + drivers/media/video/videobuf2-core.c | 186 +++++++++++++++++++++++++++- drivers/media/video/videobuf2-dma-contig.c | 125 +++++++++++++++++++ include/linux/videodev2.h | 8 ++ include/media/videobuf2-core.h | 30 +++++ 5 files changed, 352 insertions(+), 1 deletions(-) -- 1.7.5.4

13 years, 3 months

[RFCv1 0/6] PASR: Partial Array Self-Refresh Framework

by Maxime Coquelin

PASR Frameworks brings support for the Partial Array Self-Refresh DDR power management feature. PASR has been introduced in LP-DDR2, and is also present in DDR3. PASR provides 4 modes: * Single-Ended: Only 1/1, 1/2, 1/4 or 1/8 are refreshed, masking starting at the end of the DDR die. * Double-Ended: Same as Single-Ended, but refresh-masking does not start necessairly at the end of the DDR die. * Bank-Selective: Refresh of each bank of a die can be masked or unmasked via a dedicated DDR register (MR16). This mode is convenient for DDR configured in BRC (Bank-Row-Column) mode. * Segment-Selective: Refresh of each segment of a die can be masked or unmasked via a dedicated DDR register (MR17). This mode is convenient for DDR configured in RBC (Row-Bank-Column) mode. The role of this framework is to stop the refresh of unused memory to enhance DDR power consumption. It supports Bank-Selective and Segment-Selective modes, as the more adapted to modern OSes. At early boot stage, a representation of the physical DDR layout is built: Die 0 _______________________________ | I--------------------------I | | I Bank or Segment 0 I | | I--------------------------I | | I--------------------------I | | I Bank or Segment 1 I | | I--------------------------I | | I--------------------------I | | I Bank or Segment ... I | | I--------------------------I | | I--------------------------I | | I Bank or Segment n I | | I--------------------------I | |______________________________| ... Die n _______________________________ | I--------------------------I | | I Bank or Segment 0 I | | I--------------------------I | | I--------------------------I | | I Bank or Segment 1 I | | I--------------------------I | | I--------------------------I | | I Bank or Segment ... I | | I--------------------------I | | I--------------------------I | | I Bank or Segment n I | | I--------------------------I | |______________________________| The first level is a table where elements represent a die: * Base address, * Number of segments, * Table representing banks/segments, * MR16/MR17 refresh mask, * DDR Controller callback to update MR16/MR17 refresh mask. The second level is the section tables representing the banks or segments, depending on hardware configuration: * Base address, * Unused memory size counter, * Possible pointer to another section it depends on (E.g. Interleaving) When some memory becomes unused, the allocator owning this memory calls the PASR Framework's pasr_put(phys_addr, size) function. The framework finds the sections impacted and updates their counters accordingly. If a section counter reach the section size, the refresh of the section is masked. If the corresponding section has a dependency with another section (E.g. because of DDR interleaving, see figure below), it checks the "paired" section is also unused before updating the refresh mask. When some unused memory is requested by the allocator, the allocator owning this memory calls the PASR Framework's pasr_get(phys_addr, size) function. The framework find the section impacted and updates their counters accordingly. If before the update, the section counter was to the section size, the refrewh of the section is unmasked. If the corresponding section has a dependency with another section, it also unmask the refresh of the other section. Patch 3/6 contains modifications for the Buddy allocator. Overhead induced is very low because the PASR framework is notified only on "MAX_ORDER" pageblocs. Any allocator support(PMEM, HWMEM...) and Memory Hotplug would be added in next patch set revisions. Maxime Coquelin (6): PASR: Initialize DDR layout PASR: Add core Framework PASR: mm: Integrate PASR in Buddy allocator PASR: Call PASR initialization PASR: Add Documentation PASR: Ux500: Add PASR support Documentation/pasr.txt | 183 ++++++++++++ arch/arm/Kconfig | 1 + arch/arm/kernel/setup.c | 1 + arch/arm/mach-ux500/include/mach/hardware.h | 11 + arch/arm/mach-ux500/include/mach/memory.h | 8 + drivers/mfd/db8500-prcmu.c | 67 +++++ drivers/staging/Kconfig | 2 + drivers/staging/Makefile | 1 + drivers/staging/pasr/Kconfig | 19 ++ drivers/staging/pasr/Makefile | 6 + drivers/staging/pasr/core.c | 168 +++++++++++ drivers/staging/pasr/helper.c | 84 ++++++ drivers/staging/pasr/helper.h | 16 + drivers/staging/pasr/init.c | 403 +++++++++++++++++++++++++++ drivers/staging/pasr/ux500.c | 58 ++++ include/linux/pasr.h | 143 ++++++++++ include/linux/ux500-pasr.h | 11 + init/main.c | 8 + mm/page_alloc.c | 9 + 19 files changed, 1199 insertions(+), 0 deletions(-) create mode 100644 Documentation/pasr.txt create mode 100644 drivers/staging/pasr/Kconfig create mode 100644 drivers/staging/pasr/Makefile create mode 100644 drivers/staging/pasr/core.c create mode 100644 drivers/staging/pasr/helper.c create mode 100644 drivers/staging/pasr/helper.h create mode 100644 drivers/staging/pasr/init.c create mode 100644 drivers/staging/pasr/ux500.c create mode 100644 include/linux/pasr.h create mode 100644 include/linux/ux500-pasr.h -- 1.7.8

13 years, 3 months

[PATCH] dma-buf: add dma_data_direction to unmap dma_buf_op

by Sumit Semwal

Some exporters may use DMA map/unmap APIs in dma-buf ops, which require enum dma_data_direction for both map and unmap operations. Thus, the unmap dma_buf_op also needs to have enum dma_data_direction as a parameter. Reported-by: Tomasz Stanislawski <t.stanislaws(a)samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal(a)ti.com> --- drivers/base/dma-buf.c | 7 +++++-- include/linux/dma-buf.h | 8 +++++--- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 8afe2dd..c9a945f 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -271,16 +271,19 @@ EXPORT_SYMBOL_GPL(dma_buf_map_attachment); * dma_buf_ops. * @attach: [in] attachment to unmap buffer from * @sg_table: [in] scatterlist info of the buffer to unmap + * @direction: [in] direction of DMA transfer * */ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, - struct sg_table *sg_table) + struct sg_table *sg_table, + enum dma_data_direction direction) { if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; mutex_lock(&attach->dmabuf->lock); - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table); + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, + direction); mutex_unlock(&attach->dmabuf->lock); } diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 86f6241..847b026 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -63,7 +63,8 @@ struct dma_buf_ops { struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *, enum dma_data_direction); void (*unmap_dma_buf)(struct dma_buf_attachment *, - struct sg_table *); + struct sg_table *, + enum dma_data_direction); /* TODO: Add try_map_dma_buf version, to return immed with -EBUSY * if the call would block. */ @@ -122,7 +123,8 @@ void dma_buf_put(struct dma_buf *dmabuf); struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); -void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *); +void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, + enum dma_data_direction); #else static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, @@ -166,7 +168,7 @@ static inline struct sg_table *dma_buf_map_attachment( } static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, - struct sg_table *sg) + struct sg_table *sg, enum dma_data_direction write) { return; } -- 1.7.5.4

13 years, 3 months

[PATCH] videobuf2: Use buffer length for DMABUF in non-planar mode

by Laurent Pinchart

When using DMABUF streaming in non-planar mode, the v4l2_buffer::length field holds the length of the buffer as required by userspace. Copy it to the length of the first plane at QBUF time, as the plane length is later checked against the dma-buf size. Signed-off-by: Laurent Pinchart <laurent.pinchart(a)ideasonboard.com> --- drivers/media/video/videobuf2-core.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index 29cf6ed..8eb4d08 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c @@ -927,6 +927,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b, } if (b->memory == V4L2_MEMORY_DMABUF) { v4l2_planes[0].m.fd = b->m.fd; + v4l2_planes[0].length = b->length; } } -- 1.7.3.4

13 years, 3 months

[PATCH] dma-buf: add dma_data_direction to unmap dma_buf_op

by Sumit Semwal

Some exporters may use DMA map/unmap APIs in dma-buf ops, which require enum dma_data_direction while unmapping. Thus, the unmap dma_buf_op also needs to have enum dma_data_direction as a parameter. Reported-by: Tomasz Stanislawski <t.stanislaws(a)samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal(a)ti.com> --- drivers/base/Kconfig | 2 +- drivers/base/dma-buf.c | 7 +++++-- include/linux/dma-buf.h | 8 +++++--- 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 7be9f79..5edc5db 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -179,7 +179,7 @@ config GENERIC_CPU_DEVICES source "drivers/base/regmap/Kconfig" config DMA_SHARED_BUFFER - bool + bool "Temporary mechanism to enable build of dma-buf" default n select ANON_INODES depends on EXPERIMENTAL diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 8afe2dd..c9a945f 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -271,16 +271,19 @@ EXPORT_SYMBOL_GPL(dma_buf_map_attachment); * dma_buf_ops. * @attach: [in] attachment to unmap buffer from * @sg_table: [in] scatterlist info of the buffer to unmap + * @direction: [in] direction of DMA transfer * */ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, - struct sg_table *sg_table) + struct sg_table *sg_table, + enum dma_data_direction direction) { if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; mutex_lock(&attach->dmabuf->lock); - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table); + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, + direction); mutex_unlock(&attach->dmabuf->lock); } diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 86f6241..847b026 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -63,7 +63,8 @@ struct dma_buf_ops { struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *, enum dma_data_direction); void (*unmap_dma_buf)(struct dma_buf_attachment *, - struct sg_table *); + struct sg_table *, + enum dma_data_direction); /* TODO: Add try_map_dma_buf version, to return immed with -EBUSY * if the call would block. */ @@ -122,7 +123,8 @@ void dma_buf_put(struct dma_buf *dmabuf); struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); -void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *); +void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, + enum dma_data_direction); #else static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, @@ -166,7 +168,7 @@ static inline struct sg_table *dma_buf_map_attachment( } static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, - struct sg_table *sg) + struct sg_table *sg, enum dma_data_direction write) { return; } -- 1.7.5.4

13 years, 3 months

Re: [Linaro-mm-sig] [PATCH 2/2] ARM: IOMMU: Tegra30: Add iommu_ops for SMMU driver

by Hiroshi Doyu

From: "joro(a)8bytes.org" <joro(a)8bytes.org> Subject: Re: [PATCH 2/2] ARM: IOMMU: Tegra30: Add iommu_ops for SMMU driver Date: Tue, 24 Jan 2012 15:25:21 +0100 Message-ID: <20120124142521.GE6269(a)8bytes.org> > On Tue, Jan 24, 2012 at 03:46:01PM +0200, Felipe Balbi wrote: > > On Tue, Jan 24, 2012 at 02:41:21PM +0100, Hiroshi Doyu wrote: > > > Actually I really like the concept of this "domain" now, which hides > > > the H/W hierarchy from users. > > > > > > But in Tegra SMMU/GART case, there's a single one IOMMU device in the > > > system. Keeping a iommu device list in a domain and iterating iommu > > > device list in each iommu_ops seem to be so nice, but I'm afraid that > > > this may be a bit too much when one already knows that there's only > > > one IOMMU device in the system. > > > > > > If there's no actual problem for 1-1 mapping between IOMMU H/Ws and > > > domains, I think that it may not so bad to keep the original code(1-1) > > > for GART and SMMU. What do you think? > > > > I think it boils down to "extensability". If you can truly/fully > > guarantee that there will *always* be a single IOMMU on all upcoming > > Tegras, then it's really overkill. > > > > But if there's even a remote possibility of the HW being changed and you > > end up with more IOMMUs, things start to feel necessary for the sake of > > making it easy to extend. > > Right. But I am fine with the logic as-is when there is only one SMMU in > the system. But please also change the IOMMU driver so that it really > only initializes a single SMMU. When boards pop up with more than one > you we notice that assumption in the code again and are reminded to > change it. Fixed. I'll revisit 4MB pagesize support and the above multiple iommu device support in a domain later. Attached the update patch.

13 years, 3 months

[PATCH 0/3] Introduce DMA buffer sharing mechanism

by Sumit Semwal

Hello Everyone, Post some discussion as an RFC, here is the patch for introducing DMA buffer sharing mechanism - change history is in the changelog below. Various subsystems - V4L2, GPU-accessors, DRI to name a few - have felt the need to have a common mechanism to share memory buffers across different devices - ARM, video hardware, GPU. This need comes forth from a variety of use cases including cameras, image processing, video recorders, sound processing, DMA engines, GPU and display buffers, amongst others. This patch attempts to define such a buffer sharing mechanism - it is the result of discussions from a couple of memory-management mini-summits held by Linaro to understand and address common needs around memory management. [1] A new dma_buf buffer object is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - a new buffer object to be created with fixed size, associated with a file pointer and allocator-defined operations for this buffer object. This operation is called the 'export' operation. - different devices to 'attach' themselves to this buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - this exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the buffer object's scatterlist using map_dma_buf and unmap_dma_buf operations. Documentation present in the patch-set gives more details. For 1st version, dma-buf is marked as an EXPERIMENTAL driver, which we can remove for later versions with additional usage and testing. *IMPORTANT*: [see https://lkml.org/lkml/2011/12/20/211 for more details] For this first version, A buffer shared using the dma_buf sharing API: - *may* be exported to user space using "mmap" *ONLY* by exporter, outside of this framework. - may be used *ONLY* by importers that do not need CPU access to the buffer. This is based on design suggestions from many people at the mini-summits, most notably from Arnd Bergmann <arnd(a)arndb.de>, Rob Clark <rob(a)ti.com> and Daniel Vetter <daniel(a)ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws(a)samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] Some sample implementations and WIP for dma-buf users and exporters are available at [3] and [4]. [These are not being submitted for discussion / inclusion right now, but are for reference only] References: [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 [3]: Dave Airlie's prime support: http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-prime-dmabuf [4]: Rob Clark's sharing between DRM and V4L2: https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf Patchset based on top of 3.2-rc7, the current version can be found at http://git.linaro.org/gitweb?p=people/sumitsemwal/linux-3.x.git Branch: dmabuf-patch-v1 Earlier versions: RFC: v3 at: https://lkml.org/lkml/2011/12/19/50 v2 at: https://lkml.org/lkml/2011/12/2/53 v1 at: https://lkml.org/lkml/2011/10/11/92 Wish you all happy vacations and a very happy, joyous and prosperous new year 2012 :) Best regards, ~Sumit Semwal History: v4: - Review comments incorporated: - from Konrad Rzeszutek Wilk [https://lkml.org/lkml/2011/12/20/209] - corrected language in some comments - re-ordered struct definitions for readability - added might_sleep() call in dma_buf_map_attachment() wrapper - from Rob Clark [https://lkml.org/lkml/2011/12/23/196] - Made dma-buf EXPERIMENTAL for 1st version. v3: - Review comments incorporated: - from Konrad Rzeszutek Wilk [https://lkml.org/lkml/2011/12/3/45] - replaced BUG_ON with WARN_ON - various places - added some error-checks - replaced EXPORT_SYMBOL with EXPORT_SYMBOL_GPL - some cosmetic / documentation comments - from Arnd Bergmann, Daniel Vetter, Rob Clark [https://lkml.org/lkml/2011/12/5/321] - removed mmap() fop and dma_buf_op, also the sg_sync* operations, and documented that mmap is not allowed for exported buffer - updated documentation to clearly state when migration is allowed - changed kconfig - some error code checks - from Rob Clark [https://lkml.org/lkml/2011/12/5/572] - update documentation to allow map_dma_buf to return -EINTR v2: - Review comments incorporated: - from Tomasz Stanislawski [https://lkml.org/lkml/2011/10/14/136] - kzalloc moved out of critical section - corrected some in-code comments - from Dave Airlie [https://lkml.org/lkml/2011/11/25/123] - from Daniel Vetter and Rob Clark [https://lkml.org/lkml/2011/11/26/53] - use struct sg_table in place of struct scatterlist - rename {get,put}_scatterlist to {map,unmap}_dma_buf - add new wrapper APIs dma_buf_{map,unmap}_attachment for ease of users - documentation updates as per review comments from Randy Dunlap [https://lkml.org/lkml/2011/10/12/439] v1: original Sumit Semwal (3): dma-buf: Introduce dma buffer sharing mechanism dma-buf: Documentation for buffer sharing framework dma-buf: mark EXPERIMENTAL for 1st release. Documentation/dma-buf-sharing.txt | 224 ++++++++++++++++++++++++++++ drivers/base/Kconfig | 11 ++ drivers/base/Makefile | 1 + drivers/base/dma-buf.c | 291 +++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 176 ++++++++++++++++++++++ 5 files changed, 703 insertions(+), 0 deletions(-) create mode 100644 Documentation/dma-buf-sharing.txt create mode 100644 drivers/base/dma-buf.c create mode 100644 include/linux/dma-buf.h -- 1.7.5.4

13 years, 3 months

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