kernel/linux.git/include/linux/cma.h, branch v6.12.80

mm/cma: add cma_{alloc,free}_folio()

2024-09-04T04:15:36+00:00

With alloc_contig_range() and free_contig_range() supporting large folios, CMA can allocate and free large folios too, by cma_alloc_folio() and cma_free_folio(). [yuzhao@google.com: fix WARN in cma_alloc_folio()] Link: https://lkml.kernel.org/r/Zsd0PgAQmbpR8jS6@google.com Link: https://lkml.kernel.org/r/20240814035451.773331-3-yuzhao@google.com Signed-off-by: Yu Zhao Acked-by: Zi Yan Cc: Frank van der Linden Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Signed-off-by: Andrew Morton

mm/cma: make MAX_CMA_AREAS = CONFIG_CMA_AREAS

2024-02-22T18:24:53+00:00

There is no real difference between the global area, and other additionally configured CMA areas via CONFIG_CMA_AREAS that always defaults without user input. This makes MAX_CMA_AREAS same as CONFIG_CMA_AREAS, also incrementing its default values, thus maintaining current default for MAX_CMA_AREAS both for UMA and NUMA systems. Link: https://lkml.kernel.org/r/20240205051929.298559-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton

mm: cma: use pageblock_order as the single alignment

2022-05-13T14:20:13+00:00

Now alloc_contig_range() works at pageblock granularity. Change CMA allocation, which uses alloc_contig_range(), to use pageblock_nr_pages alignment. Link: https://lkml.kernel.org/r/20220425143118.2850746-6-zi.yan@sent.com Signed-off-by: Zi Yan Cc: Christophe Leroy Cc: David Hildenbrand Cc: Eric Ren Cc: kernel test robot Cc: Mel Gorman Cc: Mike Rapoport Cc: Minchan Kim Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton

Merge tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-03-31T18:43:01+00:00

Pull hardening updates from Kees Cook: "This addresses an -Warray-bounds warning found under a few ARM defconfigs, and disables long-broken HARDENED_USERCOPY_PAGESPAN" * tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ARM/dma-mapping: Remove CMA code when not built with CMA usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN

ARM/dma-mapping: Remove CMA code when not built with CMA

2022-03-31T18:19:25+00:00

The MAX_CMA_AREAS could be set to 0, which would result in code that would attempt to operate beyond the end of a zero-sized array. If CONFIG_CMA is disabled, just remove this code entirely. Found when building arm on GCC 10.x for several defconfigs (e.g. axm55xx_defconfig) under -Warray-bounds: arch/arm/mm/dma-mapping.c:396:22: warning: array subscript is outside array bounds of 'struct dma_contig_early_reserve[0]' [-Warray-bounds] 396 | dma_mmu_remap[dma_mmu_remap_num].size = size; | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ arch/arm/mm/dma-mapping.c:389:40: note: while referencing 'dma_mmu_remap' 389 | static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; | ^~~~~~~~~~~~~ Cc: Russell King Cc: Logan Gunthorpe Cc: Martin Oliveira Cc: David Hildenbrand Cc: Andrew Morton Cc: Stephen Rothwell Cc: Zi Yan Cc: Hari Bathini Cc: Minchan Kim Cc: Mike Kravetz Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/all/6243ee60.1c69fb81.16de6.7dbf@mx.google.com/ Signed-off-by: Kees Cook Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/lkml/20220310070041.GA24874@lst.de Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/lkml/9059fa71-330f-f04f-b155-2850abb72a71@redhat.com

mm/cma: provide option to opt out from exposing pages on activation failure

2022-03-22T22:57:09+00:00

Patch series "powerpc/fadump: handle CMA activation failure appropriately", v3. Commit 072355c1cf2d ("mm/cma: expose all pages to the buddy if activation of an area fails") started exposing all pages to buddy allocator on CMA activation failure. But there can be CMA users that want to handle the reserved memory differently on CMA allocation failure. Provide an option to opt out from exposing pages to buddy for such cases. Link: https://lkml.kernel.org/r/20220117075246.36072-1-hbathini@linux.ibm.com Link: https://lkml.kernel.org/r/20220117075246.36072-2-hbathini@linux.ibm.com Signed-off-by: Hari Bathini Reviewed-by: David Hildenbrand Cc: Oscar Salvador Cc: Mike Kravetz Cc: Mahesh Salgaonkar Cc: Sourabh Jain Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: enforce pageblock_order < MAX_ORDER

2022-03-22T22:57:06+00:00

Some places in the kernel don't really expect pageblock_order >= MAX_ORDER, and it looks like this is only possible in corner cases: 1) CONFIG_DEFERRED_STRUCT_PAGE_INIT we'll end up freeing pageblock_order pages via __free_pages_core(), which cannot possibly work. 2) find_zone_movable_pfns_for_nodes() will roundup the ZONE_MOVABLE start PFN to MAX_ORDER_NR_PAGES. Consequently with a bigger pageblock_order, we could have a single pageblock partially managed by two zones. 3) compaction code runs into __fragmentation_index() with order >= MAX_ORDER, when checking WARN_ON_ONCE(order >= MAX_ORDER). [1] 4) mm/page_reporting.c won't be reporting any pages with default page_reporting_order == pageblock_order, as we'll be skipping the reporting loop inside page_reporting_process_zone(). 5) __rmqueue_fallback() will never be able to steal with ALLOC_NOFRAGMENT. pageblock_order >= MAX_ORDER is weird either way: it's a pure optimization for making alloc_contig_range(), as used for allcoation of gigantic pages, a little more reliable to succeed. However, if there is demand for somewhat reliable allocation of gigantic pages, affected setups should be using CMA or boottime allocations instead. So let's make sure that pageblock_order < MAX_ORDER and simplify. [1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20220214174132.219303-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Cc: Aneesh Kumar K.V Cc: Benjamin Herrenschmidt Cc: Christoph Hellwig Cc: Frank Rowand Cc: John Garry via iommu Cc: Marek Szyprowski Cc: Michael Ellerman Cc: Michael S. Tsirkin Cc: Minchan Kim Cc: Paul Mackerras Cc: Rob Herring Cc: Robin Murphy Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cma: factor out minimum alignment requirement

2022-03-22T22:57:05+00:00

Patch series "mm: enforce pageblock_order < MAX_ORDER". Having pageblock_order >= MAX_ORDER seems to be able to happen in corner cases and some parts of the kernel are not prepared for it. For example, Aneesh has shown [1] that such kernels can be compiled on ppc64 with 64k base pages by setting FORCE_MAX_ZONEORDER=8, which will run into a WARN_ON_ONCE(order >= MAX_ORDER) in comapction code right during boot. We can get pageblock_order >= MAX_ORDER when the default hugetlb size is bigger than the maximum allocation granularity of the buddy, in which case we are no longer talking about huge pages but instead gigantic pages. Having pageblock_order >= MAX_ORDER can only make alloc_contig_range() of such gigantic pages more likely to succeed. Reliable use of gigantic pages either requires boot time allcoation or CMA, no need to overcomplicate some places in the kernel to optimize for corner cases that are broken in other areas of the kernel. This patch (of 2): Let's enforce pageblock_order < MAX_ORDER and simplify. Especially patch #1 can be regarded a cleanup before: [PATCH v5 0/6] Use pageblock_order for cma and alloc_contig_range alignment. [2] [1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com [2] https://lkml.kernel.org/r/20220211164135.1803616-1-zi.yan@sent.com Link: https://lkml.kernel.org/r/20220214174132.219303-2-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Acked-by: Rob Herring Cc: Aneesh Kumar K.V Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Frank Rowand Cc: Michael S. Tsirkin Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Robin Murphy Cc: Minchan Kim Cc: Vlastimil Babka Cc: John Garry via iommu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/cma: add cma_pages_valid to determine if pages are in CMA

2021-11-06T20:30:39+00:00

Add new interface cma_pages_valid() which indicates if the specified pages are part of a CMA region. This interface will be used in a subsequent patch by hugetlb code. In order to keep the same amount of DEBUG information, a pr_debug() call was added to cma_pages_valid(). In the case where the page passed to cma_release is not in cma region, the debug message will be printed from cma_pages_valid as opposed to cma_release. Link: https://lkml.kernel.org/r/20211007181918.136982-3-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz Acked-by: David Hildenbrand Reviewed-by: Oscar Salvador Cc: "Aneesh Kumar K . V" Cc: David Rientjes Cc: Michal Hocko Cc: Muchun Song Cc: Naoya Horiguchi Cc: Nghia Le Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: use proper type for cma_[alloc|release]

2021-05-05T18:27:24+00:00

size_t in cma_alloc is confusing since it makes people think it's byte count, not pages. Change it to unsigned long[1]. The unsigned int in cma_release is also not right so change it. Since we have unsigned long in cma_release, free_contig_range should also respect it. [1] 67a2e213e7e9, mm: cma: fix incorrect type conversion for size during dma allocation Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/ Link: https://lkml.kernel.org/r/20210331164018.710560-1-minchan@kernel.org Signed-off-by: Minchan Kim Reviewed-by: David Hildenbrand Cc: Matthew Wilcox Cc: David Hildenbrand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds