From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 666C0171D5 for ; Wed, 31 May 2023 15:48:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69AD3C4339E; Wed, 31 May 2023 15:48:42 +0000 (UTC) From: Catalin Marinas To: Linus Torvalds , Christoph Hellwig , Robin Murphy Cc: Arnd Bergmann , Greg Kroah-Hartman , Will Deacon , Marc Zyngier , Andrew Morton , Herbert Xu , Ard Biesheuvel , Isaac Manjarres , Saravana Kannan , Alasdair Kergon , Daniel Vetter , Joerg Roedel , Mark Brown , Mike Snitzer , "Rafael J. Wysocki" , Jonathan Cameron , linux-mm@kvack.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 01/17] mm/slab: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN Date: Wed, 31 May 2023 16:48:20 +0100 Message-Id: <20230531154836.1366225-2-catalin.marinas@arm.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230531154836.1366225-1-catalin.marinas@arm.com> References: <20230531154836.1366225-1-catalin.marinas@arm.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In preparation for supporting a kmalloc() minimum alignment smaller than the arch DMA alignment, decouple the two definitions. This requires that either the kmalloc() caches are aligned to a (run-time) cache-line size or the DMA API bounces unaligned kmalloc() allocations. Subsequent patches will implement both options. After this patch, ARCH_DMA_MINALIGN is expected to be used in static alignment annotations and defined by an architecture to be the maximum alignment for all supported configurations/SoCs in a single Image. Architectures opting in to a smaller ARCH_KMALLOC_MINALIGN will need to define its value in the arch headers. Since ARCH_DMA_MINALIGN is now always defined, adjust the #ifdef in dma_get_cache_alignment() so that there is no change for architectures not requiring a minimum DMA alignment. Signed-off-by: Catalin Marinas Cc: Andrew Morton Cc: Christoph Hellwig Cc: Robin Murphy --- include/linux/dma-mapping.h | 2 +- include/linux/slab.h | 14 +++++++++++--- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0ee20b764000..3288a1339271 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -545,7 +545,7 @@ static inline int dma_set_min_align_mask(struct device *dev, static inline int dma_get_cache_alignment(void) { -#ifdef ARCH_DMA_MINALIGN +#ifdef ARCH_HAS_DMA_MINALIGN return ARCH_DMA_MINALIGN; #endif return 1; diff --git a/include/linux/slab.h b/include/linux/slab.h index 6b3e155b70bf..50dcf9cfbf62 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -235,12 +235,20 @@ void kmem_dump_obj(void *object); * alignment larger than the alignment of a 64-bit integer. * Setting ARCH_DMA_MINALIGN in arch headers allows that. */ -#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 +#ifdef ARCH_DMA_MINALIGN +#define ARCH_HAS_DMA_MINALIGN +#if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN) #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN -#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN -#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) +#endif #else +#define ARCH_DMA_MINALIGN __alignof__(unsigned long long) +#endif + +#ifndef ARCH_KMALLOC_MINALIGN #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) +#elif ARCH_KMALLOC_MINALIGN > 8 +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) #endif /*