From patchwork Fri Jan 5 16:26:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 10146747 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C64B1601A1 for ; Fri, 5 Jan 2018 16:27:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B10F9285FF for ; Fri, 5 Jan 2018 16:27:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A5EBA287A3; Fri, 5 Jan 2018 16:27:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 27C3D285FF for ; Fri, 5 Jan 2018 16:27:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752247AbeAEQ1C (ORCPT ); Fri, 5 Jan 2018 11:27:02 -0500 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:5246 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751628AbeAEQ0w (ORCPT ); Fri, 5 Jan 2018 11:26:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1515169612; x=1546705612; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=n06lQozQpaIj3RskbtHeZDSBmTsaFh3Ji+JRWNVNCis=; b=me5aA1Kr0CzXg6Nhg5GdRieNFWZREjpWpFJ60p/IVjBLUBxDsIwBwVxP /iF4/MNvdSKdWkwVIYbLSWlPhimGYil6i3Scn7vCSXKbdxmoDjyuJXbjL f5Ebz1JGZ4+B6PoFEx4SVUjLtWEN0q51KDeBb8UnvejGSJV8NQJyX4hYa xR/LhxZ40YgQfFGODvjnXoMI8IA970RaViB/TcsoSdGILF7kLPVgHb3WF LGSxf/RoQEha784+oiUeZqVsnQLhTbeqWFz+gwprMJjObsa7WX6aNuMDJ cXo9ozuJVk8qhihc/N/W9yzMAlgEbGO06shpmavXRQEPKHKV+XifGew3B Q==; X-IronPort-AV: E=Sophos;i="5.46,318,1511798400"; d="scan'208";a="170689599" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 06 Jan 2018 00:26:51 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP; 05 Jan 2018 08:22:57 -0800 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.171.236]) by uls-op-cesaip02.wdc.com with ESMTP; 05 Jan 2018 08:26:51 -0800 From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, Christoph Hellwig , Ard Biesheuvel , Herbert Xu , linux-nvme@lists.infradead.org, Bart Van Assche Subject: [PATCH v4 1/5] lib/scatterlist: Introduce sgl_alloc() and sgl_free() Date: Fri, 5 Jan 2018 08:26:46 -0800 Message-Id: <20180105162650.31083-2-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180105162650.31083-1-bart.vanassche@wdc.com> References: <20180105162650.31083-1-bart.vanassche@wdc.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn --- include/linux/scatterlist.h | 10 +++++ lib/Kconfig | 4 ++ lib/scatterlist.c | 105 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 119 insertions(+) diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index b7c83254c566..b8a7c1d1dbe3 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -276,6 +276,16 @@ int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int n_pages, unsigned int offset, unsigned long size, gfp_t gfp_mask); +#ifdef CONFIG_SGL_ALLOC +struct scatterlist *sgl_alloc_order(unsigned long long length, + unsigned int order, bool chainable, + gfp_t gfp, unsigned int *nent_p); +struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp, + unsigned int *nent_p); +void sgl_free_order(struct scatterlist *sgl, int order); +void sgl_free(struct scatterlist *sgl); +#endif /* CONFIG_SGL_ALLOC */ + size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen, off_t skip, bool to_buffer); diff --git a/lib/Kconfig b/lib/Kconfig index c5e84fbcb30b..4dd5c11366f9 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -409,6 +409,10 @@ config HAS_DMA depends on !NO_DMA default y +config SGL_ALLOC + bool + default n + config DMA_NOOP_OPS bool depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT) diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 7c1c55f7daaa..9afc9b432083 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -474,6 +474,111 @@ int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, } EXPORT_SYMBOL(sg_alloc_table_from_pages); +#ifdef CONFIG_SGL_ALLOC + +/** + * sgl_alloc_order - allocate a scatterlist and its pages + * @length: Length in bytes of the scatterlist. Must be at least one + * @order: Second argument for alloc_pages() + * @chainable: Whether or not to allocate an extra element in the scatterlist + * for scatterlist chaining purposes + * @gfp: Memory allocation flags + * @nent_p: [out] Number of entries in the scatterlist that have pages + * + * Returns: A pointer to an initialized scatterlist or %NULL upon failure. + */ +struct scatterlist *sgl_alloc_order(unsigned long long length, + unsigned int order, bool chainable, + gfp_t gfp, unsigned int *nent_p) +{ + struct scatterlist *sgl, *sg; + struct page *page; + unsigned int nent, nalloc; + u32 elem_len; + + nent = round_up(length, PAGE_SIZE << order) >> (PAGE_SHIFT + order); + /* Check for integer overflow */ + if (length > (nent << (PAGE_SHIFT + order))) + return NULL; + nalloc = nent; + if (chainable) { + /* Check for integer overflow */ + if (nalloc + 1 < nalloc) + return NULL; + nalloc++; + } + sgl = kmalloc_array(nalloc, sizeof(struct scatterlist), + (gfp & ~GFP_DMA) | __GFP_ZERO); + if (!sgl) + return NULL; + + sg_init_table(sgl, nent); + sg = sgl; + while (length) { + elem_len = min_t(u64, length, PAGE_SIZE << order); + page = alloc_pages(gfp, order); + if (!page) { + sgl_free(sgl); + return NULL; + } + + sg_set_page(sg, page, elem_len, 0); + length -= elem_len; + sg = sg_next(sg); + } + WARN_ON_ONCE(sg); + if (nent_p) + *nent_p = nent; + return sgl; +} +EXPORT_SYMBOL(sgl_alloc_order); + +/** + * sgl_alloc - allocate a scatterlist and its pages + * @length: Length in bytes of the scatterlist + * @gfp: Memory allocation flags + * @nent_p: [out] Number of entries in the scatterlist + * + * Returns: A pointer to an initialized scatterlist or %NULL upon failure. + */ +struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp, + unsigned int *nent_p) +{ + return sgl_alloc_order(length, 0, false, gfp, nent_p); +} +EXPORT_SYMBOL(sgl_alloc); + +/** + * sgl_free_order - free a scatterlist and its pages + * @sgl: Scatterlist with one or more elements + * @order: Second argument for __free_pages() + */ +void sgl_free_order(struct scatterlist *sgl, int order) +{ + struct scatterlist *sg; + struct page *page; + + for (sg = sgl; sg; sg = sg_next(sg)) { + page = sg_page(sg); + if (page) + __free_pages(page, order); + } + kfree(sgl); +} +EXPORT_SYMBOL(sgl_free_order); + +/** + * sgl_free - free a scatterlist and its pages + * @sgl: Scatterlist with one or more elements + */ +void sgl_free(struct scatterlist *sgl) +{ + sgl_free_order(sgl, 0); +} +EXPORT_SYMBOL(sgl_free); + +#endif /* CONFIG_SGL_ALLOC */ + void __sg_page_iter_start(struct sg_page_iter *piter, struct scatterlist *sglist, unsigned int nents, unsigned long pgoffset)