From patchwork Tue Oct 20 10:38:59 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Or Gerlitz X-Patchwork-Id: 54923 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n9KAdAvb018565 for ; Tue, 20 Oct 2009 10:39:10 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750899AbZJTKjE (ORCPT ); Tue, 20 Oct 2009 06:39:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750996AbZJTKjE (ORCPT ); Tue, 20 Oct 2009 06:39:04 -0400 Received: from fwil.voltaire.com ([193.47.165.2]:38100 "EHLO exil.voltaire.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750899AbZJTKjC (ORCPT ); Tue, 20 Oct 2009 06:39:02 -0400 Received: from bitan-450980b21 ([172.25.5.15]) by exil.voltaire.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 20 Oct 2009 12:38:59 +0200 Date: Tue, 20 Oct 2009 12:38:59 +0200 (IST) From: Or Gerlitz To: Roland Dreier cc: linux-rdma , Mike Christie , Alexander Nezhinsky Subject: [PATCH] ib/iser: re-write SG handling for rdma logic Message-ID: MIME-Version: 1.0 X-OriginalArrivalTime: 20 Oct 2009 10:38:59.0104 (UTC) FILETIME=[88294200:01CA5171] Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Index: linux-2.6.32-rc5/drivers/infiniband/ulp/iser/iser_memory.c =================================================================== --- linux-2.6.32-rc5.orig/drivers/infiniband/ulp/iser/iser_memory.c +++ linux-2.6.32-rc5/drivers/infiniband/ulp/iser/iser_memory.c @@ -209,6 +209,8 @@ void iser_finalize_rdma_unaligned_sg(str mem_copy->copy_buf = NULL; } +#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0) + /** * iser_sg_to_page_vec - Translates scatterlist entries to physical addresses * and returns the length of resulting physical address array (may be less than @@ -221,62 +223,52 @@ void iser_finalize_rdma_unaligned_sg(str * where --few fragments of the same page-- are present in the SG as * consecutive elements. Also, it handles one entry SG. */ + static int iser_sg_to_page_vec(struct iser_data_buf *data, struct iser_page_vec *page_vec, struct ib_device *ibdev) { - struct scatterlist *sgl = (struct scatterlist *)data->buf; - struct scatterlist *sg; - u64 first_addr, last_addr, page; - int end_aligned; - unsigned int cur_page = 0; + struct scatterlist *sg, *sgl = (struct scatterlist *)data->buf; + u64 start_addr, end_addr, page, chunk_start = 0; unsigned long total_sz = 0; - int i; + unsigned int dma_len; + int i, new_chunk, cur_page, last_ent = data->dma_nents - 1; /* compute the offset of first element */ page_vec->offset = (u64) sgl[0].offset & ~MASK_4K; + new_chunk = 1; + cur_page = 0; for_each_sg(sgl, sg, data->dma_nents, i) { - unsigned int dma_len = ib_sg_dma_len(ibdev, sg); - + start_addr = ib_sg_dma_address(ibdev, sg); + if (new_chunk) + chunk_start = start_addr; + dma_len = ib_sg_dma_len(ibdev, sg); + end_addr = start_addr + dma_len; total_sz += dma_len; - first_addr = ib_sg_dma_address(ibdev, sg); - last_addr = first_addr + dma_len; - - end_aligned = !(last_addr & ~MASK_4K); - - /* continue to collect page fragments till aligned or SG ends */ - while (!end_aligned && (i + 1 < data->dma_nents)) { - sg = sg_next(sg); - i++; - dma_len = ib_sg_dma_len(ibdev, sg); - total_sz += dma_len; - last_addr = ib_sg_dma_address(ibdev, sg) + dma_len; - end_aligned = !(last_addr & ~MASK_4K); + /* collect page fragments until aligned or end of SG list */ + if (!IS_4K_ALIGNED(end_addr) && i < last_ent) { + new_chunk = 0; + continue; } + new_chunk = 1; - /* handle the 1st page in the 1st DMA element */ - if (cur_page == 0) { - page = first_addr & MASK_4K; - page_vec->pages[cur_page] = page; - cur_page++; + /* address of the first page in the contiguous chunk; + masking relevant for the very first SG entry, + which might be unaligned */ + page = chunk_start & MASK_4K; + do { + page_vec->pages[cur_page++] = page; page += SIZE_4K; - } else - page = first_addr; - - for (; page < last_addr; page += SIZE_4K) { - page_vec->pages[cur_page] = page; - cur_page++; - } - + } while (page < end_addr); } + page_vec->data_size = total_sz; iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page); return cur_page; } -#define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0) /** * iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned @@ -284,42 +276,40 @@ static int iser_sg_to_page_vec(struct is * the number of entries which are aligned correctly. Supports the case where * consecutive SG elements are actually fragments of the same physcial page. */ -static unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data, - struct ib_device *ibdev) +static int iser_data_buf_aligned_len(struct iser_data_buf *data, + struct ib_device *ibdev) { - struct scatterlist *sgl, *sg; - u64 end_addr, next_addr; - int i, cnt; - unsigned int ret_len = 0; + struct scatterlist *sgl, *sg, *next_sg = NULL; + u64 start_addr, end_addr; + int i, ret_len, start_check = 0; + + if (data->dma_nents == 1) + return 1; sgl = (struct scatterlist *)data->buf; + start_addr = ib_sg_dma_address(ibdev, sgl); - cnt = 0; for_each_sg(sgl, sg, data->dma_nents, i) { - /* iser_dbg("Checking sg iobuf [%d]: phys=0x%08lX " - "offset: %ld sz: %ld\n", i, - (unsigned long)sg_phys(sg), - (unsigned long)sg->offset, - (unsigned long)sg->length); */ - end_addr = ib_sg_dma_address(ibdev, sg) + - ib_sg_dma_len(ibdev, sg); - /* iser_dbg("Checking sg iobuf end address " - "0x%08lX\n", end_addr); */ - if (i + 1 < data->dma_nents) { - next_addr = ib_sg_dma_address(ibdev, sg_next(sg)); - /* are i, i+1 fragments of the same page? */ - if (end_addr == next_addr) { - cnt++; - continue; - } else if (!IS_4K_ALIGNED(end_addr)) { - ret_len = cnt + 1; - break; - } - } - cnt++; + if (start_check && !IS_4K_ALIGNED(start_addr)) + break; + + next_sg = sg_next(sg); + if (!next_sg) + break; + + end_addr = start_addr + ib_sg_dma_len(ibdev, sg); + start_addr = ib_sg_dma_address(ibdev, next_sg); + + if (end_addr == start_addr) { + start_check = 0; + continue; + } else + start_check = 1; + + if (!IS_4K_ALIGNED(end_addr)) + break; } - if (i == data->dma_nents) - ret_len = cnt; /* loop ended */ + ret_len = (next_sg) ? i : i+1; iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n", ret_len, data->dma_nents, data); return ret_len;