From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id ED64A21D4919D for ; Mon, 31 Jul 2017 15:22:26 -0700 (PDT) Subject: [PATCH 3/5] dmaengine: add SG support to dmaengine_unmap From: Dave Jiang Date: Mon, 31 Jul 2017 15:24:35 -0700 Message-ID: <150153987513.49768.17123101509082248111.stgit@djiang5-desk3.ch.intel.com> In-Reply-To: <150153948477.49768.5767882242140065474.stgit@djiang5-desk3.ch.intel.com> References: <150153948477.49768.5767882242140065474.stgit@djiang5-desk3.ch.intel.com> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: vinod.koul@intel.com, dan.j.williams@intel.com Cc: dmaengine@vger.kernel.org, linux-nvdimm@lists.01.org List-ID: This should provide support to unmap scatterlist with the dmaengine_unmap_data. We will support only 1 scatterlist per direction. The DMA addresses array has been overloaded for the 2 or less entries DMA unmap data structure in order to store the SG pointer(s). Signed-off-by: Dave Jiang --- drivers/dma/dmaengine.c | 45 ++++++++++++++++++++++++++++++++++++--------- include/linux/dmaengine.h | 4 ++++ 2 files changed, 40 insertions(+), 9 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index d9118ec..81d10c97 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -1126,16 +1126,35 @@ static void dmaengine_unmap(struct kref *kref) { struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref); struct device *dev = unmap->dev; - int cnt, i; + int cnt, i, sg_nents; + struct scatterlist *sg; + + sg_nents = dma_unmap_data_sg_to_nents(unmap, unmap->map_cnt); + if (sg_nents) { + i = 0; + cnt = 1; + sg = (struct scatterlist *)unmap->addr[i]; + dma_unmap_sg(dev, sg, sg_nents, DMA_TO_DEVICE); + } else { + cnt = unmap->to_cnt; + for (i = 0; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_TO_DEVICE); + } + + sg_nents = dma_unmap_data_sg_from_nents(unmap, unmap->map_cnt); + if (sg_nents) { + sg = (struct scatterlist *)unmap->addr[i]; + dma_unmap_sg(dev, sg, sg_nents, DMA_FROM_DEVICE); + cnt++; + i++; + } else { + cnt += unmap->from_cnt; + for (; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_FROM_DEVICE); + } - cnt = unmap->to_cnt; - for (i = 0; i < cnt; i++) - dma_unmap_page(dev, unmap->addr[i], unmap->len, - DMA_TO_DEVICE); - cnt += unmap->from_cnt; - for (; i < cnt; i++) - dma_unmap_page(dev, unmap->addr[i], unmap->len, - DMA_FROM_DEVICE); cnt += unmap->bidi_cnt; for (; i < cnt; i++) { if (unmap->addr[i] == 0) @@ -1179,6 +1198,10 @@ static int __init dmaengine_init_unmap_pool(void) size = sizeof(struct dmaengine_unmap_data) + sizeof(dma_addr_t) * p->size; + /* add 2 more entries for SG nents overload */ + if (i == 0) + size += sizeof(dma_addr_t) * 2; + p->cache = kmem_cache_create(p->name, size, 0, SLAB_HWCACHE_ALIGN, NULL); if (!p->cache) @@ -1205,6 +1228,10 @@ dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags) return NULL; memset(unmap, 0, sizeof(*unmap)); + /* clear the overloaded sg nents entries */ + if (nr < 3) + memset(&unmap->addr[nr], 0, + DMA_UNMAP_SG_ENTS * sizeof(dma_addr_t)); kref_init(&unmap->kref); unmap->dev = dev; unmap->map_cnt = nr; diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 6202e7c..ec65b9b 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -475,6 +475,10 @@ struct dmaengine_unmap_data { dma_addr_t addr[0]; }; +#define DMA_UNMAP_SG_ENTS 2 +#define dma_unmap_data_sg_to_nents(x, n) x->addr[n] +#define dma_unmap_data_sg_from_nents(x, n) x->addr[n+1] + /** * struct dma_async_tx_descriptor - async transaction descriptor * ---dma generic offload fields--- _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm