Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754062Ab3H0W7f (ORCPT ); Tue, 27 Aug 2013 18:59:35 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:59789 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141Ab3H0W7e (ORCPT ); Tue, 27 Aug 2013 18:59:34 -0400 Date: Tue, 27 Aug 2013 17:59:24 -0500 From: "Philip J. Kelleher" To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, brking@linux.vnet.ibm.com Subject: [PATCH v2 2/2] rsxx: Moving pci_map_page to prevent overflow Message-ID: <20130827225924.GC7368@oc6784271780.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-12-10) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13082722-5518-0000-0000-0000118075FF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5305 Lines: 154 From: Philip J Kelleher The pci_map_page function has been moved into our issued workqueue to prevent an us running out of mappable addresses on non-HWWD PCIe x8 slots. The maximum amount that can possible be mapped at one time now is: 255 dmas X 4 dma channels X 4096 Bytes. Signed-off-by: Philip J Kelleher ------------------------------------------------------------------------------- diff -uprN -X linux-block-vanilla/Documentation/dontdiff linux-block-vanilla/drivers/block/rsxx/core.c linux-block/drivers/block/rsxx/core.c --- linux-block-vanilla/drivers/block/rsxx/core.c 2013-08-12 15:22:18.608859980 -0500 +++ linux-block/drivers/block/rsxx/core.c 2013-08-12 15:23:14.508859632 -0500 @@ -749,10 +749,6 @@ static pci_ers_result_t rsxx_slot_reset( card->eeh_state = 0; - st = rsxx_eeh_remap_dmas(card); - if (st) - goto failed_remap_dmas; - spin_lock_irqsave(&card->irq_lock, flags); if (card->n_targets & RSXX_MAX_TARGETS) rsxx_enable_ier_and_isr(card, CR_INTR_ALL_G); @@ -779,7 +775,6 @@ static pci_ers_result_t rsxx_slot_reset( return PCI_ERS_RESULT_RECOVERED; failed_hw_buffers_init: -failed_remap_dmas: for (i = 0; i < card->n_targets; i++) { if (card->ctrl[i].status.buf) pci_free_consistent(card->dev, diff -uprN -X linux-block-vanilla/Documentation/dontdiff linux-block-vanilla/drivers/block/rsxx/dma.c linux-block/drivers/block/rsxx/dma.c --- linux-block-vanilla/drivers/block/rsxx/dma.c 2013-08-12 15:22:18.612863489 -0500 +++ linux-block/drivers/block/rsxx/dma.c 2013-08-12 15:23:22.158858765 -0500 @@ -397,6 +397,7 @@ static void rsxx_issue_dmas(struct rsxx_ int tag; int cmds_pending = 0; struct hw_cmd *hw_cmd_buf; + int dir; hw_cmd_buf = ctrl->cmd.buf; @@ -433,6 +434,27 @@ static void rsxx_issue_dmas(struct rsxx_ continue; } + if (dma->cmd == HW_CMD_BLK_WRITE) + dir = PCI_DMA_TODEVICE; + else + dir = PCI_DMA_FROMDEVICE; + + /* + * The function pci_map_page is placed here because we can + * only, by design, issue up to 255 commands to the hardware + * at one time per DMA channel. So the maximum amount of mapped + * memory would be 255 * 4 channels * 4096 Bytes which is less + * than 2GB, the limit of a x8 Non-HWWD PCIe slot. This way the + * pci_map_page function should never fail because of a + * lack of mappable memory. + */ + dma->dma_addr = pci_map_page(ctrl->card->dev, dma->page, + dma->pg_off, dma->sub_page.cnt << 9, dir); + if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) { + kmem_cache_free(rsxx_dma_pool, dma); + return; + } + set_tracker_dma(ctrl->trackers, tag, dma); hw_cmd_buf[ctrl->cmd.idx].command = dma->cmd; hw_cmd_buf[ctrl->cmd.idx].tag = tag; @@ -629,14 +651,6 @@ static int rsxx_queue_dma(struct rsxx_ca if (!dma) return -ENOMEM; - dma->dma_addr = pci_map_page(card->dev, page, pg_off, dma_len, - dir ? PCI_DMA_TODEVICE : - PCI_DMA_FROMDEVICE); - if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) { - kmem_cache_free(rsxx_dma_pool, dma); - return -ENOMEM; - } - dma->cmd = dir ? HW_CMD_BLK_WRITE : HW_CMD_BLK_READ; dma->laddr = laddr; dma->sub_page.off = (dma_off >> 9); @@ -1039,6 +1053,11 @@ int rsxx_eeh_save_issued_dmas(struct rsx else card->ctrl[i].stats.reads_issued--; + pci_unmap_page(card->dev, dma->dma_addr, + get_dma_size(dma), + dma->cmd == HW_CMD_BLK_WRITE ? + PCI_DMA_TODEVICE : + PCI_DMA_FROMDEVICE); list_add_tail(&dma->list, &issued_dmas[i]); push_tracker(card->ctrl[i].trackers, j); cnt++; @@ -1050,15 +1069,6 @@ int rsxx_eeh_save_issued_dmas(struct rsx atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth); card->ctrl[i].stats.sw_q_depth += cnt; card->ctrl[i].e_cnt = 0; - - list_for_each_entry(dma, &card->ctrl[i].queue, list) { - if (!pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) - pci_unmap_page(card->dev, dma->dma_addr, - get_dma_size(dma), - dma->cmd == HW_CMD_BLK_WRITE ? - PCI_DMA_TODEVICE : - PCI_DMA_FROMDEVICE); - } spin_unlock_bh(&card->ctrl[i].queue_lock); } @@ -1067,31 +1077,6 @@ int rsxx_eeh_save_issued_dmas(struct rsx return 0; } -int rsxx_eeh_remap_dmas(struct rsxx_cardinfo *card) -{ - struct rsxx_dma *dma; - int i; - - for (i = 0; i < card->n_targets; i++) { - spin_lock_bh(&card->ctrl[i].queue_lock); - list_for_each_entry(dma, &card->ctrl[i].queue, list) { - dma->dma_addr = pci_map_page(card->dev, dma->page, - dma->pg_off, get_dma_size(dma), - dma->cmd == HW_CMD_BLK_WRITE ? - PCI_DMA_TODEVICE : - PCI_DMA_FROMDEVICE); - if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) { - spin_unlock_bh(&card->ctrl[i].queue_lock); - kmem_cache_free(rsxx_dma_pool, dma); - return -ENOMEM; - } - } - spin_unlock_bh(&card->ctrl[i].queue_lock); - } - - return 0; -} - int rsxx_dma_init(void) { rsxx_dma_pool = KMEM_CACHE(rsxx_dma, SLAB_HWCACHE_ALIGN); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/