diff options
author | Philip J Kelleher <pjk1939@linux.vnet.ibm.com> | 2013-09-04 18:59:35 (GMT) |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2013-11-08 16:10:28 (GMT) |
commit | 1b21f5b2ad6047995b19b15024353a9fa64810f1 (patch) | |
tree | e0ecbc01dfe685322485b801540bd7a289283378 /drivers/block/rsxx/dma.c | |
parent | e5feab229f199dadee91073fbef5b507046086fd (diff) | |
download | linux-1b21f5b2ad6047995b19b15024353a9fa64810f1.tar.xz |
rsxx: Moving pci_map_page to prevent overflow.
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 <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/rsxx/dma.c')
-rw-r--r-- | drivers/block/rsxx/dma.c | 70 |
1 files changed, 28 insertions, 42 deletions
diff --git a/drivers/block/rsxx/dma.c b/drivers/block/rsxx/dma.c index 71d1ca2..34fd101 100644 --- a/drivers/block/rsxx/dma.c +++ b/drivers/block/rsxx/dma.c @@ -397,6 +397,7 @@ static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl) int tag; int cmds_pending = 0; struct hw_cmd *hw_cmd_buf; + int dir; hw_cmd_buf = ctrl->cmd.buf; @@ -433,6 +434,28 @@ static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl) 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)) { + push_tracker(ctrl->trackers, tag); + rsxx_complete_dma(ctrl, dma, DMA_CANCELLED); + continue; + } + 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 +652,6 @@ static int rsxx_queue_dma(struct rsxx_cardinfo *card, 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(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 +1054,11 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card) 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 +1070,6 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card) 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(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 +1078,6 @@ int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card) 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(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); |