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| author | Philip J Kelleher <pjk1939@linux.vnet.ibm.com> | 2013-10-18 17:11:46 -0500 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-11-08 09:10:29 -0700 |
| commit | e35f38bf73b6c9ec9521d9deb94198a419692db5 (patch) | |
| tree | 4ecd863d83eeb7e9752312f8757f5c6e03f4ea06 /drivers/block/rsxx/dma.c | |
| parent | 35f47ef1a1f069cd2f346314fb8212bb49571eac (diff) | |
| download | linux-e35f38bf73b6c9ec9521d9deb94198a419692db5.tar.gz linux-e35f38bf73b6c9ec9521d9deb94198a419692db5.tar.bz2 linux-e35f38bf73b6c9ec9521d9deb94198a419692db5.zip | |
rsxx: Disallow discards from being unmapped.
This patch fixes a bug in which discards were always
calling pci_unmap_page. Discards should never call the
pci_unmap_page function call because they are never mapped.
This caused a race condition on PowerPC systems when issuing
discards, writes, and reads all at the same time. The
pci_map_page function would eventually map logical address
0 for a read or write. Discards are always assigned a DMA
address of 0 because they are never mapped. So if
pci_map_page mapped address 0 for a DMA and a discard was
"unmapped" then the address would be freed and would cause
an EEH event to occur when Hardware accesses the address.
This was injected/uncovered in commit:
b347f9cf0bc8d42ee95ba1d3837fd93045ab336b
The pci_dma_mapping_error function declares -1 a DMA_ERROR
not 0 like initially thought So before we would never unmap
discards because they were considered NULL.
This patch should fall on top of commit id:
fc1967bb08a6184ed44ef990e1dd4389901b809c
Also, the driver version is being up dated.
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 | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/drivers/block/rsxx/dma.c b/drivers/block/rsxx/dma.c index 4103601ae675..fc88ba3e1bd2 100644 --- a/drivers/block/rsxx/dma.c +++ b/drivers/block/rsxx/dma.c @@ -223,12 +223,14 @@ static void dma_intr_coal_auto_tune(struct rsxx_cardinfo *card) /*----------------- RSXX DMA Handling -------------------*/ static void rsxx_free_dma(struct rsxx_dma_ctrl *ctrl, struct rsxx_dma *dma) { - if (!pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) { - pci_unmap_page(ctrl->card->dev, dma->dma_addr, - get_dma_size(dma), - dma->cmd == HW_CMD_BLK_WRITE ? - PCI_DMA_TODEVICE : - PCI_DMA_FROMDEVICE); + if (dma->cmd != HW_CMD_BLK_DISCARD) { + if (!pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) { + pci_unmap_page(ctrl->card->dev, dma->dma_addr, + get_dma_size(dma), + dma->cmd == HW_CMD_BLK_WRITE ? + PCI_DMA_TODEVICE : + PCI_DMA_FROMDEVICE); + } } kmem_cache_free(rsxx_dma_pool, dma); @@ -1057,11 +1059,14 @@ 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); + if (dma->cmd != HW_CMD_BLK_DISCARD) { + 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++; |