From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: [PATCH 2/8] ioat3: dca and raid operations are incompatible Date: Fri, 20 Nov 2009 00:06:24 -0700 Message-ID: <20091120070624.13478.24768.stgit@dwillia2-linux.ch.intel.com> References: <20091120070506.13478.77838.stgit@dwillia2-linux.ch.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091120070506.13478.77838.stgit@dwillia2-linux.ch.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org, maciej.sosnowski@intel.com List-Id: linux-raid.ids RAID operations cause a system hang on platforms with DCA (Direct-Cache-Access) enabled. So turn off RAID capabilities in this case. Signed-off-by: Dan Williams --- drivers/dma/ioat/dca.c | 2 +- drivers/dma/ioat/dma_v3.c | 6 ++++++ drivers/dma/ioat/hw.h | 2 ++ 3 files changed, 9 insertions(+), 1 deletions(-) diff --git a/drivers/dma/ioat/dca.c b/drivers/dma/ioat/dca.c index 14f0a78..abd9038 100644 --- a/drivers/dma/ioat/dca.c +++ b/drivers/dma/ioat/dca.c @@ -103,7 +103,7 @@ static int dca_enabled_in_bios(struct pci_dev *pdev) return res; } -static int system_has_dca_enabled(struct pci_dev *pdev) +int system_has_dca_enabled(struct pci_dev *pdev) { if (boot_cpu_has(X86_FEATURE_DCA)) return dca_enabled_in_bios(pdev); diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c index 35d1e33..4f305f6 100644 --- a/drivers/dma/ioat/dma_v3.c +++ b/drivers/dma/ioat/dma_v3.c @@ -1117,6 +1117,7 @@ static int __devinit ioat3_dma_self_test(struct ioatdma_device *device) int __devinit ioat3_dma_probe(struct ioatdma_device *device, int dca) { struct pci_dev *pdev = device->pdev; + int dca_en = system_has_dca_enabled(pdev); struct dma_device *dma; struct dma_chan *c; struct ioat_chan_common *chan; @@ -1137,6 +1138,11 @@ int __devinit ioat3_dma_probe(struct ioatdma_device *device, int dca) dma->device_prep_dma_interrupt = ioat3_prep_interrupt_lock; cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET); + + /* dca is incompatible with raid operations */ + if (dca_en && (cap & (IOAT_CAP_XOR|IOAT_CAP_PQ))) + cap &= ~(IOAT_CAP_XOR|IOAT_CAP_PQ); + if (cap & IOAT_CAP_XOR) { is_raid_device = true; dma->max_xor = 8; diff --git a/drivers/dma/ioat/hw.h b/drivers/dma/ioat/hw.h index 99afb12..60e6754 100644 --- a/drivers/dma/ioat/hw.h +++ b/drivers/dma/ioat/hw.h @@ -39,6 +39,8 @@ #define IOAT_VER_3_0 0x30 /* Version 3.0 */ #define IOAT_VER_3_2 0x32 /* Version 3.2 */ +int system_has_dca_enabled(struct pci_dev *pdev); + struct ioat_dma_descriptor { uint32_t size; union {