[PATCH 2/8] ioat3: dca and raid operations are incompatible
From: Dan Williams <hidden>
Date: 2009-11-20 07:08:06
Also in:
lkml
Subsystem:
dma generic offload engine subsystem, intel i/oat dma driver, the rest · Maintainers:
Vinod Koul, Dave Jiang, Linus Torvalds
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 <redacted> --- 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 {