2013-03-25 08:21:42

by Li, ZhenHua

Subject: [PATCH 1/1] iommu: dmar_fault should only clear PPF/PFO field.

When there is a dmar irq, dmar_fault is called and all of the fields
in FSTS are cleared. But ICE/IQE/ITE should not be cleared here,
they need to be processed and cleared in function qi_check_fault.

Signed-off-by: Li, Zhen-Hua <[email protected]>
---
drivers/iommu/dmar.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index e5cdaf8..d620117 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1204,7 +1204,7 @@ irqreturn_t dmar_fault(int irq, void *dev_id)

/* TBD: ignore advanced fault log currently */
if (!(fault_status & DMA_FSTS_PPF))
- goto clear_rest;
+ goto unlock_exit;

fault_index = dma_fsts_fault_record_index(fault_status);
reg = cap_fault_reg_offset(iommu->cap);
@@ -1245,11 +1245,12 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
fault_index = 0;
raw_spin_lock_irqsave(&iommu->register_lock, flag);
}
-clear_rest:
- /* clear all the other faults */
- fault_status = readl(iommu->reg + DMAR_FSTS_REG);
- writel(fault_status, iommu->reg + DMAR_FSTS_REG);

+ writel(DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);
+ if (fault_status & DMA_FSTS_PFO)
+ writel(DMA_FSTS_PFO, iommu->reg + DMAR_FSTS_REG);
+
+unlock_exit:
raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
return IRQ_HANDLED;
}
@@ -1297,6 +1298,7 @@ int __init enable_drhd_fault_handling(void)
for_each_drhd_unit(drhd) {
int ret;
struct intel_iommu *iommu = drhd->iommu;
+ u32 fault_status;
ret = dmar_set_interrupt(iommu);

if (ret) {
@@ -1309,6 +1311,8 @@ int __init enable_drhd_fault_handling(void)
* Clear any previous faults.
*/
dmar_fault(iommu->irq, iommu);
+ fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+ writel(fault_status, iommu->reg + DMAR_FSTS_REG);
}

return 0;
--
1.7.10.4

2013-03-26 15:03:18

by Joerg Roedel

Subject: Re: [PATCH 1/1] iommu: dmar_fault should only clear PPF/PFO field.

On Mon, Mar 25, 2013 at 04:20:52PM +0800, Li, Zhen-Hua wrote:
> + writel(DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);
> + if (fault_status & DMA_FSTS_PFO)
> + writel(DMA_FSTS_PFO, iommu->reg + DMAR_FSTS_REG);

Changes this to:

writel(DMA_FSTS_PFO | DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);

and applied the patch to iommu/vt-d, thanks.


Joerg