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Diffstat (limited to 'arch/powerpc/platforms/pseries/iommu.c')
-rw-r--r--arch/powerpc/platforms/pseries/iommu.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 1b2a174e7c59..86ae364900d6 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -924,6 +924,13 @@ static void restore_default_window(struct pci_dev *dev,
__restore_default_window(pci_dev_to_eeh_dev(dev), ddw_restore_token);
}
+struct failed_ddw_pdn {
+ struct device_node *pdn;
+ struct list_head list;
+};
+
+static LIST_HEAD(failed_ddw_pdn_list);
+
/*
* If the PE supports dynamic dma windows, and there is space for a table
* that can map all pages in a linear offset, then setup such a table,
@@ -951,6 +958,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
struct dynamic_dma_window_prop *ddwprop;
const void *dma_window = NULL;
unsigned long liobn, offset, size;
+ struct failed_ddw_pdn *fpdn;
mutex_lock(&direct_window_init_mutex);
@@ -959,6 +967,18 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
goto out_unlock;
/*
+ * If we already went through this for a previous function of
+ * the same device and failed, we don't want to muck with the
+ * DMA window again, as it will race with in-flight operations
+ * and can lead to EEHs. The above mutex protects access to the
+ * list.
+ */
+ list_for_each_entry(fpdn, &failed_ddw_pdn_list, list) {
+ if (!strcmp(fpdn->pdn->full_name, pdn->full_name))
+ goto out_unlock;
+ }
+
+ /*
* the ibm,ddw-applicable property holds the tokens for:
* ibm,query-pe-dma-window
* ibm,create-pe-dma-window
@@ -1114,6 +1134,12 @@ out_restore_window:
if (ddw_restore_token)
restore_default_window(dev, ddw_restore_token);
+ fpdn = kzalloc(sizeof(*fpdn), GFP_KERNEL);
+ if (!fpdn)
+ goto out_unlock;
+ fpdn->pdn = pdn;
+ list_add(&fpdn->list, &failed_ddw_pdn_list);
+
out_unlock:
mutex_unlock(&direct_window_init_mutex);
return dma_addr;