s390/pci: handle insufficient resources during dma tlb flush
In a virtualized setup lazy flushing can lead to the hypervisor
running out of resources when lots of guest pages need to be
pinned. In this situation simply trigger a global flush to give
the hypervisor a chance to free some of these resources.
Signed-off-by: Sebastian Ott <[email protected]>
Reviewed-by: Gerald Schaefer <[email protected]>
Reviewed-by: Pierre Morel <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index f7aa5a7..2d15d84 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -181,6 +181,9 @@ static int __dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
size_t size, int flags)
{
+ unsigned long irqflags;
+ int ret;
+
/*
* With zdev->tlb_refresh == 0, rpcit is not required to establish new
* translations when previously invalid translation-table entries are
@@ -196,8 +199,22 @@ static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
return 0;
}
- return zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
- PAGE_ALIGN(size));
+ ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
+ PAGE_ALIGN(size));
+ if (ret == -ENOMEM && !s390_iommu_strict) {
+ /* enable the hypervisor to free some resources */
+ if (zpci_refresh_global(zdev))
+ goto out;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags);
+ bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
+ zdev->lazy_bitmap, zdev->iommu_pages);
+ bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags);
+ ret = 0;
+ }
+out:
+ return ret;
}
static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
