s390/pci_dma: handle dma table failures
We use lazy allocation for translation table entries but don't handle
allocation (and other) failures during translation table updates.
Handle these failures and undo translation table updates when it's
meaningful.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index cbe198c..471ee36b 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -216,6 +216,7 @@
u8 *page_addr = (u8 *) (pa & PAGE_MASK);
dma_addr_t start_dma_addr = dma_addr;
unsigned long irq_flags, nr_pages, i;
+ unsigned long *entry;
int rc = 0;
if (dma_addr < s390_domain->domain.geometry.aperture_start ||
@@ -228,8 +229,12 @@
spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags);
for (i = 0; i < nr_pages; i++) {
- dma_update_cpu_trans(s390_domain->dma_table, page_addr,
- dma_addr, flags);
+ entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr);
+ if (!entry) {
+ rc = -ENOMEM;
+ goto undo_cpu_trans;
+ }
+ dma_update_cpu_trans(entry, page_addr, flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
@@ -242,6 +247,20 @@
break;
}
spin_unlock(&s390_domain->list_lock);
+
+undo_cpu_trans:
+ if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
+ flags = ZPCI_PTE_INVALID;
+ while (i-- > 0) {
+ page_addr -= PAGE_SIZE;
+ dma_addr -= PAGE_SIZE;
+ entry = dma_walk_cpu_trans(s390_domain->dma_table,
+ dma_addr);
+ if (!entry)
+ break;
+ dma_update_cpu_trans(entry, page_addr, flags);
+ }
+ }
spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags);
return rc;