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s390/pci_dma: handle dma table failures

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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>
This commit is contained in:
Sebastian Ott
2015-10-26 11:19:13 +01:00
committed by Martin Schwidefsky
parent 4d5a6b7295
commit 66728eeea6
3 changed files with 48 additions and 17 deletions
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23
drivers/iommu/s390-iommu.c
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@@ -216,6 +216,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
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 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
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 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
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;