powerpc/iommu: Incorrect DDW Table is referenced for SR-IOV device
For an SR-IOV device, while enabling DDW, a new table is created and
added at index 1 in the group. In the below 2 scenarios, the table is
incorrectly referenced at index 0 (which is where the table is for
default DMA window).
1. When adding DDW
This issue is exposed with "slub_debug". Error thrown out from
dma_iommu_dma_supported()
Warning: IOMMU offset too big for device mask
mask: 0xffffffff, table offset: 0x800000000000000
2. During Dynamic removal of the PCI device.
Error is from iommu_tce_table_put() since a NULL table pointer is
passed in.
Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Gaurav Batra <gbatra@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230505184701.91613-1-gbatra@linux.vnet.ibm.com
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 038ce8d..8920862 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -144,7 +144,7 @@
/* We support DMA to/from any memory page via the iommu */
int dma_iommu_dma_supported(struct device *dev, u64 mask)
{
- struct iommu_table *tbl = get_iommu_table_base(dev);
+ struct iommu_table *tbl;
if (dev_is_pci(dev) && dma_iommu_bypass_supported(dev, mask)) {
/*
@@ -162,6 +162,8 @@
return 1;
}
+ tbl = get_iommu_table_base(dev);
+
if (!tbl) {
dev_err(dev, "Warning: IOMMU dma not supported: mask 0x%08llx, table unavailable\n", mask);
return 0;
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index e44d3c4..918f511 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -91,19 +91,24 @@
static void iommu_pseries_free_group(struct iommu_table_group *table_group,
const char *node_name)
{
- struct iommu_table *tbl;
-
if (!table_group)
return;
- tbl = table_group->tables[0];
#ifdef CONFIG_IOMMU_API
if (table_group->group) {
iommu_group_put(table_group->group);
BUG_ON(table_group->group);
}
#endif
- iommu_tce_table_put(tbl);
+
+ /* Default DMA window table is at index 0, while DDW at 1. SR-IOV
+ * adapters only have table on index 1.
+ */
+ if (table_group->tables[0])
+ iommu_tce_table_put(table_group->tables[0]);
+
+ if (table_group->tables[1])
+ iommu_tce_table_put(table_group->tables[1]);
kfree(table_group);
}
