From: Gaurav Batra <gbatra@linux.vnet.ibm.com>

Date: Fri, 5 May 2023 13:47:01 -0500

Subject: [PATCH] powerpc/iommu: Incorrect DDW Table is referenced for SR-IOV

 device

References: bsc#1012628

Patch-mainline: 6.3.4

Git-commit: 1f7aacc5eb9ed2cc17be7a90da5cd559effb9d59

commit 1f7aacc5eb9ed2cc17be7a90da5cd559effb9d59 upstream.

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

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 arch/powerpc/kernel/dma-iommu.c        |  4 +++-

 arch/powerpc/platforms/pseries/iommu.c | 13 +++++++++----

 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c

index 038ce8d9..8920862f 100644

--- a/arch/powerpc/kernel/dma-iommu.c

+++ b/arch/powerpc/kernel/dma-iommu.c

@@ -144,7 +144,7 @@ static bool dma_iommu_bypass_supported(struct device *dev, u64 mask)

 /* 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 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask)

 		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 c74b71d4..a8acd3b4 100644

--- a/arch/powerpc/platforms/pseries/iommu.c

+++ b/arch/powerpc/platforms/pseries/iommu.c

@@ -85,19 +85,24 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)

 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);

 }

-- 

2.35.3