diff mbox series

[kernel,3/4] powerpc/pseries/iommu: Check if the default window in use before removing it

Message ID 20211020132315.2287178-4-aik@ozlabs.ru (mailing list archive)
State Accepted
Headers show
Series Fixes for powerpc/pseries/iommu: Make use of DDW for indirect mapping | expand

Commit Message

Alexey Kardashevskiy Oct. 20, 2021, 1:23 p.m. UTC
At the moment this check is performed after we remove the default window
which is late and disallows to revert whatever changes enable_ddw()
has made to DMA windows.

This moves the check and error exit before removing the window.

This raised the message severity from "debug" to "warning" as this
should not happen in practice and cannot be triggered by the userspace.

Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/platforms/pseries/iommu.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 45564547cd80..9bbcfdece9e3 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1302,6 +1302,12 @@  static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 		struct property *default_win;
 		int reset_win_ext;
 
+		/* DDW + IOMMU on single window may fail if there is any allocation */
+		if (iommu_table_in_use(tbl)) {
+			dev_warn(&dev->dev, "current IOMMU table in use, can't be replaced.\n");
+			goto out_failed;
+		}
+
 		default_win = of_find_property(pdn, "ibm,dma-window", NULL);
 		if (!default_win)
 			goto out_failed;
@@ -1356,12 +1362,6 @@  static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 			query.largest_available_block,
 			1ULL << page_shift);
 
-		/* DDW + IOMMU on single window may fail if there is any allocation */
-		if (default_win_removed && iommu_table_in_use(tbl)) {
-			dev_dbg(&dev->dev, "current IOMMU table in use, can't be replaced.\n");
-			goto out_failed;
-		}
-
 		len = order_base_2(query.largest_available_block << page_shift);
 		win_name = DMA64_PROPNAME;
 	} else {