IOMMU Fixes for Linux v4.12-rc4

Including:
 
 	* Another compile-fix for my header cleanup
 
 	* A couple of fixes for the recently merged IOMMU probe
 	  deferal code
 
 	* Includes fixes for ACPI/IORT code necessary with
 	  IOMMU probe deferal
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Merge tag 'iommu-fixes-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU fixes from Joerg Roedel:

 - another compile-fix for my header cleanup

 - a couple of fixes for the recently merged IOMMU probe deferal code

 - fixes for ACPI/IORT code necessary with IOMMU probe deferal

* tag 'iommu-fixes-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  arm: dma-mapping: Reset the device's dma_ops
  ACPI/IORT: Move the check to get iommu_ops from translated fwspec
  ARM: dma-mapping: Don't tear down third-party mappings
  ACPI/IORT: Ignore all errors except EPROBE_DEFER
  iommu/of: Ignore all errors except EPROBE_DEFER
  iommu/of: Fix check for returning EPROBE_DEFER
  iommu/dma: Fix function declaration

arch/arm/include/asm/device.h

@@ -19,7 +19,8 @@ struct dev_archdata {
 #ifdef CONFIG_XEN
 	const struct dma_map_ops *dev_dma_ops;
 #endif
-	bool dma_coherent;
+	unsigned int dma_coherent:1;
+	unsigned int dma_ops_setup:1;
 };
 
 struct omap_device;

arch/arm/mm/dma-mapping.c

@@ -2311,7 +2311,14 @@ int arm_iommu_attach_device(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
 
-static void __arm_iommu_detach_device(struct device *dev)
+/**
+ * arm_iommu_detach_device
+ * @dev: valid struct device pointer
+ *
+ * Detaches the provided device from a previously attached map.
+ * This voids the dma operations (dma_map_ops pointer)
+ */
+void arm_iommu_detach_device(struct device *dev)
 {
 	struct dma_iommu_mapping *mapping;
 
@@ -2324,22 +2331,10 @@ static void __arm_iommu_detach_device(struct device *dev)
 	iommu_detach_device(mapping->domain, dev);
 	kref_put(&mapping->kref, release_iommu_mapping);
 	to_dma_iommu_mapping(dev) = NULL;
+	set_dma_ops(dev, NULL);
 
 	pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
 }
-
-/**
- * arm_iommu_detach_device
- * @dev: valid struct device pointer
- *
- * Detaches the provided device from a previously attached map.
- * This voids the dma operations (dma_map_ops pointer)
- */
-void arm_iommu_detach_device(struct device *dev)
-{
-	__arm_iommu_detach_device(dev);
-	set_dma_ops(dev, NULL);
-}
 EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
 
 static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
@@ -2379,7 +2374,7 @@ static void arm_teardown_iommu_dma_ops(struct device *dev)
 	if (!mapping)
 		return;
 
-	__arm_iommu_detach_device(dev);
+	arm_iommu_detach_device(dev);
 	arm_iommu_release_mapping(mapping);
 }
 
@@ -2430,9 +2425,13 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 		dev->dma_ops = xen_dma_ops;
 	}
 #endif
+	dev->archdata.dma_ops_setup = true;
 }
 
 void arch_teardown_dma_ops(struct device *dev)
 {
+	if (!dev->archdata.dma_ops_setup)
+		return;
+
 	arm_teardown_iommu_dma_ops(dev);
 }

drivers/acpi/arm64/iort.c

@@ -666,14 +666,6 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
 	int ret = -ENODEV;
 	struct fwnode_handle *iort_fwnode;
 
-	/*
-	 * If we already translated the fwspec there
-	 * is nothing left to do, return the iommu_ops.
-	 */
-	ops = iort_fwspec_iommu_ops(dev->iommu_fwspec);
-	if (ops)
-		return ops;
-
 	if (node) {
 		iort_fwnode = iort_get_fwnode(node);
 		if (!iort_fwnode)
@@ -735,6 +727,14 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 	u32 streamid = 0;
 	int err;
 
+	/*
+	 * If we already translated the fwspec there
+	 * is nothing left to do, return the iommu_ops.
+	 */
+	ops = iort_fwspec_iommu_ops(dev->iommu_fwspec);
+	if (ops)
+		return ops;
+
 	if (dev_is_pci(dev)) {
 		struct pci_bus *bus = to_pci_dev(dev)->bus;
 		u32 rid;
@@ -782,6 +782,12 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 	if (err)
 		ops = ERR_PTR(err);
 
+	/* Ignore all other errors apart from EPROBE_DEFER */
+	if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) {
+		dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops));
+		ops = NULL;
+	}
+
 	return ops;
 }
 

drivers/acpi/scan.c

@@ -1371,8 +1371,8 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
 	iort_set_dma_mask(dev);
 
 	iommu = iort_iommu_configure(dev);
-	if (IS_ERR(iommu))
+	if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
-		return PTR_ERR(iommu);
+		return -EPROBE_DEFER;
 
 	size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 	/*

drivers/iommu/of_iommu.c

@@ -118,6 +118,7 @@ static const struct iommu_ops
 
 	ops = iommu_ops_from_fwnode(fwnode);
 	if ((ops && !ops->of_xlate) ||
+	    !of_device_is_available(iommu_spec->np) ||
 	    (!ops && !of_iommu_driver_present(iommu_spec->np)))
 		return NULL;
 
@@ -236,6 +237,12 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 			ops = ERR_PTR(err);
 	}
 
+	/* Ignore all other errors apart from EPROBE_DEFER */
+	if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) {
+		dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops));
+		ops = NULL;
+	}
+
 	return ops;
 }
 

drivers/of/device.c

@@ -144,8 +144,8 @@ int of_dma_configure(struct device *dev, struct device_node *np)
 		coherent ? " " : " not ");
 
 	iommu = of_iommu_configure(dev, np);
-	if (IS_ERR(iommu))
+	if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
-		return PTR_ERR(iommu);
+		return -EPROBE_DEFER;
 
 	dev_dbg(dev, "device is%sbehind an iommu\n",
 		iommu ? " " : " not ");

include/linux/dma-iommu.h

@@ -78,6 +78,7 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
 struct iommu_domain;
 struct msi_msg;
+struct device;
 
 static inline int iommu_dma_init(void)
 {