From 2a0c57545a291f257cd231b1c4b18285b84608d8 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 10 Apr 2017 16:50:56 +0530 Subject: [PATCH] iommu/of: Refactor of_iommu_configure() for error handling In preparation for some upcoming cleverness, rework the control flow in of_iommu_configure() to minimise duplication and improve the propogation of errors. It's also as good a time as any to switch over from the now-just-a-compatibility-wrapper of_iommu_get_ops() to using the generic IOMMU instance interface directly. Tested-by: Marek Szyprowski Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel --- drivers/iommu/of_iommu.c | 83 +++++++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 30 deletions(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 2683e9fc0dcf..8f4e59985f6e 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -96,6 +96,28 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, } EXPORT_SYMBOL_GPL(of_get_dma_window); +static const struct iommu_ops +*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec) +{ + const struct iommu_ops *ops; + struct fwnode_handle *fwnode = &iommu_spec->np->fwnode; + int err; + + ops = iommu_ops_from_fwnode(fwnode); + if (!ops || !ops->of_xlate) + return NULL; + + err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); + if (err) + return ERR_PTR(err); + + err = ops->of_xlate(dev, iommu_spec); + if (err) + return ERR_PTR(err); + + return ops; +} + static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) { struct of_phandle_args *iommu_spec = data; @@ -105,10 +127,11 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) } static const struct iommu_ops -*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np) +*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np) { const struct iommu_ops *ops; struct of_phandle_args iommu_spec; + int err; /* * Start by tracing the RID alias down the PCI topology as @@ -123,56 +146,56 @@ static const struct iommu_ops * bus into the system beyond, and which IOMMU it ends up at. */ iommu_spec.np = NULL; - if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map", - "iommu-map-mask", &iommu_spec.np, iommu_spec.args)) - return NULL; + err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map", + "iommu-map-mask", &iommu_spec.np, + iommu_spec.args); + if (err) + return err == -ENODEV ? NULL : ERR_PTR(err); - ops = iommu_ops_from_fwnode(&iommu_spec.np->fwnode); - if (!ops || !ops->of_xlate || - iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) || - ops->of_xlate(&pdev->dev, &iommu_spec)) - ops = NULL; + ops = of_iommu_xlate(&pdev->dev, &iommu_spec); of_node_put(iommu_spec.np); return ops; } -const struct iommu_ops *of_iommu_configure(struct device *dev, - struct device_node *master_np) +static const struct iommu_ops +*of_platform_iommu_init(struct device *dev, struct device_node *np) { struct of_phandle_args iommu_spec; - struct device_node *np; const struct iommu_ops *ops = NULL; int idx = 0; - if (dev_is_pci(dev)) - return of_pci_iommu_configure(to_pci_dev(dev), master_np); - /* * We don't currently walk up the tree looking for a parent IOMMU. * See the `Notes:' section of * Documentation/devicetree/bindings/iommu/iommu.txt */ - while (!of_parse_phandle_with_args(master_np, "iommus", - "#iommu-cells", idx, - &iommu_spec)) { - np = iommu_spec.np; - ops = iommu_ops_from_fwnode(&np->fwnode); - - if (!ops || !ops->of_xlate || - iommu_fwspec_init(dev, &np->fwnode, ops) || - ops->of_xlate(dev, &iommu_spec)) - goto err_put_node; - - of_node_put(np); + while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", + idx, &iommu_spec)) { + ops = of_iommu_xlate(dev, &iommu_spec); + of_node_put(iommu_spec.np); idx++; + if (IS_ERR_OR_NULL(ops)) + break; } return ops; +} -err_put_node: - of_node_put(np); - return NULL; +const struct iommu_ops *of_iommu_configure(struct device *dev, + struct device_node *master_np) +{ + const struct iommu_ops *ops; + + if (!master_np) + return NULL; + + if (dev_is_pci(dev)) + ops = of_pci_iommu_init(to_pci_dev(dev), master_np); + else + ops = of_platform_iommu_init(dev, master_np); + + return IS_ERR(ops) ? NULL : ops; } static int __init of_iommu_init(void)