diff options
Diffstat (limited to 'drivers/iommu/of_iommu.c')
| -rw-r--r-- | drivers/iommu/of_iommu.c | 59 |
1 files changed, 29 insertions, 30 deletions
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 34160e7a8dd7..e60e3dba85a0 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -25,6 +25,8 @@ #include <linux/of_pci.h> #include <linux/slab.h> +#define NO_IOMMU 1 + static const struct of_device_id __iommu_of_table_sentinel __used __section(__iommu_of_table_end); @@ -109,8 +111,8 @@ static bool of_iommu_driver_present(struct device_node *np) return of_match_node(&__iommu_of_table, np); } -static const struct iommu_ops -*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec) +static int 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; @@ -120,24 +122,20 @@ static const struct iommu_ops if ((ops && !ops->of_xlate) || !of_device_is_available(iommu_spec->np) || (!ops && !of_iommu_driver_present(iommu_spec->np))) - return NULL; + return NO_IOMMU; err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); if (err) - return ERR_PTR(err); + return err; /* * The otherwise-empty fwspec handily serves to indicate the specific * IOMMU device we're waiting for, which will be useful if we ever get * a proper probe-ordering dependency mechanism in future. */ if (!ops) - return ERR_PTR(-EPROBE_DEFER); - - err = ops->of_xlate(dev, iommu_spec); - if (err) - return ERR_PTR(err); + return -EPROBE_DEFER; - return ops; + return ops->of_xlate(dev, iommu_spec); } struct of_pci_iommu_alias_info { @@ -148,7 +146,6 @@ struct of_pci_iommu_alias_info { static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data) { struct of_pci_iommu_alias_info *info = data; - const struct iommu_ops *ops; struct of_phandle_args iommu_spec = { .args_count = 1 }; int err; @@ -156,13 +153,12 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data) "iommu-map-mask", &iommu_spec.np, iommu_spec.args); if (err) - return err == -ENODEV ? 1 : err; + return err == -ENODEV ? NO_IOMMU : err; - ops = of_iommu_xlate(info->dev, &iommu_spec); + err = of_iommu_xlate(info->dev, &iommu_spec); of_node_put(iommu_spec.np); - - if (IS_ERR(ops)) - return PTR_ERR(ops); + if (err) + return err; return info->np == pdev->bus->dev.of_node; } @@ -172,7 +168,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, { const struct iommu_ops *ops = NULL; struct iommu_fwspec *fwspec = dev->iommu_fwspec; - int err; + int err = NO_IOMMU; if (!master_np) return NULL; @@ -198,10 +194,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, err = pci_for_each_dma_alias(to_pci_dev(dev), of_pci_iommu_init, &info); - if (err) /* err > 0 means the walk stopped, but non-fatally */ - ops = ERR_PTR(min(err, 0)); - else /* success implies both fwspec and ops are now valid */ - ops = dev->iommu_fwspec->ops; } else { struct of_phandle_args iommu_spec; int idx = 0; @@ -209,27 +201,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, while (!of_parse_phandle_with_args(master_np, "iommus", "#iommu-cells", idx, &iommu_spec)) { - ops = of_iommu_xlate(dev, &iommu_spec); + err = of_iommu_xlate(dev, &iommu_spec); of_node_put(iommu_spec.np); idx++; - if (IS_ERR_OR_NULL(ops)) + if (err) break; } } + + /* + * Two success conditions can be represented by non-negative err here: + * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons + * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately + * <0 : any actual error + */ + if (!err) + ops = dev->iommu_fwspec->ops; /* * If we have reason to believe the IOMMU driver missed the initial * add_device callback for dev, replay it to get things in order. */ - if (!IS_ERR_OR_NULL(ops) && ops->add_device && - dev->bus && !dev->iommu_group) { + if (ops && ops->add_device && dev->bus && !dev->iommu_group) err = ops->add_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)); + if (err == -EPROBE_DEFER) { + ops = ERR_PTR(err); + } else if (err < 0) { + dev_dbg(dev, "Adding to IOMMU failed: %d\n", err); ops = NULL; } |