| Message ID | 69952eda726c370ed6e5739bdd2e32cdc4466bfb.1464966939.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 03, 2016 at 06:15:39PM +0100, Robin Murphy wrote: > Now that we have a way to pick up the RID translation and target IOMMU, > hook up of_iommu_configure() to bring PCI devices into the of_xlate > mechanism and allow them IOMMU-backed DMA ops without the need for > driver-specific handling. > > CC: Rob Herring <robh+dt@kernel.org> > CC: Frank Rowand <frowand.list@gmail.com> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > > v2: Skip disabled IOMMUs. > > drivers/iommu/of_iommu.c | 44 +++++++++++++++++++++++++++++++++++++------- > 1 file changed, 37 insertions(+), 7 deletions(-) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index 662f9a600f4f..5716131199b3 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -22,6 +22,7 @@ > #include <linux/limits.h> > #include <linux/of.h> > #include <linux/of_iommu.h> > +#include <linux/of_pci.h> > #include <linux/slab.h> > > static const struct of_device_id __iommu_of_table_sentinel > @@ -134,20 +135,49 @@ const struct iommu_ops *of_iommu_get_ops(struct device_node *np) > return ops; > } > > +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) > +{ > + struct of_phandle_args *iommu_spec = data; > + > + iommu_spec->args[0] = alias; > + return iommu_spec->np == pdev->bus->dev.of_node; > +} > + > const struct iommu_ops *of_iommu_configure(struct device *dev, > struct device_node *master_np) > { > struct of_phandle_args iommu_spec; > - struct device_node *np; > + struct device_node *np = NULL; > const struct iommu_ops *ops = NULL; > int idx; > > - /* > - * We can't do much for PCI devices without knowing how > - * device IDs are wired up from the PCI bus to the IOMMU. > - */ > - if (dev_is_pci(dev)) > - return NULL; > + if (dev_is_pci(dev)) { > + /* > + * Start by tracing the RID alias down the PCI topology as > + * far as the host bridge whose OF node we have... > + */ > + iommu_spec.np = master_np; > + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, > + &iommu_spec); > + /* > + * ...then find out what that becomes once it escapes the PCI > + * bus into the system beyond, and which IOMMU it ends up at. > + */ > + if (of_pci_map_rid(master_np, "iommu-map", iommu_spec.args[0], > + &np, iommu_spec.args) || > + !of_device_is_available(np)) > + return NULL; Hmm, do we need to of_node_put(np) in the case that it's not available? Will
On 14/06/16 15:45, Will Deacon wrote: > On Fri, Jun 03, 2016 at 06:15:39PM +0100, Robin Murphy wrote: >> Now that we have a way to pick up the RID translation and target IOMMU, >> hook up of_iommu_configure() to bring PCI devices into the of_xlate >> mechanism and allow them IOMMU-backed DMA ops without the need for >> driver-specific handling. >> >> CC: Rob Herring <robh+dt@kernel.org> >> CC: Frank Rowand <frowand.list@gmail.com> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> >> v2: Skip disabled IOMMUs. >> >> drivers/iommu/of_iommu.c | 44 +++++++++++++++++++++++++++++++++++++------- >> 1 file changed, 37 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c >> index 662f9a600f4f..5716131199b3 100644 >> --- a/drivers/iommu/of_iommu.c >> +++ b/drivers/iommu/of_iommu.c >> @@ -22,6 +22,7 @@ >> #include <linux/limits.h> >> #include <linux/of.h> >> #include <linux/of_iommu.h> >> +#include <linux/of_pci.h> >> #include <linux/slab.h> >> >> static const struct of_device_id __iommu_of_table_sentinel >> @@ -134,20 +135,49 @@ const struct iommu_ops *of_iommu_get_ops(struct device_node *np) >> return ops; >> } >> >> +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) >> +{ >> + struct of_phandle_args *iommu_spec = data; >> + >> + iommu_spec->args[0] = alias; >> + return iommu_spec->np == pdev->bus->dev.of_node; >> +} >> + >> const struct iommu_ops *of_iommu_configure(struct device *dev, >> struct device_node *master_np) >> { >> struct of_phandle_args iommu_spec; >> - struct device_node *np; >> + struct device_node *np = NULL; >> const struct iommu_ops *ops = NULL; >> int idx; >> >> - /* >> - * We can't do much for PCI devices without knowing how >> - * device IDs are wired up from the PCI bus to the IOMMU. >> - */ >> - if (dev_is_pci(dev)) >> - return NULL; >> + if (dev_is_pci(dev)) { >> + /* >> + * Start by tracing the RID alias down the PCI topology as >> + * far as the host bridge whose OF node we have... >> + */ >> + iommu_spec.np = master_np; >> + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, >> + &iommu_spec); >> + /* >> + * ...then find out what that becomes once it escapes the PCI >> + * bus into the system beyond, and which IOMMU it ends up at. >> + */ >> + if (of_pci_map_rid(master_np, "iommu-map", iommu_spec.args[0], >> + &np, iommu_spec.args) || >> + !of_device_is_available(np)) >> + return NULL; > > Hmm, do we need to of_node_put(np) in the case that it's not available? Ah yes, now I see; I moved the put into the loop iteration for the non-PCI case so that a "continue" does the job, but I've not handled the equivalent here. Robin. > > Will >
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 662f9a600f4f..5716131199b3 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -22,6 +22,7 @@ #include <linux/limits.h> #include <linux/of.h> #include <linux/of_iommu.h> +#include <linux/of_pci.h> #include <linux/slab.h> static const struct of_device_id __iommu_of_table_sentinel @@ -134,20 +135,49 @@ const struct iommu_ops *of_iommu_get_ops(struct device_node *np) return ops; } +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) +{ + struct of_phandle_args *iommu_spec = data; + + iommu_spec->args[0] = alias; + return iommu_spec->np == pdev->bus->dev.of_node; +} + const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { struct of_phandle_args iommu_spec; - struct device_node *np; + struct device_node *np = NULL; const struct iommu_ops *ops = NULL; int idx; - /* - * We can't do much for PCI devices without knowing how - * device IDs are wired up from the PCI bus to the IOMMU. - */ - if (dev_is_pci(dev)) - return NULL; + if (dev_is_pci(dev)) { + /* + * Start by tracing the RID alias down the PCI topology as + * far as the host bridge whose OF node we have... + */ + iommu_spec.np = master_np; + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, + &iommu_spec); + /* + * ...then find out what that becomes once it escapes the PCI + * bus into the system beyond, and which IOMMU it ends up at. + */ + if (of_pci_map_rid(master_np, "iommu-map", iommu_spec.args[0], + &np, iommu_spec.args) || + !of_device_is_available(np)) + return NULL; + + /* We're not attempting to handle multi-alias devices yet */ + iommu_spec.np = np; + iommu_spec.args_count = 1; + ops = of_iommu_get_ops(np); + if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec)) + ops = NULL; + + of_node_put(np); + return ops; + } /* * We don't currently walk up the tree looking for a parent IOMMU.
Now that we have a way to pick up the RID translation and target IOMMU, hook up of_iommu_configure() to bring PCI devices into the of_xlate mechanism and allow them IOMMU-backed DMA ops without the need for driver-specific handling. CC: Rob Herring <robh+dt@kernel.org> CC: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- v2: Skip disabled IOMMUs. drivers/iommu/of_iommu.c | 44 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 37 insertions(+), 7 deletions(-)