| Message ID | 1491301105-5274-9-git-send-email-sricharan@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 04/04/17 11:18, Sricharan R wrote: > From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > Failures to look up an IOMMU when parsing the DT iommus property need to > be handled separately from the .of_xlate() failures to support deferred > probing. > > The lack of a registered IOMMU can be caused by the lack of a driver for > the IOMMU, the IOMMU device probe not having been performed yet, having > been deferred, or having failed. > > The first case occurs when the device tree describes the bus master and > IOMMU topology correctly but no device driver exists for the IOMMU yet > or the device driver has not been compiled in. Return NULL, the caller > will configure the device without an IOMMU. > > The second and third cases are handled by deferring the probe of the bus > master device which will eventually get reprobed after the IOMMU. > > The last case is currently handled by deferring the probe of the bus > master device as well. A mechanism to either configure the bus master > device without an IOMMU or to fail the bus master device probe depending > on whether the IOMMU is optional or mandatory would be a good > enhancement. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Signed-off-by: Laurent Pichart <laurent.pinchart+renesas@ideasonboard.com> > Signed-off-by: Sricharan R <sricharan@codeaurora.org> > --- > drivers/base/dma-mapping.c | 5 +++-- > drivers/iommu/of_iommu.c | 4 ++-- > drivers/of/device.c | 7 ++++++- > include/linux/of_device.h | 9 ++++++--- > 4 files changed, 17 insertions(+), 8 deletions(-) > > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c > index 449b948..82bd45c 100644 > --- a/drivers/base/dma-mapping.c > +++ b/drivers/base/dma-mapping.c > @@ -353,6 +353,7 @@ int dma_configure(struct device *dev) > { > struct device *bridge = NULL, *dma_dev = dev; > enum dev_dma_attr attr; > + int ret = 0; > > if (dev_is_pci(dev)) { > bridge = pci_get_host_bridge_device(to_pci_dev(dev)); > @@ -363,7 +364,7 @@ int dma_configure(struct device *dev) > } > > if (dma_dev->of_node) { > - of_dma_configure(dev, dma_dev->of_node); > + ret = of_dma_configure(dev, dma_dev->of_node); > } else if (has_acpi_companion(dma_dev)) { > attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); > if (attr != DEV_DMA_NOT_SUPPORTED) > @@ -373,7 +374,7 @@ int dma_configure(struct device *dev) > if (bridge) > pci_put_host_bridge_device(bridge); > > - return 0; > + return ret; > } > > void dma_deconfigure(struct device *dev) > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index c8be889..9f44ee8 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -236,7 +236,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, > ops = ERR_PTR(err); > } > > - return IS_ERR(ops) ? NULL : ops; > + return ops; > } > > static int __init of_iommu_init(void) > @@ -247,7 +247,7 @@ static int __init of_iommu_init(void) > for_each_matching_node_and_match(np, matches, &match) { > const of_iommu_init_fn init_fn = match->data; > > - if (init_fn(np)) > + if (init_fn && init_fn(np)) > pr_err("Failed to initialise IOMMU %s\n", > of_node_full_name(np)); > } > diff --git a/drivers/of/device.c b/drivers/of/device.c > index c2ae6bb..bea8aec 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -82,7 +82,7 @@ int of_device_add(struct platform_device *ofdev) > * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events > * to fix up DMA configuration. > */ > -void of_dma_configure(struct device *dev, struct device_node *np) > +int of_dma_configure(struct device *dev, struct device_node *np) > { > u64 dma_addr, paddr, size; > int ret; > @@ -129,10 +129,15 @@ void of_dma_configure(struct device *dev, struct device_node *np) > coherent ? " " : " not "); > > iommu = of_iommu_configure(dev, np); > + if (IS_ERR(iommu)) > + return PTR_ERR(iommu); > + > dev_dbg(dev, "device is%sbehind an iommu\n", > iommu ? " " : " not "); > > arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); > + > + return 0; > } > EXPORT_SYMBOL_GPL(of_dma_configure); > > diff --git a/include/linux/of_device.h b/include/linux/of_device.h > index af98455..2cacdd8 100644 > --- a/include/linux/of_device.h > +++ b/include/linux/of_device.h > @@ -55,7 +55,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu) > return of_node_get(cpu_dev->of_node); > } > > -void of_dma_configure(struct device *dev, struct device_node *np); > +int of_dma_configure(struct device *dev, struct device_node *np); > void of_dma_deconfigure(struct device *dev); > #else /* CONFIG_OF */ > > @@ -104,8 +104,11 @@ static inline struct device_node *of_cpu_device_node_get(int cpu) > { > return NULL; > } > -static inline void of_dma_configure(struct device *dev, struct device_node *np) > -{} > + > +static inline int of_dma_configure(struct device *dev, struct device_node *np) > +{ > + return 0; > +} > static inline void of_dma_deconfigure(struct device *dev) > {} > #endif /* CONFIG_OF */ >
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 449b948..82bd45c 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -353,6 +353,7 @@ int dma_configure(struct device *dev) { struct device *bridge = NULL, *dma_dev = dev; enum dev_dma_attr attr; + int ret = 0; if (dev_is_pci(dev)) { bridge = pci_get_host_bridge_device(to_pci_dev(dev)); @@ -363,7 +364,7 @@ int dma_configure(struct device *dev) } if (dma_dev->of_node) { - of_dma_configure(dev, dma_dev->of_node); + ret = of_dma_configure(dev, dma_dev->of_node); } else if (has_acpi_companion(dma_dev)) { attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); if (attr != DEV_DMA_NOT_SUPPORTED) @@ -373,7 +374,7 @@ int dma_configure(struct device *dev) if (bridge) pci_put_host_bridge_device(bridge); - return 0; + return ret; } void dma_deconfigure(struct device *dev) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index c8be889..9f44ee8 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -236,7 +236,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, ops = ERR_PTR(err); } - return IS_ERR(ops) ? NULL : ops; + return ops; } static int __init of_iommu_init(void) @@ -247,7 +247,7 @@ static int __init of_iommu_init(void) for_each_matching_node_and_match(np, matches, &match) { const of_iommu_init_fn init_fn = match->data; - if (init_fn(np)) + if (init_fn && init_fn(np)) pr_err("Failed to initialise IOMMU %s\n", of_node_full_name(np)); } diff --git a/drivers/of/device.c b/drivers/of/device.c index c2ae6bb..bea8aec 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -82,7 +82,7 @@ int of_device_add(struct platform_device *ofdev) * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events * to fix up DMA configuration. */ -void of_dma_configure(struct device *dev, struct device_node *np) +int of_dma_configure(struct device *dev, struct device_node *np) { u64 dma_addr, paddr, size; int ret; @@ -129,10 +129,15 @@ void of_dma_configure(struct device *dev, struct device_node *np) coherent ? " " : " not "); iommu = of_iommu_configure(dev, np); + if (IS_ERR(iommu)) + return PTR_ERR(iommu); + dev_dbg(dev, "device is%sbehind an iommu\n", iommu ? " " : " not "); arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); + + return 0; } EXPORT_SYMBOL_GPL(of_dma_configure); diff --git a/include/linux/of_device.h b/include/linux/of_device.h index af98455..2cacdd8 100644 --- a/include/linux/of_device.h +++ b/include/linux/of_device.h @@ -55,7 +55,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu) return of_node_get(cpu_dev->of_node); } -void of_dma_configure(struct device *dev, struct device_node *np); +int of_dma_configure(struct device *dev, struct device_node *np); void of_dma_deconfigure(struct device *dev); #else /* CONFIG_OF */ @@ -104,8 +104,11 @@ static inline struct device_node *of_cpu_device_node_get(int cpu) { return NULL; } -static inline void of_dma_configure(struct device *dev, struct device_node *np) -{} + +static inline int of_dma_configure(struct device *dev, struct device_node *np) +{ + return 0; +} static inline void of_dma_deconfigure(struct device *dev) {} #endif /* CONFIG_OF */