| Message ID | 20221117185424.2359687-4-thierry.reding@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iommu: Support mappings/reservations in reserved-memory regions | expand |
On Thu, Nov 17, 2022 at 07:54:23PM +0100, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > This is an implementation that IOMMU drivers can use to obtain reserved > memory regions from a device tree node. It uses the reserved-memory DT > bindings to find the regions associated with a given device. If these > regions are marked accordingly, identity mappings will be created for > them in the IOMMU domain that the devices will be attached to. > > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: devicetree@vger.kernel.org > Reviewed-by: Rob Herring <robh@kernel.org> > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > Changes in v10: > - extract more code into the new iommu_resv_region_get_type() function > - rename variables for physical and I/O virtual addresses for clarity > - default to IOMMU_RESV_DIRECT instead of IOMMU_RESV_DIRECT_RELAXABLE > - use newly introduced of_translate_dma_region() > > Changes in v9: > - address review comments by Robin Murphy: > - warn about non-direct mappings since they are not supported yet > - cleanup code to require less indentation > - narrow scope of variables > > Changes in v8: > - cleanup set-but-unused variables > > Changes in v6: > - remove reference to now unused dt-bindings/reserved-memory.h include > > Changes in v5: > - update for new "iommu-addresses" device tree bindings > > Changes in v4: > - fix build failure on !CONFIG_OF_ADDRESS > > Changes in v3: > - change "active" property to identity mapping flag that is part of the > memory region specifier (as defined by #memory-region-cells) to allow > per-reference flags to be used > > Changes in v2: > - use "active" property to determine whether direct mappings are needed > > drivers/iommu/of_iommu.c | 94 ++++++++++++++++++++++++++++++++++++++++ > include/linux/of_iommu.h | 8 ++++ > 2 files changed, 102 insertions(+) Hi Robin, can you take a look at this to see if all your concerns have now been addressed? Thanks, Thierry > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index 5696314ae69e..fa7c63a4abbf 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -11,6 +11,7 @@ > #include <linux/module.h> > #include <linux/msi.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/of_iommu.h> > #include <linux/of_pci.h> > #include <linux/pci.h> > @@ -172,3 +173,96 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, > > return ops; > } > + > +static enum iommu_resv_type iommu_resv_region_get_type(struct device *dev, struct resource *phys, > + phys_addr_t start, size_t length) > +{ > + phys_addr_t end = start + length - 1; > + > + /* > + * IOMMU regions without an associated physical region cannot be > + * mapped and are simply reservations. > + */ > + if (phys->start >= phys->end) > + return IOMMU_RESV_RESERVED; > + > + /* may be IOMMU_RESV_DIRECT_RELAXABLE for certain cases */ > + if (start == phys->start && end == phys->end) > + return IOMMU_RESV_DIRECT; > + > + dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", &phys, > + &start, &end); > + return IOMMU_RESV_RESERVED; > +} > + > +/** > + * of_iommu_get_resv_regions - reserved region driver helper for device tree > + * @dev: device for which to get reserved regions > + * @list: reserved region list > + * > + * IOMMU drivers can use this to implement their .get_resv_regions() callback > + * for memory regions attached to a device tree node. See the reserved-memory > + * device tree bindings on how to use these: > + * > + * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt > + */ > +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list) > +{ > +#if IS_ENABLED(CONFIG_OF_ADDRESS) > + struct of_phandle_iterator it; > + int err; > + > + of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) { > + const __be32 *maps, *end; > + struct resource phys; > + int size; > + > + memset(&phys, 0, sizeof(phys)); > + > + /* > + * The "reg" property is optional and can be omitted by reserved-memory regions > + * that represent reservations in the IOVA space, which are regions that should > + * not be mapped. > + */ > + if (of_find_property(it.node, "reg", NULL)) { > + err = of_address_to_resource(it.node, 0, &phys); > + if (err < 0) { > + dev_err(dev, "failed to parse memory region %pOF: %d\n", > + it.node, err); > + continue; > + } > + } > + > + maps = of_get_property(it.node, "iommu-addresses", &size); > + if (!maps) > + continue; > + > + end = maps + size / sizeof(__be32); > + > + while (maps < end) { > + struct device_node *np; > + u32 phandle; > + > + phandle = be32_to_cpup(maps++); > + np = of_find_node_by_phandle(phandle); > + > + if (np == dev->of_node) { > + int prot = IOMMU_READ | IOMMU_WRITE; > + struct iommu_resv_region *region; > + enum iommu_resv_type type; > + phys_addr_t iova; > + size_t length; > + > + maps = of_translate_dma_region(np, maps, &iova, &length); > + type = iommu_resv_region_get_type(dev, &phys, iova, length); > + > + region = iommu_alloc_resv_region(iova, length, prot, type, > + GFP_KERNEL); > + if (region) > + list_add_tail(®ion->list, list); > + } > + } > + } > +#endif > +} > +EXPORT_SYMBOL(of_iommu_get_resv_regions); > diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h > index 55c1eb300a86..9a5e6b410dd2 100644 > --- a/include/linux/of_iommu.h > +++ b/include/linux/of_iommu.h > @@ -12,6 +12,9 @@ extern const struct iommu_ops *of_iommu_configure(struct device *dev, > struct device_node *master_np, > const u32 *id); > > +extern void of_iommu_get_resv_regions(struct device *dev, > + struct list_head *list); > + > #else > > static inline const struct iommu_ops *of_iommu_configure(struct device *dev, > @@ -21,6 +24,11 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, > return NULL; > } > > +static inline void of_iommu_get_resv_regions(struct device *dev, > + struct list_head *list) > +{ > +} > + > #endif /* CONFIG_OF_IOMMU */ > > #endif /* __OF_IOMMU_H */ > -- > 2.38.1 >
On 2022-11-17 18:54, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > This is an implementation that IOMMU drivers can use to obtain reserved > memory regions from a device tree node. It uses the reserved-memory DT > bindings to find the regions associated with a given device. If these > regions are marked accordingly, identity mappings will be created for > them in the IOMMU domain that the devices will be attached to. Acked-by: Robin Murphy <robin.murphy@arm.com> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: devicetree@vger.kernel.org > Reviewed-by: Rob Herring <robh@kernel.org> > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > Changes in v10: > - extract more code into the new iommu_resv_region_get_type() function > - rename variables for physical and I/O virtual addresses for clarity > - default to IOMMU_RESV_DIRECT instead of IOMMU_RESV_DIRECT_RELAXABLE > - use newly introduced of_translate_dma_region() > > Changes in v9: > - address review comments by Robin Murphy: > - warn about non-direct mappings since they are not supported yet > - cleanup code to require less indentation > - narrow scope of variables > > Changes in v8: > - cleanup set-but-unused variables > > Changes in v6: > - remove reference to now unused dt-bindings/reserved-memory.h include > > Changes in v5: > - update for new "iommu-addresses" device tree bindings > > Changes in v4: > - fix build failure on !CONFIG_OF_ADDRESS > > Changes in v3: > - change "active" property to identity mapping flag that is part of the > memory region specifier (as defined by #memory-region-cells) to allow > per-reference flags to be used > > Changes in v2: > - use "active" property to determine whether direct mappings are needed > > drivers/iommu/of_iommu.c | 94 ++++++++++++++++++++++++++++++++++++++++ > include/linux/of_iommu.h | 8 ++++ > 2 files changed, 102 insertions(+) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index 5696314ae69e..fa7c63a4abbf 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -11,6 +11,7 @@ > #include <linux/module.h> > #include <linux/msi.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/of_iommu.h> > #include <linux/of_pci.h> > #include <linux/pci.h> > @@ -172,3 +173,96 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, > > return ops; > } > + > +static enum iommu_resv_type iommu_resv_region_get_type(struct device *dev, struct resource *phys, > + phys_addr_t start, size_t length) > +{ > + phys_addr_t end = start + length - 1; > + > + /* > + * IOMMU regions without an associated physical region cannot be > + * mapped and are simply reservations. > + */ > + if (phys->start >= phys->end) > + return IOMMU_RESV_RESERVED; > + > + /* may be IOMMU_RESV_DIRECT_RELAXABLE for certain cases */ > + if (start == phys->start && end == phys->end) > + return IOMMU_RESV_DIRECT; > + > + dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", &phys, > + &start, &end); > + return IOMMU_RESV_RESERVED; > +} > + > +/** > + * of_iommu_get_resv_regions - reserved region driver helper for device tree > + * @dev: device for which to get reserved regions > + * @list: reserved region list > + * > + * IOMMU drivers can use this to implement their .get_resv_regions() callback > + * for memory regions attached to a device tree node. See the reserved-memory > + * device tree bindings on how to use these: > + * > + * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt > + */ > +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list) > +{ > +#if IS_ENABLED(CONFIG_OF_ADDRESS) > + struct of_phandle_iterator it; > + int err; > + > + of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) { > + const __be32 *maps, *end; > + struct resource phys; > + int size; > + > + memset(&phys, 0, sizeof(phys)); > + > + /* > + * The "reg" property is optional and can be omitted by reserved-memory regions > + * that represent reservations in the IOVA space, which are regions that should > + * not be mapped. > + */ > + if (of_find_property(it.node, "reg", NULL)) { > + err = of_address_to_resource(it.node, 0, &phys); > + if (err < 0) { > + dev_err(dev, "failed to parse memory region %pOF: %d\n", > + it.node, err); > + continue; > + } > + } > + > + maps = of_get_property(it.node, "iommu-addresses", &size); > + if (!maps) > + continue; > + > + end = maps + size / sizeof(__be32); > + > + while (maps < end) { > + struct device_node *np; > + u32 phandle; > + > + phandle = be32_to_cpup(maps++); > + np = of_find_node_by_phandle(phandle); > + > + if (np == dev->of_node) { > + int prot = IOMMU_READ | IOMMU_WRITE; > + struct iommu_resv_region *region; > + enum iommu_resv_type type; > + phys_addr_t iova; > + size_t length; > + > + maps = of_translate_dma_region(np, maps, &iova, &length); > + type = iommu_resv_region_get_type(dev, &phys, iova, length); > + > + region = iommu_alloc_resv_region(iova, length, prot, type, > + GFP_KERNEL); > + if (region) > + list_add_tail(®ion->list, list); > + } > + } > + } > +#endif > +} > +EXPORT_SYMBOL(of_iommu_get_resv_regions); > diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h > index 55c1eb300a86..9a5e6b410dd2 100644 > --- a/include/linux/of_iommu.h > +++ b/include/linux/of_iommu.h > @@ -12,6 +12,9 @@ extern const struct iommu_ops *of_iommu_configure(struct device *dev, > struct device_node *master_np, > const u32 *id); > > +extern void of_iommu_get_resv_regions(struct device *dev, > + struct list_head *list); > + > #else > > static inline const struct iommu_ops *of_iommu_configure(struct device *dev, > @@ -21,6 +24,11 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, > return NULL; > } > > +static inline void of_iommu_get_resv_regions(struct device *dev, > + struct list_head *list) > +{ > +} > + > #endif /* CONFIG_OF_IOMMU */ > > #endif /* __OF_IOMMU_H */
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5696314ae69e..fa7c63a4abbf 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -11,6 +11,7 @@ #include <linux/module.h> #include <linux/msi.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_iommu.h> #include <linux/of_pci.h> #include <linux/pci.h> @@ -172,3 +173,96 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +static enum iommu_resv_type iommu_resv_region_get_type(struct device *dev, struct resource *phys, + phys_addr_t start, size_t length) +{ + phys_addr_t end = start + length - 1; + + /* + * IOMMU regions without an associated physical region cannot be + * mapped and are simply reservations. + */ + if (phys->start >= phys->end) + return IOMMU_RESV_RESERVED; + + /* may be IOMMU_RESV_DIRECT_RELAXABLE for certain cases */ + if (start == phys->start && end == phys->end) + return IOMMU_RESV_DIRECT; + + dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", &phys, + &start, &end); + return IOMMU_RESV_RESERVED; +} + +/** + * of_iommu_get_resv_regions - reserved region driver helper for device tree + * @dev: device for which to get reserved regions + * @list: reserved region list + * + * IOMMU drivers can use this to implement their .get_resv_regions() callback + * for memory regions attached to a device tree node. See the reserved-memory + * device tree bindings on how to use these: + * + * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt + */ +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list) +{ +#if IS_ENABLED(CONFIG_OF_ADDRESS) + struct of_phandle_iterator it; + int err; + + of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) { + const __be32 *maps, *end; + struct resource phys; + int size; + + memset(&phys, 0, sizeof(phys)); + + /* + * The "reg" property is optional and can be omitted by reserved-memory regions + * that represent reservations in the IOVA space, which are regions that should + * not be mapped. + */ + if (of_find_property(it.node, "reg", NULL)) { + err = of_address_to_resource(it.node, 0, &phys); + if (err < 0) { + dev_err(dev, "failed to parse memory region %pOF: %d\n", + it.node, err); + continue; + } + } + + maps = of_get_property(it.node, "iommu-addresses", &size); + if (!maps) + continue; + + end = maps + size / sizeof(__be32); + + while (maps < end) { + struct device_node *np; + u32 phandle; + + phandle = be32_to_cpup(maps++); + np = of_find_node_by_phandle(phandle); + + if (np == dev->of_node) { + int prot = IOMMU_READ | IOMMU_WRITE; + struct iommu_resv_region *region; + enum iommu_resv_type type; + phys_addr_t iova; + size_t length; + + maps = of_translate_dma_region(np, maps, &iova, &length); + type = iommu_resv_region_get_type(dev, &phys, iova, length); + + region = iommu_alloc_resv_region(iova, length, prot, type, + GFP_KERNEL); + if (region) + list_add_tail(®ion->list, list); + } + } + } +#endif +} +EXPORT_SYMBOL(of_iommu_get_resv_regions); diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index 55c1eb300a86..9a5e6b410dd2 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -12,6 +12,9 @@ extern const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np, const u32 *id); +extern void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list); + #else static inline const struct iommu_ops *of_iommu_configure(struct device *dev, @@ -21,6 +24,11 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, return NULL; } +static inline void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list) +{ +} + #endif /* CONFIG_OF_IOMMU */ #endif /* __OF_IOMMU_H */