Message ID | 20220512190052.1152377-3-thierry.reding@gmail.com |
---|---|
State | Not Applicable, archived |
Headers | show |
Series | iommu: Support mappings/reservations in reserved-memory regions | expand |
Context | Check | Description |
---|---|---|
robh/checkpatch | success | |
robh/patch-applied | fail | build log |
On 2022-05-12 21:00:49 +0200, 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. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > 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 | 90 ++++++++++++++++++++++++++++++++++++++++ > include/linux/of_iommu.h | 8 ++++ > 2 files changed, 98 insertions(+) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index 5696314ae69e..9e341b5e307f 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -11,12 +11,15 @@ > #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> > #include <linux/slab.h> > #include <linux/fsl/mc.h> > > +#include <dt-bindings/reserved-memory.h> > + > #define NO_IOMMU 1 > > static int of_iommu_xlate(struct device *dev, > @@ -172,3 +175,90 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, > > return ops; > } > + > +/** > + * 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) { > + struct iommu_resv_region *region; > + struct resource res; > + const __be32 *maps; > + int size; Adding 'if (!of_device_is_available(it.node)) continue;' here would help backwards compatibility. My plan was to add the reserved regions with "iommu-addresses" with all zero adresses and sizes with status = "disabled" to the devicetree. A bootloader update is required to fill those. > + > + memset(&res, 0, sizeof(res)); > + > + /* > + * 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, &res); > + 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) { > + const __be32 *end = maps + size / sizeof(__be32); > + struct device_node *np; > + unsigned int index = 0; > + u32 phandle; > + int na, ns; > + > + while (maps < end) { > + phys_addr_t start, end; > + size_t length; > + > + phandle = be32_to_cpup(maps++); > + np = of_find_node_by_phandle(phandle); > + na = of_n_addr_cells(np); > + ns = of_n_size_cells(np); > + > + start = of_translate_dma_address(np, maps); > + length = of_read_number(maps + na, ns); alternatively we could handle mappings/reservations with length 0 as error and skip them. > + end = start + length - 1; > + > + if (np == dev->of_node) { > + int prot = IOMMU_READ | IOMMU_WRITE; > + enum iommu_resv_type type; > + > + /* > + * IOMMU regions without an associated physical region > + * cannot be mapped and are simply reservations. > + */ > + if (res.end > res.start) > + type = IOMMU_RESV_DIRECT_RELAXABLE; > + else > + type = IOMMU_RESV_RESERVED; > + > + region = iommu_alloc_resv_region(start, length, prot, type); > + if (region) > + list_add_tail(®ion->list, list); > + } > + > + maps += na + ns; > + index++; > + } > + } > + } > +#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 */ > -- > 2.36.1 > Janne
On Sun, May 15, 2022 at 01:10:38PM +0200, Janne Grunau wrote: > On 2022-05-12 21:00:49 +0200, 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. > > > > Signed-off-by: Thierry Reding <treding@nvidia.com> > > --- > > 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 | 90 ++++++++++++++++++++++++++++++++++++++++ > > include/linux/of_iommu.h | 8 ++++ > > 2 files changed, 98 insertions(+) > > > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > > index 5696314ae69e..9e341b5e307f 100644 > > --- a/drivers/iommu/of_iommu.c > > +++ b/drivers/iommu/of_iommu.c > > @@ -11,12 +11,15 @@ > > #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> > > #include <linux/slab.h> > > #include <linux/fsl/mc.h> > > > > +#include <dt-bindings/reserved-memory.h> > > + > > #define NO_IOMMU 1 > > > > static int of_iommu_xlate(struct device *dev, > > @@ -172,3 +175,90 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, > > > > return ops; > > } > > + > > +/** > > + * 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) { > > + struct iommu_resv_region *region; > > + struct resource res; > > + const __be32 *maps; > > + int size; > > Adding 'if (!of_device_is_available(it.node)) continue;' here would help > backwards compatibility. My plan was to add the reserved regions with > "iommu-addresses" with all zero adresses and sizes with status = > "disabled" to the devicetree. A bootloader update is required to fill > those. Yes, good point. My plan was originally to have the bootloader/firmware generate these nodes in their entirety, but yeah, prepopulating them and having firmware just fill in updated values and setting status = "okay" seems reasonable to me. > > + > > + memset(&res, 0, sizeof(res)); > > + > > + /* > > + * 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, &res); > > + 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) { > > + const __be32 *end = maps + size / sizeof(__be32); > > + struct device_node *np; > > + unsigned int index = 0; > > + u32 phandle; > > + int na, ns; > > + > > + while (maps < end) { > > + phys_addr_t start, end; > > + size_t length; > > + > > + phandle = be32_to_cpup(maps++); > > + np = of_find_node_by_phandle(phandle); > > + na = of_n_addr_cells(np); > > + ns = of_n_size_cells(np); > > + > > + start = of_translate_dma_address(np, maps); > > + length = of_read_number(maps + na, ns); > > alternatively we could handle mappings/reservations with length 0 as > error and skip them. I think we could do both. Thanks for the feedback, Thierry
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5696314ae69e..9e341b5e307f 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -11,12 +11,15 @@ #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> #include <linux/slab.h> #include <linux/fsl/mc.h> +#include <dt-bindings/reserved-memory.h> + #define NO_IOMMU 1 static int of_iommu_xlate(struct device *dev, @@ -172,3 +175,90 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +/** + * 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) { + struct iommu_resv_region *region; + struct resource res; + const __be32 *maps; + int size; + + memset(&res, 0, sizeof(res)); + + /* + * 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, &res); + 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) { + const __be32 *end = maps + size / sizeof(__be32); + struct device_node *np; + unsigned int index = 0; + u32 phandle; + int na, ns; + + while (maps < end) { + phys_addr_t start, end; + size_t length; + + phandle = be32_to_cpup(maps++); + np = of_find_node_by_phandle(phandle); + na = of_n_addr_cells(np); + ns = of_n_size_cells(np); + + start = of_translate_dma_address(np, maps); + length = of_read_number(maps + na, ns); + end = start + length - 1; + + if (np == dev->of_node) { + int prot = IOMMU_READ | IOMMU_WRITE; + enum iommu_resv_type type; + + /* + * IOMMU regions without an associated physical region + * cannot be mapped and are simply reservations. + */ + if (res.end > res.start) + type = IOMMU_RESV_DIRECT_RELAXABLE; + else + type = IOMMU_RESV_RESERVED; + + region = iommu_alloc_resv_region(start, length, prot, type); + if (region) + list_add_tail(®ion->list, list); + } + + maps += na + ns; + index++; + } + } + } +#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 */