The generic IOMMU device-tree bindings can be used to add arbitrary OF masters to an IOMMU with a compliant binding.
This patch introduces of_iommu_configure, which does exactly that. Signed-off-by: Will Deacon <[email protected]> --- drivers/iommu/Kconfig | 2 +- drivers/iommu/of_iommu.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-mapping.h | 7 ++++++ include/linux/of_iommu.h | 8 +++++++ 4 files changed, 68 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index dd5112265cc9..6d13f962f156 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -15,7 +15,7 @@ if IOMMU_SUPPORT config OF_IOMMU def_bool y - depends on OF + depends on OF && IOMMU_API config FSL_PAMU bool "Freescale IOMMU support" diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index f9209666157c..1188c929ffa7 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -18,6 +18,7 @@ */ #include <linux/export.h> +#include <linux/iommu.h> #include <linux/limits.h> #include <linux/of.h> #include <linux/of_iommu.h> @@ -90,6 +91,57 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, } EXPORT_SYMBOL_GPL(of_get_dma_window); +struct iommu_dma_mapping *of_iommu_configure(struct device *dev) +{ + struct of_phandle_args iommu_spec; + struct iommu_dma_mapping *mapping; + struct bus_type *bus = dev->bus; + const struct iommu_ops *ops = bus->iommu_ops; + struct iommu_data *iommu = NULL; + int idx = 0; + + if (!iommu_present(bus) || !ops->of_xlate) + return NULL; + + /* + * We don't currently walk up the tree looking for a parent IOMMU. + * See the `Notes:' section of + * Documentation/devicetree/bindings/iommu/iommu.txt + */ + while (!of_parse_phandle_with_args(dev->of_node, "iommus", + "#iommu-cells", idx, + &iommu_spec)) { + struct device_node *np = iommu_spec.np; + struct iommu_data *data = of_iommu_get_data(np); + + if (!iommu) { + if (!ops->of_xlate(dev, &iommu_spec)) + iommu = data; + } else if (iommu != data) { + pr_warn("Rejecting device %s with multiple IOMMU instances\n", + dev_name(dev)); + iommu = NULL; + } + + of_node_put(np); + + if (!iommu) + break; + + idx++; + } + + if (!iommu) + return NULL; + + mapping = devm_kzalloc(dev, sizeof(*mapping), GFP_KERNEL); + if (!mapping) + return NULL; + + mapping->iommu = iommu; + return mapping; +} + void __init of_iommu_init(void) { struct device_node *np; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0f7f7b68b0db..16bf92f71c3e 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -62,6 +62,13 @@ struct dma_map_ops { int is_phys; }; +struct iommu_data; + +struct iommu_dma_mapping { + struct iommu_data *iommu; + struct list_head node; +}; + #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) #define DMA_MASK_NONE 0x0ULL diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index a39e2d78f735..f2d3b1e780d7 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -1,9 +1,12 @@ #ifndef __OF_IOMMU_H #define __OF_IOMMU_H +#include <linux/device.h> #include <linux/iommu.h> #include <linux/of.h> +struct iommu_dma_mapping; + #ifdef CONFIG_OF_IOMMU extern int of_get_dma_window(struct device_node *dn, const char *prefix, @@ -11,6 +14,7 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix, size_t *size); extern void of_iommu_init(void); +extern struct iommu_dma_mapping *of_iommu_configure(struct device *dev); #else @@ -22,6 +26,10 @@ static inline int of_get_dma_window(struct device_node *dn, const char *prefix, } static inline void of_iommu_init(void) { } +static inline struct iommu_dma_mapping *of_iommu_configure(struct device *dev) +{ + return NULL; +} #endif /* CONFIG_OF_IOMMU */ -- 2.1.0 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
