[PATCH v6 04/20] iommu/of: Introduce iommu_fwspec
From: robin.murphy@arm.com (Robin Murphy)
Date: 2016-09-06 15:33:37
Also in:
linux-devicetree, linux-iommu
Subsystem:
iommu subsystem, open firmware and flattened device tree, the rest · Maintainers:
Joerg Roedel, Will Deacon, Rob Herring, Saravana Kannan, Linus Torvalds
Introduce a common structure to hold the per-device firmware data that non-architectural IOMMU drivers generally need to keep track of. Initially this is DT-specific to complement the existing of_iommu support code, but will generalise further once other firmware methods (e.g. ACPI IORT) come along. Ultimately the aim is to promote the fwspec to a first-class member of struct device, and handle the init/free automatically in the firmware code. That way we can have API calls look for dev->fwspec->iommu_ops before falling back to dev->bus->iommu_ops, and thus gracefully handle those troublesome multi-IOMMU systems which we currently cannot. To start with, though, make use of the existing archdata field and delegate the init/free to drivers to allow an incremental conversion rather than the impractical pain of trying to attempt everything in one go. Suggested-by: Will Deacon <redacted> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- - Replace crazy while loop with sane code --- drivers/iommu/of_iommu.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 15 ++++++++++++++ 2 files changed, 69 insertions(+)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 19e1e8f2f871..04d616daffa3 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c@@ -226,3 +226,57 @@ static int __init of_iommu_init(void) return 0; } postcore_initcall_sync(of_iommu_init); + +int iommu_fwspec_init(struct device *dev, struct device_node *iommu_np) +{ + struct iommu_fwspec *fwspec = dev->archdata.iommu; + + if (fwspec) + return 0; + + fwspec = kzalloc(sizeof(*fwspec), GFP_KERNEL); + if (!fwspec) + return -ENOMEM; + + fwspec->iommu_np = of_node_get(iommu_np); + fwspec->iommu_ops = of_iommu_get_ops(iommu_np); + dev->archdata.iommu = fwspec; + return 0; +} + +void iommu_fwspec_free(struct device *dev) +{ + struct iommu_fwspec *fwspec = dev->archdata.iommu; + + if (fwspec) { + of_node_put(fwspec->iommu_np); + kfree(fwspec); + } +} + +int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids) +{ + struct iommu_fwspec *fwspec = dev->archdata.iommu; + size_t size; + int i; + + if (!fwspec) + return -EINVAL; + + size = offsetof(struct iommu_fwspec, ids[fwspec->num_ids + num_ids]); + fwspec = krealloc(dev->archdata.iommu, size, GFP_KERNEL); + if (!fwspec) + return -ENOMEM; + + for (i = 0; i < num_ids; i++) + fwspec->ids[fwspec->num_ids + i] = ids[i]; + + fwspec->num_ids += num_ids; + dev->archdata.iommu = fwspec; + return 0; +} + +inline struct iommu_fwspec *dev_iommu_fwspec(struct device *dev) +{ + return dev->archdata.iommu; +}
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index e80b9c762a03..accdc0525f28 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h@@ -14,6 +14,14 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix, extern const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np); +struct iommu_fwspec { + const struct iommu_ops *iommu_ops; + struct device_node *iommu_np; + void *iommu_priv; + unsigned int num_ids; + u32 ids[]; +}; + #else static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
@@ -29,8 +37,15 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, return NULL; } +struct iommu_fwspec; + #endif /* CONFIG_OF_IOMMU */ +int iommu_fwspec_init(struct device *dev, struct device_node *iommu_np); +void iommu_fwspec_free(struct device *dev); +int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids); +struct iommu_fwspec *dev_iommu_fwspec(struct device *dev); + void of_iommu_set_ops(struct device_node *np, const struct iommu_ops *ops); const struct iommu_ops *of_iommu_get_ops(struct device_node *np);
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2.8.1.dirty