[PATCH v6 3/9] iommu/dma: Introduce generic helper to retrieve RMR info
From: Shameer Kolothum <hidden>
Date: 2021-07-16 08:38:28
Also in:
linux-acpi, linux-iommu
Subsystem:
iommu dma-api layer, iommu subsystem, the rest · Maintainers:
Robin Murphy, Joerg Roedel, Will Deacon, Linus Torvalds
Reserved Memory Regions(RMR) associated with an IOMMU can be described through ACPI IORT tables in systems with devices that require a unity mapping or bypass for those regions. Introduce a generic interface so that IOMMU drivers can retrieve and set up necessary mappings. Signed-off-by: Shameer Kolothum <redacted> --- drivers/iommu/dma-iommu.c | 29 +++++++++++++++++++++++++++++ include/linux/dma-iommu.h | 13 +++++++++++++ 2 files changed, 42 insertions(+)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 98ba927aee1a..2fa2445e9070 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c@@ -174,6 +174,35 @@ void iommu_put_dma_cookie(struct iommu_domain *domain) } EXPORT_SYMBOL(iommu_put_dma_cookie); +/** + * + * iommu_dma_get_rmrs - Retrieve Reserved Memory Regions(RMRs) associated + * with a given IOMMU + * @iommu_fwnode: fwnode associated with IOMMU + * @list: RMR list to be populated + * + */ +int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, + struct list_head *list) +{ + return -EINVAL; +} +EXPORT_SYMBOL(iommu_dma_get_rmrs); + +/** + * + * iommu_dma_put_rmrs - Release Reserved Memory Regions(RMRs) associated + * with a given IOMMU + * @iommu_fwnode: fwnode associated with IOMMU + * @list: RMR list + * + */ +void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode, + struct list_head *list) +{ +} +EXPORT_SYMBOL(iommu_dma_put_rmrs); + /** * iommu_dma_get_resv_regions - Reserved region driver helper * @dev: Device from iommu_get_resv_regions()
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 758ca4694257..3b7b2d096c6e 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h@@ -42,12 +42,16 @@ void iommu_dma_free_cpu_cached_iovas(unsigned int cpu, extern bool iommu_dma_forcedac; +int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list); +void iommu_dma_put_rmrs(struct fwnode_handle *iommu, struct list_head *list); + #else /* CONFIG_IOMMU_DMA */ struct iommu_domain; struct msi_desc; struct msi_msg; struct device; +struct fwnode_handle; static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)
@@ -83,5 +87,14 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he { } +static int iommu_dma_get_rmrs(struct fwnode_handle *iommu, struct list_head *list) +{ + return -ENODEV; +} + +static void iommu_dma_put_rmrs(struct fwnode_handle *iommu, struct list_head *list) +{ +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __DMA_IOMMU_H */
--
2.17.1
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