Re: [PATCH v4 3/8] ACPI/IORT: Add a helper to retrieve RMR memory regions
From: Lorenzo Pieralisi <hidden>
Date: 2021-06-03 11:22:51
Also in:
linux-arm-kernel, linux-iommu
On Thu, May 13, 2021 at 02:45:45PM +0100, Shameer Kolothum wrote:
Add a helper function that retrieves RMR memory descriptors associated with a given IOMMU. This will be used by IOMMU drivers to setup necessary mappings. Now that we have this, invoke it from the generic helper
"Add a helper function (iort_iommu_get_rmrs()) that retrieves RMR memory descriptors associated with a given IOMMU. This will be used by IOMMU drivers to setup necessary mappings. Invoke it from the generic helper iommu_dma_get_rmrs()."
quoted hunk ↗ jump to hunk
interface. Signed-off-by: Shameer Kolothum <redacted> --- drivers/acpi/arm64/iort.c | 40 +++++++++++++++++++++++++++++++++++++++ drivers/iommu/dma-iommu.c | 3 +++ include/linux/acpi_iort.h | 7 +++++++ 3 files changed, 50 insertions(+)diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index fea1ffaedf3b..6ca88c38987a 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c@@ -12,6 +12,7 @@ #include <linux/acpi_iort.h> #include <linux/bitfield.h> +#include <linux/dma-iommu.h> #include <linux/iommu.h> #include <linux/kernel.h> #include <linux/list.h>@@ -837,6 +838,43 @@ static inline int iort_add_device_replay(struct device *dev) return err; } +/** + * iort_iommu_get_rmrs - Helper to retrieve RMR info associated with IOMMU
iort_iommu_get_rmrs() please check other functions comments in the patchset.
+ * @iommu: fwnode for the IOMMU
Does not match the parameter.
+ * @head: RMR list head to be populated
+ *
+ * Returns: 0 on success, <0 failure
+ */
+int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode,
+ struct list_head *head)
+{
+ struct iort_rmr_entry *e;
+ struct acpi_iort_node *iommu;
+
+ iommu = iort_get_iort_node(iommu_fwnode);
+ if (!iommu)
+ return -EINVAL;
+
+ list_for_each_entry(e, &iort_rmr_list, list) {
+ struct acpi_iort_rmr_desc *rmr_desc;
+ struct iommu_rmr *rmr;
+
+ if (e->smmu != iommu)
+ continue;
+
+ rmr_desc = e->rmr_desc;
+ rmr = iommu_dma_alloc_rmr(rmr_desc->base_address,
+ rmr_desc->length, e->sid,
+ e->flags);
+ if (!rmr)
+ return -ENOMEM;I suppose it is OK to leave the already allocated regions allocated on -ENOMEM. Probably worth clarifying it in the function comment. Lorenzo
quoted hunk ↗ jump to hunk
+ + list_add_tail(&rmr->list, head); + } + + return 0; +} + /** * iort_iommu_msi_get_resv_regions - Reserved region driver helper * @dev: Device from iommu_get_resv_regions()@@ -1108,6 +1146,8 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head) const struct iommu_ops *iort_iommu_configure_id(struct device *dev, const u32 *input_id) { return NULL; } +int iort_iommu_get_rmrs(struct fwnode_handle *fwnode, struct list_head *head) +{ return -ENODEV; } #endif static int nc_dma_get_range(struct device *dev, u64 *size)diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 674bd8815159..2d9caf548a32 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c@@ -203,6 +203,9 @@ EXPORT_SYMBOL(iommu_dma_get_resv_regions); int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, struct list_head *list) { + if (!is_of_node(iommu_fwnode)) + return iort_iommu_get_rmrs(iommu_fwnode, list); + return -EINVAL; } EXPORT_SYMBOL(iommu_dma_get_rmrs);diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h index 1a12baa58e40..e8c45fa59531 100644 --- a/include/linux/acpi_iort.h +++ b/include/linux/acpi_iort.h@@ -39,6 +39,8 @@ const struct iommu_ops *iort_iommu_configure_id(struct device *dev, const u32 *id_in); int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head); phys_addr_t acpi_iort_dma_get_max_cpu_address(void); +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, + struct list_head *list); #else static inline void acpi_iort_init(void) { } static inline u32 iort_msi_map_id(struct device *dev, u32 id)@@ -59,6 +61,11 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head) static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void) { return PHYS_ADDR_MAX; } + +static inline +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, + struct list_head *list) +{ return -ENODEV; } #endif #endif /* __ACPI_IORT_H__ */-- 2.17.1