Re: [PATCH v8 05/11] ACPI/IORT: Add a helper to retrieve RMR memory regions

Lorenzo Pieralisi
2022-02-23T18:06:01Z

On Mon, Feb 21, 2022 at 03:43:38PM +0000, Shameer Kolothum wrote:
> Add helper functions (iort_iommu_get/put_rmrs()) that
> retrieves/releases RMR memory descriptors associated
> with a given IOMMU. This will be used by IOMMU drivers
> to set up necessary mappings.
>
> Invoke it from the generic iommu helper functions.
>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
> drivers/acpi/arm64/iort.c | 56 +++++++++++++++++++++++++++++++++++++++
> drivers/iommu/dma-iommu.c | 4 +++
> include/linux/acpi_iort.h | 14 ++++++++++
> 3 files changed, 74 insertions(+)

I would squash this patch with the previous one - at least the
iommu_dma_get/put_rmrs() are actually used in the patch that is
adding them.

Lorenzo

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 05da9ebff50a..b2c959c72fb2 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1055,6 +1055,57 @@ static void iort_find_rmrs(struct acpi_iort_node *iommu, struct device *dev,
> }
> }
>
> +/**
> + * iort_iommu_dma_put_rmrs - Free any memory associated with RMRs.
> + * @iommu_fwnode: fwnode associated with IOMMU
> + * @head: Resereved region list
> + *
> + * This function go through the provided reserved region list and
> + * free up memory associated with RMR entries and delete them from
> + * the list.
> + */
> +void iort_iommu_put_rmrs(struct fwnode_handle *iommu_fwnode,
> + struct list_head *head)
> +{
> + struct iommu_resv_region *e, *tmp;
> +
> + /*
> + * RMR entries will have mem allocated for fw_data.rmr.sids.
> + * Free the mem and delete the node.
> + */
> + list_for_each_entry_safe(e, tmp, head, list) {
> + if (e->fw_data.rmr.sids) {
> + kfree(e->fw_data.rmr.sids);
> + list_del(&e->list);
> + kfree(e);
> + }
> + }
> +}
> +
> +/**
> + *
> + * iort_iommu_dma_get_rmrs - Retrieve Reserved Memory Regions(RMRs) associated
> + * with a given IOMMU and dev.
> + * @iommu_fwnode: fwnode associated with IOMMU
> + * @dev: Device associated with RMR(Optional)
> + * @list: RMR list to be populated
> + *
> + * This function populates the RMR list associated with a given IOMMU and
> + * dev(if provided). If dev is NULL, the function populates all the RMRs
> + * associated with the given IOMMU.
> + */
> +void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
> + struct list_head *head)
> +{
> + struct acpi_iort_node *iommu;
> +
> + iommu = iort_get_iort_node(iommu_fwnode);
> + if (!iommu)
> + return;
> +
> + iort_find_rmrs(iommu, dev, head);
> +}
> +
> /**
> * iort_iommu_msi_get_resv_regions - Reserved region driver helper
> * @dev: Device from iommu_get_resv_regions()
> @@ -1287,6 +1338,11 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
> { return 0; }
> int iort_iommu_configure_id(struct device *dev, const u32 *input_id)
> { return -ENODEV; }
> +void iort_iommu_get_rmrs(struct fwnode_handle *fwnode, struct device *dev,
> + struct list_head *head)
> +{ }
> +void iort_iommu_put_rmrs(struct fwnode_handle *fwnode, struct list_head *head)
> +{ }
> #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 65ab01d5128b..b33e4df85de1 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -382,12 +382,16 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
> void iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
> struct list_head *list)
> {
> + if (!is_of_node(iommu_fwnode))
> + iort_iommu_get_rmrs(iommu_fwnode, dev, list);
> }
> EXPORT_SYMBOL(iommu_dma_get_rmrs);
>
> void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode,
> struct list_head *list)
> {
> + if (!is_of_node(iommu_fwnode))
> + iort_iommu_put_rmrs(iommu_fwnode, list);
> }
> EXPORT_SYMBOL(iommu_dma_put_rmrs);
>
> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> index f1f0842a2cb2..212f7f178ec3 100644
> --- a/include/linux/acpi_iort.h
> +++ b/include/linux/acpi_iort.h
> @@ -38,6 +38,10 @@ int iort_dma_get_ranges(struct device *dev, u64 *size);
> int 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);
> +void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
> + struct list_head *list);
> +void iort_iommu_put_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)
> @@ -57,6 +61,16 @@ 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
> +void iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode, struct device *dev,
> + struct list_head *list)
> +{ }
> +void iort_iommu_put_rmrs(struct fwnode_handle *iommu_fwnode,
> + struct list_head *list)
> +{ }
> +
> +{ }
> #endif
>
> #endif /* __ACPI_IORT_H__ */
> --
> 2.25.1
>