Hi,
On 8/26/25 10:18 AM, Jason Gunthorpe wrote:
>
> Tested-by: Alejandro Jimenez <[email protected]>
> Signed-off-by: Jason Gunthorpe <[email protected]>
> ---
> drivers/iommu/generic_pt/iommu_pt.h | 155 ++++++++++++++++++++++++++++
> include/linux/generic_pt/iommu.h | 10 +-
> 2 files changed, 163 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/generic_pt/iommu_pt.h
> b/drivers/iommu/generic_pt/iommu_pt.h
> index 9413f868a65bfa..53901a4a977935 100644
> --- a/drivers/iommu/generic_pt/iommu_pt.h
> +++ b/drivers/iommu/generic_pt/iommu_pt.h
> @@ -14,6 +14,29 @@
> #include <linux/iommu.h>
> #include "../iommu-pages.h"
> #include <linux/export.h>
> +#include <linux/cleanup.h>
> +#include <linux/dma-mapping.h>
> +
> +static void gather_range_pages(struct iommu_iotlb_gather *iotlb_gather,
> + struct pt_iommu *iommu_table, pt_vaddr_t iova,
> + pt_vaddr_t len,
> + struct iommu_pages_list *free_list)
> +{
> + struct pt_common *common = common_from_iommu(iommu_table);
> +
> + if (pt_feature(common, PT_FEAT_FLUSH_RANGE_NO_GAPS) &&
> + iommu_iotlb_gather_is_disjoint(iotlb_gather, iova, len)) {
> + iommu_iotlb_sync(&iommu_table->domain, iotlb_gather);
> + /*
> + * Note that the sync frees the gather's free list, so we must
> + * not have any pages on that list that are covered by iova/len
> + */
> + } else if (pt_feature(common, PT_FEAT_FLUSH_RANGE)) {
> + iommu_iotlb_gather_add_range(iotlb_gather, iova, len);
> + }
> +
> + iommu_pages_list_splice(free_list, &iotlb_gather->freelist);
> +}
>
> #define DOMAIN_NS(op) CONCATENATE(CONCATENATE(pt_iommu_, PTPFX), op)
>
> @@ -167,6 +190,138 @@ static inline struct pt_table_p *table_alloc_top(struct
> pt_common *common,
> log2_to_int(pt_top_memsize_lg2(common, top_of_table)));
> }
>
[snip]
> +
> +/**
> + * unmap_pages() - Make a range of IOVA empty/not present
> + * @iommu_table: Table to manipulate
> + * @iova: IO virtual address to start
> + * @pgsize: Length of each page
> + * @pgcount: Length of the range in pgsize units starting from @iova
> + * @gather: Gather struct that must be flushed on return
Eh, 2 of these @params don't match the function's arguments (names).
> + *
> + * unmap_pages() will remove a translation created by map_pages(). It cannot
> + * subdivide a mapping created by map_pages(), so it should be called with
> IOVA
> + * ranges that match those passed to map_pages(). The IOVA range can
> aggregate
> + * contiguous map_pages() calls so long as no individual range is split.
> + *
> + * Context: The caller must hold a write range lock that includes
> + * the whole range.
> + *
> + * Returns: Number of bytes of VA unmapped. iova + res will be the point
> + * unmapping stopped.
> + */
> +size_t DOMAIN_NS(unmap_pages)(struct iommu_domain *domain, unsigned long
> iova,
> + size_t pgsize, size_t pgcount,
> + struct iommu_iotlb_gather *iotlb_gather)
> +{
> + struct pt_iommu *iommu_table =
> + container_of(domain, struct pt_iommu, domain);
> + struct pt_unmap_args unmap = { .free_list = IOMMU_PAGES_LIST_INIT(
> + unmap.free_list) };
> + pt_vaddr_t len = pgsize * pgcount;
> + struct pt_range range;
> + int ret;
> +
> + ret = make_range(common_from_iommu(iommu_table), &range, iova, len);
> + if (ret)
> + return 0;
> +
> + pt_walk_range(&range, __unmap_range, &unmap);
> +
> + gather_range_pages(iotlb_gather, iommu_table, iova, len,
> + &unmap.free_list);
> +
> + return unmap.unmapped;
> +}
> +EXPORT_SYMBOL_NS_GPL(DOMAIN_NS(unmap_pages), "GENERIC_PT_IOMMU");
--
~Randy
