diff options
| -rw-r--r-- | drivers/iommu/generic_pt/iommu_pt.h | 156 | ||||
| -rw-r--r-- | include/linux/generic_pt/iommu.h | 10 |
2 files changed, 164 insertions, 2 deletions
diff --git a/drivers/iommu/generic_pt/iommu_pt.h b/drivers/iommu/generic_pt/iommu_pt.h index 5ff1b887928a..e3d1b272723d 100644 --- a/drivers/iommu/generic_pt/iommu_pt.h +++ b/drivers/iommu/generic_pt/iommu_pt.h @@ -14,6 +14,29 @@ #include <linux/export.h> #include <linux/iommu.h> #include "../iommu-pages.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) @@ -164,6 +187,139 @@ static inline struct pt_table_p *table_alloc_top(struct pt_common *common, log2_to_int(pt_top_memsize_lg2(common, top_of_table))); } +struct pt_unmap_args { + struct iommu_pages_list free_list; + pt_vaddr_t unmapped; +}; + +static __maybe_unused int __unmap_range(struct pt_range *range, void *arg, + unsigned int level, + struct pt_table_p *table) +{ + struct pt_state pts = pt_init(range, level, table); + struct pt_unmap_args *unmap = arg; + unsigned int num_oas = 0; + unsigned int start_index; + int ret = 0; + + _pt_iter_first(&pts); + start_index = pts.index; + pts.type = pt_load_entry_raw(&pts); + /* + * A starting index is in the middle of a contiguous entry + * + * The IOMMU API does not require drivers to support unmapping parts of + * large pages. Long ago VFIO would try to split maps but the current + * version never does. + * + * Instead when unmap reaches a partial unmap of the start of a large + * IOPTE it should remove the entire IOPTE and return that size to the + * caller. + */ + if (pts.type == PT_ENTRY_OA) { + if (log2_mod(range->va, pt_entry_oa_lg2sz(&pts))) + return -EINVAL; + /* Micro optimization */ + goto start_oa; + } + + do { + if (pts.type != PT_ENTRY_OA) { + bool fully_covered; + + if (pts.type != PT_ENTRY_TABLE) { + ret = -EINVAL; + break; + } + + if (pts.index != start_index) + pt_index_to_va(&pts); + pts.table_lower = pt_table_ptr(&pts); + + fully_covered = pt_entry_fully_covered( + &pts, pt_table_item_lg2sz(&pts)); + + ret = pt_descend(&pts, arg, __unmap_range); + if (ret) + break; + + /* + * If the unmapping range fully covers the table then we + * can free it as well. The clear is delayed until we + * succeed in clearing the lower table levels. + */ + if (fully_covered) { + iommu_pages_list_add(&unmap->free_list, + pts.table_lower); + pt_clear_entries(&pts, ilog2(1)); + } + pts.index++; + } else { + unsigned int num_contig_lg2; +start_oa: + /* + * If the caller requested an last that falls within a + * single entry then the entire entry is unmapped and + * the length returned will be larger than requested. + */ + num_contig_lg2 = pt_entry_num_contig_lg2(&pts); + pt_clear_entries(&pts, num_contig_lg2); + num_oas += log2_to_int(num_contig_lg2); + pts.index += log2_to_int(num_contig_lg2); + } + if (pts.index >= pts.end_index) + break; + pts.type = pt_load_entry_raw(&pts); + } while (true); + + unmap->unmapped += log2_mul(num_oas, pt_table_item_lg2sz(&pts)); + return ret; +} + +/** + * unmap_pages() - Make a range of IOVA empty/not present + * @domain: Domain to manipulate + * @iova: IO virtual address to start + * @pgsize: Length of each page + * @pgcount: Length of the range in pgsize units starting from @iova + * @iotlb_gather: Gather struct that must be flushed on return + * + * 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"); + static void NS(get_info)(struct pt_iommu *iommu_table, struct pt_iommu_info *info) { diff --git a/include/linux/generic_pt/iommu.h b/include/linux/generic_pt/iommu.h index 5622856e1998..ceb6bc9cea37 100644 --- a/include/linux/generic_pt/iommu.h +++ b/include/linux/generic_pt/iommu.h @@ -9,6 +9,7 @@ #include <linux/iommu.h> #include <linux/mm_types.h> +struct iommu_iotlb_gather; struct pt_iommu_ops; /** @@ -119,6 +120,10 @@ struct pt_iommu_cfg { #define IOMMU_PROTOTYPES(fmt) \ phys_addr_t pt_iommu_##fmt##_iova_to_phys(struct iommu_domain *domain, \ dma_addr_t iova); \ + size_t pt_iommu_##fmt##_unmap_pages( \ + struct iommu_domain *domain, unsigned long iova, \ + size_t pgsize, size_t pgcount, \ + struct iommu_iotlb_gather *iotlb_gather); \ int pt_iommu_##fmt##_init(struct pt_iommu_##fmt *table, \ const struct pt_iommu_##fmt##_cfg *cfg, \ gfp_t gfp); \ @@ -135,8 +140,9 @@ struct pt_iommu_cfg { * A driver uses IOMMU_PT_DOMAIN_OPS to populate the iommu_domain_ops for the * iommu_pt */ -#define IOMMU_PT_DOMAIN_OPS(fmt) \ - .iova_to_phys = &pt_iommu_##fmt##_iova_to_phys, +#define IOMMU_PT_DOMAIN_OPS(fmt) \ + .iova_to_phys = &pt_iommu_##fmt##_iova_to_phys, \ + .unmap_pages = &pt_iommu_##fmt##_unmap_pages /* * The driver should setup its domain struct like |