+static void kvmppc_rm_clear_tce(struct iommu_table *tbl, unsigned long entry)
+{
+ unsigned long hpa = 0;
+ enum dma_data_direction dir = DMA_NONE;
+
+ iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
+}
+
+static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm,
+ struct iommu_table *tbl, unsigned long entry)
+{
+ struct mm_iommu_table_group_mem_t *mem = NULL;
+ const unsigned long pgsize = 1ULL << tbl->it_page_shift;
+ unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
+
+ if (!pua)
+ /* it_userspace allocation might be delayed */
+ return H_TOO_HARD;
+
+ pua = (void *) vmalloc_to_phys(pua);
+ if (WARN_ON_ONCE_RM(!pua))
+ return H_HARDWARE;
+
+ mem = mm_iommu_lookup_rm(kvm->mm, *pua, pgsize);
+ if (!mem)
+ return H_TOO_HARD;
+
+ mm_iommu_mapped_dec(mem);
+
+ *pua = 0;
+
+ return H_SUCCESS;
+}
+
+static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
+ struct iommu_table *tbl, unsigned long entry)
+{
+ enum dma_data_direction dir = DMA_NONE;
+ unsigned long hpa = 0;
+ long ret;
+
+ if (iommu_tce_xchg_rm(tbl, entry, &hpa, &dir))
+ /*
+ * real mode xchg can fail if struct page crosses
+ * a page boundary
+ */
+ return H_TOO_HARD;
+
+ if (dir == DMA_NONE)
+ return H_SUCCESS;
+
+ ret = kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);
+ if (ret)
+ iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
+
+ return ret;
+}
+
+static long kvmppc_rm_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
+ unsigned long entry, unsigned long ua,
+ enum dma_data_direction dir)
+{
+ long ret;
+ unsigned long hpa = 0;
+ unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
+ struct mm_iommu_table_group_mem_t *mem;
+
+ if (!pua)
+ /* it_userspace allocation might be delayed */
+ return H_TOO_HARD;
+
+ mem = mm_iommu_lookup_rm(kvm->mm, ua, 1ULL << tbl->it_page_shift);
+ if (!mem)
+ return H_TOO_HARD;
+
+ if (WARN_ON_ONCE_RM(mm_iommu_ua_to_hpa_rm(mem, ua, &hpa)))
+ return H_HARDWARE;
+
+ pua = (void *) vmalloc_to_phys(pua);
+ if (WARN_ON_ONCE_RM(!pua))
+ return H_HARDWARE;
+
+ if (WARN_ON_ONCE_RM(mm_iommu_mapped_inc(mem)))
+ return H_CLOSED;
+
+ ret = iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
+ if (ret) {
+ mm_iommu_mapped_dec(mem);
+ /*
+ * real mode xchg can fail if struct page crosses
+ * a page boundary
+ */
+ return H_TOO_HARD;
+ }
+
+ if (dir != DMA_NONE)
+ kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);
+
+ *pua = ua;
+
+ return 0;
+}
+