mm: insert hugepage pte by pa

scend inclusion
category: feature
bugzilla: NA
CVE: NA

-------------------

The cross OS sdma copy needs to map the OS's physical address
to the tx-atu of the remote device through PCIE.
However, the sdma copy only receives the virtual address,
thus a page table is necessary to provide mapping between
tx-atu and the virtual address.
Signed-off-by: NGuanghui Zhou <zhouguanghui1@huawei.com>
Signed-off-by: NLI Heng <liheng40@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mm/hugetlb.c

@@ -5196,4 +5196,28 @@ int hugetlb_insert_hugepage_pte(struct mm_struct *mm, unsigned long addr,
 }
 EXPORT_SYMBOL_GPL(hugetlb_insert_hugepage_pte);
 
+int hugetlb_insert_hugepage_pte_by_pa(struct mm_struct *mm,
+				    unsigned long vir_addr,
+				    pgprot_t prot, unsigned long phy_addr)
+{
+	pte_t *ptep, entry;
+	struct hstate *h = &default_hstate;
+
+	ptep = hugetlb_huge_pte_alloc(mm, vir_addr, huge_page_size(h));
+	if (!ptep)
+		return -ENXIO;
+
+	WARN_ON(ptep && !pte_none(*ptep) && !pte_huge(*ptep));
+
+	entry = pfn_pte(phy_addr >> PAGE_SHIFT, prot);
+	entry = huge_pte_mkdirty(entry);
+	entry = huge_pte_mkwrite(entry);
+	entry = pte_mkyoung(entry);
+	entry = pte_mkhuge(entry);
+	entry = pte_mkspecial(entry);
+	set_huge_pte_at(mm, vir_addr, ptep, entry);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hugetlb_insert_hugepage_pte_by_pa);
+
 #endif