loongarch: convert various functions to use ptdescs

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions.  Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Link: https://lkml.kernel.org/r/20230807230513.102486-22-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/loongarch/include/asm/pgalloc.h

@@ -45,9 +45,9 @@ extern void pagetable_init(void);
 extern pgd_t *pgd_alloc(struct mm_struct *mm);
 
 #define __pte_free_tlb(tlb, pte, address)			\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb), pte);			\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
 } while (0)
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -55,18 +55,18 @@ do {							\
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pmd_t *pmd;
-	struct page *pg;
+	struct ptdesc *ptdesc;
 
-	pg = alloc_page(GFP_KERNEL_ACCOUNT);
-	if (!pg)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, 0);
+	if (!ptdesc)
 		return NULL;
 
-	if (!pgtable_pmd_page_ctor(pg)) {
-		__free_page(pg);
+	if (!pagetable_pmd_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	pmd = (pmd_t *)page_address(pg);
+	pmd = ptdesc_address(ptdesc);
 	pmd_init(pmd);
 	return pmd;
 }
@@ -80,10 +80,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pud_t *pud;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
 
-	pud = (pud_t *) __get_free_page(GFP_KERNEL);
-	if (pud)
-		pud_init(pud);
+	if (!ptdesc)
+		return NULL;
+	pud = ptdesc_address(ptdesc);
+
+	pud_init(pud);
 	return pud;
 }
 

arch/loongarch/mm/pgtable.c

@@ -11,10 +11,11 @@
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	pgd_t *ret, *init;
+	pgd_t *init, *ret = NULL;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
 
-	ret = (pgd_t *) __get_free_page(GFP_KERNEL);
-	if (ret) {
+	if (ptdesc) {
+		ret = (pgd_t *)ptdesc_address(ptdesc);
 		init = pgd_offset(&init_mm, 0UL);
 		pgd_init(ret);
 		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,