loongarch: implement the new page table range API

Add update_mmu_cache_range() and change _PFN_SHIFT to PFN_PTE_SHIFT.  It
would probably be more efficient to implement __update_tlb() by flushing
the entire folio instead of calling __update_tlb() N times, but I'll leave
that for someone who understands the architecture better.

Link: https://lkml.kernel.org/r/20230802151406.3735276-15-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/loongarch/include/asm/cacheflush.h

@@ -47,6 +47,7 @@ void local_flush_icache_range(unsigned long start, unsigned long end);
 #define flush_cache_vmap(start, end)			do { } while (0)
 #define flush_cache_vunmap(start, end)			do { } while (0)
 #define flush_icache_page(vma, page)			do { } while (0)
+#define flush_icache_pages(vma, page)			do { } while (0)
 #define flush_icache_user_page(vma, page, addr, len)	do { } while (0)
 #define flush_dcache_page(page)				do { } while (0)
 #define flush_dcache_mmap_lock(mapping)			do { } while (0)

arch/loongarch/include/asm/pgtable-bits.h

@@ -50,12 +50,12 @@
 #define _PAGE_NO_EXEC		(_ULCAST_(1) << _PAGE_NO_EXEC_SHIFT)
 #define _PAGE_RPLV		(_ULCAST_(1) << _PAGE_RPLV_SHIFT)
 #define _CACHE_MASK		(_ULCAST_(3) << _CACHE_SHIFT)
-#define _PFN_SHIFT		(PAGE_SHIFT - 12 + _PAGE_PFN_SHIFT)
+#define PFN_PTE_SHIFT		(PAGE_SHIFT - 12 + _PAGE_PFN_SHIFT)
 
 #define _PAGE_USER	(PLV_USER << _PAGE_PLV_SHIFT)
 #define _PAGE_KERN	(PLV_KERN << _PAGE_PLV_SHIFT)
 
-#define _PFN_MASK (~((_ULCAST_(1) << (_PFN_SHIFT)) - 1) & \
+#define _PFN_MASK (~((_ULCAST_(1) << (PFN_PTE_SHIFT)) - 1) & \
 		  ((_ULCAST_(1) << (_PAGE_PFN_END_SHIFT)) - 1))
 
 /*

arch/loongarch/include/asm/pgtable.h

@@ -237,9 +237,9 @@ extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd);
 
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
-#define pte_pfn(x)		((unsigned long)(((x).pte & _PFN_MASK) >> _PFN_SHIFT))
-#define pfn_pte(pfn, prot)	__pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
-#define pfn_pmd(pfn, prot)	__pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pte_pfn(x)		((unsigned long)(((x).pte & _PFN_MASK) >> PFN_PTE_SHIFT))
+#define pfn_pte(pfn, prot)	__pte(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot)	__pmd(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
 
 /*
  * Initialize a new pgd / pud / pmd table with invalid pointers.
@@ -334,19 +334,13 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
 	}
 }
 
-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep, pte_t pteval)
-{
-	set_pte(ptep, pteval);
-}
-
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	/* Preserve global status for the pair */
 	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
-		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
+		set_pte(ptep, __pte(_PAGE_GLOBAL));
 	else
-		set_pte_at(mm, addr, ptep, __pte(0));
+		set_pte(ptep, __pte(0));
 }
 
 #define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
@@ -445,11 +439,20 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 extern void __update_tlb(struct vm_area_struct *vma,
 			unsigned long address, pte_t *ptep);
 
-static inline void update_mmu_cache(struct vm_area_struct *vma,
-			unsigned long address, pte_t *ptep)
+static inline void update_mmu_cache_range(struct vm_fault *vmf,
+		struct vm_area_struct *vma, unsigned long address,
+		pte_t *ptep, unsigned int nr)
 {
-	__update_tlb(vma, address, ptep);
+	for (;;) {
+		__update_tlb(vma, address, ptep);
+		if (--nr == 0)
+			break;
+		address += PAGE_SIZE;
+		ptep++;
+	}
 }
+#define update_mmu_cache(vma, addr, ptep) \
+	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
 
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 #define update_mmu_tlb	update_mmu_cache
@@ -462,7 +465,7 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 
 static inline unsigned long pmd_pfn(pmd_t pmd)
 {
-	return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT;
+	return (pmd_val(pmd) & _PFN_MASK) >> PFN_PTE_SHIFT;
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE

arch/loongarch/mm/pgtable.c

@@ -108,7 +108,7 @@ pmd_t mk_pmd(struct page *page, pgprot_t prot)
 {
 	pmd_t pmd;
 
-	pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
+	pmd_val(pmd) = (page_to_pfn(page) << PFN_PTE_SHIFT) | pgprot_val(prot);
 
 	return pmd;
 }

arch/loongarch/mm/tlb.c

@@ -252,7 +252,7 @@ static void output_pgtable_bits_defines(void)
 	pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
 	pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
 	pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
-	pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
+	pr_define("PFN_PTE_SHIFT %d\n", PFN_PTE_SHIFT);
 	pr_debug("\n");
 }