m68k: mm: Change ColdFire pgtable_t

To match what we did to the Motorola MMU routines, change the ColdFire
pgalloc.

The result is that ColdFire and Sun3 pgalloc are actually very similar
and could conceivably be unified.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200131125403.995781825@infradead.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/mcf_pgalloc.h

@@ -28,21 +28,22 @@ extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
 	return (pmd_t *) pgd;
 }
 
-#define pmd_populate(mm, pmd, page) (pmd_val(*pmd) = \
-	(unsigned long)(page_address(page)))
+#define pmd_populate(mm, pmd, pte) (pmd_val(*pmd) = (unsigned long)(pte))
 
-#define pmd_populate_kernel(mm, pmd, pte) (pmd_val(*pmd) = (unsigned long)(pte))
+#define pmd_populate_kernel pmd_populate
 
-#define pmd_pgtable(pmd) pmd_page(pmd)
+#define pmd_pgtable(pmd) pfn_to_virt(pmd_val(pmd) >> PAGE_SHIFT)
 
-static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t page,
+static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable,
 				  unsigned long address)
 {
+	struct page *page = virt_to_page(pgtable);
+
 	pgtable_pte_page_dtor(page);
 	__free_page(page);
 }
 
-static inline struct page *pte_alloc_one(struct mm_struct *mm)
+static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
 {
 	struct page *page = alloc_pages(GFP_DMA, 0);
 	pte_t *pte;
@@ -54,16 +55,16 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm)
 		return NULL;
 	}
 
-	pte = kmap(page);
-	if (pte)
-		clear_page(pte);
-	kunmap(page);
+	pte = page_address(page);
+	clear_page(pte);
 
-	return page;
+	return pte;
 }
 
-static inline void pte_free(struct mm_struct *mm, struct page *page)
+static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
 {
+	struct page *page = virt_to_page(pgtable);
+
 	pgtable_pte_page_dtor(page);
 	__free_page(page);
 }

arch/m68k/include/asm/page.h

@@ -31,7 +31,12 @@ typedef struct { unsigned long pte; } pte_t;
 typedef struct { unsigned long pgd; } pgd_t;
 typedef struct { unsigned long pgprot; } pgprot_t;
 
-#if defined(CONFIG_SUN3) || defined(CONFIG_COLDFIRE)
+#if defined(CONFIG_SUN3)
+/*
+ * Sun3 still uses the asm-generic/pgalloc.h code and thus needs this
+ * definition. It would be possible to unify Sun3 and ColdFire pgalloc and have
+ * all of m68k use the same type.
+ */
 typedef struct page *pgtable_t;
 #else
 typedef pte_t *pgtable_t;