powerpc: Refactor update_mmu_cache_range()

On nohash, this function voids except for E500 with hugepages.

On book3s, this function is for hash MMUs only.

Combine those tests and rename E500 update_mmu_cache_range()
as __update_mmu_cache() which gets called by
update_mmu_cache_range().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/b029842cb6783cbeb43d202e69a90341d65295a4.1695659959.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/book3s/pgtable.h

@@ -8,28 +8,4 @@
 #include <asm/book3s/32/pgtable.h>
 #endif
 
-#ifndef __ASSEMBLY__
-void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
-
-/*
- * This gets called at the end of handling a page fault, when
- * the kernel has put a new PTE into the page table for the process.
- * We use it to ensure coherency between the i-cache and d-cache
- * for the page which has just been mapped in.
- * On machines which use an MMU hash table, we use this to put a
- * corresponding HPTE into the hash table ahead of time, instead of
- * waiting for the inevitable extra hash-table miss exception.
- */
-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)
-{
-	if (IS_ENABLED(CONFIG_PPC32) && !mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		return;
-	if (radix_enabled())
-		return;
-	__update_mmu_cache(vma, address, ptep);
-}
-
-#endif /* __ASSEMBLY__ */
 #endif

arch/powerpc/include/asm/nohash/pgtable.h

@@ -259,20 +259,5 @@ static inline int pud_huge(pud_t pud)
 #define is_hugepd(hpd)		(hugepd_ok(hpd))
 #endif
 
-/*
- * This gets called at the end of handling a page fault, when
- * the kernel has put a new PTE into the page table for the process.
- * We use it to ensure coherency between the i-cache and d-cache
- * for the page which has just been mapped in.
- */
-#if defined(CONFIG_PPC_E500) && defined(CONFIG_HUGETLB_PAGE)
-void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
-		unsigned long address, pte_t *ptep, unsigned int nr);
-#else
-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) {}
-#endif
-
 #endif /* __ASSEMBLY__ */
 #endif

arch/powerpc/include/asm/pgtable.h

@@ -119,6 +119,25 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot);
 #define __HAVE_PHYS_MEM_ACCESS_PROT
 
+void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
+
+/*
+ * This gets called at the end of handling a page fault, when
+ * the kernel has put a new PTE into the page table for the process.
+ * We use it to ensure coherency between the i-cache and d-cache
+ * for the page which has just been mapped in.
+ * On machines which use an MMU hash table, we use this to put a
+ * corresponding HPTE into the hash table ahead of time, instead of
+ * waiting for the inevitable extra hash-table miss exception.
+ */
+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)
+{
+	if ((mmu_has_feature(MMU_FTR_HPTE_TABLE) && !radix_enabled()) ||
+	    (IS_ENABLED(CONFIG_PPC_E500) && IS_ENABLED(CONFIG_HUGETLB_PAGE)))
+		__update_mmu_cache(vma, address, ptep);
+}
 
 /*
  * When used, PTE_FRAG_NR is defined in subarch pgtable.h

arch/powerpc/mm/nohash/e500_hugetlbpage.c

@@ -178,8 +178,7 @@ book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea, pte_t pte)
  *
  * This must always be called with the pte lock held.
  */
-void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
-		unsigned long address, pte_t *ptep, unsigned int nr)
+void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 {
 	if (is_vm_hugetlb_page(vma))
 		book3e_hugetlb_preload(vma, address, *ptep);