powerpc/book3s: Inline first level of update_mmu_cache()

update_mmu_cache() voids when hash page tables are not used.
On PPC32 that means when MMU_FTR_HPTE_TABLE is not defined.
On PPC64 that means when RADIX is enabled.

Rename core part of update_mmu_cache() as __update_mmu_cache()
and include the initial verification in an inlined caller.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bea5ad0de7f83eff256116816d46c84fa0a444de.1662370698.git.christophe.leroy@csgroup.eu

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

@@ -25,7 +25,8 @@ extern 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
 
-#if defined(CONFIG_PPC32) || defined(CONFIG_PPC_64S_HASH_MMU)
+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.
@@ -35,10 +36,14 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  * corresponding HPTE into the hash table ahead of time, instead of
  * waiting for the inevitable extra hash-table miss exception.
  */
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
-#else
-static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) {}
-#endif
+static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+	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/mm/book3s32/mmu.c

@@ -314,11 +314,9 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea)
  *
  * This must always be called with the pte lock held.
  */
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 		      pte_t *ptep)
 {
-	if (!mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		return;
 	/*
 	 * We don't need to worry about _PAGE_PRESENT here because we are
 	 * called with either mm->page_table_lock held or ptl lock held

arch/powerpc/mm/book3s64/hash_utils.c

@@ -1781,7 +1781,7 @@ static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
  *
  * This must always be called with the pte lock held.
  */
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 		      pte_t *ptep)
 {
 	/*
@@ -1791,9 +1791,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 	unsigned long trap;
 	bool is_exec;
 
-	if (radix_enabled())
-		return;
-
 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 	if (!pte_young(*ptep) || address >= TASK_SIZE)
 		return;