powerpc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes

[platform/kernel/linux-starfive.git] / arch / powerpc / mm / pgtable.c

diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 3f86fd2..c3e9fef 100644 (file)
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -104,6 +104,8 @@ static pte_t set_pte_filter_hash(pte_t pte) { return pte; }
 /* Embedded type MMU with HW exec support. This is a bit more complicated
  * as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so
  * instead we "filter out" the exec permission for non clean pages.
+ *
+ * This is also called once for the folio. So only work with folio->flags here.
  */
 static inline pte_t set_pte_filter(pte_t pte)
 {
@@ -190,29 +192,39 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma,
 void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
                pte_t pte, unsigned int nr)
 {
-       /*
-        * Make sure hardware valid bit is not set. We don't do
-        * tlb flush for this update.
-        */
-       VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
 
        /* Note: mm->context.id might not yet have been assigned as
         * this context might not have been activated yet when this
-        * is called.
+        * is called. Filter the pte value and use the filtered value
+        * to setup all the ptes in the range.
         */
        pte = set_pte_filter(pte);
 
-       /* Perform the setting of the PTE */
-       arch_enter_lazy_mmu_mode();
+       /*
+        * We don't need to call arch_enter/leave_lazy_mmu_mode()
+        * because we expect set_ptes to be only be used on not present
+        * and not hw_valid ptes. Hence there is no translation cache flush
+        * involved that need to be batched.
+        */
        for (;;) {
+
+               /*
+                * Make sure hardware valid bit is not set. We don't do
+                * tlb flush for this update.
+                */
+               VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
+
+               /* Perform the setting of the PTE */
                __set_pte_at(mm, addr, ptep, pte, 0);
                if (--nr == 0)
                        break;
                ptep++;
-               pte = __pte(pte_val(pte) + (1UL << PTE_RPN_SHIFT));
                addr += PAGE_SIZE;
+               /*
+                * increment the pfn.
+                */
+               pte = pfn_pte(pte_pfn(pte) + 1, pte_pgprot((pte)));
        }
-       arch_leave_lazy_mmu_mode();
 }
 
 void unmap_kernel_page(unsigned long va)