[POWERPC] Make tlb flush batch use lazy MMU mode

[firefly-linux-kernel-4.4.55.git] / arch / powerpc / mm / tlb_64.c

diff --git a/arch/powerpc/mm/tlb_64.c b/arch/powerpc/mm/tlb_64.c
index b58baa65c4a74f11978baf41bee0e04c428d19f6..fd8d08c325ebecca3083759360cbf6e6c30b1e8e 100644 (file)
--- a/arch/powerpc/mm/tlb_64.c
+++ b/arch/powerpc/mm/tlb_64.c
@@ -120,17 +120,20 @@ void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
 }
 
 /*
- * Update the MMU hash table to correspond with a change to
- * a Linux PTE.  If wrprot is true, it is permissible to
- * change the existing HPTE to read-only rather than removing it
- * (if we remove it we should clear the _PTE_HPTEFLAGS bits).
+ * A linux PTE was changed and the corresponding hash table entry
+ * neesd to be flushed. This function will either perform the flush
+ * immediately or will batch it up if the current CPU has an active
+ * batch on it.
+ *
+ * Must be called from within some kind of spinlock/non-preempt region...
  */
-void hpte_update(struct mm_struct *mm, unsigned long addr,
-                pte_t *ptep, unsigned long pte, int huge)
+void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
+                    pte_t *ptep, unsigned long pte, int huge)
 {
        struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
-       unsigned long vsid;
+       unsigned long vsid, vaddr;
        unsigned int psize;
+       real_pte_t rpte;
        int i;
 
        i = batch->index;
@@ -151,6 +154,26 @@ void hpte_update(struct mm_struct *mm, unsigned long addr,
        } else
                psize = pte_pagesize_index(pte);
 
+       /* Build full vaddr */
+       if (!is_kernel_addr(addr)) {
+               vsid = get_vsid(mm->context.id, addr);
+               WARN_ON(vsid == 0);
+       } else
+               vsid = get_kernel_vsid(addr);
+       vaddr = (vsid << 28 ) | (addr & 0x0fffffff);
+       rpte = __real_pte(__pte(pte), ptep);
+
+       /*
+        * Check if we have an active batch on this CPU. If not, just
+        * flush now and return. For now, we don global invalidates
+        * in that case, might be worth testing the mm cpu mask though
+        * and decide to use local invalidates instead...
+        */
+       if (!batch->active) {
+               flush_hash_page(vaddr, rpte, psize, 0);
+               return;
+       }
+
        /*
         * This can happen when we are in the middle of a TLB batch and
         * we encounter memory pressure (eg copy_page_range when it tries
@@ -162,47 +185,42 @@ void hpte_update(struct mm_struct *mm, unsigned long addr,
         * batch
         */
        if (i != 0 && (mm != batch->mm || batch->psize != psize)) {
-               flush_tlb_pending();
+               __flush_tlb_pending(batch);
                i = 0;
        }
        if (i == 0) {
                batch->mm = mm;
                batch->psize = psize;
        }
-       if (!is_kernel_addr(addr)) {
-               vsid = get_vsid(mm->context.id, addr);
-               WARN_ON(vsid == 0);
-       } else
-               vsid = get_kernel_vsid(addr);
-       batch->vaddr[i] = (vsid << 28 ) | (addr & 0x0fffffff);
-       batch->pte[i] = __real_pte(__pte(pte), ptep);
+       batch->pte[i] = rpte;
+       batch->vaddr[i] = vaddr;
        batch->index = ++i;
        if (i >= PPC64_TLB_BATCH_NR)
-               flush_tlb_pending();
+               __flush_tlb_pending(batch);
 }
 
+/*
+ * This function is called when terminating an mmu batch or when a batch
+ * is full. It will perform the flush of all the entries currently stored
+ * in a batch.
+ *
+ * Must be called from within some kind of spinlock/non-preempt region...
+ */
 void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
 {
-       int i;
-       int cpu;
        cpumask_t tmp;
-       int local = 0;
+       int i, local = 0;
 
-       BUG_ON(in_interrupt());
-
-       cpu = get_cpu();
        i = batch->index;
-       tmp = cpumask_of_cpu(cpu);
+       tmp = cpumask_of_cpu(smp_processor_id());
        if (cpus_equal(batch->mm->cpu_vm_mask, tmp))
                local = 1;
-
        if (i == 1)
                flush_hash_page(batch->vaddr[0], batch->pte[0],
                                batch->psize, local);
        else
                flush_hash_range(i, local);
        batch->index = 0;
-       put_cpu();
 }
 
 void pte_free_finish(void)