[SPARC64]: Avoid dcache-dirty page state management on sun4v.

It is totally wasted work, since we have no D-cache aliasing
issues on sun4v.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/mm/init.c

@@ -188,8 +188,9 @@ atomic_t dcpage_flushes_xcall = ATOMIC_INIT(0);
 #endif
 #endif
 
-__inline__ void flush_dcache_page_impl(struct page *page)
+inline void flush_dcache_page_impl(struct page *page)
 {
+	BUG_ON(tlb_type == hypervisor);
 #ifdef CONFIG_DEBUG_DCFLUSH
 	atomic_inc(&dcpage_flushes);
 #endif
@@ -279,11 +280,12 @@ unsigned long _PAGE_SZBITS __read_mostly;
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 {
 	struct mm_struct *mm;
-	struct page *page;
-	unsigned long pfn;
+
+	if (tlb_type != hypervisor) {
+		unsigned long pfn = pte_pfn(pte);
 		unsigned long pg_flags;
+		struct page *page;
 
-	pfn = pte_pfn(pte);
 		if (pfn_valid(pfn) &&
 		    (page = pfn_to_page(pfn), page_mapping(page)) &&
 		    ((pg_flags = page->flags) & (1UL << PG_dcache_dirty))) {
@@ -303,6 +305,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t p
 
 			put_cpu();
 		}
+	}
 
 	mm = vma->vm_mm;
 	if ((pte_val(pte) & _PAGE_ALL_SZ_BITS) == _PAGE_SZBITS) {
@@ -321,6 +324,9 @@ void flush_dcache_page(struct page *page)
 	struct address_space *mapping;
 	int this_cpu;
 
+	if (tlb_type == hypervisor)
+		return;
+
 	/* Do not bother with the expensive D-cache flush if it
 	 * is merely the zero page.  The 'bigcore' testcase in GDB
 	 * causes this case to run millions of times.

arch/sparc64/mm/tlb.c

@@ -49,7 +49,8 @@ void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t
 	if (pte_exec(orig))
 		vaddr |= 0x1UL;
 
-	if (pte_dirty(orig)) {
+	if (tlb_type != hypervisor &&
+	    pte_dirty(orig)) {
 		unsigned long paddr, pfn = pte_pfn(orig);
 		struct address_space *mapping;
 		struct page *page;