MIPS: Flush huge TLB

When flushing TLB, if @vma is backed by huge page, we could flush huge
TLB, due to that huge page is defined to be far from normal page.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: "Jayachandran C." <jayachandranc@netlogicmicro.com>
Patchwork: https://patchwork.linux-mips.org/patch/2825/Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/3114/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/page.h

@@ -38,6 +38,14 @@
 #define HPAGE_SIZE	(_AC(1,UL) << HPAGE_SHIFT)
 #define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
+#else /* !CONFIG_HUGETLB_PAGE */
+# ifndef BUILD_BUG
+#  define BUILD_BUG() do { extern void __build_bug(void); __build_bug(); } while (0)
+# endif
+#define HPAGE_SHIFT	({BUILD_BUG(); 0; })
+#define HPAGE_SIZE	({BUILD_BUG(); 0; })
+#define HPAGE_MASK	({BUILD_BUG(); 0; })
+#define HUGETLB_PAGE_ORDER	({BUILD_BUG(); 0; })
 #endif /* CONFIG_HUGETLB_PAGE */
 
 #ifndef __ASSEMBLY__

arch/mips/mm/tlb-r4k.c

@@ -120,21 +120,29 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 
 	if (cpu_context(cpu, mm) != 0) {
 		unsigned long size, flags;
+		int huge = is_vm_hugetlb_page(vma);
 
 		ENTER_CRITICAL(flags);
-		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
-		size = (size + 1) >> 1;
+		if (huge) {
+			start = round_down(start, HPAGE_SIZE);
+			end = round_up(end, HPAGE_SIZE);
+			size = (end - start) >> HPAGE_SHIFT;
+		} else {
+			start = round_down(start, PAGE_SIZE << 1);
+			end = round_up(end, PAGE_SIZE << 1);
+			size = (end - start) >> (PAGE_SHIFT + 1);
+		}
 		if (size <= current_cpu_data.tlbsize/2) {
 			int oldpid = read_c0_entryhi();
 			int newpid = cpu_asid(cpu, mm);
 
-			start &= (PAGE_MASK << 1);
-			end += ((PAGE_SIZE << 1) - 1);
-			end &= (PAGE_MASK << 1);
 			while (start < end) {
 				int idx;
 
 				write_c0_entryhi(start | newpid);
+				if (huge)
+					start += HPAGE_SIZE;
+				else
 					start += (PAGE_SIZE << 1);
 				mtc0_tlbw_hazard();
 				tlb_probe();