From d3e0c885770951c7285ea79d11b1cdfc96e6600f Mon Sep 17 00:00:00 2001
From: Kautuk Consul <consul.kautuk@gmail.com>
Date: Tue, 20 Mar 2012 09:21:40 -0400
Subject: [PATCH] --- yaml --- r: 308490 b: refs/heads/master c:
 f397c077e114df07bd2b94a16681a04be8d59dff h: refs/heads/master v: v3

---
 [refs]                           |  2 +-
 trunk/arch/microblaze/mm/fault.c | 33 +++++++++++++++++++++++++++-----
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index a3ffe9ff6d8a..0174f4335b09 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 59516b07b4ffa7e607a5787674ea3c405f1b390c
+refs/heads/master: f397c077e114df07bd2b94a16681a04be8d59dff
diff --git a/trunk/arch/microblaze/mm/fault.c b/trunk/arch/microblaze/mm/fault.c
index c38a265846de..eb365d6795fa 100644
--- a/trunk/arch/microblaze/mm/fault.c
+++ b/trunk/arch/microblaze/mm/fault.c
@@ -92,6 +92,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 	int code = SEGV_MAPERR;
 	int is_write = error_code & ESR_S;
 	int fault;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
+					 (is_write ? FAULT_FLAG_WRITE : 0);
 
 	regs->ear = address;
 	regs->esr = error_code;
@@ -138,6 +140,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 		if (kernel_mode(regs) && !search_exception_tables(regs->pc))
 			goto bad_area_nosemaphore;
 
+retry:
 		down_read(&mm->mmap_sem);
 	}
 
@@ -210,7 +213,11 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 	 * make sure we exit gracefully rather than endlessly redo
 	 * the fault.
 	 */
-	fault = handle_mm_fault(mm, vma, address, is_write ? FAULT_FLAG_WRITE : 0);
+	fault = handle_mm_fault(mm, vma, address, flags);
+
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return;
+
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		if (fault & VM_FAULT_OOM)
 			goto out_of_memory;
@@ -218,11 +225,27 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 			goto do_sigbus;
 		BUG();
 	}
-	if (unlikely(fault & VM_FAULT_MAJOR))
-		current->maj_flt++;
-	else
-		current->min_flt++;
+
+	if (flags & FAULT_FLAG_ALLOW_RETRY) {
+		if (unlikely(fault & VM_FAULT_MAJOR))
+			current->maj_flt++;
+		else
+			current->min_flt++;
+		if (fault & VM_FAULT_RETRY) {
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+
+			/*
+			 * No need to up_read(&mm->mmap_sem) as we would
+			 * have already released it in __lock_page_or_retry
+			 * in mm/filemap.c.
+			 */
+
+			goto retry;
+		}
+	}
+
 	up_read(&mm->mmap_sem);
+
 	/*
 	 * keep track of tlb+htab misses that are good addrs but
 	 * just need pte's created via handle_mm_fault()