[PATCH 14/29] csky: Fixup FAULT_FLAG_XXX param for handle_mm_fault

[guoren]

From: Guo Ren <guo...@linux.alibaba.com>

The past code only passes the FAULT_FLAG_WRITE into
handle_mm_fault and missing USER & DEFAULT & RETRY.

The patch references to arch/riscv/mm/fault.c, but there is no
FAULT_FLAG_INSTRUCTION in csky hw.

Signed-off-by: Guo Ren <guo...@linux.alibaba.com>
---
 arch/csky/mm/fault.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index e888acf1c403..cecca6729b04 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -80,6 +80,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
        struct vm_area_struct *vma = NULL;
        struct task_struct *tsk = current;
        struct mm_struct *mm = tsk->mm;
+       unsigned int flags = FAULT_FLAG_DEFAULT;
        int si_code;
        int fault;
        unsigned long address = read_mmu_entryhi() & PAGE_MASK;
@@ -150,6 +151,13 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
        if (in_atomic() || !mm)
                goto bad_area_nosemaphore;
 
+       if (user_mode(regs))
+               flags |= FAULT_FLAG_USER;
+
+       if (is_write(regs))
+               flags |= FAULT_FLAG_WRITE;
+
+retry:
        mmap_read_lock(mm);
        vma = find_vma(mm, address);
        if (!vma)
@@ -180,8 +188,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
         * make sure we exit gracefully rather than endlessly redo
         * the fault.
         */
-       fault = handle_mm_fault(vma, address, is_write(regs) ? FAULT_FLAG_WRITE 
: 0,
-                               regs);
+       fault = handle_mm_fault(vma, address, flags, regs);
        if (unlikely(fault & VM_FAULT_ERROR)) {
                if (fault & VM_FAULT_OOM)
                        goto out_of_memory;
@@ -191,6 +198,18 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
                        goto bad_area;
                BUG();
        }
+
+       if (unlikely((fault & VM_FAULT_RETRY) && (flags & 
FAULT_FLAG_ALLOW_RETRY))) {
+               flags |= FAULT_FLAG_TRIED;
+
+               /*
+                * No need to mmap_read_unlock(mm) as we would
+                * have already released it in __lock_page_or_retry
+                * in mm/filemap.c.
+                */
+               goto retry;
+       }
+
        mmap_read_unlock(mm);
        return;
 
-- 
2.17.1