sgi-gru: restructure the GRU vtop functions

Restructure the GRU vtop functions in preparation for future changes.
This patch simply moves code around & does not change the algorithm.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 44 insertions, 24 deletions

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 8ae426edc854..bf6e9f7bed54 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -267,6 +267,44 @@ err:
         return 1;
 }
 
+static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
+                    int write, int atomic, unsigned long *gpa, int *pageshift)
+{
+        struct mm_struct *mm = gts->ts_mm;
+        struct vm_area_struct *vma;
+        unsigned long paddr;
+        int ret, ps;
+
+        vma = find_vma(mm, vaddr);
+        if (!vma)
+                goto inval;
+
+        /*
+         * Atomic lookup is faster & usually works even if called in non-atomic
+         * context.
+         */
+        rmb();  /* Must/check ms_range_active before loading PTEs */
+        ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &ps);
+        if (ret) {
+                if (atomic)
+                        goto upm;
+                if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps))
+                        goto inval;
+        }
+        if (is_gru_paddr(paddr))
+                goto inval;
+        paddr = paddr & ~((1UL << ps) - 1);
+        *gpa = uv_soc_phys_ram_to_gpa(paddr);
+        *pageshift = ps;
+        return 0;
+
+inval:
+        return -1;
+upm:
+        return -2;
+}
+
+
 /*
  * Drop a TLB entry into the GRU. The fault is described by info in an TFH.
  *      Input:
@@ -281,10 +319,8 @@ static int gru_try_dropin(struct gru_thread_state *gts,
                           struct gru_tlb_fault_handle *tfh,
                           unsigned long __user *cb)
 {
-        struct mm_struct *mm = gts->ts_mm;
-        struct vm_area_struct *vma;
-        int pageshift, asid, write, ret;
-        unsigned long paddr, gpa, vaddr;
+        int pageshift = 0, asid, write, ret, atomic = !cb;
+        unsigned long gpa = 0, vaddr = 0;
 
         /*
          * NOTE: The GRU contains magic hardware that eliminates races between
@@ -318,28 +354,12 @@ static int gru_try_dropin(struct gru_thread_state *gts,
         if (atomic_read(&gts->ts_gms->ms_range_active))
                 goto failactive;
 
-        vma = find_vma(mm, vaddr);
-        if (!vma)
-                goto failinval;
-
-        /*
-         * Atomic lookup is faster & usually works even if called in non-atomic
-         * context.
-         */
-        rmb();  /* Must/check ms_range_active before loading PTEs */
-        ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &pageshift);
-        if (ret) {
-                if (!cb)
-                        goto failupm;
-                if (non_atomic_pte_lookup(vma, vaddr, write, &paddr,
-                                          &pageshift))
-                        goto failinval;
-        }
-        if (is_gru_paddr(paddr))
+        ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
+        if (ret == -1)
                 goto failinval;
+        if (ret == -2)
+                goto failupm;
 
-        paddr = paddr & ~((1UL << pageshift) - 1);
-        gpa = uv_soc_phys_ram_to_gpa(paddr);
         gru_cb_set_istatus_active(cb);
         tfh_write_restart(tfh, gpa, GAA_RAM, vaddr, asid, write,
                           GRU_PAGESIZE(pageshift));