[PATCH v4 12/16] cputlb: Handle TLB_NOTDIRTY in probe_access

[Richard Henderson <richard.henderson@linaro.org>]

We can use notdirty_write for the write and
return a valid host pointer for this case.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 accel/tcg/cputlb.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index 09b0df87c6..d0bdef1eb3 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -1167,16 +1167,24 @@ void *probe_access(CPUArchState *env, target_ulong addr, int size,
         return NULL;
     }
 
-    /* Handle watchpoints.  */
-    if (tlb_addr & TLB_WATCHPOINT) {
-        cpu_check_watchpoint(env_cpu(env), addr, size,
-                             env_tlb(env)->d[mmu_idx].iotlb[index].attrs,
-                             wp_access, retaddr);
-    }
+    if (unlikely(tlb_addr & TLB_FLAGS_MASK)) {
+        CPUIOTLBEntry *iotlbentry = &env_tlb(env)->d[mmu_idx].iotlb[index];
 
-    /* Reject I/O access, or other required slow-path.  */
-    if (tlb_addr & (TLB_NOTDIRTY | TLB_MMIO | TLB_BSWAP | TLB_ROM)) {
-        return NULL;
+        /* Reject I/O access, or other required slow-path.  */
+        if (tlb_addr & (TLB_MMIO | TLB_BSWAP | TLB_ROM)) {
+            return NULL;
+        }
+
+        /* Handle watchpoints.  */
+        if (tlb_addr & TLB_WATCHPOINT) {
+            cpu_check_watchpoint(env_cpu(env), addr, size,
+                                 iotlbentry->attrs, wp_access, retaddr);
+        }
+
+        /* Handle clean RAM pages.  */
+        if (tlb_addr & TLB_NOTDIRTY) {
+            notdirty_write(env_cpu(env), addr, size, iotlbentry, retaddr);
+        }
     }
 
     return (void *)((uintptr_t)addr + entry->addend);
-- 
2.17.1