mmu-hash*: Don't use full ppc_hash{32, 64}_translate() path for get_phys_page_debug()

Currently the hash mmu versionsof get_phys_page_debug() use the same
ppc64_hash64_translate() function to do the translation logic as the normal
mm fault handler code.

That sounds like a good idea, but has some complications. The debug path
doesn't need, or even want some parts of the full translation path, like
permissions checking.  Furthermore, the pte flags update included in the
normal path means that the debug call is not quite side effect free.

This patch, therefore, reimplements get_phys_page_debug as the minimal
required subset of the full translation path.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>`z
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/target-ppc/mmu-hash32.c b/target-ppc/mmu-hash32.c
index 07e9b8c..5ec1a09 100644
--- a/target-ppc/mmu-hash32.c
+++ b/target-ppc/mmu-hash32.c
@@ -437,18 +437,38 @@
     return 0;
 }
 
-hwaddr ppc_hash32_get_phys_page_debug(CPUPPCState *env, target_ulong addr)
+hwaddr ppc_hash32_get_phys_page_debug(CPUPPCState *env, target_ulong eaddr)
 {
-    struct mmu_ctx_hash32 ctx;
+    target_ulong sr;
+    hwaddr pte_offset;
+    ppc_hash_pte32_t pte;
+    int prot;
 
-    /* FIXME: Will not behave sanely for direct store segments, but
-     * they're almost never used */
-    if (unlikely(ppc_hash32_translate(env, &ctx, addr, 0)
-                 != 0)) {
+    if (msr_dr == 0) {
+        /* Translation is off */
+        return eaddr;
+    }
+
+    if (env->nb_BATs != 0) {
+        hwaddr raddr = ppc_hash32_bat_lookup(env, eaddr, 0, &prot);
+        if (raddr != -1) {
+            return raddr;
+        }
+    }
+
+    sr = env->sr[eaddr >> 28];
+
+    if (sr & SR32_T) {
+        /* FIXME: Add suitable debug support for Direct Store segments */
         return -1;
     }
 
-    return ctx.raddr & TARGET_PAGE_MASK;
+    pte_offset = ppc_hash32_htab_lookup(env, sr, eaddr, &pte);
+    if (pte_offset == -1) {
+        return -1;
+    }
+
+    return ppc_hash32_pte_raddr(sr, pte, eaddr) & TARGET_PAGE_MASK;
 }
 
 int ppc_hash32_handle_mmu_fault(CPUPPCState *env, target_ulong address, int rwx,