[Qemu-ppc] [PATCH 20/32] mmu-hash64: Cleanup segment-level access checks

[David Gibson]

On the 64-bit hash mmu model, no-execute can be set at the segment level
(as well as the page level).  This patch separates out this check to make
it clearer what is going on, and avoiding excessive indentation of the
remaining translation code.

Signed-off-by: David Gibson <address@hidden>
---
 target-ppc/mmu-hash64.c |   68 +++++++++++++++++++++++------------------------
 1 file changed, 34 insertions(+), 34 deletions(-)

diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 17781a4..14585c0 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -454,14 +454,20 @@ static int ppc_hash64_translate(CPUPPCState *env, struct 
mmu_ctx_hash64 *ctx,
         return 0;
     }
 
-    pr = msr_pr;
-
-    LOG_MMU("Check SLBs\n");
+    /* 2. Translation is on, so look up the SLB */
     slb = slb_lookup(env, eaddr);
+
     if (!slb) {
         return -5;
     }
 
+    /* 3. Check for segment level no-execute violation */
+    if ((rwx == 2) && (slb->vsid & SLB_VSID_N)) {
+        return -3;
+    }
+
+    pr = msr_pr;
+
     if (slb->vsid & SLB_VSID_B) {
         vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT_1T;
         segment_bits = 40;
@@ -490,38 +496,32 @@ static int ppc_hash64_translate(CPUPPCState *env, struct 
mmu_ctx_hash64 *ctx,
             ctx->key, !!(slb->vsid & SLB_VSID_N), vsid);
     ret = -1;
 
-    /* Check if instruction fetch is allowed, if needed */
-    if (rwx != 2 || !(slb->vsid & SLB_VSID_N)) {
-        /* Page address translation */
-        LOG_MMU("htab_base " TARGET_FMT_plx " htab_mask " TARGET_FMT_plx
-                " hash " TARGET_FMT_plx "\n",
-                env->htab_base, env->htab_mask, hash);
-        ctx->hash[0] = hash;
-        ctx->hash[1] = ~hash;
-
-        /* Initialize real address with an invalid value */
-        ctx->raddr = (hwaddr)-1ULL;
-        LOG_MMU("0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
-                " vsid=" TARGET_FMT_lx " ptem=" TARGET_FMT_lx
-                " hash=" TARGET_FMT_plx "\n",
-                env->htab_base, env->htab_mask, vsid, ctx->ptem,
-                ctx->hash[0]);
-        /* Primary table lookup */
-        ret = find_pte64(env, ctx, eaddr, 0, rwx, target_page_bits);
-        if (ret < 0) {
-            /* Secondary table lookup */
-            LOG_MMU("1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
-                    " vsid=" TARGET_FMT_lx " api=" TARGET_FMT_lx
-                    " hash=" TARGET_FMT_plx "\n", env->htab_base,
-                    env->htab_mask, vsid, ctx->ptem, ctx->hash[1]);
-            ret2 = find_pte64(env, ctx, eaddr, 1, rwx, target_page_bits);
-            if (ret2 != -1) {
-                ret = ret2;
-            }
+    /* Page address translation */
+    LOG_MMU("htab_base " TARGET_FMT_plx " htab_mask " TARGET_FMT_plx
+            " hash " TARGET_FMT_plx "\n",
+            env->htab_base, env->htab_mask, hash);
+    ctx->hash[0] = hash;
+    ctx->hash[1] = ~hash;
+
+    /* Initialize real address with an invalid value */
+    ctx->raddr = (hwaddr)-1ULL;
+    LOG_MMU("0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
+            " vsid=" TARGET_FMT_lx " ptem=" TARGET_FMT_lx
+            " hash=" TARGET_FMT_plx "\n",
+            env->htab_base, env->htab_mask, vsid, ctx->ptem,
+            ctx->hash[0]);
+    /* Primary table lookup */
+    ret = find_pte64(env, ctx, eaddr, 0, rwx, target_page_bits);
+    if (ret < 0) {
+        /* Secondary table lookup */
+        LOG_MMU("1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
+                " vsid=" TARGET_FMT_lx " api=" TARGET_FMT_lx
+                " hash=" TARGET_FMT_plx "\n", env->htab_base,
+                env->htab_mask, vsid, ctx->ptem, ctx->hash[1]);
+        ret2 = find_pte64(env, ctx, eaddr, 1, rwx, target_page_bits);
+        if (ret2 != -1) {
+            ret = ret2;
         }
-    } else {
-        LOG_MMU("No access allowed\n");
-        ret = -3;
     }
 
     return ret;
-- 
1.7.10.4