1 files changed, 128 insertions, 0 deletions
diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index d754273fa1..af9ad42028 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -487,6 +487,134 @@ do_fault:
     return true;
 }
 
+/*
+ * Translate S2 section/page access permissions to protection flags
+ * @env:     CPUARMState
+ * @s2ap:    The 2-bit stage2 access permissions (S2AP)
+ * @xn:      XN (execute-never) bits
+ * @s1_is_el0: true if this is S2 of an S1+2 walk for EL0
+ */
+static int get_S2prot(CPUARMState *env, int s2ap, int xn, bool s1_is_el0)
+{
+    int prot = 0;
+
+    if (s2ap & 1) {
+        prot |= PAGE_READ;
+    }
+    if (s2ap & 2) {
+        prot |= PAGE_WRITE;
+    }
+
+    if (cpu_isar_feature(any_tts2uxn, env_archcpu(env))) {
+        switch (xn) {
+        case 0:
+            prot |= PAGE_EXEC;
+            break;
+        case 1:
+            if (s1_is_el0) {
+                prot |= PAGE_EXEC;
+            }
+            break;
+        case 2:
+            break;
+        case 3:
+            if (!s1_is_el0) {
+                prot |= PAGE_EXEC;
+            }
+            break;
+        default:
+            g_assert_not_reached();
+        }
+    } else {
+        if (!extract32(xn, 1, 1)) {
+            if (arm_el_is_aa64(env, 2) || prot & PAGE_READ) {
+                prot |= PAGE_EXEC;
+            }
+        }
+    }
+    return prot;
+}
+
+/*
+ * Translate section/page access permissions to protection flags
+ * @env:     CPUARMState
+ * @mmu_idx: MMU index indicating required translation regime
+ * @is_aa64: TRUE if AArch64
+ * @ap:      The 2-bit simple AP (AP[2:1])
+ * @ns:      NS (non-secure) bit
+ * @xn:      XN (execute-never) bit
+ * @pxn:     PXN (privileged execute-never) bit
+ */
+static int get_S1prot(CPUARMState *env, ARMMMUIdx mmu_idx, bool is_aa64,
+                      int ap, int ns, int xn, int pxn)
+{
+    bool is_user = regime_is_user(env, mmu_idx);
+    int prot_rw, user_rw;
+    bool have_wxn;
+    int wxn = 0;
+
+    assert(mmu_idx != ARMMMUIdx_Stage2);
+    assert(mmu_idx != ARMMMUIdx_Stage2_S);
+
+    user_rw = simple_ap_to_rw_prot_is_user(ap, true);
+    if (is_user) {
+        prot_rw = user_rw;
+    } else {
+        if (user_rw && regime_is_pan(env, mmu_idx)) {
+            /* PAN forbids data accesses but doesn't affect insn fetch */
+            prot_rw = 0;
+        } else {
+            prot_rw = simple_ap_to_rw_prot_is_user(ap, false);
+        }
+    }
+
+    if (ns && arm_is_secure(env) && (env->cp15.scr_el3 & SCR_SIF)) {
+        return prot_rw;
+    }
+
+    /* TODO have_wxn should be replaced with
+     *   ARM_FEATURE_V8 || (ARM_FEATURE_V7 && ARM_FEATURE_EL2)
+     * when ARM_FEATURE_EL2 starts getting set. For now we assume all LPAE
+     * compatible processors have EL2, which is required for [U]WXN.
+     */
+    have_wxn = arm_feature(env, ARM_FEATURE_LPAE);
+
+    if (have_wxn) {
+        wxn = regime_sctlr(env, mmu_idx) & SCTLR_WXN;
+    }
+
+    if (is_aa64) {
+        if (regime_has_2_ranges(mmu_idx) && !is_user) {
+            xn = pxn || (user_rw & PAGE_WRITE);
+        }
+    } else if (arm_feature(env, ARM_FEATURE_V7)) {
+        switch (regime_el(env, mmu_idx)) {
+        case 1:
+        case 3:
+            if (is_user) {
+                xn = xn || !(user_rw & PAGE_READ);
+            } else {
+                int uwxn = 0;
+                if (have_wxn) {
+                    uwxn = regime_sctlr(env, mmu_idx) & SCTLR_UWXN;
+                }
+                xn = xn || !(prot_rw & PAGE_READ) || pxn ||
+                     (uwxn && (user_rw & PAGE_WRITE));
+            }
+            break;
+        case 2:
+            break;
+        }
+    } else {
+        xn = wxn = 0;
+    }
+
+    if (xn || (wxn && (prot_rw & PAGE_WRITE))) {
+        return prot_rw;
+    }
+    return prot_rw | PAGE_EXEC;
+}
+
 /**
  * get_phys_addr_lpae: perform one stage of page table walk, LPAE format
  *