target-arm: Move setting of exception info into tlb_fill

Move the code which sets exception information out of
arm_cpu_handle_mmu_fault and into tlb_fill. tlb_fill
is the only caller which wants to raise_exception()
so it makes more sense for it to handle the whole of
the exception setup.

As part of this cleanup, move the user-mode-only
implementation function for the handle_mmu_fault CPU
method into cpu.c so we don't need to make it globally
visible, and rename the softmmu-only utility function
arm_cpu_handle_mmu_fault to arm_tlb_fill so it's clear
that it's not the same thing.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>

target-arm/cpu.c

@@ -1197,6 +1197,23 @@ static Property arm_cpu_properties[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
+#ifdef CONFIG_USER_ONLY
+static int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
+                                    int mmu_idx)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+
+    env->exception.vaddress = address;
+    if (rw == 2) {
+        cs->exception_index = EXCP_PREFETCH_ABORT;
+    } else {
+        cs->exception_index = EXCP_DATA_ABORT;
+    }
+    return 1;
+}
+#endif
+
 static void arm_cpu_class_init(ObjectClass *oc, void *data)
 {
     ARMCPUClass *acc = ARM_CPU_CLASS(oc);

target-arm/cpu.h

@@ -504,8 +504,6 @@ static inline bool is_a64(CPUARMState *env)
    is returned if the signal was handled by the virtual CPU.  */
 int cpu_arm_signal_handler(int host_signum, void *pinfo,
                            void *puc);
-int arm_cpu_handle_mmu_fault(CPUState *cpu, vaddr address, int rw,
-                             int mmu_idx);
 
 /**
  * pmccntr_sync

target-arm/helper.c

@@ -4047,21 +4047,6 @@ uint32_t HELPER(rbit)(uint32_t x)
 
 #if defined(CONFIG_USER_ONLY)
 
-int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
-                             int mmu_idx)
-{
-    ARMCPU *cpu = ARM_CPU(cs);
-    CPUARMState *env = &cpu->env;
-
-    env->exception.vaddress = address;
-    if (rw == 2) {
-        cs->exception_index = EXCP_PREFETCH_ABORT;
-    } else {
-        cs->exception_index = EXCP_DATA_ABORT;
-    }
-    return 1;
-}
-
 /* These should probably raise undefined insn exceptions.  */
 void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val)
 {
@@ -5826,8 +5811,12 @@ static inline int get_phys_addr(CPUARMState *env, target_ulong address,
     }
 }
 
-int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
+/* Walk the page table and (if the mapping exists) add the page
-                             int access_type, int mmu_idx)
+ * to the TLB. Return 0 on success, or an ARM DFSR/IFSR fault
+ * register format value on failure.
+ */
+int arm_tlb_fill(CPUState *cs, vaddr address,
+                 int access_type, int mmu_idx)
 {
     ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
@@ -5835,8 +5824,6 @@ int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
     target_ulong page_size;
     int prot;
     int ret;
-    uint32_t syn;
-    bool same_el = (arm_current_el(env) != 0);
     MemTxAttrs attrs = {};
 
     ret = get_phys_addr(env, address, access_type, mmu_idx, &phys_addr,
@@ -5850,27 +5837,7 @@ int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
         return 0;
     }
 
-    /* AArch64 syndrome does not have an LPAE bit */
+    return ret;
-    syn = ret & ~(1 << 9);
-
-    /* For insn and data aborts we assume there is no instruction syndrome
-     * information; this is always true for exceptions reported to EL1.
-     */
-    if (access_type == 2) {
-        syn = syn_insn_abort(same_el, 0, 0, syn);
-        cs->exception_index = EXCP_PREFETCH_ABORT;
-    } else {
-        syn = syn_data_abort(same_el, 0, 0, 0, access_type == 1, syn);
-        if (access_type == 1 && arm_feature(env, ARM_FEATURE_V6)) {
-            ret |= (1 << 11);
-        }
-        cs->exception_index = EXCP_DATA_ABORT;
-    }
-
-    env->exception.syndrome = syn;
-    env->exception.vaddress = address;
-    env->exception.fsr = ret;
-    return 1;
 }
 
 hwaddr arm_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)

target-arm/internals.h

@@ -387,4 +387,7 @@ bool arm_is_psci_call(ARMCPU *cpu, int excp_type);
 void arm_handle_psci_call(ARMCPU *cpu);
 #endif
 
+/* Do a page table walk and add page to TLB if possible */
+int arm_tlb_fill(CPUState *cpu, vaddr address, int rw, int mmu_idx);
+
 #endif

target-arm/op_helper.c

@@ -80,16 +80,39 @@ void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
 {
     int ret;
 
-    ret = arm_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
+    ret = arm_tlb_fill(cs, addr, is_write, mmu_idx);
     if (unlikely(ret)) {
         ARMCPU *cpu = ARM_CPU(cs);
         CPUARMState *env = &cpu->env;
+        uint32_t syn, exc;
+        bool same_el = (arm_current_el(env) != 0);
 
         if (retaddr) {
             /* now we have a real cpu fault */
             cpu_restore_state(cs, retaddr);
         }
-        raise_exception(env, cs->exception_index);
+
+        /* AArch64 syndrome does not have an LPAE bit */
+        syn = ret & ~(1 << 9);
+
+        /* For insn and data aborts we assume there is no instruction syndrome
+         * information; this is always true for exceptions reported to EL1.
+         */
+        if (is_write == 2) {
+            syn = syn_insn_abort(same_el, 0, 0, syn);
+            exc = EXCP_PREFETCH_ABORT;
+        } else {
+            syn = syn_data_abort(same_el, 0, 0, 0, is_write == 1, syn);
+            if (is_write == 1 && arm_feature(env, ARM_FEATURE_V6)) {
+                ret |= (1 << 11);
+            }
+            exc = EXCP_DATA_ABORT;
+        }
+
+        env->exception.syndrome = syn;
+        env->exception.vaddress = addr;
+        env->exception.fsr = ret;
+        raise_exception(env, exc);
     }
 }
 #endif