target/loongarch: Adjust the layout of hardware flags bit fields

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Rui Wang <wangrui@loongson.cn>
Message-Id: <20221104040517.222059-2-wangrui@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>

target/loongarch/cpu.h

@@ -14,6 +14,7 @@
 #include "qemu/timer.h"
 #include "exec/memory.h"
 #include "hw/sysbus.h"
+#include "cpu-csr.h"
 
 #define IOCSRF_TEMP             0
 #define IOCSRF_NODECNT          1
@@ -391,14 +392,20 @@ static inline int cpu_mmu_index(CPULoongArchState *env, bool ifetch)
 #endif
 }
 
+/*
+ * LoongArch CPUs hardware flags.
+ */
+#define HW_FLAGS_PLV_MASK   R_CSR_CRMD_PLV_MASK  /* 0x03 */
+#define HW_FLAGS_CRMD_PG    R_CSR_CRMD_PG_MASK   /* 0x10 */
+
 static inline void cpu_get_tb_cpu_state(CPULoongArchState *env,
                                         target_ulong *pc,
                                         target_ulong *cs_base,
                                         uint32_t *flags)
 {
     *pc = env->pc;
     *cs_base = 0;
-    *flags = cpu_mmu_index(env, false);
+    *flags = env->CSR_CRMD & (R_CSR_CRMD_PLV_MASK | R_CSR_CRMD_PG_MASK);
 }
 
 void loongarch_cpu_list(void);

target/loongarch/insn_trans/trans_privileged.c.inc

@@ -159,7 +159,7 @@ static const CSRInfo csr_info[] = {
 
 static bool check_plv(DisasContext *ctx)
 {
-    if (ctx->base.tb->flags == MMU_USER_IDX) {
+    if (ctx->mem_idx == MMU_USER_IDX) {
         generate_exception(ctx, EXCCODE_IPE);
         return true;
     }

target/loongarch/translate.c

@@ -75,7 +75,11 @@ static void loongarch_tr_init_disas_context(DisasContextBase *dcbase,
     DisasContext *ctx = container_of(dcbase, DisasContext, base);
 
     ctx->page_start = ctx->base.pc_first & TARGET_PAGE_MASK;
-    ctx->mem_idx = ctx->base.tb->flags;
+    if (ctx->base.tb->flags & HW_FLAGS_CRMD_PG) {
+        ctx->mem_idx = ctx->base.tb->flags & HW_FLAGS_PLV_MASK;
+    } else {
+        ctx->mem_idx = MMU_DA_IDX;
+    }
 
     /* Bound the number of insns to execute to those left on the page.  */
     bound = -(ctx->base.pc_first | TARGET_PAGE_MASK) / 4;