[RFC v1 5/8] target/riscv: Add pointer masking tb flags

[Alexey Baturo <baturo.alexey@gmail.com>]

Signed-off-by: Alexey Baturo <baturo.alexey@gmail.com>
---
 target/riscv/cpu.h        | 19 +++++++++++++------
 target/riscv/cpu_helper.c |  4 ++++
 target/riscv/translate.c  | 10 ++++++++++
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 25fe60476b..17d0088cb4 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -356,6 +356,10 @@ struct CPUArchState {
     target_ulong senvcfg;
     uint64_t henvcfg;
 #endif
+    /* current number of masked top bits by pointer masking */
+    target_ulong pm_n_bits;
+    /* if pointer masking should do sign extension */
+    bool pm_signext;
 
     /* Fields from here on are preserved across CPU reset. */
     QEMUTimer *stimer; /* Internal timer for S-mode interrupt */
@@ -492,14 +496,17 @@ FIELD(TB_FLAGS, VILL, 14, 1)
 FIELD(TB_FLAGS, VSTART_EQ_ZERO, 15, 1)
 /* The combination of MXL/SXL/UXL that applies to the current cpu mode. */
 FIELD(TB_FLAGS, XL, 16, 2)
-FIELD(TB_FLAGS, VTA, 18, 1)
-FIELD(TB_FLAGS, VMA, 19, 1)
+/* If pointer masking should be applied and address sign extended */
+FIELD(TB_FLAGS, PM_ENABLED, 18, 1)
+FIELD(TB_FLAGS, PM_SIGNEXTEND, 19, 1)
+FIELD(TB_FLAGS, VTA, 20, 1)
+FIELD(TB_FLAGS, VMA, 21, 1)
 /* Native debug itrigger */
-FIELD(TB_FLAGS, ITRIGGER, 20, 1)
+FIELD(TB_FLAGS, ITRIGGER, 22, 1)
 /* Virtual mode enabled */
-FIELD(TB_FLAGS, VIRT_ENABLED, 21, 1)
-FIELD(TB_FLAGS, PRIV, 22, 2)
-FIELD(TB_FLAGS, AXL, 24, 2)
+FIELD(TB_FLAGS, VIRT_ENABLED, 23, 1)
+FIELD(TB_FLAGS, PRIV, 24, 2)
+FIELD(TB_FLAGS, AXL, 25, 2)
 
 #ifdef TARGET_RISCV32
 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 57859314e3..b3871b0a28 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -136,6 +136,10 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc,
     flags = FIELD_DP32(flags, TB_FLAGS, VS, vs);
     flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
     flags = FIELD_DP32(flags, TB_FLAGS, AXL, cpu_address_xl(env));
+    if (env->pm_n_bits != 0) {
+        flags = FIELD_DP32(flags, TB_FLAGS, PM_ENABLED, 1);
+    }
+    flags = FIELD_DP32(flags, TB_FLAGS, PM_SIGNEXTEND, env->pm_signext);
 
     *pflags = flags;
 }
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index ce47904590..3434ba58b6 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -42,6 +42,8 @@ static TCGv cpu_gpr[32], cpu_gprh[32], cpu_pc, cpu_vl, cpu_vstart;
 static TCGv_i64 cpu_fpr[32]; /* assume F and D extensions */
 static TCGv load_res;
 static TCGv load_val;
+/* number of top masked address bits by pointer masking extension */
+static TCGv pm_n_bits;
 
 /*
  * If an operation is being performed on less than TARGET_LONG_BITS,
@@ -103,6 +105,9 @@ typedef struct DisasContext {
     bool vl_eq_vlmax;
     CPUState *cs;
     TCGv zero;
+    /* pointer masking extension */
+    bool pm_enabled;
+    bool pm_signext;
     /* Use icount trigger for native debug */
     bool itrigger;
     /* FRM is known to contain a valid value. */
@@ -1175,6 +1180,8 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->xl = FIELD_EX32(tb_flags, TB_FLAGS, XL);
     ctx->address_xl = FIELD_EX32(tb_flags, TB_FLAGS, AXL);
     ctx->cs = cs;
+    ctx->pm_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_ENABLED);
+    ctx->pm_signext = FIELD_EX32(tb_flags, TB_FLAGS, PM_SIGNEXTEND);
     ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
     ctx->zero = tcg_constant_tl(0);
     ctx->virt_inst_excp = false;
@@ -1306,4 +1313,7 @@ void riscv_translate_init(void)
                              "load_res");
     load_val = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, load_val),
                              "load_val");
+    /* Assign var with number of pointer masking masked bits to tcg global */
+    pm_n_bits = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, pm_n_bits),
+                                   "pmbits");
 }
-- 
2.34.1