[PATCH 6/8] target/riscv: Combine minstretcfg and minstretcfgh

[alistair23]

From: Anton Johansson <a...@rev.ng>

According to version 20250508 of the privileged specification,
minstretcfg is a 64-bit register and minstretcfgh refers to the top
32 bits of this register when XLEN == 32.  No real advantage is
gained by keeping them separate, and combining them allows for slight
simplification.

Signed-off-by: Anton Johansson <a...@rev.ng>
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
Message-ID: <20251027181831.27016-8-a...@rev.ng>
Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
---
 target/riscv/cpu.h |  3 +--
 target/riscv/csr.c | 18 ++++++++++--------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index e15439dab7..2d41105ca5 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -421,8 +421,7 @@ struct CPUArchState {
 
     /* PMU cycle & instret privilege mode filtering */
     uint64_t mcyclecfg;
-    target_ulong minstretcfg;
-    target_ulong minstretcfgh;
+    uint64_t minstretcfg;
 
     /* PMU counter state */
     PMUCTRState pmu_ctrs[RV_MAX_MHPMCOUNTERS];
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 838e50d813..9bff118e2c 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1116,7 +1116,8 @@ static RISCVException write_mcyclecfgh(CPURISCVState 
*env, int csrno,
 static RISCVException read_minstretcfg(CPURISCVState *env, int csrno,
                                        target_ulong *val)
 {
-    *val = env->minstretcfg;
+    bool rv32 = riscv_cpu_mxl(env) == MXL_RV32;
+    *val = extract64(env->minstretcfg, 0, rv32 ? 32 : 64);
     return RISCV_EXCP_NONE;
 }
 
@@ -1143,7 +1144,7 @@ static RISCVException write_minstretcfg(CPURISCVState 
*env, int csrno,
 static RISCVException read_minstretcfgh(CPURISCVState *env, int csrno,
                                         target_ulong *val)
 {
-    *val = env->minstretcfgh;
+    *val = extract64(env->minstretcfg, 32, 32);
     return RISCV_EXCP_NONE;
 }
 
@@ -1160,7 +1161,8 @@ static RISCVException write_minstretcfgh(CPURISCVState 
*env, int csrno,
     inh_avail_mask |= (riscv_has_ext(env, RVH) &&
                        riscv_has_ext(env, RVS)) ? MINSTRETCFGH_BIT_VSINH : 0;
 
-    env->minstretcfgh = val & inh_avail_mask;
+    env->minstretcfg = deposit64(env->minstretcfg, 32, 32,
+                                 val & inh_avail_mask);
     return RISCV_EXCP_NONE;
 }
 
@@ -1247,8 +1249,7 @@ static target_ulong 
riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
     if (counter_idx == 0) {
         cfg_val = env->mcyclecfg;
     } else if (counter_idx == 2) {
-        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
-                  env->minstretcfg;
+        cfg_val = env->minstretcfg;
     } else {
         cfg_val = env->mhpmevent_val[counter_idx];
         cfg_val &= MHPMEVENT_FILTER_MASK;
@@ -1576,12 +1577,13 @@ static int rmw_cd_ctr_cfgh(CPURISCVState *env, int 
cfg_index, target_ulong *val,
         }
         break;
     case 2:          /* INSTRETCFGH */
+        cfgh = extract64(env->minstretcfg, 32, 32);
         if (wr_mask) {
             wr_mask &= ~MINSTRETCFGH_BIT_MINH;
-            env->minstretcfgh = (new_val & wr_mask) |
-                                (env->minstretcfgh & ~wr_mask);
+            cfgh = (new_val & wr_mask) | (cfgh & ~wr_mask);
+            env->minstretcfg = deposit64(env->minstretcfg, 32, 32, cfgh);
         } else {
-            *val = env->minstretcfgh;
+            *val = cfgh;
         }
         break;
     default:
-- 
2.51.1