[PATCH v2 2/6] target/riscv: Introduce extension implied rule helpers

[frank . chang]

From: Frank Chang <frank.chang@sifive.com>

Introduce helpers to enable the extensions based on the implied rules.
The implied extensions are enabled recursively, so we don't have to
expand all of them manually. This also eliminates the old-fashioned
ordering requirement. For example, Zvksg implies Zvks, Zvks implies
Zvksed, etc., removing the need to check the implied rules of Zvksg
before Zvks.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Jerry Zhang Jian <jerry.zhangjian@sifive.com>
Tested-by: Max Chou <max.chou@sifive.com>
---
 target/riscv/tcg/tcg-cpu.c | 91 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index eb6f7b9d12..f8d6371764 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -36,6 +36,9 @@
 static GHashTable *multi_ext_user_opts;
 static GHashTable *misa_ext_user_opts;
 
+static GHashTable *misa_implied_rules;
+static GHashTable *ext_implied_rules;
+
 static bool cpu_cfg_ext_is_user_set(uint32_t ext_offset)
 {
     return g_hash_table_contains(multi_ext_user_opts,
@@ -836,11 +839,97 @@ static void riscv_cpu_validate_profiles(RISCVCPU *cpu)
     }
 }
 
+static void riscv_cpu_init_implied_exts_rules(void)
+{
+    RISCVCPUImpliedExtsRule *rule;
+    int i;
+
+    for (i = 0; (rule = riscv_misa_implied_rules[i]); i++) {
+        g_hash_table_insert(misa_implied_rules, GUINT_TO_POINTER(rule->ext),
+                            (gpointer)rule);
+    }
+
+    for (i = 0; (rule = riscv_ext_implied_rules[i]); i++) {
+        g_hash_table_insert(ext_implied_rules, GUINT_TO_POINTER(rule->ext),
+                            (gpointer)rule);
+    }
+}
+
+static void cpu_enable_implied_rule(RISCVCPU *cpu,
+                                    RISCVCPUImpliedExtsRule *rule)
+{
+    CPURISCVState *env = &cpu->env;
+    RISCVCPUImpliedExtsRule *ir;
+    bool enabled = false;
+    int i;
+
+#ifndef CONFIG_USER_ONLY
+    enabled = qatomic_read(&rule->enabled) & BIT_ULL(cpu->env.mhartid);
+#endif
+
+    if (!enabled) {
+        /* Enable the implied MISAs. */
+        if (rule->implied_misas) {
+            riscv_cpu_set_misa_ext(env, env->misa_ext | rule->implied_misas);
+
+            for (i = 0; misa_bits[i] != 0; i++) {
+                if (rule->implied_misas & misa_bits[i]) {
+                    ir = g_hash_table_lookup(misa_implied_rules,
+                                             GUINT_TO_POINTER(misa_bits[i]));
+
+                    if (ir) {
+                        cpu_enable_implied_rule(cpu, ir);
+                    }
+                }
+            }
+        }
+
+        /* Enable the implied extensions. */
+        for (i = 0; rule->implied_exts[i] != RISCV_IMPLIED_EXTS_RULE_END; i++) 
{
+            cpu_cfg_ext_auto_update(cpu, rule->implied_exts[i], true);
+
+            ir = g_hash_table_lookup(ext_implied_rules,
+                                     GUINT_TO_POINTER(rule->implied_exts[i]));
+
+            if (ir) {
+                cpu_enable_implied_rule(cpu, ir);
+            }
+        }
+
+#ifndef CONFIG_USER_ONLY
+        qatomic_or(&rule->enabled, BIT_ULL(cpu->env.mhartid));
+#endif
+    }
+}
+
+static void riscv_cpu_enable_implied_rules(RISCVCPU *cpu)
+{
+    RISCVCPUImpliedExtsRule *rule;
+    int i;
+
+    /* Enable the implied MISAs. */
+    for (i = 0; (rule = riscv_misa_implied_rules[i]); i++) {
+        if (riscv_has_ext(&cpu->env, rule->ext)) {
+            cpu_enable_implied_rule(cpu, rule);
+        }
+    }
+
+    /* Enable the implied extensions. */
+    for (i = 0; (rule = riscv_ext_implied_rules[i]); i++) {
+        if (isa_ext_is_enabled(cpu, rule->ext)) {
+            cpu_enable_implied_rule(cpu, rule);
+        }
+    }
+}
+
 void riscv_tcg_cpu_finalize_features(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
     Error *local_err = NULL;
 
+    riscv_cpu_init_implied_exts_rules();
+    riscv_cpu_enable_implied_rules(cpu);
+
     riscv_cpu_validate_misa_priv(env, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -1346,6 +1435,8 @@ static void riscv_tcg_cpu_instance_init(CPUState *cs)
 
     misa_ext_user_opts = g_hash_table_new(NULL, g_direct_equal);
     multi_ext_user_opts = g_hash_table_new(NULL, g_direct_equal);
+    misa_implied_rules = g_hash_table_new(NULL, g_direct_equal);
+    ext_implied_rules = g_hash_table_new(NULL, g_direct_equal);
     riscv_cpu_add_user_properties(obj);
 
     if (riscv_cpu_has_max_extensions(obj)) {
-- 
2.43.2