On Sun, Jun 16, 2024 at 12:48 PM <frank.chang@sifive.com> wrote:
>
> 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);
enabled is a uint64_t, so this limits us to 64 harts right?
The virt machine currently has a limit of 512, so this won't work right?
Alistair
Yes, that's true.
Though it wouldn't impact the result as this is just the optimization
of not iterating the rules that have been applied already.
Maybe I can replace it with the dynamic hart bitmask.
Regards,
Frank Chang
> +#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
>
>