RISC-V: Add support for the Zicsr extension

The various CSR instructions have been split out of the base ISA as part
of the ratification process.  This patch adds a Zicsr argument, which
disables all the CSR instructions.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Palmer Dabbelt 2019-06-24 01:59:51 -07:00
parent 50fba816cd
commit 591bddea8d
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3 changed files with 8 additions and 0 deletions

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@ -442,6 +442,7 @@ static Property riscv_cpu_properties[] = {
DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),

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@ -224,6 +224,7 @@ typedef struct RISCVCPU {
bool ext_u;
bool ext_counters;
bool ext_ifencei;
bool ext_icsr;
char *priv_spec;
char *user_spec;

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@ -793,6 +793,7 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
{
int ret;
target_ulong old_value;
RISCVCPU *cpu = env_archcpu(env);
/* check privileges and return -1 if check fails */
#if !defined(CONFIG_USER_ONLY)
@ -803,6 +804,11 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
}
#endif
/* ensure the CSR extension is enabled. */
if (!cpu->cfg.ext_icsr) {
return -1;
}
/* check predicate */
if (!csr_ops[csrno].predicate || csr_ops[csrno].predicate(env, csrno) < 0) {
return -1;