stimecmp allows the supervisor mode to update stimecmp CSR directly
to program the next timer interrupt. This CSR is part of the Sstc
extension which was ratified recently.
Signed-off-by: Atish Patra <ati...@rivosinc.com>
---
target/riscv/cpu.c | 12 +++++
target/riscv/cpu.h | 5 ++
target/riscv/cpu_bits.h | 4 ++
target/riscv/csr.c | 81 +++++++++++++++++++++++++++++++
target/riscv/machine.c | 1 +
target/riscv/meson.build | 3 +-
target/riscv/time_helper.c | 98 ++++++++++++++++++++++++++++++++++++++
target/riscv/time_helper.h | 30 ++++++++++++
8 files changed, 233 insertions(+), 1 deletion(-)
create mode 100644 target/riscv/time_helper.c
create mode 100644 target/riscv/time_helper.h
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index d4635c7df46b..e0c3e786849f 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -23,6 +23,7 @@
#include "qemu/log.h"
#include "cpu.h"
#include "internals.h"
+#include "time_helper.h"
#include "exec/exec-all.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
@@ -99,6 +100,7 @@ static const struct isa_ext_data isa_edata_arr[] = {
ISA_EXT_DATA_ENTRY(zve64f, true, PRIV_VERSION_1_12_0, ext_zve64f),
ISA_EXT_DATA_ENTRY(zhinx, true, PRIV_VERSION_1_12_0, ext_zhinx),
ISA_EXT_DATA_ENTRY(zhinxmin, true, PRIV_VERSION_1_12_0, ext_zhinxmin),
+ ISA_EXT_DATA_ENTRY(sstc, true, PRIV_VERSION_1_12_0, ext_sstc),
ISA_EXT_DATA_ENTRY(svinval, true, PRIV_VERSION_1_12_0, ext_svinval),
ISA_EXT_DATA_ENTRY(svnapot, true, PRIV_VERSION_1_12_0, ext_svnapot),
ISA_EXT_DATA_ENTRY(svpbmt, true, PRIV_VERSION_1_12_0, ext_svpbmt),
@@ -675,6 +677,13 @@ static void riscv_cpu_realize(DeviceState *dev, Error
**errp)
set_resetvec(env, cpu->cfg.resetvec);
+#ifndef CONFIG_USER_ONLY
+ if (cpu->cfg.ext_sstc) {
+ riscv_timer_init(cpu);
+ }
+#endif /* CONFIG_USER_ONLY */
+
+
/* Validate that MISA_MXL is set properly. */
switch (env->misa_mxl_max) {
#ifdef TARGET_RISCV64
@@ -968,7 +977,9 @@ static void riscv_cpu_init(Object *obj)
#ifndef CONFIG_USER_ONLY
qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq,
IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX);
+
#endif /* CONFIG_USER_ONLY */
+
}
static Property riscv_cpu_extensions[] = {
@@ -995,6 +1006,7 @@ static Property riscv_cpu_extensions[] = {
DEFINE_PROP_BOOL("Zve64f", RISCVCPU, cfg.ext_zve64f, false),
DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
+ DEFINE_PROP_BOOL("sstc", RISCVCPU, cfg.ext_sstc, true),
DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0fae1569945c..4cda2905661e 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -309,6 +309,9 @@ struct CPUArchState {
uint64_t mfromhost;
uint64_t mtohost;
+ /* Sstc CSRs */
+ uint64_t stimecmp;
+
/* physical memory protection */
pmp_table_t pmp_state;
target_ulong mseccfg;
@@ -362,6 +365,7 @@ struct CPUArchState {
float_status fp_status;
/* Fields from here on are preserved across CPU reset. */
+ QEMUTimer *stimer; /* Internal timer for S-mode interrupt */
hwaddr kernel_addr;
hwaddr fdt_addr;
@@ -425,6 +429,7 @@ struct RISCVCPUConfig {
bool ext_ifencei;
bool ext_icsr;
bool ext_zihintpause;
+ bool ext_sstc;
bool ext_svinval;
bool ext_svnapot;
bool ext_svpbmt;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 6be5a9e9f046..ac17cf1515c0 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -206,6 +206,10 @@
#define CSR_STVAL 0x143
#define CSR_SIP 0x144
+/* Sstc supervisor CSRs */
+#define CSR_STIMECMP 0x14D
+#define CSR_STIMECMPH 0x15D
+
/* Supervisor Protection and Translation */
#define CSR_SPTBR 0x180
#define CSR_SATP 0x180
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 0fb042b2fd0f..b71e2509b64f 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -22,6 +22,7 @@
#include "qemu/timer.h"
#include "cpu.h"
#include "pmu.h"
+#include "time_helper.h"
#include "qemu/main-loop.h"
#include "exec/exec-all.h"
#include "sysemu/cpu-timers.h"
@@ -803,6 +804,76 @@ static RISCVException read_timeh(CPURISCVState *env, int
csrno,
return RISCV_EXCP_NONE;
}
+static RISCVException sstc(CPURISCVState *env, int csrno)
+{
+ CPUState *cs = env_cpu(env);
+ RISCVCPU *cpu = RISCV_CPU(cs);
+
+ if (!cpu->cfg.ext_sstc || !env->rdtime_fn) {
+ return RISCV_EXCP_ILLEGAL_INST;
+ }
+
+ if (env->priv == PRV_M) {
+ return RISCV_EXCP_NONE;
+ }
+
+ if (env->priv != PRV_S) {
+ return RISCV_EXCP_ILLEGAL_INST;
+ }
