[Qemu-devel] [RFC v1 04/23] target/riscv: Add the force HS exception mode

[Alistair Francis <alistair.francis@wdc.com>]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h        |  2 ++
 target/riscv/cpu_bits.h   |  6 ++++++
 target/riscv/cpu_helper.c | 23 +++++++++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index de4843b879..eeb3756c91 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -282,6 +282,8 @@ int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_virt_enabled(CPURISCVState *env);
 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env);
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 07c95e8d2c..c898bb1102 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -423,6 +423,12 @@
 #define VIRT_MODE_SHIFT     0
 #define VIRT_MODE_MASK      (1 << VIRT_MODE_SHIFT)
 
+/* HS-level exceptions modes */
+#define CLEAR_HS_EXCEP        0
+#define FORCE_HS_EXCEP        1
+#define FORCE_HS_EXCEP_SHIFT  1
+#define FORCE_HS_EXCEP_MASK   (1 << FORCE_HS_EXCEP_SHIFT)
+
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
 #define SATP32_ASID         0x7fc00000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 5912ae63b7..0fdc81f71f 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -94,6 +94,29 @@ void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
     env->virt |= enable << VIRT_MODE_SHIFT;
 }
 
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
+{
+    bool tmp;
+
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    tmp = (env->virt & FORCE_HS_EXCEP_MASK) >> FORCE_HS_EXCEP_SHIFT;
+
+    return tmp == FORCE_HS_EXCEP;
+}
+
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt &= ~FORCE_HS_EXCEP_MASK;
+    env->virt |= enable << FORCE_HS_EXCEP_SHIFT;
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
2.21.0