hw/riscv: clint: Avoid using hard-coded timebase frequency

At present the CLINT timestamp is using a hard-coded timebase
frequency value SIFIVE_CLINT_TIMEBASE_FREQ. This might not be
true for all boards.

Add a new 'timebase-freq' property to the CLINT device, and
update various functions to accept this as a parameter.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <1598924352-89526-16-git-send-email-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

3 files changed, 9 insertions, 5 deletions

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0d1728a..65daa73 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -219,7 +219,8 @@ struct CPURISCVState {
     pmp_table_t pmp_state;
 
     /* machine specific rdtime callback */
-    uint64_t (*rdtime_fn)(void);
+    uint64_t (*rdtime_fn)(uint32_t);
+    uint32_t rdtime_fn_arg;
 
     /* True if in debugger mode.  */
     bool debugger;
@@ -350,7 +351,8 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
-void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void));
+void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
+                             uint32_t arg);
 #endif
 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv);
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 0058806..f4c4111 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -276,9 +276,11 @@ uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
     return old;
 }
 
-void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void))
+void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
+                             uint32_t arg)
 {
     env->rdtime_fn = fn;
+    env->rdtime_fn_arg = arg;
 }
 
 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 200001d..26ae347 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -351,7 +351,7 @@ static int read_time(CPURISCVState *env, int csrno, target_ulong *val)
         return -RISCV_EXCP_ILLEGAL_INST;
     }
 
-    *val = env->rdtime_fn() + delta;
+    *val = env->rdtime_fn(env->rdtime_fn_arg) + delta;
     return 0;
 }
 
@@ -364,7 +364,7 @@ static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
         return -RISCV_EXCP_ILLEGAL_INST;
     }
 
-    *val = (env->rdtime_fn() + delta) >> 32;
+    *val = (env->rdtime_fn(env->rdtime_fn_arg) + delta) >> 32;
     return 0;
 }
 #endif