[PATCH 3/5] lib: sbi: Fix sbi_timer for Asymmetric Multi-Processing

[Xiang W]

The original get_time_val is assigned to get_ticks by detecting
Zicntr during cold boot. However, if the multi-core system is not
symmetrical, some cores do not have the Zicntr extension, and an
error will occur when executing sbi_timer_value.

Signed-off-by: Xiang W <wxjstz at 126.com>
---
 lib/sbi/sbi_timer.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/sbi/sbi_timer.c b/lib/sbi/sbi_timer.c
index 14e5ee46..5266c612 100644
--- a/lib/sbi/sbi_timer.c
+++ b/lib/sbi/sbi_timer.c
@@ -19,7 +19,6 @@
 #include <sbi/sbi_timer.h>
 
 static unsigned long time_delta_off;
-static u64 (*get_time_val)(void);
 static const struct sbi_timer_device *timer_dev = NULL;
 
 #if __riscv_xlen == 32
@@ -52,16 +51,19 @@ static void nop_delay_fn(void *opaque)
 void sbi_timer_delay_loop(ulong units, u64 unit_freq,
 			  void (*delay_fn)(void *), void *opaque)
 {
+	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
 	u64 start_val, delta;
 
 	/* Do nothing if we don't have timer device */
-	if (!timer_dev || !get_time_val) {
+	if (!timer_dev ||
+	    (!sbi_hart_has_extension(scratch, SBI_HART_EXT_ZICNTR) &&
+	     !timer_dev->timer_value)) {
 		sbi_printf("%s: called without timer device\n", __func__);
 		return;
 	}
 
 	/* Save starting timer value */
-	start_val = get_time_val();
+	start_val = sbi_timer_value();
 
 	/* Compute desired timer value delta */
 	delta = ((u64)timer_dev->timer_freq * (u64)units);
@@ -72,7 +74,7 @@ void sbi_timer_delay_loop(ulong units, u64 unit_freq,
 		delay_fn = nop_delay_fn;
 
 	/* Busy loop until desired timer value delta reached */
-	while ((get_time_val() - start_val) < delta)
+	while ((sbi_timer_value() - start_val) < delta)
 		delay_fn(opaque);
 }
 
@@ -91,8 +93,11 @@ bool sbi_timer_waitms_until(bool (*predicate)(void *), void *arg,
 
 u64 sbi_timer_value(void)
 {
-	if (get_time_val)
-		return get_time_val();
+	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
+	if (sbi_hart_has_extension(scratch, SBI_HART_EXT_ZICNTR))
+		return get_ticks();
+	if (timer_dev && timer_dev->timer_value)
+		return timer_dev->timer_value();
 	return 0;
 }
 
@@ -181,8 +186,6 @@ void sbi_timer_set_device(const struct sbi_timer_device *dev)
 		return;
 
 	timer_dev = dev;
-	if (!get_time_val && timer_dev->timer_value)
-		get_time_val = timer_dev->timer_value;
 }
 
 int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
@@ -196,9 +199,6 @@ int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
 		if (!time_delta_off)
 			return SBI_ENOMEM;
 
-		if (sbi_hart_has_extension(scratch, SBI_HART_EXT_ZICNTR))
-			get_time_val = get_ticks;
-
 		ret = sbi_platform_timer_init(plat);
 		if (ret)
 			return ret;
-- 
2.47.2