Re: [PATCH 2/3] lib: sbi_timer: Introduce per-HART timer state

[Nicholas Piggin <npiggin@gmail.com>]

On Wed, Apr 15, 2026 at 04:30:01PM +0530, Anup Patel wrote:
> Currently, only time_delta is per-HART so introduce per-HART timer
> state for having more per-HART timer information.
> 
> Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

> ---
>  lib/sbi/sbi_timer.c | 44 +++++++++++++++++++++++++-------------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/lib/sbi/sbi_timer.c b/lib/sbi/sbi_timer.c
> index 4088a597..9806c033 100644
> --- a/lib/sbi/sbi_timer.c
> +++ b/lib/sbi/sbi_timer.c
> @@ -18,7 +18,11 @@
>  #include <sbi/sbi_scratch.h>
>  #include <sbi/sbi_timer.h>
>  
> -static unsigned long time_delta_off;
> +struct timer_state {
> +	u64 time_delta;
> +};
> +
> +static unsigned long timer_state_off;
>  static u64 (*get_time_val)(void);
>  static const struct sbi_timer_device *timer_dev = NULL;
>  
> @@ -98,35 +102,37 @@ u64 sbi_timer_value(void)
>  
>  u64 sbi_timer_virt_value(void)
>  {
> -	u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
> -						 time_delta_off);
> +	struct timer_state *tstate = sbi_scratch_thishart_offset_ptr(timer_state_off);
>  
> -	return sbi_timer_value() + *time_delta;
> +	return sbi_timer_value() + tstate->time_delta;
>  }
>  
>  u64 sbi_timer_get_delta(void)
>  {
> -	u64 *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
> -						 time_delta_off);
> +	struct timer_state *tstate = sbi_scratch_thishart_offset_ptr(timer_state_off);
>  
> -	return *time_delta;
> +	return tstate->time_delta;
>  }
>  
>  void sbi_timer_set_delta(ulong delta)
>  {
> -	ulong *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
> -						   time_delta_off);
> +	struct timer_state *tstate = sbi_scratch_thishart_offset_ptr(timer_state_off);
>  
> -	*time_delta = delta;
> +#if __riscv_xlen == 32
> +	tstate->time_delta &= ~0xffffffffUL;
> +	tstate->time_delta |= (u32)delta;
> +#else
> +	tstate->time_delta = delta;
> +#endif
>  }
>  
>  #if __riscv_xlen == 32
>  void sbi_timer_set_delta_upper(ulong delta_upper)
>  {
> -	ulong *time_delta = sbi_scratch_offset_ptr(sbi_scratch_thishart_ptr(),
> -						   time_delta_off);
> +	struct timer_state *tstate = sbi_scratch_thishart_offset_ptr(timer_state_off);
>  
> -	*(time_delta + 1) = delta_upper;
> +	tstate->time_delta &= 0xffffffffUL;
> +	tstate->time_delta |= (u64)delta << 32;
>  }
>  #endif
>  
> @@ -176,13 +182,13 @@ void sbi_timer_set_device(const struct sbi_timer_device *dev)
>  
>  int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
>  {
> -	u64 *time_delta;
>  	const struct sbi_platform *plat = sbi_platform_ptr(scratch);
> +	struct timer_state *tstate;
>  	int ret;
>  
>  	if (cold_boot) {
> -		time_delta_off = sbi_scratch_alloc_offset(sizeof(*time_delta));
> -		if (!time_delta_off)
> +		timer_state_off = sbi_scratch_alloc_offset(sizeof(*tstate));
> +		if (!timer_state_off)
>  			return SBI_ENOMEM;
>  
>  		if (sbi_hart_has_csr(scratch, SBI_HART_CSR_TIME))
> @@ -192,12 +198,12 @@ int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
>  		if (ret)
>  			return ret;
>  	} else {
> -		if (!time_delta_off)
> +		if (!timer_state_off)
>  			return SBI_ENOMEM;
>  	}
>  
> -	time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
> -	*time_delta = 0;
> +	tstate = sbi_scratch_offset_ptr(scratch, timer_state_off);
> +	tstate->time_delta = 0;
>  
>  	if (timer_dev && timer_dev->warm_init) {
>  		ret = timer_dev->warm_init();
> -- 
> 2.43.0
> 
> 
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