[PATCH v4 09/16] lib: sbi: Optimize sbi_hsm_hart_started_mask() implementation

[Anup Patel]

> -----Original Message-----
> From: Anup Patel <Anup.Patel at wdc.com>
> Sent: 20 October 2020 15:09
> To: Atish Patra <Atish.Patra at wdc.com>; Alistair Francis
> <Alistair.Francis at wdc.com>
> Cc: Anup Patel <anup at brainfault.org>; opensbi at lists.infradead.org; Anup
> Patel <Anup.Patel at wdc.com>
> Subject: [PATCH v4 09/16] lib: sbi: Optimize sbi_hsm_hart_started_mask()
> implementation
> 
> Instead of calling sbi_hsm_hart_get_state() in a loop, we can simply call a
> new inline __sbi_hsm_hart_get_state() which only takes "hartid"
> and enforce domain checks using sbi_domain_assigned_hartmask().
> 
> This patch optimizes sbi_hsm_hart_started_mask() as-per above.
> 
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> Reviewed-by: Atish Patra <atish.patra at wdc.com>
> ---
>  lib/sbi/sbi_hsm.c | 34 ++++++++++++++++++++++------------
>  1 file changed, 22 insertions(+), 12 deletions(-)
> 
> diff --git a/lib/sbi/sbi_hsm.c b/lib/sbi/sbi_hsm.c index 8121efb..e1b2b2c
> 100644
> --- a/lib/sbi/sbi_hsm.c
> +++ b/lib/sbi/sbi_hsm.c
> @@ -57,20 +57,27 @@ int sbi_hsm_hart_state_to_status(int state)
>  	return ret;
>  }
> 
> -int sbi_hsm_hart_get_state(const struct sbi_domain *dom, u32 hartid)
> +static inline int __sbi_hsm_hart_get_state(u32 hartid)
>  {
>  	struct sbi_hsm_data *hdata;
>  	struct sbi_scratch *scratch;
> 
>  	scratch = sbi_hartid_to_scratch(hartid);
> -	if (!scratch || !sbi_domain_is_assigned_hart(dom, hartid))
> +	if (!scratch)
>  		return SBI_HART_UNKNOWN;
> 
>  	hdata = sbi_scratch_offset_ptr(scratch, hart_data_offset);
> -
>  	return atomic_read(&hdata->state);
>  }
> 
> +int sbi_hsm_hart_get_state(const struct sbi_domain *dom, u32 hartid) {
> +	if (!sbi_domain_is_assigned_hart(dom, hartid))
> +		return SBI_HART_UNKNOWN;
> +
> +	return __sbi_hsm_hart_get_state(hartid); }
> +
>  static bool sbi_hsm_hart_started(const struct sbi_domain *dom, u32 hartid)
> {
>  	if (sbi_hsm_hart_get_state(dom, hartid) == SBI_HART_STARTED)
> @@ -90,18 +97,21 @@ static bool sbi_hsm_hart_started(const struct
> sbi_domain *dom, u32 hartid)  int sbi_hsm_hart_started_mask(const struct
> sbi_domain *dom,
>  			      ulong hbase, ulong *out_hmask)  {
> -	ulong i;
> -	ulong hcount = sbi_scratch_last_hartid() + 1;
> +	ulong i, hmask, dmask;
> +	ulong hend = sbi_scratch_last_hartid() + 1;
> 
>  	*out_hmask = 0;
> -	if (hcount <= hbase)
> +	if (hend <= hbase)
>  		return SBI_EINVAL;
> -	if (BITS_PER_LONG < (hcount - hbase))
> -		hcount = BITS_PER_LONG;
> -
> -	for (i = hbase; i < hcount; i++) {
> -		if (sbi_hsm_hart_get_state(dom, i) == SBI_HART_STARTED)
> -			*out_hmask |= 1UL << (i - hbase);
> +	if (BITS_PER_LONG < (hend - hbase))
> +		hend = hbase + BITS_PER_LONG;
> +
> +	dmask = sbi_domain_get_assigned_hartmask(dom, hbase);
> +	for (i = hbase; i < hend; i++) {
> +		hmask = 1UL << (i - hbase);
> +		if ((dmask & hmask) &&
> +		    (__sbi_hsm_hart_get_state(i) == SBI_HART_STARTED))
> +			*out_hmask |= hmask;
>  	}
> 
>  	return 0;
> --
> 2.25.1

Applied this patch to the riscv/opensbi repo

Regards,
Anup