On 2022/05/16 15:39, Pankaj Raghav wrote:
> Remove the condition which disallows non-power_of_2 zone size ZNS drive
> to be updated and use generic method to calculate number of zones
> instead of relying on log and shift based calculation on zone size.
>
> The power_of_2 calculation has been replaced directly with generic
> calculation without special handling. Both modified functions are not
> used in hot paths, they are only used during initialization &
> revalidation of the ZNS device.
>
> Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Reviewed by: Adam Manzanares <a.manzanares@xxxxxxxxxxx>
> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
> ---
> drivers/nvme/host/zns.c | 24 +++++++++++++++---------
> 1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
> index 9f81beb4d..65d2aa68a 100644
> --- a/drivers/nvme/host/zns.c
> +++ b/drivers/nvme/host/zns.c
> @@ -101,13 +101,6 @@ int nvme_update_zone_info(struct nvme_ns *ns, unsigned lbaf)
> }
>
> ns->zsze = nvme_lba_to_sect(ns, le64_to_cpu(id->lbafe[lbaf].zsze));
> - if (!is_power_of_2(ns->zsze)) {
> - dev_warn(ns->ctrl->device,
> - "invalid zone size:%llu for namespace:%u\n",
> - ns->zsze, ns->head->ns_id);
> - status = -ENODEV;
> - goto free_data;
> - }
>
> blk_queue_set_zoned(ns->disk, BLK_ZONED_HM);
> blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
> @@ -128,8 +121,13 @@ static void *nvme_zns_alloc_report_buffer(struct nvme_ns *ns,
> const size_t min_bufsize = sizeof(struct nvme_zone_report) +
> sizeof(struct nvme_zone_descriptor);
>
> + /*
> + * Division is used to calculate nr_zones with no special handling
> + * for power of 2 zone sizes as this function is not invoked in a
> + * hot path
> + */
Comment not very useful.
> nr_zones = min_t(unsigned int, nr_zones,
> - get_capacity(ns->disk) >> ilog2(ns->zsze));
> + div64_u64(get_capacity(ns->disk), ns->zsze));
>
> bufsize = sizeof(struct nvme_zone_report) +
> nr_zones * sizeof(struct nvme_zone_descriptor);
> @@ -182,6 +180,7 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
> int ret, zone_idx = 0;
> unsigned int nz, i;
> size_t buflen;
> + u64 remainder = 0;
>
> if (ns->head->ids.csi != NVME_CSI_ZNS)
> return -EINVAL;
> @@ -197,7 +196,14 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
> c.zmr.zrasf = NVME_ZRASF_ZONE_REPORT_ALL;
> c.zmr.pr = NVME_REPORT_ZONE_PARTIAL;
>
> - sector &= ~(ns->zsze - 1);
> + /*
> + * rounddown the sector value to the nearest zone size. roundown macro
> + * provided in math.h will not work for 32 bit architectures.
> + * Division is used here with no special handling for power of 2
> + * zone sizes as this function is not invoked in a hot path
> + */
Please simplify this to:
/* Round down the sector value to the nearest zone start */
> + div64_u64_rem(sector, ns->zsze, &remainder);
> + sector -= remainder;
> while (zone_idx < nr_zones && sector < get_capacity(ns->disk)) {
> memset(report, 0, buflen);
>
--
Damien Le Moal
Western Digital Research
