[PATCH 01/16] nvme: set max_hw_sectors unconditionally

[John Garry]

return ctrl->max_hw_sectors / (NVME_CTRL_PAGE_SIZE >> SECTOR_SHIFT) + 1;
On 04/03/2024 14:04, Christoph Hellwig wrote:
> All transports set a max_hw_sectors value in the nvme_ctrl, so make
> the code using it unconditional and clean it up using a little helper.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Max Gurtovoy <mgurtovoy at nvidia.com>

FWIW, but I do have a small comment, below:

Reviewed-by: John Garry <john.g.garry at oracle.com>

> ---
>   drivers/nvme/host/core.c | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index cb13f7c79eaf9c..6ae9aedf7bc278 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1944,19 +1944,19 @@ static int nvme_configure_metadata(struct nvme_ctrl *ctrl,
>   	return 0;
>   }
>   
> +static u32 nvme_max_drv_segments(struct nvme_ctrl *ctrl)
> +{
> +	return ctrl->max_hw_sectors / (NVME_CTRL_PAGE_SIZE >> SECTOR_SHIFT) + 1;

I think that it would be nicer to keep the parenthesis, like:

return (ctrl->max_hw_sectors / (NVME_CTRL_PAGE_SIZE >> SECTOR_SHIFT)) + 1;

> +}
> +
>   static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
>   		struct request_queue *q)
>   {
>   	bool vwc = ctrl->vwc & NVME_CTRL_VWC_PRESENT;
>   
> -	if (ctrl->max_hw_sectors) {
> -		u32 max_segments =
> -			(ctrl->max_hw_sectors / (NVME_CTRL_PAGE_SIZE >> 9)) + 1;
> -
> -		max_segments = min_not_zero(max_segments, ctrl->max_segments);
> -		blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors);
> -		blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX));
> -	}
> +	blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors);
> +	blk_queue_max_segments(q, min_t(u32, USHRT_MAX,
> +		min_not_zero(nvme_max_drv_segments(ctrl), ctrl->max_segments)));
>   	blk_queue_virt_boundary(q, NVME_CTRL_PAGE_SIZE - 1);
>   	blk_queue_dma_alignment(q, 3);
>   	blk_queue_write_cache(q, vwc, vwc);