RE: [PATCH v3 1/9] NTB: Make link-state API being declared first

From: Allen Hubbe
Date: Wed Dec 14 2016 - 02:07:55 EST


From: Serge Semin
> Since link operations are usually performed before memory window access
> operations, it's logically better to declare link-related API before any
> of MW/Doorbell/Scratchpad methods.
>
> Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>

Acked-by: Allen Hubbe <Allen.Hubbe@xxxxxxxx>

> ---
> include/linux/ntb.h | 137 ++++++++++++++++++++++++++--------------------------
> 1 file changed, 69 insertions(+), 68 deletions(-)
>
> diff --git a/include/linux/ntb.h b/include/linux/ntb.h
> index 6f47562..5d1f260 100644
> --- a/include/linux/ntb.h
> +++ b/include/linux/ntb.h
> @@ -179,13 +179,13 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops
> *ops)
>
> /**
> * struct ntb_ctx_ops - ntb device operations
> + * @link_is_up: See ntb_link_is_up().
> + * @link_enable: See ntb_link_enable().
> + * @link_disable: See ntb_link_disable().
> * @mw_count: See ntb_mw_count().
> * @mw_get_range: See ntb_mw_get_range().
> * @mw_set_trans: See ntb_mw_set_trans().
> * @mw_clear_trans: See ntb_mw_clear_trans().
> - * @link_is_up: See ntb_link_is_up().
> - * @link_enable: See ntb_link_enable().
> - * @link_disable: See ntb_link_disable().
> * @db_is_unsafe: See ntb_db_is_unsafe().
> * @db_valid_mask: See ntb_db_valid_mask().
> * @db_vector_count: See ntb_db_vector_count().
> @@ -212,6 +212,12 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
> * @peer_spad_write: See ntb_peer_spad_write().
> */
> struct ntb_dev_ops {
> + int (*link_is_up)(struct ntb_dev *ntb,
> + enum ntb_speed *speed, enum ntb_width *width);
> + int (*link_enable)(struct ntb_dev *ntb,
> + enum ntb_speed max_speed, enum ntb_width max_width);
> + int (*link_disable)(struct ntb_dev *ntb);
> +
> int (*mw_count)(struct ntb_dev *ntb);
> int (*mw_get_range)(struct ntb_dev *ntb, int idx,
> phys_addr_t *base, resource_size_t *size,
> @@ -220,12 +226,6 @@ struct ntb_dev_ops {
> dma_addr_t addr, resource_size_t size);
> int (*mw_clear_trans)(struct ntb_dev *ntb, int idx);
>
> - int (*link_is_up)(struct ntb_dev *ntb,
> - enum ntb_speed *speed, enum ntb_width *width);
> - int (*link_enable)(struct ntb_dev *ntb,
> - enum ntb_speed max_speed, enum ntb_width max_width);
> - int (*link_disable)(struct ntb_dev *ntb);
> -
> int (*db_is_unsafe)(struct ntb_dev *ntb);
> u64 (*db_valid_mask)(struct ntb_dev *ntb);
> int (*db_vector_count)(struct ntb_dev *ntb);
> @@ -265,13 +265,14 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops
> *ops)
> {
> /* commented callbacks are not required: */
> return
> + ops->link_is_up &&
> + ops->link_enable &&
> + ops->link_disable &&
> ops->mw_count &&
> ops->mw_get_range &&
> ops->mw_set_trans &&
> /* ops->mw_clear_trans && */
> - ops->link_is_up &&
> - ops->link_enable &&
> - ops->link_disable &&
> +
> /* ops->db_is_unsafe && */
> ops->db_valid_mask &&
>
> @@ -441,6 +442,62 @@ void ntb_link_event(struct ntb_dev *ntb);
> void ntb_db_event(struct ntb_dev *ntb, int vector);
>
> /**
> + * ntb_link_is_up() - get the current ntb link state
> + * @ntb: NTB device context.
> + * @speed: OUT - The link speed expressed as PCIe generation number.
> + * @width: OUT - The link width expressed as the number of PCIe lanes.
> + *
> + * Get the current state of the ntb link. It is recommended to query the link
> + * state once after every link event. It is safe to query the link state in
> + * the context of the link event callback.
> + *
> + * Return: One if the link is up, zero if the link is down, otherwise a
> + * negative value indicating the error number.
> + */
> +static inline int ntb_link_is_up(struct ntb_dev *ntb,
> + enum ntb_speed *speed, enum ntb_width *width)
> +{
> + return ntb->ops->link_is_up(ntb, speed, width);
> +}
> +
> +/**
> + * ntb_link_enable() - enable the link on the secondary side of the ntb
> + * @ntb: NTB device context.
> + * @max_speed: The maximum link speed expressed as PCIe generation number.
> + * @max_width: The maximum link width expressed as the number of PCIe lanes.
> + *
> + * Enable the link on the secondary side of the ntb. This can only be done
> + * from the primary side of the ntb in primary or b2b topology. The ntb device
> + * should train the link to its maximum speed and width, or the requested speed
> + * and width, whichever is smaller, if supported.
> + *
> + * Return: Zero on success, otherwise an error number.
> + */
> +static inline int ntb_link_enable(struct ntb_dev *ntb,
> + enum ntb_speed max_speed,
> + enum ntb_width max_width)
> +{
> + return ntb->ops->link_enable(ntb, max_speed, max_width);
> +}
> +
> +/**
> + * ntb_link_disable() - disable the link on the secondary side of the ntb
> + * @ntb: NTB device context.
> + *
> + * Disable the link on the secondary side of the ntb. This can only be
> + * done from the primary side of the ntb in primary or b2b topology. The ntb
> + * device should disable the link. Returning from this call must indicate that
> + * a barrier has passed, though with no more writes may pass in either
> + * direction across the link, except if this call returns an error number.
> + *
> + * Return: Zero on success, otherwise an error number.
> + */
> +static inline int ntb_link_disable(struct ntb_dev *ntb)
> +{
> + return ntb->ops->link_disable(ntb);
> +}
> +
> +/**
> * ntb_mw_count() - get the number of memory windows
> * @ntb: NTB device context.
> *
> @@ -517,62 +574,6 @@ static inline int ntb_mw_clear_trans(struct ntb_dev *ntb, int idx)
> }
>
> /**
> - * ntb_link_is_up() - get the current ntb link state
> - * @ntb: NTB device context.
> - * @speed: OUT - The link speed expressed as PCIe generation number.
> - * @width: OUT - The link width expressed as the number of PCIe lanes.
> - *
> - * Get the current state of the ntb link. It is recommended to query the link
> - * state once after every link event. It is safe to query the link state in
> - * the context of the link event callback.
> - *
> - * Return: One if the link is up, zero if the link is down, otherwise a
> - * negative value indicating the error number.
> - */
> -static inline int ntb_link_is_up(struct ntb_dev *ntb,
> - enum ntb_speed *speed, enum ntb_width *width)
> -{
> - return ntb->ops->link_is_up(ntb, speed, width);
> -}
> -
> -/**
> - * ntb_link_enable() - enable the link on the secondary side of the ntb
> - * @ntb: NTB device context.
> - * @max_speed: The maximum link speed expressed as PCIe generation number.
> - * @max_width: The maximum link width expressed as the number of PCIe lanes.
> - *
> - * Enable the link on the secondary side of the ntb. This can only be done
> - * from the primary side of the ntb in primary or b2b topology. The ntb device
> - * should train the link to its maximum speed and width, or the requested speed
> - * and width, whichever is smaller, if supported.
> - *
> - * Return: Zero on success, otherwise an error number.
> - */
> -static inline int ntb_link_enable(struct ntb_dev *ntb,
> - enum ntb_speed max_speed,
> - enum ntb_width max_width)
> -{
> - return ntb->ops->link_enable(ntb, max_speed, max_width);
> -}
> -
> -/**
> - * ntb_link_disable() - disable the link on the secondary side of the ntb
> - * @ntb: NTB device context.
> - *
> - * Disable the link on the secondary side of the ntb. This can only be
> - * done from the primary side of the ntb in primary or b2b topology. The ntb
> - * device should disable the link. Returning from this call must indicate that
> - * a barrier has passed, though with no more writes may pass in either
> - * direction across the link, except if this call returns an error number.
> - *
> - * Return: Zero on success, otherwise an error number.
> - */
> -static inline int ntb_link_disable(struct ntb_dev *ntb)
> -{
> - return ntb->ops->link_disable(ntb);
> -}
> -
> -/**
> * ntb_db_is_unsafe() - check if it is safe to use hardware doorbell
> * @ntb: NTB device context.
> *
> --
> 2.6.6