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Commit bc3e49ad authored by Serge Semin's avatar Serge Semin Committed by Jon Mason
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NTB: Add Messaging NTB API 



Some IDT NTB-capable PCIe-switches have message registers to communicate with
peer devices. This patch adds new NTB API callback methods, which can be used
to utilize these registers functionality:
 ntb_msg_count(); - get number of message registers
 ntb_msg_inbits(); - get bitfield of inbound message registers status
 ntb_msg_outbits(); - get bitfield of outbound message registers status
 ntb_msg_read_sts(); - read the inbound and outbound message registers status
 ntb_msg_clear_sts(); - clear status bits of message registers
 ntb_msg_set_mask(); - mask interrupts raised by status bits of message
registers.
 ntb_msg_clear_mask(); - clear interrupts mask bits of message registers
 ntb_msg_read(midx, *pidx); - read message register with specified index,
additionally getting peer port index which data received from
 ntb_msg_write(midx, pidx); - write data to the specified message register
sending it to the passed peer device connected over a pidx port
 ntb_msg_event(); - notify driver context of a new message event

Of course there is hardware which doesn't support Message registers, so
this API is made optional.

Signed-off-by: default avatarSerge Semin <fancer.lancer@gmail.com>
Acked-by: default avatarAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent d67288a3

drivers/ntb/ntb.c

+13 −0
Original line number Diff line number Diff line
@@ -193,6 +193,19 @@ void ntb_db_event(struct ntb_dev *ntb, int vector) 
}

EXPORT_SYMBOL(ntb_db_event);



void ntb_msg_event(struct ntb_dev *ntb)

{

	unsigned long irqflags;



	spin_lock_irqsave(&ntb->ctx_lock, irqflags);

	{

		if (ntb->ctx_ops && ntb->ctx_ops->msg_event)

			ntb->ctx_ops->msg_event(ntb->ctx);

	}

	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);

}

EXPORT_SYMBOL(ntb_msg_event);



int ntb_default_port_number(struct ntb_dev *ntb)

{

	switch (ntb->topo) {

include/linux/ntb.h

+205 −0
Original line number Diff line number Diff line
@@ -178,10 +178,12 @@ static inline int ntb_client_ops_is_valid(const struct ntb_client_ops *ops) 
 * struct ntb_ctx_ops - ntb driver context operations

 * @link_event:		See ntb_link_event().

 * @db_event:		See ntb_db_event().

 * @msg_event:		See ntb_msg_event().

 */

struct ntb_ctx_ops {

	void (*link_event)(void *ctx);

	void (*db_event)(void *ctx, int db_vector);

	void (*msg_event)(void *ctx);

};



static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
@@ -190,6 +192,7 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops) 
	return

		/* ops->link_event		&& */

		/* ops->db_event		&& */

		/* ops->msg_event		&& */

		1;

}
@@ -234,6 +237,15 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops) 
 * @peer_spad_addr:	See ntb_peer_spad_addr().

 * @peer_spad_read:	See ntb_peer_spad_read().

 * @peer_spad_write:	See ntb_peer_spad_write().

 * @msg_count:		See ntb_msg_count().

 * @msg_inbits:		See ntb_msg_inbits().

 * @msg_outbits:	See ntb_msg_outbits().

 * @msg_read_sts:	See ntb_msg_read_sts().

 * @msg_clear_sts:	See ntb_msg_clear_sts().

 * @msg_set_mask:	See ntb_msg_set_mask().

 * @msg_clear_mask:	See ntb_msg_clear_mask().

 * @msg_read:		See ntb_msg_read().

 * @msg_write:		See ntb_msg_write().

 */

struct ntb_dev_ops {

	int (*port_number)(struct ntb_dev *ntb);
@@ -296,6 +308,16 @@ struct ntb_dev_ops { 
	u32 (*peer_spad_read)(struct ntb_dev *ntb, int pidx, int sidx);

	int (*peer_spad_write)(struct ntb_dev *ntb, int pidx, int sidx,

			       u32 val);



	int (*msg_count)(struct ntb_dev *ntb);

	u64 (*msg_inbits)(struct ntb_dev *ntb);

	u64 (*msg_outbits)(struct ntb_dev *ntb);

	u64 (*msg_read_sts)(struct ntb_dev *ntb);

	int (*msg_clear_sts)(struct ntb_dev *ntb, u64 sts_bits);

	int (*msg_set_mask)(struct ntb_dev *ntb, u64 mask_bits);

	int (*msg_clear_mask)(struct ntb_dev *ntb, u64 mask_bits);

	int (*msg_read)(struct ntb_dev *ntb, int midx, int *pidx, u32 *msg);

	int (*msg_write)(struct ntb_dev *ntb, int midx, int pidx, u32 msg);

};



static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
@@ -342,6 +364,15 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops) 
		/* !ops->peer_spad_addr == !ops->spad_count	&& */

		/* !ops->peer_spad_read == !ops->spad_count	&& */

		!ops->peer_spad_write == !ops->spad_count	&&



		!ops->msg_inbits == !ops->msg_count		&&

		!ops->msg_outbits == !ops->msg_count		&&

		!ops->msg_read_sts == !ops->msg_count		&&

		!ops->msg_clear_sts == !ops->msg_count		&&

		/* !ops->msg_set_mask == !ops->msg_count	&& */

		/* !ops->msg_clear_mask == !ops->msg_count	&& */

		!ops->msg_read == !ops->msg_count		&&

		!ops->msg_write == !ops->msg_count		&&

		1;

}
@@ -484,6 +515,18 @@ void ntb_link_event(struct ntb_dev *ntb); 
 */

void ntb_db_event(struct ntb_dev *ntb, int vector);



/**

 * ntb_msg_event() - notify driver context of a message event

 * @ntb:	NTB device context.

 *

 * Notify the driver context of a message event.  If hardware supports

 * message registers, this event indicates, that a new message arrived in

 * some incoming message register or last sent message couldn't be delivered.

 * The events can be masked/unmasked by the methods ntb_msg_set_mask() and

 * ntb_msg_clear_mask().

 */

void ntb_msg_event(struct ntb_dev *ntb);



/**

 * ntb_default_port_number() - get the default local port number

 * @ntb:	NTB device context.
@@ -1282,4 +1325,166 @@ static inline int ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx, 
	return ntb->ops->peer_spad_write(ntb, pidx, sidx, val);

}



/**

 * ntb_msg_count() - get the number of message registers

 * @ntb:	NTB device context.

 *

 * Hardware may support a different number of message registers.

 *

 * Return: the number of message registers.

 */

static inline int ntb_msg_count(struct ntb_dev *ntb)

{

	if (!ntb->ops->msg_count)

		return 0;



	return ntb->ops->msg_count(ntb);

}



/**

 * ntb_msg_inbits() - get a bitfield of inbound message registers status

 * @ntb:	NTB device context.

 *

 * The method returns the bitfield of status and mask registers, which related

 * to inbound message registers.

 *

 * Return: bitfield of inbound message registers.

 */

static inline u64 ntb_msg_inbits(struct ntb_dev *ntb)

{

	if (!ntb->ops->msg_inbits)

		return 0;



	return ntb->ops->msg_inbits(ntb);

}



/**

 * ntb_msg_outbits() - get a bitfield of outbound message registers status

 * @ntb:	NTB device context.

 *

 * The method returns the bitfield of status and mask registers, which related

 * to outbound message registers.

 *

 * Return: bitfield of outbound message registers.

 */

static inline u64 ntb_msg_outbits(struct ntb_dev *ntb)

{

	if (!ntb->ops->msg_outbits)

		return 0;



	return ntb->ops->msg_outbits(ntb);

}



/**

 * ntb_msg_read_sts() - read the message registers status

 * @ntb:	NTB device context.

 *

 * Read the status of message register. Inbound and outbound message registers

 * related bits can be filtered by masks retrieved from ntb_msg_inbits() and

 * ntb_msg_outbits().

 *

 * Return: status bits of message registers

 */

static inline u64 ntb_msg_read_sts(struct ntb_dev *ntb)

{

	if (!ntb->ops->msg_read_sts)

		return 0;



	return ntb->ops->msg_read_sts(ntb);

}



/**

 * ntb_msg_clear_sts() - clear status bits of message registers

 * @ntb:	NTB device context.

 * @sts_bits:	Status bits to clear.

 *

 * Clear bits in the status register.

 *

 * Return: Zero on success, otherwise a negative error number.

 */

static inline int ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)

{

	if (!ntb->ops->msg_clear_sts)

		return -EINVAL;



	return ntb->ops->msg_clear_sts(ntb, sts_bits);

}



/**

 * ntb_msg_set_mask() - set mask of message register status bits

 * @ntb:	NTB device context.

 * @mask_bits:	Mask bits.

 *

 * Mask the message registers status bits from raising the message event.

 *

 * Return: Zero on success, otherwise a negative error number.

 */

static inline int ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)

{

	if (!ntb->ops->msg_set_mask)

		return -EINVAL;



	return ntb->ops->msg_set_mask(ntb, mask_bits);

}



/**

 * ntb_msg_clear_mask() - clear message registers mask

 * @ntb:	NTB device context.

 * @mask_bits:	Mask bits to clear.

 *

 * Clear bits in the message events mask register.

 *

 * Return: Zero on success, otherwise a negative error number.

 */

static inline int ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)

{

	if (!ntb->ops->msg_clear_mask)

		return -EINVAL;



	return ntb->ops->msg_clear_mask(ntb, mask_bits);

}



/**

 * ntb_msg_read() - read message register with specified index

 * @ntb:	NTB device context.

 * @midx:	Message register index

 * @pidx:	OUT - Port index of peer device a message retrieved from

 * @msg:	OUT - Data

 *

 * Read data from the specified message register. Source port index of a

 * message is retrieved as well.

 *

 * Return: Zero on success, otherwise a negative error number.

 */

static inline int ntb_msg_read(struct ntb_dev *ntb, int midx, int *pidx,

			       u32 *msg)

{

	if (!ntb->ops->msg_read)

		return -EINVAL;



	return ntb->ops->msg_read(ntb, midx, pidx, msg);

}



/**

 * ntb_msg_write() - write data to the specified message register

 * @ntb:	NTB device context.

 * @midx:	Message register index

 * @pidx:	Port index of peer device a message being sent to

 * @msg:	Data to send

 *

 * Send data to a specified peer device using the defined message register.

 * Message event can be raised if the midx registers isn't empty while

 * calling this method and the corresponding interrupt isn't masked.

 *

 * Return: Zero on success, otherwise a negative error number.

 */

static inline int ntb_msg_write(struct ntb_dev *ntb, int midx, int pidx,

				u32 msg)

{

	if (!ntb->ops->msg_write)

		return -EINVAL;



	return ntb->ops->msg_write(ntb, midx, pidx, msg);

}



#endif