drivers/s390/scsi/zfcp_qdio.h - kernel/mindspeed - Git at Google

 /*
  * zfcp device driver
  *
  * Header file for zfcp qdio interface
  *
  * Copyright IBM Corporation 2010
  */

 #ifndef ZFCP_QDIO_H
 #define ZFCP_QDIO_H

 #include <asm/qdio.h>

 #define ZFCP_QDIO_SBALE_LEN	PAGE_SIZE

 /* Max SBALS for chaining */
 #define ZFCP_QDIO_MAX_SBALS_PER_REQ	36

 /**
  * struct zfcp_qdio - basic qdio data structure
  * @res_q: response queue
  * @req_q: request queue
  * @req_q_idx: index of next free buffer
  * @req_q_free: number of free buffers in queue
  * @stat_lock: lock to protect req_q_util and req_q_time
  * @req_q_lock: lock to serialize access to request queue
  * @req_q_time: time of last fill level change
  * @req_q_util: used for accounting
  * @req_q_full: queue full incidents
  * @req_q_wq: used to wait for SBAL availability
  * @adapter: adapter used in conjunction with this qdio structure
  */
 struct zfcp_qdio {
 	struct qdio_buffer	*res_q[QDIO_MAX_BUFFERS_PER_Q];
 	struct qdio_buffer	*req_q[QDIO_MAX_BUFFERS_PER_Q];
 	u8			req_q_idx;
 	atomic_t		req_q_free;
 	spinlock_t		stat_lock;
 	spinlock_t		req_q_lock;
 	unsigned long long	req_q_time;
 	u64			req_q_util;
 	atomic_t		req_q_full;
 	wait_queue_head_t	req_q_wq;
 	struct zfcp_adapter	*adapter;
 	u16			max_sbale_per_sbal;
 	u16			max_sbale_per_req;
 };

 /**
  * struct zfcp_qdio_req - qdio queue related values for a request
  * @sbtype: sbal type flags for sbale 0
  * @sbal_number: number of free sbals
  * @sbal_first: first sbal for this request
  * @sbal_last: last sbal for this request
  * @sbal_limit: last possible sbal for this request
  * @sbale_curr: current sbale at creation of this request
  * @sbal_response: sbal used in interrupt
  * @qdio_outb_usage: usage of outbound queue
  */
 struct zfcp_qdio_req {
 	u8	sbtype;
 	u8	sbal_number;
 	u8	sbal_first;
 	u8	sbal_last;
 	u8	sbal_limit;
 	u8	sbale_curr;
 	u8	sbal_response;
 	u16	qdio_outb_usage;
 };

 /**
  * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
  * @qdio: pointer to struct zfcp_qdio
  * @q_rec: pointer to struct zfcp_qdio_req
  * Returns: pointer to qdio_buffer_element (sbale) structure
  */
 static inline struct qdio_buffer_element *
 zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
 	return &qdio->req_q[q_req->sbal_last]->element[0];
 }

 /**
  * zfcp_qdio_sbale_curr - return current sbale on req_q for a request
  * @qdio: pointer to struct zfcp_qdio
  * @fsf_req: pointer to struct zfcp_fsf_req
  * Returns: pointer to qdio_buffer_element (sbale) structure
  */
 static inline struct qdio_buffer_element *
 zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
 	return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
 }

 /**
  * zfcp_qdio_req_init - initialize qdio request
  * @qdio: request queue where to start putting the request
  * @q_req: the qdio request to start
  * @req_id: The request id
  * @sbtype: type flags to set for all sbals
  * @data: First data block
  * @len: Length of first data block
  *
  * This is the start of putting the request into the queue, the last
  * step is passing the request to zfcp_qdio_send. The request queue
  * lock must be held during the whole process from init to send.
  */
 static inline
 void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 			unsigned long req_id, u8 sbtype, void *data, u32 len)
 {
 	struct qdio_buffer_element *sbale;
 	int count = min(atomic_read(&qdio->req_q_free),
 			ZFCP_QDIO_MAX_SBALS_PER_REQ);

 	q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
 	q_req->sbal_number = 1;
 	q_req->sbtype = sbtype;
 	q_req->sbale_curr = 1;
 	q_req->sbal_limit = (q_req->sbal_first + count - 1)
 					% QDIO_MAX_BUFFERS_PER_Q;

 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
 	sbale->addr = (void *) req_id;
 	sbale->eflags = 0;
 	sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype;

 	if (unlikely(!data))
 		return;
 	sbale++;
 	sbale->addr = data;
 	sbale->length = len;
 }

 /**
  * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
  * @qdio: pointer to struct zfcp_qdio
  * @q_req: pointer to struct zfcp_queue_req
  *
  * This is only required for single sbal requests, calling it when
  * wrapping around to the next sbal is a bug.
  */
 static inline
 void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 			 void *data, u32 len)
 {
 	struct qdio_buffer_element *sbale;

 	BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
 	q_req->sbale_curr++;
 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 	sbale->addr = data;
 	sbale->length = len;
 }

 /**
  * zfcp_qdio_set_sbale_last - set last entry flag in current sbale
  * @qdio: pointer to struct zfcp_qdio
  * @q_req: pointer to struct zfcp_queue_req
  */
 static inline
 void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
 			      struct zfcp_qdio_req *q_req)
 {
 	struct qdio_buffer_element *sbale;

 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
 	sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
 }

 /**
  * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
  * @sg: The scatterlist where to check the data size
  *
  * Returns: 1 when one sbale is enough for the data in the scatterlist,
  *	    0 if not.
  */
 static inline
 int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
 {
 	return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
 }

 /**
  * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
  * @q_req: The current zfcp_qdio_req
  */
 static inline
 void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
 				  struct zfcp_qdio_req *q_req)
 {
 	q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
 }

 /**
  * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
  * @qdio: pointer to struct zfcp_qdio
  * @q_req: The current zfcp_qdio_req
  * @max_sbals: maximum number of SBALs allowed
  */
 static inline
 void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
 			  struct zfcp_qdio_req *q_req, int max_sbals)
 {
 	int count = min(atomic_read(&qdio->req_q_free), max_sbals);

 	q_req->sbal_limit = (q_req->sbal_first + count - 1) %
 				QDIO_MAX_BUFFERS_PER_Q;
 }

 /**
  * zfcp_qdio_set_data_div - set data division count
  * @qdio: pointer to struct zfcp_qdio
  * @q_req: The current zfcp_qdio_req
  * @count: The data division count
  */
 static inline
 void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
 			    struct zfcp_qdio_req *q_req, u32 count)
 {
 	struct qdio_buffer_element *sbale;

 	sbale = qdio->req_q[q_req->sbal_first]->element;
 	sbale->length = count;
 }

 /**
  * zfcp_qdio_sbale_count - count sbale used
  * @sg: pointer to struct scatterlist
  */
 static inline
 unsigned int zfcp_qdio_sbale_count(struct scatterlist *sg)
 {
 	unsigned int count = 0;

 	for (; sg; sg = sg_next(sg))
 		count++;

 	return count;
 }

 /**
  * zfcp_qdio_real_bytes - count bytes used
  * @sg: pointer to struct scatterlist
  */
 static inline
 unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
 {
 	unsigned int real_bytes = 0;

 	for (; sg; sg = sg_next(sg))
 		real_bytes += sg->length;

 	return real_bytes;
 }

 /**
  * zfcp_qdio_set_scount - set SBAL count value
  * @qdio: pointer to struct zfcp_qdio
  * @q_req: The current zfcp_qdio_req
  */
 static inline
 void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
 	struct qdio_buffer_element *sbale;

 	sbale = qdio->req_q[q_req->sbal_first]->element;
 	sbale->scount = q_req->sbal_number - 1;
 }

 #endif /* ZFCP_QDIO_H */
	/*
	* zfcp device driver
	*
	* Header file for zfcp qdio interface
	*
	* Copyright IBM Corporation 2010
	*/

	#ifndef ZFCP_QDIO_H
	#define ZFCP_QDIO_H

	#include <asm/qdio.h>

	#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE

	/* Max SBALS for chaining */
	#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36

	/**
	* struct zfcp_qdio - basic qdio data structure
	* @res_q: response queue
	* @req_q: request queue
	* @req_q_idx: index of next free buffer
	* @req_q_free: number of free buffers in queue
	* @stat_lock: lock to protect req_q_util and req_q_time
	* @req_q_lock: lock to serialize access to request queue
	* @req_q_time: time of last fill level change
	* @req_q_util: used for accounting
	* @req_q_full: queue full incidents
	* @req_q_wq: used to wait for SBAL availability
	* @adapter: adapter used in conjunction with this qdio structure
	*/
	struct zfcp_qdio {
	struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q];
	struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q];
	u8 req_q_idx;
	atomic_t req_q_free;
	spinlock_t stat_lock;
	spinlock_t req_q_lock;
	unsigned long long req_q_time;
	u64 req_q_util;
	atomic_t req_q_full;
	wait_queue_head_t req_q_wq;
	struct zfcp_adapter *adapter;
	u16 max_sbale_per_sbal;
	u16 max_sbale_per_req;
	};

	/**
	* struct zfcp_qdio_req - qdio queue related values for a request
	* @sbtype: sbal type flags for sbale 0
	* @sbal_number: number of free sbals
	* @sbal_first: first sbal for this request
	* @sbal_last: last sbal for this request
	* @sbal_limit: last possible sbal for this request
	* @sbale_curr: current sbale at creation of this request
	* @sbal_response: sbal used in interrupt
	* @qdio_outb_usage: usage of outbound queue
	*/
	struct zfcp_qdio_req {
	u8 sbtype;
	u8 sbal_number;
	u8 sbal_first;
	u8 sbal_last;
	u8 sbal_limit;
	u8 sbale_curr;
	u8 sbal_response;
	u16 qdio_outb_usage;
	};

	/**
	* zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
	* @qdio: pointer to struct zfcp_qdio
	* @q_rec: pointer to struct zfcp_qdio_req
	* Returns: pointer to qdio_buffer_element (sbale) structure
	*/
	static inline struct qdio_buffer_element *
	zfcp_qdio_sbale_req(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	{
	return &qdio->req_q[q_req->sbal_last]->element[0];
	}

	/**
	* zfcp_qdio_sbale_curr - return current sbale on req_q for a request
	* @qdio: pointer to struct zfcp_qdio
	* @fsf_req: pointer to struct zfcp_fsf_req
	* Returns: pointer to qdio_buffer_element (sbale) structure
	*/
	static inline struct qdio_buffer_element *
	zfcp_qdio_sbale_curr(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	{
	return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
	}

	/**
	* zfcp_qdio_req_init - initialize qdio request
	* @qdio: request queue where to start putting the request
	* @q_req: the qdio request to start
	* @req_id: The request id
	* @sbtype: type flags to set for all sbals
	* @data: First data block
	* @len: Length of first data block
	*
	* This is the start of putting the request into the queue, the last
	* step is passing the request to zfcp_qdio_send. The request queue
	* lock must be held during the whole process from init to send.
	*/
	static inline
	void zfcp_qdio_req_init(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req,
	unsigned long req_id, u8 sbtype, void *data, u32 len)
	{
	struct qdio_buffer_element *sbale;
	int count = min(atomic_read(&qdio->req_q_free),
	ZFCP_QDIO_MAX_SBALS_PER_REQ);

	q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
	q_req->sbal_number = 1;
	q_req->sbtype = sbtype;
	q_req->sbale_curr = 1;
	q_req->sbal_limit = (q_req->sbal_first + count - 1)
	% QDIO_MAX_BUFFERS_PER_Q;

	sbale = zfcp_qdio_sbale_req(qdio, q_req);
	sbale->addr = (void *) req_id;
	sbale->eflags = 0;
	sbale->sflags = SBAL_SFLAGS0_COMMAND \| sbtype;

	if (unlikely(!data))
	return;
	sbale++;
	sbale->addr = data;
	sbale->length = len;
	}

	/**
	* zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
	* @qdio: pointer to struct zfcp_qdio
	* @q_req: pointer to struct zfcp_queue_req
	*
	* This is only required for single sbal requests, calling it when
	* wrapping around to the next sbal is a bug.
	*/
	static inline
	void zfcp_qdio_fill_next(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req,
	void *data, u32 len)
	{
	struct qdio_buffer_element *sbale;

	BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
	q_req->sbale_curr++;
	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
	sbale->addr = data;
	sbale->length = len;
	}

	/**
	* zfcp_qdio_set_sbale_last - set last entry flag in current sbale
	* @qdio: pointer to struct zfcp_qdio
	* @q_req: pointer to struct zfcp_queue_req
	*/
	static inline
	void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
	struct zfcp_qdio_req *q_req)
	{
	struct qdio_buffer_element *sbale;

	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
	sbale->eflags \|= SBAL_EFLAGS_LAST_ENTRY;
	}

	/**
	* zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
	* @sg: The scatterlist where to check the data size
	*
	* Returns: 1 when one sbale is enough for the data in the scatterlist,
	* 0 if not.
	*/
	static inline
	int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
	{
	return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
	}

	/**
	* zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
	* @q_req: The current zfcp_qdio_req
	*/
	static inline
	void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
	struct zfcp_qdio_req *q_req)
	{
	q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
	}

	/**
	* zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
	* @qdio: pointer to struct zfcp_qdio
	* @q_req: The current zfcp_qdio_req
	* @max_sbals: maximum number of SBALs allowed
	*/
	static inline
	void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
	struct zfcp_qdio_req *q_req, int max_sbals)
	{
	int count = min(atomic_read(&qdio->req_q_free), max_sbals);

	q_req->sbal_limit = (q_req->sbal_first + count - 1) %
	QDIO_MAX_BUFFERS_PER_Q;
	}

	/**
	* zfcp_qdio_set_data_div - set data division count
	* @qdio: pointer to struct zfcp_qdio
	* @q_req: The current zfcp_qdio_req
	* @count: The data division count
	*/
	static inline
	void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
	struct zfcp_qdio_req *q_req, u32 count)
	{
	struct qdio_buffer_element *sbale;

	sbale = qdio->req_q[q_req->sbal_first]->element;
	sbale->length = count;
	}

	/**
	* zfcp_qdio_sbale_count - count sbale used
	* @sg: pointer to struct scatterlist
	*/
	static inline
	unsigned int zfcp_qdio_sbale_count(struct scatterlist *sg)
	{
	unsigned int count = 0;

	for (; sg; sg = sg_next(sg))
	count++;

	return count;
	}

	/**
	* zfcp_qdio_real_bytes - count bytes used
	* @sg: pointer to struct scatterlist
	*/
	static inline
	unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
	{
	unsigned int real_bytes = 0;

	for (; sg; sg = sg_next(sg))
	real_bytes += sg->length;

	return real_bytes;
	}

	/**
	* zfcp_qdio_set_scount - set SBAL count value
	* @qdio: pointer to struct zfcp_qdio
	* @q_req: The current zfcp_qdio_req
	*/
	static inline
	void zfcp_qdio_set_scount(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	{
	struct qdio_buffer_element *sbale;

	sbale = qdio->req_q[q_req->sbal_first]->element;
	sbale->scount = q_req->sbal_number - 1;
	}

	#endif /* ZFCP_QDIO_H */