[deliverable/linux.git] / drivers / s390 / scsi / 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 */
Commit	Line	Data
34c2b712 CS	1	/*
	2	* zfcp device driver
	3	*
	4	* Header file for zfcp qdio interface
	5	*
	6	* Copyright IBM Corporation 2010
	7	*/
	8
	9	#ifndef ZFCP_QDIO_H
	10	#define ZFCP_QDIO_H
	11
	12	#include <asm/qdio.h>
	13
68322984 CS	14	#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE
68322984 CS	15
01b04759 SS	16	/* Max SBALS for chaining */
	17	#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36
	18
34c2b712 CS	19	/**
34c2b712 CS	20	* struct zfcp_qdio - basic qdio data structure
706eca49	21	* @res_q: response queue
34c2b712	22	* @req_q: request queue
706eca49 SS	23	* @req_q_idx: index of next free buffer
706eca49 SS	24	* @req_q_free: number of free buffers in queue
34c2b712 CS	25	* @stat_lock: lock to protect req_q_util and req_q_time
	26	* @req_q_lock: lock to serialize access to request queue
	27	* @req_q_time: time of last fill level change
	28	* @req_q_util: used for accounting
	29	* @req_q_full: queue full incidents
	30	* @req_q_wq: used to wait for SBAL availability
	31	* @adapter: adapter used in conjunction with this qdio structure
	32	*/
	33	struct zfcp_qdio {
706eca49 SS	34	struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q];
	35	struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q];
	36	u8 req_q_idx;
	37	atomic_t req_q_free;
34c2b712 CS	38	spinlock_t stat_lock;
	39	spinlock_t req_q_lock;
	40	unsigned long long req_q_time;
	41	u64 req_q_util;
	42	atomic_t req_q_full;
	43	wait_queue_head_t req_q_wq;
	44	struct zfcp_adapter *adapter;
86a9668a SS	45	u16 max_sbale_per_sbal;
86a9668a SS	46	u16 max_sbale_per_req;
34c2b712 CS	47	};
	48
	49	/**
	50	* struct zfcp_qdio_req - qdio queue related values for a request
1674b405	51	* @sbtype: sbal type flags for sbale 0
34c2b712 CS	52	* @sbal_number: number of free sbals
	53	* @sbal_first: first sbal for this request
	54	* @sbal_last: last sbal for this request
	55	* @sbal_limit: last possible sbal for this request
	56	* @sbale_curr: current sbale at creation of this request
	57	* @sbal_response: sbal used in interrupt
	58	* @qdio_outb_usage: usage of outbound queue
34c2b712 CS	59	*/
34c2b712 CS	60	struct zfcp_qdio_req {
3ec90878	61	u8 sbtype;
34c2b712 CS	62	u8 sbal_number;
	63	u8 sbal_first;
	64	u8 sbal_last;
	65	u8 sbal_limit;
	66	u8 sbale_curr;
	67	u8 sbal_response;
	68	u16 qdio_outb_usage;
34c2b712 CS	69	};
34c2b712 CS	70
34c2b712 CS	71	/**
	72	* zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
	73	* @qdio: pointer to struct zfcp_qdio
	74	* @q_rec: pointer to struct zfcp_qdio_req
	75	* Returns: pointer to qdio_buffer_element (sbale) structure
	76	*/
	77	static inline struct qdio_buffer_element *
	78	zfcp_qdio_sbale_req(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	79	{
706eca49	80	return &qdio->req_q[q_req->sbal_last]->element[0];
34c2b712 CS	81	}
	82
	83	/**
	84	* zfcp_qdio_sbale_curr - return current sbale on req_q for a request
	85	* @qdio: pointer to struct zfcp_qdio
	86	* @fsf_req: pointer to struct zfcp_fsf_req
	87	* Returns: pointer to qdio_buffer_element (sbale) structure
	88	*/
	89	static inline struct qdio_buffer_element *
	90	zfcp_qdio_sbale_curr(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	91	{
706eca49	92	return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
34c2b712 CS	93	}
34c2b712 CS	94
1674b405 CS	95	/**
	96	* zfcp_qdio_req_init - initialize qdio request
	97	* @qdio: request queue where to start putting the request
	98	* @q_req: the qdio request to start
	99	* @req_id: The request id
	100	* @sbtype: type flags to set for all sbals
	101	* @data: First data block
	102	* @len: Length of first data block
	103	*
	104	* This is the start of putting the request into the queue, the last
	105	* step is passing the request to zfcp_qdio_send. The request queue
	106	* lock must be held during the whole process from init to send.
	107	*/
	108	static inline
	109	void zfcp_qdio_req_init(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req,
3ec90878	110	unsigned long req_id, u8 sbtype, void *data, u32 len)
1674b405 CS	111	{
1674b405 CS	112	struct qdio_buffer_element *sbale;
706eca49	113	int count = min(atomic_read(&qdio->req_q_free),
01b04759	114	ZFCP_QDIO_MAX_SBALS_PER_REQ);
1674b405	115
706eca49	116	q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
1674b405 CS	117	q_req->sbal_number = 1;
1674b405 CS	118	q_req->sbtype = sbtype;
706eca49	119	q_req->sbale_curr = 1;
01b04759 SS	120	q_req->sbal_limit = (q_req->sbal_first + count - 1)
01b04759 SS	121	% QDIO_MAX_BUFFERS_PER_Q;
1674b405 CS	122
	123	sbale = zfcp_qdio_sbale_req(qdio, q_req);
	124	sbale->addr = (void *) req_id;
3ec90878 JG	125	sbale->eflags = 0;
3ec90878 JG	126	sbale->sflags = SBAL_SFLAGS0_COMMAND \| sbtype;
1674b405	127
706eca49 SS	128	if (unlikely(!data))
706eca49 SS	129	return;
1674b405 CS	130	sbale++;
1674b405 CS	131	sbale->addr = data;
706eca49	132	sbale->length = len;
1674b405 CS	133	}
	134
	135	/**
	136	* zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
	137	* @qdio: pointer to struct zfcp_qdio
	138	* @q_req: pointer to struct zfcp_queue_req
	139	*
	140	* This is only required for single sbal requests, calling it when
	141	* wrapping around to the next sbal is a bug.
	142	*/
	143	static inline
	144	void zfcp_qdio_fill_next(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req,
	145	void *data, u32 len)
	146	{
	147	struct qdio_buffer_element *sbale;
	148
86a9668a	149	BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
1674b405 CS	150	q_req->sbale_curr++;
	151	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
	152	sbale->addr = data;
	153	sbale->length = len;
	154	}
	155
	156	/**
	157	* zfcp_qdio_set_sbale_last - set last entry flag in current sbale
	158	* @qdio: pointer to struct zfcp_qdio
	159	* @q_req: pointer to struct zfcp_queue_req
	160	*/
	161	static inline
	162	void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
	163	struct zfcp_qdio_req *q_req)
	164	{
	165	struct qdio_buffer_element *sbale;
	166
	167	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
3ec90878	168	sbale->eflags \|= SBAL_EFLAGS_LAST_ENTRY;
1674b405 CS	169	}
	170
	171	/**
	172	* zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
	173	* @sg: The scatterlist where to check the data size
	174	*
	175	* Returns: 1 when one sbale is enough for the data in the scatterlist,
	176	* 0 if not.
	177	*/
	178	static inline
	179	int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
	180	{
	181	return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
	182	}
	183
	184	/**
	185	* zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
	186	* @q_req: The current zfcp_qdio_req
	187	*/
	188	static inline
86a9668a SS	189	void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
86a9668a SS	190	struct zfcp_qdio_req *q_req)
1674b405	191	{
86a9668a	192	q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
1674b405 CS	193	}
1674b405 CS	194
01b04759 SS	195	/**
	196	* zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
	197	* @qdio: pointer to struct zfcp_qdio
	198	* @q_req: The current zfcp_qdio_req
	199	* @max_sbals: maximum number of SBALs allowed
	200	*/
	201	static inline
	202	void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
	203	struct zfcp_qdio_req *q_req, int max_sbals)
	204	{
706eca49	205	int count = min(atomic_read(&qdio->req_q_free), max_sbals);
01b04759 SS	206
	207	q_req->sbal_limit = (q_req->sbal_first + count - 1) %
	208	QDIO_MAX_BUFFERS_PER_Q;
	209	}
	210
ef3eb71d FB	211	/**
	212	* zfcp_qdio_set_data_div - set data division count
	213	* @qdio: pointer to struct zfcp_qdio
	214	* @q_req: The current zfcp_qdio_req
	215	* @count: The data division count
	216	*/
	217	static inline
	218	void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
	219	struct zfcp_qdio_req *q_req, u32 count)
	220	{
	221	struct qdio_buffer_element *sbale;
	222
86a9668a	223	sbale = qdio->req_q[q_req->sbal_first]->element;
ef3eb71d FB	224	sbale->length = count;
	225	}
	226
86a9668a SS	227	/**
	228	* zfcp_qdio_sbale_count - count sbale used
	229	* @sg: pointer to struct scatterlist
	230	*/
	231	static inline
	232	unsigned int zfcp_qdio_sbale_count(struct scatterlist *sg)
	233	{
	234	unsigned int count = 0;
	235
	236	for (; sg; sg = sg_next(sg))
	237	count++;
	238
	239	return count;
	240	}
	241
	242	/**
	243	* zfcp_qdio_real_bytes - count bytes used
	244	* @sg: pointer to struct scatterlist
	245	*/
	246	static inline
	247	unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
	248	{
	249	unsigned int real_bytes = 0;
	250
	251	for (; sg; sg = sg_next(sg))
	252	real_bytes += sg->length;
	253
	254	return real_bytes;
	255	}
	256
	257	/**
	258	* zfcp_qdio_set_scount - set SBAL count value
	259	* @qdio: pointer to struct zfcp_qdio
	260	* @q_req: The current zfcp_qdio_req
	261	*/
	262	static inline
	263	void zfcp_qdio_set_scount(struct zfcp_qdio qdio, struct zfcp_qdio_req q_req)
	264	{
	265	struct qdio_buffer_element *sbale;
	266
	267	sbale = qdio->req_q[q_req->sbal_first]->element;
	268	sbale->scount = q_req->sbal_number - 1;
	269	}
	270
34c2b712	271	#endif /* ZFCP_QDIO_H */