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linux/drivers/s390/scsi/zfcp_qdio.h
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names 
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

272 lines
7.0 KiB
C
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/*
* zfcp device driver
*
* Header file for zfcp qdio interface
*
* Copyright IBM Corp. 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 */
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