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linux/drivers/s390/scsi/zfcp_qdio.h
Swen Schillig 86a9668a8d [SCSI] zfcp: support for hardware data router 
FICON Express8S supports hardware data router, which requires an
adapted qdio request format.
This part 2/2 exploits the functionality in zfcp.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-08-27 08:37:03 -06:00

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7.1 KiB
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/*
* 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 */
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