drivers/s390/scsi/zfcp_qdio.h

Source file repositories/reference/linux-study-clean/drivers/s390/scsi/zfcp_qdio.h

File Facts

System
Linux kernel
Corpus path
drivers/s390/scsi/zfcp_qdio.h
Extension
.h
Size
7480 bytes
Lines
268
Domain
Driver Families
Bucket
drivers/s390
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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 tasklet_struct	irq_tasklet;
	struct tasklet_struct	request_tasklet;
	struct timer_list	request_timer;
	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
 * @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;
	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_req: 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
 * @q_req: pointer to struct zfcp_qdio_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,
			u64 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;

Annotation

Implementation Notes