Initial import

1 files changed, 271 insertions, 0 deletions

diff --git a/drivers/s390/scsi/zfcp_qdio.h b/drivers/s390/scsi/zfcp_qdio.h
new file mode 100644
index 000000000..497cd379b
--- /dev/null
+++ b/drivers/s390/scsi/zfcp_qdio.h
@@ -0,0 +1,271 @@
+/*
+ * 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 */