[patch 2/5] qdio: new qdio driver, part 1.

[Martin Schwidefsky]

From: Jan Glauber <jang@xxxxxxxxxxxxxxxxxx>

List of major changes:
- split qdio driver into several files
- seperation of thin interrupt code
- improved handling for multiple thin interrupt devices
- inbound and outbound processing now always runs in tasklet context
- significant less tasklet schedules per interrupt needed
- merged qebsm with non-qebsm handling
- cleanup qdio interface and added kerneldoc
- coding style

Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Reviewed-by: Utz Bacher <utz.bacher@xxxxxxxxxx>
Reviewed-by: Ursula Braun <braunu@xxxxxxxxxx>

Signed-off-by: Jan Glauber <jang@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

 drivers/s390/cio/qdio_main.c | 1760 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1760 insertions(+)

Index: quilt-2.6/drivers/s390/cio/qdio_main.c
===================================================================
--- /dev/null
+++ quilt-2.6/drivers/s390/cio/qdio_main.c
@@ -0,0 +1,1760 @@
+/*
+ * linux/drivers/s390/cio/qdio_main.c
+ *
+ * Linux for s390 qdio support, buffer handling, qdio API and module support.
+ *
+ * Copyright 2000,2008 IBM Corp.
+ * Author(s): Utz Bacher <utz.bacher@xxxxxxxxxx>
+ *	      Jan Glauber <jang@xxxxxxxxxxxxxxxxxx>
+ * 2.6 cio integration by Cornelia Huck <cornelia.huck@xxxxxxxxxx>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+#include <asm/atomic.h>
+#include <asm/debug.h>
+#include <asm/qdio.h>
+
+#include "cio.h"
+#include "css.h"
+#include "device.h"
+#include "qdio.h"
+#include "qdio_debug.h"
+#include "qdio_perf.h"
+
+MODULE_AUTHOR("Utz Bacher <utz.bacher@xxxxxxxxxx>,"\
+	"Jan Glauber <jang@xxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("QDIO base support");
+MODULE_LICENSE("GPL");
+
+static inline int do_siga_sync(struct subchannel_id schid,
+			       unsigned int out_mask, unsigned int in_mask)
+{
+	register unsigned long __fc asm ("0") = 2;
+	register struct subchannel_id __schid asm ("1") = schid;
+	register unsigned long out asm ("2") = out_mask;
+	register unsigned long in asm ("3") = in_mask;
+	int cc;
+
+	asm volatile(
+		"	siga	0\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (cc)
+		: "d" (__fc), "d" (__schid), "d" (out), "d" (in) : "cc");
+	return cc;
+}
+
+static inline int do_siga_input(struct subchannel_id schid, unsigned int mask)
+{
+	register unsigned long __fc asm ("0") = 1;
+	register struct subchannel_id __schid asm ("1") = schid;
+	register unsigned long __mask asm ("2") = mask;
+	int cc;
+
+	asm volatile(
+		"	siga	0\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (cc)
+		: "d" (__fc), "d" (__schid), "d" (__mask) : "cc", "memory");
+	return cc;
+}
+
+/**
+ * do_siga_output - perform SIGA-w/wt function
+ * @schid: subchannel id or in case of QEBSM the subchannel token
+ * @mask: which output queues to process
+ * @bb: busy bit indicator, set only if SIGA-w/wt could not access a buffer
+ * @fc: function code to perform
+ *
+ * Returns cc or QDIO_ERROR_SIGA_ACCESS_EXCEPTION.
+ * Note: For IQDC unicast queues only the highest priority queue is processed.
+ */
+static inline int do_siga_output(unsigned long schid, unsigned long mask,
+				 u32 *bb, unsigned int fc)
+{
+	register unsigned long __fc asm("0") = fc;
+	register unsigned long __schid asm("1") = schid;
+	register unsigned long __mask asm("2") = mask;
+	int cc = QDIO_ERROR_SIGA_ACCESS_EXCEPTION;
+
+	asm volatile(
+		"	siga	0\n"
+		"0:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"1:\n"
+		EX_TABLE(0b, 1b)
+		: "+d" (cc), "+d" (__fc), "+d" (__schid), "+d" (__mask)
+		: : "cc", "memory");
+	(*bb) = ((unsigned int) __fc) >> 31;
+	return cc;
+}
+
+static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
+{
+	char dbf_text[15];
+
+	/* all done or next buffer state different */
+	if (ccq == 0 || ccq == 32)
+		return 0;
+	/* not all buffers processed */
+	if (ccq == 96 || ccq == 97)
+		return 1;
+	/* notify devices immediately */
+	sprintf(dbf_text, "%d", ccq);
+	QDIO_DBF_TEXT2(1, trace, dbf_text);
+	return -EIO;
+}
+
+/**
+ * qdio_do_eqbs - extract buffer states for QEBSM
+ * @q: queue to manipulate
+ * @state: state of the extracted buffers
+ * @start: buffer number to start at
+ * @count: count of buffers to examine
+ *
+ * Returns the number of successfull extracted equal buffer states.
+ * Stops processing if a state is different from the last buffers state.
+ */
+static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
+			int start, int count)
+{
+	unsigned int ccq = 0;
+	int tmp_count = count, tmp_start = start;
+	int nr = q->nr;
+	int rc;
+	char dbf_text[15];
+
+	if (!q->is_input_q)
+		nr += q->irq_ptr->nr_input_qs;
+again:
+	ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
+	rc = qdio_check_ccq(q, ccq);
+
+	/* At least one buffer was processed, return and extract the remaining
+	 * buffers later.
+	 */
+	if ((ccq == 96) && (count != tmp_count))
+		return (count - tmp_count);
+	if (rc == 1) {
+		QDIO_DBF_TEXT5(1, trace, "eqAGAIN");
+		goto again;
+	}
+
+	if (rc < 0) {
+		QDIO_DBF_TEXT2(1, trace, "eqberr");
+		sprintf(dbf_text, "%2x,%2x,%d,%d", count, tmp_count, ccq, nr);
+		QDIO_DBF_TEXT2(1, trace, dbf_text);
+		q->handler(q->irq_ptr->cdev,
+			   QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+			   0, -1, -1, q->irq_ptr->int_parm);
+		return 0;
+	}
+	return (count - tmp_count);
+}
+
+/**
+ * qdio_do_sqbs - set buffer states for QEBSM
+ * @q: queue to manipulate
+ * @state: new state of the buffers
+ * @start: first buffer number to change
+ * @count: how many buffers to change
+ *
+ * Returns the number of successfully changed buffers.
+ * Does retrying until the specified count of buffer states is set or an
+ * error occurs.
+ */
+static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
+			int count)
+{
+	unsigned int ccq = 0;
+	int tmp_count = count, tmp_start = start;
+	int nr = q->nr;
+	int rc;
+	char dbf_text[15];
+
+	if (!q->is_input_q)
+		nr += q->irq_ptr->nr_input_qs;
+again:
+	ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
+	rc = qdio_check_ccq(q, ccq);
+	if (rc == 1) {
+		QDIO_DBF_TEXT5(1, trace, "sqAGAIN");
+		goto again;
+	}
+	if (rc < 0) {
+		QDIO_DBF_TEXT3(1, trace, "sqberr");
+		sprintf(dbf_text, "%2x,%2x", count, tmp_count);
+		QDIO_DBF_TEXT3(1, trace, dbf_text);
+		sprintf(dbf_text, "%d,%d", ccq, nr);
+		QDIO_DBF_TEXT3(1, trace, dbf_text);
+
+		q->handler(q->irq_ptr->cdev,
+			   QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+			   0, -1, -1, q->irq_ptr->int_parm);
+		return 0;
+	}
+	WARN_ON(tmp_count);
+	return (count - tmp_count);
+}
+
+/* returns number of examined buffers and their common state in *state */
+static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
+				 unsigned char *state, unsigned int count)
+{
+	unsigned char __state = 0;
+	int i;
+
+	BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);
+	BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);
+
+	if (is_qebsm(q))
+		return qdio_do_eqbs(q, state, bufnr, count);
+
+	for (i = 0; i < count; i++) {
+		if (!__state)
+			__state = q->slsb.val[bufnr];
+		else if (q->slsb.val[bufnr] != __state)
+			break;
+		bufnr = next_buf(bufnr);
+	}
+	*state = __state;
+	return i;
+}
+
+inline int get_buf_state(struct qdio_q *q, unsigned int bufnr,
+		  unsigned char *state)
+{
+	return get_buf_states(q, bufnr, state, 1);
+}
+
+/* wrap-around safe setting of slsb states, returns number of changed buffers */
+static inline int set_buf_states(struct qdio_q *q, int bufnr,
+				 unsigned char state, int count)
+{
+	int i;
+
+	BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);
+	BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);
+
+	if (is_qebsm(q))
+		return qdio_do_sqbs(q, state, bufnr, count);
+
+	for (i = 0; i < count; i++) {
+		xchg(&q->slsb.val[bufnr], state);
+		bufnr = next_buf(bufnr);
+	}
+	return count;
+}
+
+static inline int set_buf_state(struct qdio_q *q, int bufnr,
+				unsigned char state)
+{
+	return set_buf_states(q, bufnr, state, 1);
+}
+
+/* set slsb state to initial state */
+void qdio_init_buf_states(struct qdio_q *q)
+{
+	if (q->is_input_q)
+		set_buf_states(q, 0, SLSB_P_INPUT_NOT_INIT,
+			       QDIO_MAX_BUFFERS_PER_Q);
+	else
+		set_buf_states(q, 0, SLSB_P_OUTPUT_NOT_INIT,
+			       QDIO_MAX_BUFFERS_PER_Q);
+}
+
+static int qdio_siga_sync(struct qdio_q *q, unsigned int output,
+			  unsigned int input)
+{
+	int cc;
+
+	if (!need_siga_sync(q))
+		return 0;
+
+	qdio_perf_stat_inc(&perf_stats.siga_sync);
+
+	cc = do_siga_sync(q->irq_ptr->schid, output, input);
+	if (cc) {
+		QDIO_DBF_TEXT4(0, trace, "sigasync");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		QDIO_DBF_HEX3(0, trace, &cc, sizeof(int *));
+	}
+	return cc;
+}
+
+inline int qdio_siga_sync_q(struct qdio_q *q)
+{
+	if (q->is_input_q)
+		return qdio_siga_sync(q, 0, q->mask);
+	else
+		return qdio_siga_sync(q, q->mask, 0);
+}
+
+static inline int qdio_siga_sync_out(struct qdio_q *q)
+{
+	return qdio_siga_sync(q, ~0U, 0);
+}
+
+static inline int qdio_siga_sync_all(struct qdio_q *q)
+{
+	return qdio_siga_sync(q, ~0U, ~0U);
+}
+
+static inline int qdio_do_siga_output(struct qdio_q *q, unsigned int *busy_bit)
+{
+	unsigned int fc = 0;
+	unsigned long schid;
+
+	if (!is_qebsm(q))
+		schid = *((u32 *)&q->irq_ptr->schid);
+	else {
+		schid = q->irq_ptr->sch_token;
+		fc |= 0x80;
+	}
+	return do_siga_output(schid, q->mask, busy_bit, fc);
+}
+
+static int qdio_siga_output(struct qdio_q *q)
+{
+	int cc;
+	u32 busy_bit;
+	u64 start_time = 0;
+
+	QDIO_DBF_TEXT5(0, trace, "sigaout");
+	QDIO_DBF_HEX5(0, trace, &q, sizeof(void *));
+
+	qdio_perf_stat_inc(&perf_stats.siga_out);
+again:
+	cc = qdio_do_siga_output(q, &busy_bit);
+	if (queue_type(q) == QDIO_IQDIO_QFMT && cc == 2 && busy_bit) {
+		if (!start_time)
+			start_time = get_usecs();
+		else if ((get_usecs() - start_time) < QDIO_BUSY_BIT_PATIENCE)
+			goto again;
+	}
+
+	if (cc == 2 && busy_bit)
+		cc |= QDIO_ERROR_SIGA_BUSY;
+	if (cc)
+		QDIO_DBF_HEX3(0, trace, &cc, sizeof(int *));
+	return cc;
+}
+
+static inline int qdio_siga_input(struct qdio_q *q)
+{
+	int cc;
+
+	QDIO_DBF_TEXT4(0, trace, "sigain");
+	QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+
+	qdio_perf_stat_inc(&perf_stats.siga_in);
+
+	cc = do_siga_input(q->irq_ptr->schid, q->mask);
+	if (cc)
+		QDIO_DBF_HEX3(0, trace, &cc, sizeof(int *));
+	return cc;
+}
+
+/* called from thinint inbound handler */
+void qdio_sync_after_thinint(struct qdio_q *q)
+{
+	if (pci_out_supported(q)) {
+		if (need_siga_sync_thinint(q))
+			qdio_siga_sync_all(q);
+		else if (need_siga_sync_out_thinint(q))
+			qdio_siga_sync_out(q);
+	} else
+		qdio_siga_sync_q(q);
+}
+
+inline void qdio_stop_polling(struct qdio_q *q)
+{
+	spin_lock_bh(&q->u.in.lock);
+	if (!atomic_xchg(&q->u.in.polling, 0)) {
+		spin_unlock_bh(&q->u.in.lock);
+		return;
+	}
+	qdio_perf_stat_inc(&perf_stats.debug_stop_polling);
+
+	/* show the card that we are not polling anymore */
+	set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
+	spin_unlock_bh(&q->u.in.lock);
+}
+
+static void announce_buffer_error(struct qdio_q *q)
+{
+	char dbf_text[15];
+
+	if (q->is_input_q)
+		QDIO_DBF_TEXT3(1, trace, "inperr");
+	else
+		QDIO_DBF_TEXT3(0, trace, "outperr");
+
+	sprintf(dbf_text, "%x-%x-%x", q->first_to_check,
+		q->sbal[q->first_to_check]->element[14].flags,
+		q->sbal[q->first_to_check]->element[15].flags);
+	QDIO_DBF_TEXT3(1, trace, dbf_text);
+	QDIO_DBF_HEX2(1, trace, q->sbal[q->first_to_check], 256);
+
+	q->qdio_error = QDIO_ERROR_SLSB_STATE;
+}
+
+static int get_inbound_buffer_frontier(struct qdio_q *q)
+{
+	int count, stop;
+	unsigned char state;
+
+	/*
+	 * If we still poll don't update last_move_ftc, keep the
+	 * previously ACK buffer there.
+	 */
+	if (!atomic_read(&q->u.in.polling))
+		q->last_move_ftc = q->first_to_check;
+
+	/*
+	 * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
+	 * would return 0.
+	 */
+	count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
+	stop = add_buf(q->first_to_check, count);
+
+	/*
+	 * No siga sync here, as a PCI or we after a thin interrupt
+	 * will sync the queues.
+	 */
+
+	/* need to set count to 1 for non-qebsm */
+	if (!is_qebsm(q))
+		count = 1;
+
+check_next:
+	if (q->first_to_check == stop)
+		goto out;
+
+	count = get_buf_states(q, q->first_to_check, &state, count);
+	if (!count)
+		goto out;
+
+	switch (state) {
+	case SLSB_P_INPUT_PRIMED:
+		QDIO_DBF_TEXT5(0, trace, "inptprim");
+
+		/*
+		 * Only ACK the first buffer. The ACK will be removed in
+		 * qdio_stop_polling.
+		 */
+		if (atomic_read(&q->u.in.polling))
+			state = SLSB_P_INPUT_NOT_INIT;
+		else {
+			atomic_set(&q->u.in.polling, 1);
+			state = SLSB_P_INPUT_ACK;
+		}
+		set_buf_state(q, q->first_to_check, state);
+
+		/*
+		 * Need to change all PRIMED buffers to NOT_INIT, otherwise
+		 * we're loosing initiative in the thinint code.
+		 */
+		if (count > 1)
+			set_buf_states(q, next_buf(q->first_to_check),
+				       SLSB_P_INPUT_NOT_INIT, count - 1);
+
+		/*
+		 * No siga-sync needed for non-qebsm here, as the inbound queue
+		 * will be synced on the next siga-r, resp.
+		 * tiqdio_is_inbound_q_done will do the siga-sync.
+		 */
+		q->first_to_check = add_buf(q->first_to_check, count);
+		atomic_sub(count, &q->nr_buf_used);
+		goto check_next;
+	case SLSB_P_INPUT_ERROR:
+		announce_buffer_error(q);
+		/* process the buffer, the upper layer will take care of it */
+		q->first_to_check = add_buf(q->first_to_check, count);
+		atomic_sub(count, &q->nr_buf_used);
+		break;
+	case SLSB_CU_INPUT_EMPTY:
+	case SLSB_P_INPUT_NOT_INIT:
+	case SLSB_P_INPUT_ACK:
+		QDIO_DBF_TEXT5(0, trace, "inpnipro");
+		break;
+	default:
+		BUG();
+	}
+out:
+	QDIO_DBF_HEX4(0, trace, &q->first_to_check, sizeof(int));
+	return q->first_to_check;
+}
+
+int qdio_inbound_q_moved(struct qdio_q *q)
+{
+	int bufnr;
+
+	bufnr = get_inbound_buffer_frontier(q);
+
+	if ((bufnr != q->last_move_ftc) || q->qdio_error) {
+		if (!need_siga_sync(q) && !pci_out_supported(q))
+			q->u.in.timestamp = get_usecs();
+
+		QDIO_DBF_TEXT4(0, trace, "inhasmvd");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		return 1;
+	} else {
+		QDIO_DBF_TEXT4(0, trace, "inhsntmv");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		return 0;
+	}
+}
+
+static int qdio_inbound_q_done(struct qdio_q *q)
+{
+	unsigned char state;
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[15];
+#endif
+
+	if (!atomic_read(&q->nr_buf_used))
+		return 1;
+
+	/*
+	 * We need that one for synchronization with the adapter, as it
+	 * does a kind of PCI avoidance.
+	 */
+	qdio_siga_sync_q(q);
+
+	get_buf_state(q, q->first_to_check, &state);
+	if (state == SLSB_P_INPUT_PRIMED)
+		/* we got something to do */
+		return 0;
+
+	/* on VM, we don't poll, so the q is always done here */
+	if (need_siga_sync(q) || pci_out_supported(q))
+		return 1;
+
+	/*
+	 * At this point we know, that inbound first_to_check
+	 * has (probably) not moved (see qdio_inbound_processing).
+	 */
+	if (get_usecs() > q->u.in.timestamp + QDIO_INPUT_THRESHOLD) {
+#ifdef CONFIG_QDIO_DEBUG
+		QDIO_DBF_TEXT4(0, trace, "inqisdon");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		sprintf(dbf_text, "pf%02x", q->first_to_check);
+		QDIO_DBF_TEXT4(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+		return 1;
+	} else {
+#ifdef CONFIG_QDIO_DEBUG
+		QDIO_DBF_TEXT4(0, trace, "inqisntd");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		sprintf(dbf_text, "pf%02x", q->first_to_check);
+		QDIO_DBF_TEXT4(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+		return 0;
+	}
+}
+
+void qdio_kick_inbound_handler(struct qdio_q *q)
+{
+	int count, start, end;
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[15];
+#endif
+
+	qdio_perf_stat_inc(&perf_stats.inbound_handler);
+
+	start = q->first_to_kick;
+	end = q->first_to_check;
+	if (end >= start)
+		count = end - start;
+	else
+		count = end + QDIO_MAX_BUFFERS_PER_Q - start;
+
+#ifdef CONFIG_QDIO_DEBUG
+	sprintf(dbf_text, "s=%2xc=%2x", start, count);
+	QDIO_DBF_TEXT4(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+
+	if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
+		return;
+
+	q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr,
+		   start, count, q->irq_ptr->int_parm);
+
+	/* for the next time */
+	q->first_to_kick = q->first_to_check;
+	q->qdio_error = 0;
+}
+
+static void __qdio_inbound_processing(struct qdio_q *q)
+{
+	qdio_perf_stat_inc(&perf_stats.tasklet_inbound);
+again:
+	if (!qdio_inbound_q_moved(q))
+		return;
+
+	qdio_kick_inbound_handler(q);
+
+	if (!qdio_inbound_q_done(q))
+		/* means poll time is not yet over */
+		goto again;
+
+	qdio_stop_polling(q);
+	/*
+	 * We need to check again to not lose initiative after
+	 * resetting the ACK state.
+	 */
+	if (!qdio_inbound_q_done(q))
+		goto again;
+}
+
+/* inbound tasklet */
+void qdio_inbound_processing(unsigned long data)
+{
+	struct qdio_q *q = (struct qdio_q *)data;
+	__qdio_inbound_processing(q);
+}
+
+static int get_outbound_buffer_frontier(struct qdio_q *q)
+{
+	int count, stop;
+	unsigned char state;
+
+	if (((queue_type(q) != QDIO_IQDIO_QFMT) && !pci_out_supported(q)) ||
+	    (queue_type(q) == QDIO_IQDIO_QFMT && multicast_outbound(q)))
+		qdio_siga_sync_q(q);
+
+	/*
+	 * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
+	 * would return 0.
+	 */
+	count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
+	stop = add_buf(q->first_to_check, count);
+
+	/* need to set count to 1 for non-qebsm */
+	if (!is_qebsm(q))
+		count = 1;
+
+check_next:
+	if (q->first_to_check == stop)
+		return q->first_to_check;
+
+	count = get_buf_states(q, q->first_to_check, &state, count);
+	if (!count)
+		return q->first_to_check;
+
+	switch (state) {
+	case SLSB_P_OUTPUT_EMPTY:
+		/* the adapter got it */
+		QDIO_DBF_TEXT5(0, trace, "outpempt");
+
+		atomic_sub(count, &q->nr_buf_used);
+		q->first_to_check = add_buf(q->first_to_check, count);
+		/*
+		 * We fetch all buffer states at once. get_buf_states may
+		 * return count < stop. For QEBSM we do not loop.
+		 */
+		if (is_qebsm(q))
+			break;
+		goto check_next;
+	case SLSB_P_OUTPUT_ERROR:
+		announce_buffer_error(q);
+		/* process the buffer, the upper layer will take care of it */
+		q->first_to_check = add_buf(q->first_to_check, count);
+		atomic_sub(count, &q->nr_buf_used);
+		break;
+	case SLSB_CU_OUTPUT_PRIMED:
+		/* the adapter has not fetched the output yet */
+		QDIO_DBF_TEXT5(0, trace, "outpprim");
+		break;
+	case SLSB_P_OUTPUT_NOT_INIT:
+	case SLSB_P_OUTPUT_HALTED:
+		break;
+	default:
+		BUG();
+	}
+	return q->first_to_check;
+}
+
+/* all buffers processed? */
+static inline int qdio_outbound_q_done(struct qdio_q *q)
+{
+	return (atomic_read(&q->nr_buf_used) == 0);
+}
+
+static inline int qdio_outbound_q_moved(struct qdio_q *q)
+{
+	int bufnr;
+
+	bufnr = get_outbound_buffer_frontier(q);
+
+	if ((bufnr != q->last_move_ftc) || q->qdio_error) {
+		q->last_move_ftc = bufnr;
+		QDIO_DBF_TEXT4(0, trace, "oqhasmvd");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		return 1;
+	} else {
+		QDIO_DBF_TEXT4(0, trace, "oqhsntmv");
+		QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+		return 0;
+	}
+}
+
+/*
+ * VM could present us cc=2 and busy bit set on SIGA-write
+ * during reconfiguration of their Guest LAN (only in iqdio mode,
+ * otherwise qdio is asynchronous and cc=2 and busy bit there will take
+ * the queues down immediately).
+ *
+ * Therefore qdio_siga_output will try for a short time constantly,
+ * if such a condition occurs. If it doesn't change, it will
+ * increase the busy_siga_counter and save the timestamp, and
+ * schedule the queue for later processing. qdio_outbound_processing
+ * will check out the counter. If non-zero, it will call qdio_kick_outbound_q
+ * as often as the value of the counter. This will attempt further SIGA
+ * instructions. For each successful SIGA, the counter is
+ * decreased, for failing SIGAs the counter remains the same, after
+ * all. After some time of no movement, qdio_kick_outbound_q will
+ * finally fail and reflect corresponding error codes to call
+ * the upper layer module and have it take the queues down.
+ *
+ * Note that this is a change from the original HiperSockets design
+ * (saying cc=2 and busy bit means take the queues down), but in
+ * these days Guest LAN didn't exist... excessive cc=2 with busy bit
+ * conditions will still take the queues down, but the threshold is
+ * higher due to the Guest LAN environment.
+ *
+ * Called from outbound tasklet and do_QDIO handler.
+ */
+static void qdio_kick_outbound_q(struct qdio_q *q)
+{
+	int rc;
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[15];
+
+	QDIO_DBF_TEXT5(0, trace, "kickoutq");
+	QDIO_DBF_HEX5(0, trace, &q, sizeof(void *));
+#endif /* CONFIG_QDIO_DEBUG */
+
+	if (!need_siga_out(q))
+		return;
+
+	rc = qdio_siga_output(q);
+	switch (rc) {
+	case 0:
+		/* went smooth this time, reset timestamp */
+		q->u.out.timestamp = 0;
+
+		/* TODO: improve error handling for CC=0 case */
+#ifdef CONFIG_QDIO_DEBUG
+		QDIO_DBF_TEXT3(0, trace, "cc2reslv");
+		sprintf(dbf_text, "%4x%2x%2x", q->irq_ptr->schid.sch_no, q->nr,
+			atomic_read(&q->u.out.busy_siga_counter));
+		QDIO_DBF_TEXT3(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+		break;
+	/* cc=2 and busy bit */
+	case (2 | QDIO_ERROR_SIGA_BUSY):
+		atomic_inc(&q->u.out.busy_siga_counter);
+
+		/* if the last siga was successful, save timestamp here */
+		if (!q->u.out.timestamp)
+			q->u.out.timestamp = get_usecs();
+
+		/* if we're in time, don't touch qdio_error */
+		if (get_usecs() - q->u.out.timestamp < QDIO_BUSY_BIT_GIVE_UP) {
+			tasklet_schedule(&q->tasklet);
+			break;
+		}
+		QDIO_DBF_TEXT2(0, trace, "cc2REPRT");
+#ifdef CONFIG_QDIO_DEBUG
+		sprintf(dbf_text, "%4x%2x%2x", q->irq_ptr->schid.sch_no, q->nr,
+			atomic_read(&q->u.out.busy_siga_counter));
+		QDIO_DBF_TEXT3(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+	default:
+		/* for plain cc=1, 2 or 3 */
+		q->qdio_error = rc;
+	}
+}
+
+static void qdio_kick_outbound_handler(struct qdio_q *q)
+{
+	int start, end, count;
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[15];
+#endif
+
+	start = q->first_to_kick;
+	end = q->last_move_ftc;
+	if (end >= start)
+		count = end - start;
+	else
+		count = end + QDIO_MAX_BUFFERS_PER_Q - start;
+
+#ifdef CONFIG_QDIO_DEBUG
+	QDIO_DBF_TEXT4(0, trace, "kickouth");
+	QDIO_DBF_HEX4(0, trace, &q, sizeof(void *));
+
+	sprintf(dbf_text, "s=%2xc=%2x", start, count);
+	QDIO_DBF_TEXT4(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+
+	if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
+		return;
+
+	q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count,
+		   q->irq_ptr->int_parm);
+
+	/* for the next time: */
+	q->first_to_kick = q->last_move_ftc;
+	q->qdio_error = 0;
+}
+
+static void __qdio_outbound_processing(struct qdio_q *q)
+{
+	int siga_attempts;
+
+	qdio_perf_stat_inc(&perf_stats.tasklet_outbound);
+
+	/* see comment in qdio_kick_outbound_q */
+	siga_attempts = atomic_read(&q->u.out.busy_siga_counter);
+	while (siga_attempts--) {
+		atomic_dec(&q->u.out.busy_siga_counter);
+		qdio_kick_outbound_q(q);
+	}
+
+	BUG_ON(atomic_read(&q->nr_buf_used) < 0);
+
+	if (qdio_outbound_q_moved(q))
+		qdio_kick_outbound_handler(q);
+
+	if (queue_type(q) == QDIO_ZFCP_QFMT) {
+		if (!pci_out_supported(q) && !qdio_outbound_q_done(q))
+			tasklet_schedule(&q->tasklet);
+		return;
+	}
+
+	/* bail out for HiperSockets unicast queues */
+	if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
+		return;
+
+	if (q->u.out.pci_out_enabled)
+		return;
+
+	/*
+	 * Now we know that queue type is either qeth without pci enabled
+	 * or HiperSockets multicast. Make sure buffer switch from PRIMED to
+	 * EMPTY is noticed and outbound_handler is called after some time.
+	 */
+	if (qdio_outbound_q_done(q))
+		del_timer(&q->u.out.timer);
+	else {
+		if (!timer_pending(&q->u.out.timer)) {
+			mod_timer(&q->u.out.timer, jiffies + 10 * HZ);
+			qdio_perf_stat_inc(&perf_stats.debug_tl_out_timer);
+		}
+	}
+}
+
+/* outbound tasklet */
+void qdio_outbound_processing(unsigned long data)
+{
+	struct qdio_q *q = (struct qdio_q *)data;
+	__qdio_outbound_processing(q);
+}
+
+void qdio_outbound_timer(unsigned long data)
+{
+	struct qdio_q *q = (struct qdio_q *)data;
+	tasklet_schedule(&q->tasklet);
+}
+
+/* called from thinint inbound tasklet */
+void qdio_check_outbound_after_thinint(struct qdio_q *q)
+{
+	struct qdio_q *out;
+	int i;
+
+	if (!pci_out_supported(q))
+		return;
+
+	for_each_output_queue(q->irq_ptr, out, i)
+		if (!qdio_outbound_q_done(out))
+			tasklet_schedule(&out->tasklet);
+}
+
+static inline void qdio_set_state(struct qdio_irq *irq_ptr,
+				  enum qdio_irq_states state)
+{
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[15];
+
+	QDIO_DBF_TEXT5(0, trace, "newstate");
+	sprintf(dbf_text, "%4x%4x", irq_ptr->schid.sch_no, state);
+	QDIO_DBF_TEXT5(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+
+	irq_ptr->state = state;
+	mb();
+}
+
+static void qdio_irq_check_sense(struct subchannel_id schid, struct irb *irb)
+{
+	char dbf_text[15];
+
+	if (irb->esw.esw0.erw.cons) {
+		sprintf(dbf_text, "sens%4x", schid.sch_no);
+		QDIO_DBF_TEXT2(1, trace, dbf_text);
+		QDIO_DBF_HEX0(0, trace, irb, 64);
+		QDIO_DBF_HEX0(0, trace, irb->ecw, 64);
+	}
+}
+
+/* PCI interrupt handler */
+static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
+{
+	int i;
+	struct qdio_q *q;
+
+	qdio_perf_stat_inc(&perf_stats.pci_int);
+
+	for_each_input_queue(irq_ptr, q, i)
+		tasklet_schedule(&q->tasklet);
+
+	if (!(irq_ptr->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED))
+		return;
+
+	for_each_output_queue(irq_ptr, q, i) {
+		if (qdio_outbound_q_done(q))
+			continue;
+
+		if (!siga_syncs_out_pci(q))
+			qdio_siga_sync_q(q);
+
+		tasklet_schedule(&q->tasklet);
+	}
+}
+
+static void qdio_handle_activate_check(struct ccw_device *cdev,
+				unsigned long intparm, int cstat, int dstat)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+	struct qdio_q *q;
+	char dbf_text[15];
+
+	QDIO_DBF_TEXT2(1, trace, "ick2");
+	sprintf(dbf_text, "%s", cdev->dev.bus_id);
+	QDIO_DBF_TEXT2(1, trace, dbf_text);
+	QDIO_DBF_HEX2(0, trace, &intparm, sizeof(int));
+	QDIO_DBF_HEX2(0, trace, &dstat, sizeof(int));
+	QDIO_DBF_HEX2(0, trace, &cstat, sizeof(int));
+
+	if (irq_ptr->nr_input_qs) {
+		q = irq_ptr->input_qs[0];
+	} else if (irq_ptr->nr_output_qs) {
+		q = irq_ptr->output_qs[0];
+	} else {
+		dump_stack();
+		goto no_handler;
+	}
+	q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+		   0, -1, -1, irq_ptr->int_parm);
+no_handler:
+	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
+}
+
+static void qdio_call_shutdown(struct work_struct *work)
+{
+	struct ccw_device_private *priv;
+	struct ccw_device *cdev;
+
+	priv = container_of(work, struct ccw_device_private, kick_work);
+	cdev = priv->cdev;
+	qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
+	put_device(&cdev->dev);
+}
+
+static void qdio_int_error(struct ccw_device *cdev)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+
+	switch (irq_ptr->state) {
+	case QDIO_IRQ_STATE_INACTIVE:
+	case QDIO_IRQ_STATE_CLEANUP:
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
+		break;
+	case QDIO_IRQ_STATE_ESTABLISHED:
+	case QDIO_IRQ_STATE_ACTIVE:
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
+		if (get_device(&cdev->dev)) {
+			/* Can't call shutdown from interrupt context. */
+			PREPARE_WORK(&cdev->private->kick_work,
+				     qdio_call_shutdown);
+			queue_work(ccw_device_work, &cdev->private->kick_work);
+		}
+		break;
+	default:
+		WARN_ON(1);
+	}
+	wake_up(&cdev->private->wait_q);
+}
+
+static int qdio_establish_check_errors(struct ccw_device *cdev, int cstat,
+					   int dstat)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+
+	if (cstat || (dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))) {
+		QDIO_DBF_TEXT2(1, setup, "eq:ckcon");
+		goto error;
+	}
+
+	if (!(dstat & DEV_STAT_DEV_END)) {
+		QDIO_DBF_TEXT2(1, setup, "eq:no de");
+		goto error;
+	}
+
+	if (dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) {
+		QDIO_DBF_TEXT2(1, setup, "eq:badio");
+		goto error;
+	}
+	return 0;
+error:
+	QDIO_DBF_HEX2(0, trace, &cstat, sizeof(int));
+	QDIO_DBF_HEX2(0, trace, &dstat, sizeof(int));
+	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
+	return 1;
+}
+
+static void qdio_establish_handle_irq(struct ccw_device *cdev, int cstat,
+				      int dstat)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+	char dbf_text[15];
+
+	sprintf(dbf_text, "qehi%4x", cdev->private->schid.sch_no);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+	QDIO_DBF_TEXT0(0, trace, dbf_text);
+
+	if (!qdio_establish_check_errors(cdev, cstat, dstat))
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ESTABLISHED);
+}
+
+/* qdio interrupt handler */
+void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm,
+		      struct irb *irb)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+	int cstat, dstat;
+	char dbf_text[15];
+
+	qdio_perf_stat_inc(&perf_stats.qdio_int);
+
+	if (!intparm || !irq_ptr) {
+		sprintf(dbf_text, "qihd%4x", cdev->private->schid.sch_no);
+		QDIO_DBF_TEXT2(1, setup, dbf_text);
+		return;
+	}
+
+	if (IS_ERR(irb)) {
+		switch (PTR_ERR(irb)) {
+		case -EIO:
+			sprintf(dbf_text, "ierr%4x",
+				cdev->private->schid.sch_no);
+			QDIO_DBF_TEXT2(1, setup, dbf_text);
+			qdio_int_error(cdev);
+			return;
+		case -ETIMEDOUT:
+			sprintf(dbf_text, "qtoh%4x",
+				cdev->private->schid.sch_no);
+			QDIO_DBF_TEXT2(1, setup, dbf_text);
+			qdio_int_error(cdev);
+			return;
+		default:
+			WARN_ON(1);
+			return;
+		}
+	}
+	qdio_irq_check_sense(irq_ptr->schid, irb);
+
+	cstat = irb->scsw.cmd.cstat;
+	dstat = irb->scsw.cmd.dstat;
+
+	switch (irq_ptr->state) {
+	case QDIO_IRQ_STATE_INACTIVE:
+		qdio_establish_handle_irq(cdev, cstat, dstat);
+		break;
+
+	case QDIO_IRQ_STATE_CLEANUP:
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
+		break;
+
+	case QDIO_IRQ_STATE_ESTABLISHED:
+	case QDIO_IRQ_STATE_ACTIVE:
+		if (cstat & SCHN_STAT_PCI) {
+			qdio_int_handler_pci(irq_ptr);
+			/* no state change so no need to wake up wait_q */
+			return;
+		}
+		if ((cstat & ~SCHN_STAT_PCI) || dstat) {
+			qdio_handle_activate_check(cdev, intparm, cstat,
+						   dstat);
+			break;
+		}
+	default:
+		WARN_ON(1);
+	}
+	wake_up(&cdev->private->wait_q);
+}
+
+/**
+ * qdio_get_ssqd_desc - get qdio subchannel description
+ * @cdev: ccw device to get description for
+ *
+ * Returns a pointer to the saved qdio subchannel description,
+ * or NULL for not setup qdio devices.
+ */
+struct qdio_ssqd_desc *qdio_get_ssqd_desc(struct ccw_device *cdev)
+{
+	struct qdio_irq *irq_ptr;
+
+	QDIO_DBF_TEXT0(0, setup, "getssqd");
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return NULL;
+
+	return &irq_ptr->ssqd_desc;
+}
+EXPORT_SYMBOL_GPL(qdio_get_ssqd_desc);
+
+/**
+ * qdio_cleanup - shutdown queues and free data structures
+ * @cdev: associated ccw device
+ * @how: use halt or clear to shutdown
+ *
+ * This function calls qdio_shutdown() for @cdev with method @how
+ * and on success qdio_free() for @cdev.
+ */
+int qdio_cleanup(struct ccw_device *cdev, int how)
+{
+	struct qdio_irq *irq_ptr;
+	char dbf_text[15];
+	int rc;
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+	sprintf(dbf_text, "qcln%4x", irq_ptr->schid.sch_no);
+	QDIO_DBF_TEXT1(0, trace, dbf_text);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+
+	rc = qdio_shutdown(cdev, how);
+	if (rc == 0)
+		rc = qdio_free(cdev);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(qdio_cleanup);
+
+static void qdio_shutdown_queues(struct ccw_device *cdev)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+	struct qdio_q *q;
+	int i;
+
+	for_each_input_queue(irq_ptr, q, i)
+		tasklet_disable(&q->tasklet);
+
+	for_each_output_queue(irq_ptr, q, i) {
+		tasklet_disable(&q->tasklet);
+		del_timer(&q->u.out.timer);
+	}
+}
+
+/**
+ * qdio_shutdown - shut down a qdio subchannel
+ * @cdev: associated ccw device
+ * @how: use halt or clear to shutdown
+ */
+int qdio_shutdown(struct ccw_device *cdev, int how)
+{
+	struct qdio_irq *irq_ptr;
+	int rc;
+	unsigned long flags;
+	char dbf_text[15];
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+	mutex_lock(&irq_ptr->setup_mutex);
+
+	sprintf(dbf_text, "qsqs%4x", irq_ptr->schid.sch_no);
+	QDIO_DBF_TEXT1(0, trace, dbf_text);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+
+	tiqdio_remove_input_queues(irq_ptr);
+	qdio_shutdown_queues(cdev);
+	qdio_shutdown_debug_entries(irq_ptr, cdev);
+
+	/* cleanup subchannel */
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+
+	if (how & QDIO_FLAG_CLEANUP_USING_CLEAR)
+		rc = ccw_device_clear(cdev, QDIO_DOING_CLEANUP);
+	else
+		/* default behaviour is halt */
+		rc = ccw_device_halt(cdev, QDIO_DOING_CLEANUP);
+
+	if (rc == -ENODEV) {
+		/* no need to wait for a no longer present device */
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
+		goto no_cleanup;
+	}
+
+	if (rc) {
+		sprintf(dbf_text, "sher%4x", irq_ptr->schid.sch_no);
+		QDIO_DBF_TEXT0(0, setup, dbf_text);
+		sprintf(dbf_text, "rc=%d", rc);
+		QDIO_DBF_TEXT0(0, setup, dbf_text);
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		goto out;
+	}
+
+	if ((void *)cdev->handler != (void *)qdio_int_handler) {
+		/*
+		 * Whoever put another handler there, has to cope with the
+		 * interrupt theirself. Might happen if qdio_shutdown was
+		 * called on already shutdown queues, but this shouldn't have
+		 * bad side effects.
+		 */
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
+		goto no_cleanup;
+	}
+
+	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_CLEANUP);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	wait_event_interruptible_timeout(cdev->private->wait_q,
+		irq_ptr->state == QDIO_IRQ_STATE_INACTIVE ||
+		irq_ptr->state == QDIO_IRQ_STATE_ERR,
+		10 * HZ);
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+no_cleanup:
+	qdio_shutdown_thinint(irq_ptr);
+
+	/* restore interrupt handlers, if necessary */
+	if ((void *)cdev->handler == (void *)qdio_int_handler)
+		cdev->handler = irq_ptr->orig_handler;
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	/* ignore errors */
+	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
+out:
+	mutex_unlock(&irq_ptr->setup_mutex);
+	if (rc)
+		return rc;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qdio_shutdown);
+
+/**
+ * qdio_free - free data structures for a qdio subchannel
+ * @cdev: associated ccw device
+ */
+int qdio_free(struct ccw_device *cdev)
+{
+	struct qdio_irq *irq_ptr;
+	char dbf_text[15];
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+	mutex_lock(&irq_ptr->setup_mutex);
+
+	sprintf(dbf_text, "qfqs%4x", irq_ptr->schid.sch_no);
+	QDIO_DBF_TEXT1(0, trace, dbf_text);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+
+	cdev->private->qdio_data = NULL;
+	mutex_unlock(&irq_ptr->setup_mutex);
+
+	qdio_release_memory(irq_ptr);
+	module_put(THIS_MODULE);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qdio_free);
+
+/**
+ * qdio_initialize - allocate and establish queues for a qdio subchannel
+ * @init_data: initialization data
+ *
+ * This function first allocates queues via qdio_allocate() and on success
+ * establishes them via qdio_establish().
+ */
+int qdio_initialize(struct qdio_initialize *init_data)
+{
+	int rc;
+	char dbf_text[15];
+
+	sprintf(dbf_text, "qini%4x", init_data->cdev->private->schid.sch_no);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+	QDIO_DBF_TEXT0(0, trace, dbf_text);
+
+	rc = qdio_allocate(init_data);
+	if (rc)
+		return rc;
+
+	rc = qdio_establish(init_data);
+	if (rc)
+		qdio_free(init_data->cdev);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(qdio_initialize);
+
+/**
+ * qdio_allocate - allocate qdio queues and associated data
+ * @init_data: initialization data
+ */
+int qdio_allocate(struct qdio_initialize *init_data)
+{
+	struct qdio_irq *irq_ptr;
+	char dbf_text[15];
+
+	sprintf(dbf_text, "qalc%4x", init_data->cdev->private->schid.sch_no);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+	QDIO_DBF_TEXT0(0, trace, dbf_text);
+
+	if ((init_data->no_input_qs && !init_data->input_handler) ||
+	    (init_data->no_output_qs && !init_data->output_handler))
+		return -EINVAL;
+
+	if ((init_data->no_input_qs > QDIO_MAX_QUEUES_PER_IRQ) ||
+	    (init_data->no_output_qs > QDIO_MAX_QUEUES_PER_IRQ))
+		return -EINVAL;
+
+	if ((!init_data->input_sbal_addr_array) ||
+	    (!init_data->output_sbal_addr_array))
+		return -EINVAL;
+
+	qdio_allocate_do_dbf(init_data);
+
+	irq_ptr = (void *) get_zeroed_page(GFP_KERNEL);
+	if (!irq_ptr)
+		goto out_err;
+	QDIO_DBF_TEXT0(0, setup, "irq_ptr:");
+	QDIO_DBF_HEX0(0, setup, &irq_ptr, sizeof(void *));
+
+	mutex_init(&irq_ptr->setup_mutex);
+
+	/*
+	 * Allocate a page for the chsc calls in qdio_establish.
+	 * Must be pre-allocated since a zfcp recovery will call
+	 * qdio_establish. In case of low memory and swap on a zfcp disk
+	 * we may not be able to allocate memory otherwise.
+	 */
+	irq_ptr->chsc_page = get_zeroed_page(GFP_KERNEL);
+	if (!irq_ptr->chsc_page)
+		goto out_rel;
+
+	irq_ptr->qdr = kzalloc(sizeof(struct qdr), GFP_KERNEL);
+	if (!irq_ptr->qdr)
+		goto out_rel;
+	WARN_ON((unsigned long)irq_ptr->qdr & 0xfff);
+
+	QDIO_DBF_TEXT0(0, setup, "qdr:");
+	QDIO_DBF_HEX0(0, setup, &irq_ptr->qdr, sizeof(void *));
+
+	if (qdio_allocate_qs(irq_ptr, init_data->no_input_qs,
+			     init_data->no_output_qs))
+		goto out_rel;
+
+	init_data->cdev->private->qdio_data = irq_ptr;
+	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
+	return 0;
+out_rel:
+	qdio_release_memory(irq_ptr);
+out_err:
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(qdio_allocate);
+
+/**
+ * qdio_establish - establish queues on a qdio subchannel
+ * @init_data: initialization data
+ */
+int qdio_establish(struct qdio_initialize *init_data)
+{
+	char dbf_text[20];
+	struct qdio_irq *irq_ptr;
+	struct ccw_device *cdev = init_data->cdev;
+	unsigned long saveflags;
+	int rc;
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+	if (cdev->private->state != DEV_STATE_ONLINE)
+		return -EINVAL;
+
+	mutex_lock(&irq_ptr->setup_mutex);
+	qdio_setup_irq(init_data);
+
+	rc = qdio_establish_thinint(irq_ptr);
+	if (rc) {
+		mutex_unlock(&irq_ptr->setup_mutex);
+		qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
+		return rc;
+	}
+
+	sprintf(dbf_text, "qest%4x", cdev->private->schid.sch_no);
+	QDIO_DBF_TEXT0(0, setup, dbf_text);
+	QDIO_DBF_TEXT0(0, trace, dbf_text);
+
+	/* establish q */
+	irq_ptr->ccw.cmd_code = irq_ptr->equeue.cmd;
+	irq_ptr->ccw.flags = CCW_FLAG_SLI;
+	irq_ptr->ccw.count = irq_ptr->equeue.count;
+	irq_ptr->ccw.cda = (u32)((addr_t)irq_ptr->qdr);
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), saveflags);
+	ccw_device_set_options_mask(cdev, 0);
+
+	rc = ccw_device_start(cdev, &irq_ptr->ccw, QDIO_DOING_ESTABLISH, 0, 0);
+	if (rc) {
+		sprintf(dbf_text, "eq:io%4x", irq_ptr->schid.sch_no);
+		QDIO_DBF_TEXT2(1, setup, dbf_text);
+		sprintf(dbf_text, "eq:rc%4x", rc);
+		QDIO_DBF_TEXT2(1, setup, dbf_text);
+	}
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), saveflags);
+
+	if (rc) {
+		mutex_unlock(&irq_ptr->setup_mutex);
+		qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
+		return rc;
+	}
+
+	wait_event_interruptible_timeout(cdev->private->wait_q,
+		irq_ptr->state == QDIO_IRQ_STATE_ESTABLISHED ||
+		irq_ptr->state == QDIO_IRQ_STATE_ERR, HZ);
+
+	if (irq_ptr->state != QDIO_IRQ_STATE_ESTABLISHED) {
+		mutex_unlock(&irq_ptr->setup_mutex);
+		qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
+		return -EIO;
+	}
+
+	qdio_setup_ssqd_info(irq_ptr);
+	sprintf(dbf_text, "qib ac%2x", irq_ptr->qib.ac);
+	QDIO_DBF_TEXT2(0, setup, dbf_text);
+
+	mutex_unlock(&irq_ptr->setup_mutex);
+	qdio_print_subchannel_info(irq_ptr, cdev);
+	qdio_setup_debug_entries(irq_ptr, cdev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qdio_establish);
+
+/**
+ * qdio_activate - activate queues on a qdio subchannel
+ * @cdev: associated cdev
+ */
+int qdio_activate(struct ccw_device *cdev)
+{
+	struct qdio_irq *irq_ptr;
+	int rc;
+	unsigned long saveflags;
+	char dbf_text[20];
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+	if (cdev->private->state != DEV_STATE_ONLINE)
+		return -EINVAL;
+
+	mutex_lock(&irq_ptr->setup_mutex);
+	if (irq_ptr->state == QDIO_IRQ_STATE_INACTIVE) {
+		rc = -EBUSY;
+		goto out;
+	}
+
+	sprintf(dbf_text, "qact%4x", irq_ptr->schid.sch_no);
+	QDIO_DBF_TEXT2(0, setup, dbf_text);
+	QDIO_DBF_TEXT2(0, trace, dbf_text);
+
+	irq_ptr->ccw.cmd_code = irq_ptr->aqueue.cmd;
+	irq_ptr->ccw.flags = CCW_FLAG_SLI;
+	irq_ptr->ccw.count = irq_ptr->aqueue.count;
+	irq_ptr->ccw.cda = 0;
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), saveflags);
+	ccw_device_set_options(cdev, CCWDEV_REPORT_ALL);
+
+	rc = ccw_device_start(cdev, &irq_ptr->ccw, QDIO_DOING_ACTIVATE,
+			      0, DOIO_DENY_PREFETCH);
+
+	if (rc) {
+		sprintf(dbf_text, "aq:io%4x", irq_ptr->schid.sch_no);
+		QDIO_DBF_TEXT2(1, setup, dbf_text);
+		sprintf(dbf_text, "aq:rc%4x", rc);
+		QDIO_DBF_TEXT2(1, setup, dbf_text);
+	}
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), saveflags);
+
+	if (rc)
+		goto out;
+
+	if (is_thinint_irq(irq_ptr))
+		tiqdio_add_input_queues(irq_ptr);
+
+	/* wait for subchannel to become active */
+	msleep(5);
+
+	switch (irq_ptr->state) {
+	case QDIO_IRQ_STATE_STOPPED:
+	case QDIO_IRQ_STATE_ERR:
+		mutex_unlock(&irq_ptr->setup_mutex);
+		qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
+		return -EIO;
+	default:
+		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ACTIVE);
+		rc = 0;
+	}
+out:
+	mutex_unlock(&irq_ptr->setup_mutex);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(qdio_activate);
+
+static inline int buf_in_between(int bufnr, int start, int count)
+{
+	int end = add_buf(start, count);
+
+	if (end > start) {
+		if (bufnr >= start && bufnr < end)
+			return 1;
+		else
+			return 0;
+	}
+
+	/* wrap-around case */
+	if ((bufnr >= start && bufnr <= QDIO_MAX_BUFFERS_PER_Q) ||
+	    (bufnr < end))
+		return 1;
+	else
+		return 0;
+}
+
+/**
+ * handle_inbound - reset processed input buffers
+ * @q: queue containing the buffers
+ * @callflags: flags
+ * @bufnr: first buffer to process
+ * @count: how many buffers are emptied
+ */
+static void handle_inbound(struct qdio_q *q, unsigned int callflags,
+			   int bufnr, int count)
+{
+	unsigned long flags;
+	int used, rc;
+
+	/*
+	 * do_QDIO could run in parallel with the queue tasklet so the
+	 * upper-layer programm could empty the ACK'ed buffer here.
+	 * If that happens we must clear the polling flag, otherwise
+	 * qdio_stop_polling() could set the buffer to NOT_INIT after
+	 * it was set to EMPTY which would kill us.
+	 */
+	spin_lock_irqsave(&q->u.in.lock, flags);
+	if (atomic_read(&q->u.in.polling))
+		if (buf_in_between(q->last_move_ftc, bufnr, count))
+			atomic_xchg(&q->u.in.polling, 0);
+
+	count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);
+	spin_unlock_irqrestore(&q->u.in.lock, flags);
+
+	used = atomic_add_return(count, &q->nr_buf_used) - count;
+	BUG_ON(used + count > QDIO_MAX_BUFFERS_PER_Q);
+
+	/* no need to signal as long as the adapter had free buffers */
+	if (used)
+		return;
+
+	if (need_siga_in(q)) {
+		rc = qdio_siga_input(q);
+		if (rc)
+			q->qdio_error = rc;
+	}
+}
+
+/**
+ * handle_outbound - process filled outbound buffers
+ * @q: queue containing the buffers
+ * @callflags: flags
+ * @bufnr: first buffer to process
+ * @count: how many buffers are filled
+ */
+static void handle_outbound(struct qdio_q *q, unsigned int callflags,
+			    int bufnr, int count)
+{
+	unsigned char state;
+	int used;
+
+	qdio_perf_stat_inc(&perf_stats.outbound_handler);
+
+	count = set_buf_states(q, bufnr, SLSB_CU_OUTPUT_PRIMED, count);
+	used = atomic_add_return(count, &q->nr_buf_used);
+	BUG_ON(used > QDIO_MAX_BUFFERS_PER_Q);
+
+	if (callflags & QDIO_FLAG_PCI_OUT)
+		q->u.out.pci_out_enabled = 1;
+	else
+		q->u.out.pci_out_enabled = 0;
+
+	if (queue_type(q) == QDIO_IQDIO_QFMT) {
+		if (multicast_outbound(q))
+			qdio_kick_outbound_q(q);
+		else
+			/*
+			 * One siga-w per buffer required for unicast
+			 * HiperSockets.
+			 */
+			while (count--)
+				qdio_kick_outbound_q(q);
+		goto out;
+	}
+
+	if (need_siga_sync(q)) {
+		qdio_siga_sync_q(q);
+		goto out;
+	}
+
+	/* try to fast requeue buffers */
+	get_buf_state(q, prev_buf(bufnr), &state);
+	if (state != SLSB_CU_OUTPUT_PRIMED)
+		qdio_kick_outbound_q(q);
+	else {
+		QDIO_DBF_TEXT5(0, trace, "fast-req");
+		qdio_perf_stat_inc(&perf_stats.fast_requeue);
+	}
+out:
+	/* Fixme: could wait forever if called from process context */
+	tasklet_schedule(&q->tasklet);
+}
+
+/**
+ * do_QDIO - process input or output buffers
+ * @cdev: associated ccw_device for the qdio subchannel
+ * @callflags: input or output and special flags from the program
+ * @q_nr: queue number
+ * @bufnr: buffer number
+ * @count: how many buffers to process
+ */
+int do_QDIO(struct ccw_device *cdev, unsigned int callflags,
+	    int q_nr, int bufnr, int count)
+{
+	struct qdio_irq *irq_ptr;
+#ifdef CONFIG_QDIO_DEBUG
+	char dbf_text[20];
+
+	sprintf(dbf_text, "doQD%04x", cdev->private->schid.sch_no);
+	QDIO_DBF_TEXT3(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+
+	if ((bufnr > QDIO_MAX_BUFFERS_PER_Q) ||
+	    (count > QDIO_MAX_BUFFERS_PER_Q) ||
+	    (q_nr > QDIO_MAX_QUEUES_PER_IRQ))
+		return -EINVAL;
+
+	if (!count)
+		return 0;
+
+	irq_ptr = cdev->private->qdio_data;
+	if (!irq_ptr)
+		return -ENODEV;
+
+#ifdef CONFIG_QDIO_DEBUG
+	if (callflags & QDIO_FLAG_SYNC_INPUT)
+		QDIO_DBF_HEX3(0, trace, &irq_ptr->input_qs[q_nr],
+			      sizeof(void *));
+	else
+		QDIO_DBF_HEX3(0, trace, &irq_ptr->output_qs[q_nr],
+			      sizeof(void *));
+
+	sprintf(dbf_text, "flag%04x", callflags);
+	QDIO_DBF_TEXT3(0, trace, dbf_text);
+	sprintf(dbf_text, "qi%02xct%02x", bufnr, count);
+	QDIO_DBF_TEXT3(0, trace, dbf_text);
+#endif /* CONFIG_QDIO_DEBUG */
+
+	if (irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)
+		return -EBUSY;
+
+	if (callflags & QDIO_FLAG_SYNC_INPUT)
+		handle_inbound(irq_ptr->input_qs[q_nr],
+			       callflags, bufnr, count);
+	else if (callflags & QDIO_FLAG_SYNC_OUTPUT)
+		handle_outbound(irq_ptr->output_qs[q_nr],
+				callflags, bufnr, count);
+	else {
+		QDIO_DBF_TEXT3(1, trace, "doQD:inv");
+		return -EINVAL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(do_QDIO);
+
+static int __init init_QDIO(void)
+{
+	int rc;
+
+	rc = qdio_setup_init();
+	if (rc)
+		return rc;
+	rc = tiqdio_allocate_memory();
+	if (rc)
+		goto out_cache;
+	rc = qdio_debug_init();
+	if (rc)
+		goto out_ti;
+	rc = qdio_setup_perf_stats();
+	if (rc)
+		goto out_debug;
+	rc = tiqdio_register_thinints();
+	if (rc)
+		goto out_perf;
+	return 0;
+
+out_perf:
+	qdio_remove_perf_stats();
+out_debug:
+	qdio_debug_exit();
+out_ti:
+	tiqdio_free_memory();
+out_cache:
+	qdio_setup_exit();
+	return rc;
+}
+
+static void __exit exit_QDIO(void)
+{
+	tiqdio_unregister_thinints();
+	tiqdio_free_memory();
+	qdio_remove_perf_stats();
+	qdio_debug_exit();
+	qdio_setup_exit();
+}
+
+module_init(init_QDIO);
+module_exit(exit_QDIO);

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

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