qdio.c

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/*
 *
 * linux/drivers/s390/cio/qdio.c
 *
 * Linux for S/390 QDIO base support, Hipersocket base support
 * version 2
 *
 * Copyright 2000,2002 IBM Corporation
 * Author(s):             Utz Bacher <[e-mail]>
 * 2.6 cio integration by Cornelia Huck <[e-mail]>
 *
 * Restriction: only 63 iqdio subchannels would have its own indicator,
 * after that, subsequent subchannels share one indicator
 *
 *
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/timer.h>
#include <linux/mempool.h>

#include <asm/ccwdev.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
#include <asm/timex.h>

#include <asm/debug.h>
#include <asm/qdio.h>

#include "cio.h"
#include "css.h"
#include "device.h"
#include "airq.h"
#include "qdio.h"
#include "ioasm.h"
#include "chsc.h"

/****************** MODULE PARAMETER VARIABLES ********************/
MODULE_AUTHOR("Utz Bacher <[e-mail]>");
MODULE_DESCRIPTION("QDIO base support version 2, " \
		   "Copyright 2000 IBM Corporation");
MODULE_LICENSE("GPL");

/******************** HERE WE GO ***********************************/

static const char version[] = "QDIO base support version 2";

#ifdef QDIO_PERFORMANCE_STATS
static int proc_perf_file_registration;
static unsigned long i_p_c, i_p_nc, o_p_c, o_p_nc, ii_p_c, ii_p_nc;
static struct qdio_perf_stats perf_stats;
#endif /* QDIO_PERFORMANCE_STATS */

static int hydra_thinints;
static int is_passthrough = 0;
static int omit_svs;

static int indicator_used[INDICATORS_PER_CACHELINE];
static __u32 * volatile indicators;
static __u32 volatile spare_indicator;
static atomic_t spare_indicator_usecount;
#define QDIO_MEMPOOL_SCSSC_ELEMENTS 2
static mempool_t *qdio_mempool_scssc;

static debug_info_t *qdio_dbf_setup;
static debug_info_t *qdio_dbf_sbal;
static debug_info_t *qdio_dbf_trace;
static debug_info_t *qdio_dbf_sense;
#ifdef CONFIG_QDIO_DEBUG
static debug_info_t *qdio_dbf_slsb_out;
static debug_info_t *qdio_dbf_slsb_in;
#endif /* CONFIG_QDIO_DEBUG */

/* iQDIO stuff: */
static volatile struct qdio_q *tiq_list=NULL; /* volatile as it could change
						 during a while loop */
static DEFINE_SPINLOCK(ttiq_list_lock);
static int register_thinint_result;
static void tiqdio_tl(unsigned long);
static DECLARE_TASKLET(tiqdio_tasklet,tiqdio_tl,0);

/* not a macro, as one of the arguments is atomic_read */
static inline int 
qdio_min(int a,int b)
{
	if (a<b)
		return a;
	else
		return b;
}

/***************** SCRUBBER HELPER ROUTINES **********************/

static inline __u64 
qdio_get_micros(void)
{
        return (get_clock() >> 10); /* time>>12 is microseconds */
}

/* 
 * unfortunately, we can't just xchg the values; in do_QDIO we want to reserve
 * the q in any case, so that we'll not be interrupted when we are in
 * qdio_mark_tiq... shouldn't have a really bad impact, as reserving almost
 * ever works (last famous words) 
 */
static inline int 
qdio_reserve_q(struct qdio_q *q)
{
	return atomic_add_return(1,&q->use_count) - 1;
}

static inline void 
qdio_release_q(struct qdio_q *q)
{
	atomic_dec(&q->use_count);
}

/*check ccq  */
static inline int
qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
{
	char dbf_text[15];

	if (ccq == 0 || ccq == 32 || ccq == 96)
		return 0;
	if (ccq == 97)
		return 1;
	/*notify devices immediately*/
	sprintf(dbf_text,"%d", ccq);
	QDIO_DBF_TEXT2(1,trace,dbf_text);
	return -EIO;
}
/* EQBS: extract buffer states */
static inline int
qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
	     unsigned int *start, unsigned int *cnt)
{
	struct qdio_irq *irq;
	unsigned int tmp_cnt, q_no, ccq;
	int rc ;
	char dbf_text[15];

	ccq = 0;
	tmp_cnt = *cnt;
	irq = (struct qdio_irq*)q->irq_ptr;
	q_no = q->q_no;
	if(!q->is_input_q)
		q_no += irq->no_input_qs;
again:
	ccq = do_eqbs(irq->sch_token, state, q_no, start, cnt);
	rc = qdio_check_ccq(q, ccq);
	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",tmp_cnt, *cnt, ccq, q_no);
                QDIO_DBF_TEXT2(1,trace,dbf_text);
		q->handler(q->cdev,QDIO_STATUS_ACTIVATE_CHECK_CONDITION|
				QDIO_STATUS_LOOK_FOR_ERROR,
				0, 0, 0, -1, -1, q->int_parm);
		return 0;
	}
	return (tmp_cnt - *cnt);
}

/* SQBS: set buffer states */
static inline int
qdio_do_sqbs(struct qdio_q *q, unsigned char state,
	     unsigned int *start, unsigned int *cnt)
{
	struct qdio_irq *irq;
	unsigned int tmp_cnt, q_no, ccq;
	int rc;
	char dbf_text[15];

	ccq = 0;
	tmp_cnt = *cnt;
	irq = (struct qdio_irq*)q->irq_ptr;
	q_no = q->q_no;
	if(!q->is_input_q)
		q_no += irq->no_input_qs;
again:
	ccq = do_sqbs(irq->sch_token, state, q_no, start, cnt);
	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,%d,%d",tmp_cnt,*cnt,ccq,q_no);
                QDIO_DBF_TEXT3(1,trace,dbf_text);
		q->handler(q->cdev,QDIO_STATUS_ACTIVATE_CHECK_CONDITION|
				QDIO_STATUS_LOOK_FOR_ERROR,
				0, 0, 0, -1, -1, q->int_parm);
		return 0;
	}
	return (tmp_cnt - *cnt);
}

static inline int
qdio_set_slsb(struct qdio_q *q, unsigned int *bufno,
	      unsigned char state, unsigned int *count)
{
	volatile char *slsb;
	struct qdio_irq *irq;

	irq = (struct qdio_irq*)q->irq_ptr;
	if (!irq->is_qebsm) {
		slsb = (char *)&q->slsb.acc.val[(*bufno)];
		xchg(slsb, state);
		return 1;
	}
	return qdio_do_sqbs(q, state, bufno, count);
}

#ifdef CONFIG_QDIO_DEBUG
static inline void
qdio_trace_slsb(struct qdio_q *q)
{
	if (q->queue_type==QDIO_TRACE_QTYPE) {
		if (q->is_input_q)
			QDIO_DBF_HEX2(0,slsb_in,&q->slsb,
				      QDIO_MAX_BUFFERS_PER_Q);
		else
			QDIO_DBF_HEX2(0,slsb_out,&q->slsb,
				      QDIO_MAX_BUFFERS_PER_Q);
	}
}
#endif

static inline int
set_slsb(struct qdio_q *q, unsigned int *bufno,
	 unsigned char state, unsigned int *count)
{
	int rc;
#ifdef CONFIG_QDIO_DEBUG
	qdio_trace_slsb(q);
#endif
	rc = qdio_set_slsb(q, bufno, state, count);
#ifdef CONFIG_QDIO_DEBUG
	qdio_trace_slsb(q);
#endif
	return rc;
}
static inline int 
qdio_siga_sync(struct qdio_q *q, unsigned int gpr2,
	       unsigned int gpr3)
{
	int cc;

	QDIO_DBF_TEXT4(0,trace,"sigasync");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

#ifdef QDIO_PERFORMANCE_STATS
	perf_stats.siga_syncs++;
#endif /* QDIO_PERFORMANCE_STATS */

	cc = do_siga_sync(q->schid, gpr2, gpr3);
	if (cc)
		QDIO_DBF_HEX3(0,trace,&cc,sizeof(int*));

	return cc;
}

static inline int
qdio_siga_sync_q(struct qdio_q *q)
{
	if (q->is_input_q)
		return qdio_siga_sync(q, 0, q->mask);
	return qdio_siga_sync(q, q->mask, 0);
}

static int
__do_siga_output(struct qdio_q *q, unsigned int *busy_bit)
{
       struct qdio_irq *irq;
       unsigned int fc = 0;
       unsigned long schid;

       irq = (struct qdio_irq *) q->irq_ptr;
       if (!irq->is_qebsm)
	       schid = *((u32 *)&q->schid);
       else {
	       schid = irq->sch_token;
	       fc |= 0x80;
       }
       return do_siga_output(schid, q->mask, busy_bit, fc);
}

/* 
 * returns QDIO_SIGA_ERROR_ACCESS_EXCEPTION as cc, when SIGA returns
 * an access exception 
 */
static inline int 
qdio_siga_output(struct qdio_q *q)
{
	int cc;
	__u32 busy_bit;
	__u64 start_time=0;

#ifdef QDIO_PERFORMANCE_STATS
	perf_stats.siga_outs++;
#endif /* QDIO_PERFORMANCE_STATS */

	QDIO_DBF_TEXT4(0,trace,"sigaout");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	for (;;) {
		cc = __do_siga_output(q, &busy_bit);
//QDIO_PRINT_ERR("cc=%x, busy=%x\n",cc,busy_bit);
		if ((cc==2) && (busy_bit) && (q->is_iqdio_q)) {
			if (!start_time) 
				start_time=NOW;
			if ((NOW-start_time)>QDIO_BUSY_BIT_PATIENCE)
				break;
		} else
			break;
	}
	
	if ((cc==2) && (busy_bit)) 
		cc |= QDIO_SIGA_ERROR_B_BIT_SET;

	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*));

#ifdef QDIO_PERFORMANCE_STATS
	perf_stats.siga_ins++;
#endif /* QDIO_PERFORMANCE_STATS */

	cc = do_siga_input(q->schid, q->mask);
	
	if (cc)
		QDIO_DBF_HEX3(0,trace,&cc,sizeof(int*));

	return cc;
}

/* locked by the locks in qdio_activate and qdio_cleanup */
static __u32 *
qdio_get_indicator(void)
{
	int i;

	for (i=1;i<INDICATORS_PER_CACHELINE;i++)
		if (!indicator_used[i]) {
			indicator_used[i]=1;
			return indicators+i;
		}
	atomic_inc(&spare_indicator_usecount);
	return (__u32 * volatile) &spare_indicator;
}

/* locked by the locks in qdio_activate and qdio_cleanup */
static void 
qdio_put_indicator(__u32 *addr)
{
	int i;

	if ( (addr) && (addr!=&spare_indicator) ) {
		i=addr-indicators;
		indicator_used[i]=0;
	}
	if (addr == &spare_indicator)
		atomic_dec(&spare_indicator_usecount);
}

static inline void
tiqdio_clear_summary_bit(__u32 *location)
{
	QDIO_DBF_TEXT5(0,trace,"clrsummb");
	QDIO_DBF_HEX5(0,trace,&location,sizeof(void*));

	xchg(location,0);
}

static inline  void
tiqdio_set_summary_bit(__u32 *location)
{
	QDIO_DBF_TEXT5(0,trace,"setsummb");
	QDIO_DBF_HEX5(0,trace,&location,sizeof(void*));

	xchg(location,-1);
}

static inline void 
tiqdio_sched_tl(void)
{
	tasklet_hi_schedule(&tiqdio_tasklet);
}

static inline void
qdio_mark_tiq(struct qdio_q *q)
{
	unsigned long flags;

	QDIO_DBF_TEXT4(0,trace,"mark iq");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	spin_lock_irqsave(&ttiq_list_lock,flags);
	if (unlikely(atomic_read(&q->is_in_shutdown)))
		goto out_unlock;

	if (!q->is_input_q)
		goto out_unlock;

	if ((q->list_prev) || (q->list_next)) 
		goto out_unlock;

	if (!tiq_list) {
		tiq_list=q;
		q->list_prev=q;
		q->list_next=q;
	} else {
		q->list_next=tiq_list;
		q->list_prev=tiq_list->list_prev;
		tiq_list->list_prev->list_next=q;
		tiq_list->list_prev=q;
	}
	spin_unlock_irqrestore(&ttiq_list_lock,flags);

	tiqdio_set_summary_bit((__u32*)q->dev_st_chg_ind);
	tiqdio_sched_tl();
	return;
out_unlock:
	spin_unlock_irqrestore(&ttiq_list_lock,flags);
	return;
}

static inline void
qdio_mark_q(struct qdio_q *q)
{
	QDIO_DBF_TEXT4(0,trace,"mark q");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	if (unlikely(atomic_read(&q->is_in_shutdown)))
		return;

	tasklet_schedule(&q->tasklet);
}

static inline int
qdio_stop_polling(struct qdio_q *q)
{
#ifdef QDIO_USE_PROCESSING_STATE
       unsigned int tmp, gsf, count = 1;
       unsigned char state = 0;
       struct qdio_irq *irq = (struct qdio_irq *) q->irq_ptr;

	if (!atomic_swap(&q->polling,0)) 
		return 1;

	QDIO_DBF_TEXT4(0,trace,"stoppoll");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	/* show the card that we are not polling anymore */
	if (!q->is_input_q)
		return 1;

       tmp = gsf = GET_SAVED_FRONTIER(q);
       tmp = ((tmp + QDIO_MAX_BUFFERS_PER_Q-1) & (QDIO_MAX_BUFFERS_PER_Q-1) );
       set_slsb(q, &tmp, SLSB_P_INPUT_NOT_INIT, &count);

	/* 
	 * we don't issue this SYNC_MEMORY, as we trust Rick T and
	 * moreover will not use the PROCESSING state under VM, so
	 * q->polling was 0 anyway
	 */
	/*SYNC_MEMORY;*/
       if (irq->is_qebsm) {
               count = 1;
               qdio_do_eqbs(q, &state, &gsf, &count);
       } else
               state = q->slsb.acc.val[gsf];
       if (state != SLSB_P_INPUT_PRIMED)
		return 1;
	/* 
	 * set our summary bit again, as otherwise there is a
	 * small window we can miss between resetting it and
	 * checking for PRIMED state