53c700.c

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/* -*- mode: c; c-basic-offset: 8 -*- */

/* NCR (or Symbios) 53c700 and 53c700-66 Driver
 *
 * Copyright (C) 2001 by [e-mail]
**-----------------------------------------------------------------------------
**  
**  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 of the License, 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.
**
**-----------------------------------------------------------------------------
 */

/* Notes:
 *
 * This driver is designed exclusively for these chips (virtually the
 * earliest of the scripts engine chips).  They need their own drivers
 * because they are missing so many of the scripts and snazzy register
 * features of their elder brothers (the 710, 720 and 770).
 *
 * The 700 is the lowliest of the line, it can only do async SCSI.
 * The 700-66 can at least do synchronous SCSI up to 10MHz.
 * 
 * The 700 chip has no host bus interface logic of its own.  However,
 * it is usually mapped to a location with well defined register
 * offsets.  Therefore, if you can determine the base address and the
 * irq your board incorporating this chip uses, you can probably use
 * this driver to run it (although you'll probably have to write a
 * minimal wrapper for the purpose---see the NCR_D700 driver for
 * details about how to do this).
 *
 *
 * TODO List:
 *
 * 1. Better statistics in the proc fs
 *
 * 2. Implement message queue (queues SCSI messages like commands) and make
 *    the abort and device reset functions use them.
 * */

/* CHANGELOG
 *
 * Version 2.8
 *
 * Fixed bad bug affecting tag starvation processing (previously the
 * driver would hang the system if too many tags starved.  Also fixed
 * bad bug having to do with 10 byte command processing and REQUEST
 * SENSE (the command would loop forever getting a transfer length
 * mismatch in the CMD phase).
 *
 * Version 2.7
 *
 * Fixed scripts problem which caused certain devices (notably CDRWs)
 * to hang on initial INQUIRY.  Updated NCR_700_readl/writel to use
 * __raw_readl/writel for parisc compatibility (Thomas
 * Bogendoerfer). Added missing SCp->request_bufflen initialisation
 * for sense requests (Ryan Bradetich).
 *
 * Version 2.6
 *
 * Following test of the 64 bit parisc kernel by Richard Hirst,
 * several problems have now been corrected.  Also adds support for
 * consistent memory allocation.
 *
 * Version 2.5
 * 
 * More Compatibility changes for 710 (now actually works).  Enhanced
 * support for odd clock speeds which constrain SDTR negotiations.
 * correct cacheline separation for scsi messages and status for
 * incoherent architectures.  Use of the pci mapping functions on
 * buffers to begin support for 64 bit drivers.
 *
 * Version 2.4
 *
 * Added support for the 53c710 chip (in 53c700 emulation mode only---no 
 * special 53c710 instructions or registers are used).
 *
 * Version 2.3
 *
 * More endianness/cache coherency changes.
 *
 * Better bad device handling (handles devices lying about tag
 * queueing support and devices which fail to provide sense data on
 * contingent allegiance conditions)
 *
 * Many thanks to Richard Hirst <[e-mail]> for patiently
 * debugging this driver on the parisc architecture and suggesting
 * many improvements and bug fixes.
 *
 * Thanks also go to Linuxcare Inc. for providing several PARISC
 * machines for me to debug the driver on.
 *
 * Version 2.2
 *
 * Made the driver mem or io mapped; added endian invariance; added
 * dma cache flushing operations for architectures which need it;
 * added support for more varied clocking speeds.
 *
 * Version 2.1
 *
 * Initial modularisation from the D700.  See NCR_D700.c for the rest of
 * the changelog.
 * */
#define NCR_700_VERSION "2.8"

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/byteorder.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_spi.h>

#include "53c700.h"

/* NOTE: For 64 bit drivers there are points in the code where we use
 * a non dereferenceable pointer to point to a structure in dma-able
 * memory (which is 32 bits) so that we can use all of the structure
 * operations but take the address at the end.  This macro allows us
 * to truncate the 64 bit pointer down to 32 bits without the compiler
 * complaining */
#define to32bit(x)	((__u32)((unsigned long)(x)))

#ifdef NCR_700_DEBUG
#define STATIC
#else
#define STATIC static
#endif

MODULE_AUTHOR("James Bottomley");
MODULE_DESCRIPTION("53c700 and 53c700-66 Driver");
MODULE_LICENSE("GPL");

/* This is the script */
#include "53c700_d.h"


STATIC int NCR_700_queuecommand(struct scsi_cmnd *, void (*done)(struct scsi_cmnd *));
STATIC int NCR_700_abort(struct scsi_cmnd * SCpnt);
STATIC int NCR_700_bus_reset(struct scsi_cmnd * SCpnt);
STATIC int NCR_700_dev_reset(struct scsi_cmnd * SCpnt);
STATIC int NCR_700_host_reset(struct scsi_cmnd * SCpnt);
STATIC void NCR_700_chip_setup(struct Scsi_Host *host);
STATIC void NCR_700_chip_reset(struct Scsi_Host *host);
STATIC int NCR_700_slave_configure(struct scsi_device *SDpnt);
STATIC void NCR_700_slave_destroy(struct scsi_device *SDpnt);

STATIC struct device_attribute *NCR_700_dev_attrs[];

STATIC struct scsi_transport_template *NCR_700_transport_template = NULL;

static char *NCR_700_phase[] = {
	"",
	"after selection",
	"before command phase",
	"after command phase",
	"after status phase",
	"after data in phase",
	"after data out phase",
	"during data phase",
};

static char *NCR_700_condition[] = {
	"",
	"NOT MSG_OUT",
	"UNEXPECTED PHASE",
	"NOT MSG_IN",
	"UNEXPECTED MSG",
	"MSG_IN",
	"SDTR_MSG RECEIVED",
	"REJECT_MSG RECEIVED",
	"DISCONNECT_MSG RECEIVED",
	"MSG_OUT",
	"DATA_IN",
	
};

static char *NCR_700_fatal_messages[] = {
	"unexpected message after reselection",
	"still MSG_OUT after message injection",
	"not MSG_IN after selection",
	"Illegal message length received",
};

static char *NCR_700_SBCL_bits[] = {
	"IO ",
	"CD ",
	"MSG ",
	"ATN ",
	"SEL ",
	"BSY ",
	"ACK ",
	"REQ ",
};

static char *NCR_700_SBCL_to_phase[] = {
	"DATA_OUT",
	"DATA_IN",
	"CMD_OUT",
	"STATE",
	"ILLEGAL PHASE",
	"ILLEGAL PHASE",
	"MSG OUT",
	"MSG IN",
};

static __u8 NCR_700_SDTR_msg[] = {
	0x01,			/* Extended message */
	0x03,			/* Extended message Length */
	0x01,			/* SDTR Extended message */
	NCR_700_MIN_PERIOD,
	NCR_700_MAX_OFFSET
};

/* This translates the SDTR message offset and period to a value
 * which can be loaded into the SXFER_REG.
 *
 * NOTE: According to SCSI-2, the true transfer period (in ns) is
 *       actually four times this period value */
static inline __u8
NCR_700_offset_period_to_sxfer(struct NCR_700_Host_Parameters *hostdata,
			       __u8 offset, __u8 period)
{
	int XFERP;

	__u8 min_xferp = (hostdata->chip710
			  ? NCR_710_MIN_XFERP : NCR_700_MIN_XFERP);
	__u8 max_offset = (hostdata->chip710
			   ? NCR_710_MAX_OFFSET : NCR_700_MAX_OFFSET);

	if(offset == 0)
		return 0;

	if(period < hostdata->min_period) {
		printk(KERN_WARNING "53c700: Period %dns is less than this chip's minimum, setting to %d\n", period*4, NCR_700_SDTR_msg[3]*4);
		period = hostdata->min_period;
	}
	XFERP = (period*4 * hostdata->sync_clock)/1000 - 4;
	if(offset > max_offset) {
		printk(KERN_WARNING "53c700: Offset %d exceeds chip maximum, setting to %d\n",
		       offset, max_offset);
		offset = max_offset;
	}
	if(XFERP < min_xferp) {
		printk(KERN_WARNING "53c700: XFERP %d is less than minium, setting to %d\n",
		       XFERP,  min_xferp);
		XFERP =  min_xferp;
	}
	return (offset & 0x0f) | (XFERP & 0x07)<<4;
}

static inline __u8
NCR_700_get_SXFER(struct scsi_device *SDp)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SDp->host->hostdata[0];

	return NCR_700_offset_period_to_sxfer(hostdata, spi_offset(SDp),
					      spi_period(SDp));
}

struct Scsi_Host *
NCR_700_detect(struct scsi_host_template *tpnt,
	       struct NCR_700_Host_Parameters *hostdata)
{
	dma_addr_t pScript, pSlots;
	__u8 *memory;
	__u32 *script;
	struct Scsi_Host *host;
	static int banner = 0;
	int j;

	if(tpnt->sdev_attrs == NULL)
		tpnt->sdev_attrs = NCR_700_dev_attrs;

	memory = dma_alloc_noncoherent(hostdata->dev, TOTAL_MEM_SIZE,
				       &pScript, GFP_KERNEL);
	if(memory == NULL) {
		printk(KERN_ERR "53c700: Failed to allocate memory for driver, detatching\n");
		return NULL;
	}

	script = (__u32 *)memory;
	hostdata->msgin = memory + MSGIN_OFFSET;
	hostdata->msgout = memory + MSGOUT_OFFSET;
	hostdata->status = memory + STATUS_OFFSET;
	/* all of these offsets are L1_CACHE_BYTES separated.  It is fatal
	 * if this isn't sufficient separation to avoid dma flushing issues */
	BUG_ON(!dma_is_consistent(pScript) && L1_CACHE_BYTES < dma_get_cache_alignment());
	hostdata->slots = (struct NCR_700_command_slot *)(memory + SLOTS_OFFSET);
		
	pSlots = pScript + SLOTS_OFFSET;

	/* Fill in the missing routines from the host template */
	tpnt->queuecommand = NCR_700_queuecommand;
	tpnt->eh_abort_handler = NCR_700_abort;
	tpnt->eh_device_reset_handler = NCR_700_dev_reset;
	tpnt->eh_bus_reset_handler = NCR_700_bus_reset;
	tpnt->eh_host_reset_handler = NCR_700_host_reset;
	tpnt->can_queue = NCR_700_COMMAND_SLOTS_PER_HOST;
	tpnt->sg_tablesize = NCR_700_SG_SEGMENTS;
	tpnt->cmd_per_lun = NCR_700_CMD_PER_LUN;
	tpnt->use_clustering = ENABLE_CLUSTERING;
	tpnt->slave_configure = NCR_700_slave_configure;
	tpnt->slave_destroy = NCR_700_slave_destroy;
	
	if(tpnt->name == NULL)
		tpnt->name = "53c700";
	if(tpnt->proc_name == NULL)
		tpnt->proc_name = "53c700";
	

	host = scsi_host_alloc(tpnt, 4);
	if (!host)
		return NULL;
	memset(hostdata->slots, 0, sizeof(struct NCR_700_command_slot)
	       * NCR_700_COMMAND_SLOTS_PER_HOST);
	for(j = 0; j < NCR_700_COMMAND_SLOTS_PER_HOST; j++) {
		dma_addr_t offset = (dma_addr_t)((unsigned long)&hostdata->slots[j].SG[0]
					  - (unsigned long)&hostdata->slots[0].SG[0]);
		hostdata->slots[j].pSG = (struct NCR_700_SG_List *)((unsigned long)(pSlots + offset));
		if(j == 0)
			hostdata->free_list = &hostdata->slots[j];
		else
			hostdata->slots[j-1].ITL_forw = &hostdata->slots[j];
		hostdata->slots[j].state = NCR_700_SLOT_FREE;
	}

	for(j = 0; j < sizeof(SCRIPT)/sizeof(SCRIPT[0]); j++) {
		script[j] = bS_to_host(SCRIPT[j]);
	}

	/* adjust all labels to be bus physical */
	for(j = 0; j < PATCHES; j++) {
		script[LABELPATCHES[j]] = bS_to_host(pScript + SCRIPT[LABELPATCHES[j]]);
	}
	/* now patch up fixed addresses. */
	script_patch_32(script, MessageLocation,
			pScript + MSGOUT_OFFSET);
	script_patch_32(script, StatusAddress,
			pScript + STATUS_OFFSET);
	script_patch_32(script, ReceiveMsgAddress,
			pScript + MSGIN_OFFSET);

	hostdata->script = script;
	hostdata->pScript = pScript;
	dma_sync_single_for_device(hostdata->dev, pScript, sizeof(SCRIPT), DMA_TO_DEVICE);
	hostdata->state = NCR_700_HOST_FREE;
	hostdata->cmd = NULL;
	host->max_id = 7;
	host->max_lun = NCR_700_MAX_LUNS;
	BUG_ON(NCR_700_transport_template == NULL);
	host->transportt = NCR_700_transport_template;
	host->unique_id = hostdata->base;
	host->base = hostdata->base;
	hostdata->eh_complete = NULL;
	host->hostdata[0] = (unsigned long)hostdata;
	/* kick the chip */
	NCR_700_writeb(0xff, host, CTEST9_REG);
	if(hostdata->chip710)