fas216.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

/*
 *  linux/arch/arm/drivers/scsi/fas216.c
 *
 *  Copyright (C) 1997-2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Based on information in qlogicfas.c by Tom Zerucha, Michael Griffith, and
 * other sources, including:
 *   the AMD Am53CF94 data sheet
 *   the AMD Am53C94 data sheet 
 *
 * This is a generic driver.  To use it, have a look at cumana_2.c.  You
 * should define your own structure that overlays FAS216_Info, eg:
 * struct my_host_data {
 *    FAS216_Info info;
 *    ... my host specific data ...
 * };
 *
 * Changelog:
 *  30-08-1997	RMK	Created
 *  14-09-1997	RMK	Started disconnect support
 *  08-02-1998	RMK	Corrected real DMA support
 *  15-02-1998	RMK	Started sync xfer support
 *  06-04-1998	RMK	Tightened conditions for printing incomplete
 *			transfers
 *  02-05-1998	RMK	Added extra checks in fas216_reset
 *  24-05-1998	RMK	Fixed synchronous transfers with period >= 200ns
 *  27-06-1998	RMK	Changed asm/delay.h to linux/delay.h
 *  26-08-1998	RMK	Improved message support wrt MESSAGE_REJECT
 *  02-04-2000	RMK	Converted to use the new error handling, and
 *			automatically request sense data upon check
 *			condition status from targets.
 *
 * Todo:
 *  - allow individual devices to enable sync xfers.
 */
#include <linux/module.h>
#include <linux/blk.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/unistd.h>
#include <linux/stat.h>
#include <linux/delay.h>
#include <linux/init.h>

#include <asm/dma.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/ecard.h>

#define FAS216_C

#include "../../scsi/scsi.h"
#include "../../scsi/hosts.h"
#include "fas216.h"

#define VER_MAJOR	0
#define VER_MINOR	0
#define VER_PATCH	5

/* NOTE: SCSI2 Synchronous transfers *require* DMA according to
 *  the data sheet.  This restriction is crazy, especially when
 *  you only want to send 16 bytes!  What were the guys who
 *  designed this chip on at that time?  Did they read the SCSI2
 *  spec at all?  The following sections are taken from the SCSI2
 *  standard (s2r10) concerning this:
 *
 * > IMPLEMENTORS NOTES:
 * >   (1)  Re-negotiation at every selection is not recommended, since a
 * >   significant performance impact is likely.
 *
 * >  The implied synchronous agreement shall remain in effect until a BUS DEVICE
 * >  RESET message is received, until a hard reset condition occurs, or until one
 * >  of the two SCSI devices elects to modify the agreement.  The default data
 * >  transfer mode is asynchronous data transfer mode.  The default data transfer
 * >  mode is entered at power on, after a BUS DEVICE RESET message, or after a hard
 * >  reset condition.
 *
 *  In total, this means that once you have elected to use synchronous
 *  transfers, you must always use DMA.
 *
 *  I was thinking that this was a good chip until I found this restriction ;(
 */
#define SCSI2_SYNC
#undef  SCSI2_WIDE
#undef  SCSI2_TAG

#undef DEBUG_CONNECT
#undef DEBUG_BUSSERVICE
#undef DEBUG_FUNCTIONDONE
#undef DEBUG_MESSAGES

#undef CHECK_STRUCTURE

static struct { int stat, ssr, isr, ph; } list[8];
static int ptr;

static void fas216_dumpstate(FAS216_Info *info)
{
	unsigned char is, stat, inst;

	is   = inb(REG_IS(info));
	stat = inb(REG_STAT(info));
	inst = inb(REG_INST(info));
	
	printk("FAS216: CTCL=%02X CTCM=%02X CMD=%02X STAT=%02X"
	       " INST=%02X IS=%02X CFIS=%02X",
		inb(REG_CTCL(info)), inb(REG_CTCM(info)),
		inb(REG_CMD(info)),  stat, inst, is,
		inb(REG_CFIS(info)));
	printk(" CNTL1=%02X CNTL2=%02X CNTL3=%02X CTCH=%02X\n",
		inb(REG_CNTL1(info)), inb(REG_CNTL2(info)),
		inb(REG_CNTL3(info)), inb(REG_CTCH(info)));
}

static void fas216_dumpinfo(FAS216_Info *info)
{
	static int used = 0;
	int i;

	if (used++)
		return;

	printk("FAS216_Info=\n");
	printk("  { magic_start=%lX host=%p SCpnt=%p origSCpnt=%p\n",
		info->magic_start, info->host, info->SCpnt,
		info->origSCpnt);
	printk("    scsi={ io_port=%X io_shift=%X irq=%X cfg={ %X %X %X %X }\n",
		info->scsi.io_port, info->scsi.io_shift, info->scsi.irq,
		info->scsi.cfg[0], info->scsi.cfg[1], info->scsi.cfg[2],
		info->scsi.cfg[3]);
	printk("           type=%p phase=%X reconnected={ target=%d lun=%d tag=%d }\n",
		info->scsi.type, info->scsi.phase,
		info->scsi.reconnected.target,
		info->scsi.reconnected.lun, info->scsi.reconnected.tag);
	printk("           SCp={ ptr=%p this_residual=%X buffer=%p buffers_residual=%X }\n",
		info->scsi.SCp.ptr, info->scsi.SCp.this_residual,
		info->scsi.SCp.buffer, info->scsi.SCp.buffers_residual);
	printk("      msgs async_stp=%X disconnectable=%d aborting=%d }\n",
		info->scsi.async_stp,
		info->scsi.disconnectable, info->scsi.aborting);
	printk("    stats={ queues=%X removes=%X fins=%X reads=%X writes=%X miscs=%X\n"
	       "            disconnects=%X aborts=%X bus_resets=%X host_resets=%X}\n",
		info->stats.queues, info->stats.removes, info->stats.fins,
		info->stats.reads, info->stats.writes, info->stats.miscs,
		info->stats.disconnects, info->stats.aborts, info->stats.bus_resets,
		info->stats.host_resets);
	printk("    ifcfg={ clockrate=%X select_timeout=%X asyncperiod=%X sync_max_depth=%X }\n",
		info->ifcfg.clockrate, info->ifcfg.select_timeout,
		info->ifcfg.asyncperiod, info->ifcfg.sync_max_depth);
	for (i = 0; i < 8; i++) {
		printk("    busyluns[%d]=%X dev[%d]={ disconnect_ok=%d stp=%X sof=%X sync_state=%X }\n",
			i, info->busyluns[i], i,
			info->device[i].disconnect_ok, info->device[i].stp,
			info->device[i].sof, info->device[i].sync_state);
	}
	printk("    dma={ transfer_type=%X setup=%p pseudo=%p stop=%p }\n",
		info->dma.transfer_type, info->dma.setup,
		info->dma.pseudo, info->dma.stop);
	printk("    internal_done=%X magic_end=%lX }\n",
		info->internal_done, info->magic_end);
}

#ifdef CHECK_STRUCTURE
static void __fas216_checkmagic(FAS216_Info *info, const char *func)
{
	int corruption = 0;
	if (info->magic_start != MAGIC) {
		printk(KERN_CRIT "FAS216 Error: magic at start corrupted\n");
		corruption++;
	}
	if (info->magic_end != MAGIC) {
		printk(KERN_CRIT "FAS216 Error: magic at end corrupted\n");
		corruption++;
	}
	if (corruption) {
		fas216_dumpinfo(info);
		panic("scsi memory space corrupted in %s", func);
	}
}
#define fas216_checkmagic(info) __fas216_checkmagic((info), __FUNCTION__)
#else
#define fas216_checkmagic(info)
#endif

static const char *fas216_bus_phase(int stat)
{
	static const char *phases[] = {
		"DATA OUT", "DATA IN",
		"COMMAND", "STATUS",
		"MISC OUT", "MISC IN",
		"MESG OUT", "MESG IN"
	};

	return phases[stat & STAT_BUSMASK];
}

static const char *fas216_drv_phase(FAS216_Info *info)
{
	switch (info->scsi.phase) {
	case PHASE_IDLE:		return "idle";
	case PHASE_SELECTION:		return "selection";
	case PHASE_COMMAND:		return "command";
	case PHASE_RECONNECTED:		return "reconnected";
	case PHASE_DATAOUT:		return "data out";
	case PHASE_DATAIN:		return "data in";
	case PHASE_MSGIN:		return "message in";
	case PHASE_MSGIN_DISCONNECT:	return "disconnect";
	case PHASE_MSGOUT_EXPECT:	return "expect message out";
	case PHASE_MSGOUT:		return "message out";
	case PHASE_STATUS:		return "status";
	case PHASE_DONE:		return "done";
	default:			return "???";
	}
}

static char fas216_target(FAS216_Info *info)
{
	if (info->SCpnt)
		return '0' + info->SCpnt->target;
	else
		return 'H';
}

static void add_debug_list(int stat, int ssr, int isr, int ph)
{
	list[ptr].stat = stat;
	list[ptr].ssr = ssr;
	list[ptr].isr = isr;
	list[ptr].ph = ph;

	ptr = (ptr + 1) & 7;
}

static void print_debug_list(void)
{
	int i;

	i = ptr;

	printk(KERN_ERR "SCSI IRQ trail: ");
	do {
		printk("%02X:%02X:%02X:%1X ",
			list[i].stat, list[i].ssr,
			list[i].isr, list[i].ph);
		i = (i + 1) & 7;
	} while (i != ptr);
	printk("\n");
}

static void fas216_done(FAS216_Info *info, unsigned int result);

/* Function: int fas216_clockrate(unsigned int clock)
 * Purpose : calculate correct value to be written into clock conversion
 *	     factor register.
 * Params  : clock - clock speed in MHz
 * Returns : CLKF_ value
 */
static int fas216_clockrate(int clock)
{
	if (clock <= 10 || clock > 40) {
		printk(KERN_CRIT
		       "fas216: invalid clock rate: check your driver!\n");
		clock = -1;
	} else
		clock = ((clock - 1) / 5 + 1) & 7;

	return clock;
}

/* Function: unsigned short fas216_get_last_msg(FAS216_Info *info, int pos)
 * Purpose : retrieve a last message from the list, using position in fifo
 * Params  : info - interface to search
 *         : pos  - current fifo position
 */
static inline unsigned short
fas216_get_last_msg(FAS216_Info *info, int pos)
{
	unsigned short packed_msg = NOP;
	struct message *msg;
	int msgnr = 0;

	while ((msg = msgqueue_getmsg(&info->scsi.msgs, msgnr++)) != NULL) {
		if (pos >= msg->fifo)
			break;
	}

	if (msg) {
		if (msg->msg[0] == EXTENDED_MESSAGE)
			packed_msg = EXTENDED_MESSAGE | msg->msg[2] << 8;
		else
			packed_msg = msg->msg[0];
	}

#ifdef DEBUG_MESSAGES
	printk("Message: %04X found at position %02X\n",
		packed_msg, pos);
#endif
	return packed_msg;
}

/* Function: int fas216_syncperiod(FAS216_Info *info, int ns)
 * Purpose : Calculate value to be loaded into the STP register
 *           for a given period in ns
 * Params  : info - state structure for interface connected to device
 *         : ns   - period in ns (between subsequent bytes)
 * Returns : Value suitable for REG_STP
 */
static int
fas216_syncperiod(FAS216_Info *info, int ns)
{
	int value = (info->ifcfg.clockrate * ns) / 1000;

	fas216_checkmagic(info);

	if (value < 4)
		value = 4;
	else if (value > 35)
		value = 35;

	return value & 31;
}

/* Function: void fas216_set_sync(FAS216_Info *info, int target)
 * Purpose : Correctly setup FAS216 chip for specified transfer period.
 * Params  : info   - state structure for interface
 *         : target - target
 * Notes   : we need to switch the chip out of FASTSCSI mode if we have
 *           a transfer period >= 200ns - otherwise the chip will violate
 *           the SCSI timings.
 */
static void
fas216_set_sync(FAS216_Info *info, int target)
{
	outb(info->device[target].sof, REG_SOF(info));
	outb(info->device[target].stp, REG_STP(info));
	if (info->device[target].period >= (200 / 4))
		outb(info->scsi.cfg[2] & ~CNTL3_FASTSCSI, REG_CNTL3(info));
	else
		outb(info->scsi.cfg[2], REG_CNTL3(info));
}

/* Synchronous transfer support
 *
 * Note: The SCSI II r10 spec says (5.6.12):
 *
 *  (2)  Due to historical problems with early host adapters that could
 *  not accept an SDTR message, some targets may not initiate synchronous
 *  negotiation after a power cycle as required by this standard.  Host
 *  adapters that support synchronous mode may avoid the ensuing failure
 *  modes when the target is independently power cycled by initiating a
 *  synchronous negotiation on each REQUEST SENSE and INQUIRY command.
 *  This approach increases the SCSI bus overhead and is not recommended
 *  for new implementations.  The correct method is to respond to an
 *  SDTR message with a MESSAGE REJECT message if the either the
 *  initiator or target devices does not support synchronous transfers
 *  or does not want to negotiate for synchronous transfers at the time.
 *  Using the correct method assures compatibility with wide data
 *  transfers and future enhancements.
 *
 * We will always initiate a synchronous transfer negociation request on
 * every INQUIRY or REQUEST SENSE message, unless the target itself has
 * at some point performed a synchronous transfer negociation request, or
 * we have synchronous transfers disabled for this device.
 */

/* Function: void fas216_handlesync(FAS216_Info *info, char *msg)
 * Purpose : Handle a synchronous transfer message from the target
 * Params  : info - state structure for interface
 *         : msg  - message from target
 */
static void
fas216_handlesync(FAS216_Info *info, char *msg)
{
	struct fas216_device *dev = &info->device[info->SCpnt->target];
	enum { sync, async, none, reject } res = none;

#ifdef SCSI2_SYNC
	switch (msg[0]) {
	case MESSAGE_REJECT:
		/* Synchronous transfer request failed.
		 * Note: SCSI II r10:
		 *
		 *  SCSI devices that are capable of synchronous
		 *  data transfers shall not respond to an SDTR
		 *  message with a MESSAGE REJECT message.
		 *
		 * Hence, if we get this condition, we disable
		 * negociation for this device.
		 */
		if (dev->sync_state == neg_inprogress) {
			dev->sync_state = neg_invalid;
			res = async;
		}
		break;

	case EXTENDED_MESSAGE:
		switch (dev->sync_state) {
		/* We don't accept synchronous transfer requests.
		 * Respond with a MESSAGE_REJECT to prevent a
		 * synchronous transfer agreement from being reached.
		 */
		case neg_invalid:
			res = reject;
			break;

		/* We were not negociating a synchronous transfer,
		 * but the device sent us a negociation request.
		 * Honour the request by sending back a SDTR
		 * message containing our capability, limited by
		 * the targets capability.
		 */
		default:
			outb(CMD_SETATN, REG_CMD(info));
			if (msg[4] > info->ifcfg.sync_max_depth)
				msg[4] = info->ifcfg.sync_max_depth;
			if (msg[3] < 1000 / info->ifcfg.clockrate)
				msg[3] = 1000 / info->ifcfg.clockrate;

			msgqueue_flush(&info->scsi.msgs);
			msgqueue_addmsg(&info->scsi.msgs, 5,
					EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
					msg[3], msg[4]);
			info->scsi.phase = PHASE_MSGOUT_EXPECT;

			/* This is wrong.  The agreement is not in effect
			 * until this message is accepted by the device
			 */
			dev->sync_state = neg_targcomplete;
			res = sync;
			break;

		/* We initiated the synchronous transfer negociation,
		 * and have successfully received a response from the
		 * target.  The synchronous transfer agreement has been
		 * reached.  Note: if the values returned are out of our
		 * bounds, we must reject the message.
		 */
		case neg_inprogress:
			res = reject;
			if (msg[4] <= info->ifcfg.sync_max_depth &&
			    msg[3] >= 1000 / info->ifcfg.clockrate) {
				dev->sync_state = neg_complete;
				res = sync;
			}
			break;
		}
	}
#else
	res = reject;
#endif

	switch (res) {
	case sync:
		dev->period = msg[3];
		dev->sof    = msg[4];
		dev->stp    = fas216_syncperiod(info, msg[3] * 4);
		fas216_set_sync(info, info->SCpnt->target);