fas216.c

linux-2.6.15.6

/*
 *  linux/drivers/acorn/scsi/fas216.c
 *
 *  Copyright (C) 1997-2003 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.
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/interrupt.h>

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

#include "../scsi.h"
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_host.h>
#include "fas216.h"
#include "scsi.h"

/* 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_TAG

#undef DEBUG_CONNECT
#undef DEBUG_MESSAGES

#undef CHECK_STRUCTURE

#define LOG_CONNECT		(1 << 0)
#define LOG_BUSSERVICE		(1 << 1)
#define LOG_FUNCTIONDONE	(1 << 2)
#define LOG_MESSAGES		(1 << 3)
#define LOG_BUFFER		(1 << 4)
#define LOG_ERROR		(1 << 8)

static int level_mask = LOG_ERROR;

module_param(level_mask, int, 0644);

static int __init fas216_log_setup(char *str)
{
	char *s;

	level_mask = 0;

	while ((s = strsep(&str, ",")) != NULL) {
		switch (s[0]) {
		case 'a':
			if (strcmp(s, "all") == 0)
				level_mask |= -1;
			break;
		case 'b':
			if (strncmp(s, "bus", 3) == 0)
				level_mask |= LOG_BUSSERVICE;
			if (strncmp(s, "buf", 3) == 0)
				level_mask |= LOG_BUFFER;
			break;
		case 'c':
			level_mask |= LOG_CONNECT;
			break;
		case 'e':
			level_mask |= LOG_ERROR;
			break;
		case 'm':
			level_mask |= LOG_MESSAGES;
			break;
		case 'n':
			if (strcmp(s, "none") == 0)
				level_mask = 0;
			break;
		case 's':
			level_mask |= LOG_FUNCTIONDONE;
			break;
		}
	}
	return 1;
}

__setup("fas216_logging=", fas216_log_setup);

static inline unsigned char fas216_readb(FAS216_Info *info, unsigned int reg)
{
	unsigned int off = reg << info->scsi.io_shift;
	return readb(info->scsi.io_base + off);
}

static inline void fas216_writeb(FAS216_Info *info, unsigned int reg, unsigned int val)
{
	unsigned int off = reg << info->scsi.io_shift;
	writeb(val, info->scsi.io_base + off);
}

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

	is   = fas216_readb(info, REG_IS);
	stat = fas216_readb(info, REG_STAT);
	inst = fas216_readb(info, REG_INST);
	
	printk("FAS216: CTCL=%02X CTCM=%02X CMD=%02X STAT=%02X"
	       " INST=%02X IS=%02X CFIS=%02X",
		fas216_readb(info, REG_CTCL),
		fas216_readb(info, REG_CTCM),
		fas216_readb(info, REG_CMD),  stat, inst, is,
		fas216_readb(info, REG_CFIS));
	printk(" CNTL1=%02X CNTL2=%02X CNTL3=%02X CTCH=%02X\n",
		fas216_readb(info, REG_CNTL1),
		fas216_readb(info, REG_CNTL2),
		fas216_readb(info, REG_CNTL3),
		fas216_readb(info, REG_CTCH));
}

static void print_SCp(struct scsi_pointer *SCp, const char *prefix, const char *suffix)
{
	printk("%sptr %p this_residual 0x%x buffer %p buffers_residual 0x%x%s",
		prefix, SCp->ptr, SCp->this_residual, SCp->buffer,
		SCp->buffers_residual, suffix);
}

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_shift=%X irq=%X cfg={ %X %X %X %X }\n",
		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\n",
		info->scsi.type, info->scsi.phase);
	print_SCp(&info->scsi.SCp, "           SCp={ ", " }\n");
	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]=%08lx 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)
{
	static const char *phases[] = {
		[PHASE_IDLE]		= "idle",
		[PHASE_SELECTION]	= "selection",
		[PHASE_COMMAND]		= "command",
		[PHASE_DATAOUT]		= "data out",
		[PHASE_DATAIN]		= "data in",
		[PHASE_MSGIN]		= "message in",
		[PHASE_MSGIN_DISCONNECT]= "disconnect",
		[PHASE_MSGOUT_EXPECT]	= "expect message out",
		[PHASE_MSGOUT]		= "message out",
		[PHASE_STATUS]		= "status",
		[PHASE_DONE]		= "done",
	};

	if (info->scsi.phase < ARRAY_SIZE(phases) &&
	    phases[info->scsi.phase])
		return phases[info->scsi.phase];
	return "???";
}

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

static void
fas216_do_log(FAS216_Info *info, char target, char *fmt, va_list ap)
{
	static char buf[1024];

	vsnprintf(buf, sizeof(buf), fmt, ap);
	printk("scsi%d.%c: %s", info->host->host_no, target, buf);
}

static void
fas216_log_command(FAS216_Info *info, int level, Scsi_Cmnd *SCpnt, char *fmt, ...)
{
	va_list args;

	if (level != 0 && !(level & level_mask))
		return;

	va_start(args, fmt);
	fas216_do_log(info, '0' + SCpnt->device->id, fmt, args);
	va_end(args);

	printk(" CDB: ");
	__scsi_print_command(SCpnt->cmnd);
}

static void
fas216_log_target(FAS216_Info *info, int level, int target, char *fmt, ...)
{
	va_list args;

	if (level != 0 && !(level & level_mask))
		return;

	if (target < 0)
		target = 'H';
	else
		target += '0';

	va_start(args, fmt);
	fas216_do_log(info, target, fmt, args);
	va_end(args);

	printk("\n");
}

static void fas216_log(FAS216_Info *info, int level, char *fmt, ...)
{
	va_list args;

	if (level != 0 && !(level & level_mask))
		return;

	va_start(args, fmt);
	fas216_do_log(info, fas216_target(info), fmt, args);
	va_end(args);

	printk("\n");
}

#define PH_SIZE	32

static struct { int stat, ssr, isr, ph; } ph_list[PH_SIZE];
static int ph_ptr;

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

	ph_ptr = (ph_ptr + 1) & (PH_SIZE-1);
}

static struct { int command; void *from; } cmd_list[8];
static int cmd_ptr;

static void fas216_cmd(FAS216_Info *info, unsigned int command)
{
	cmd_list[cmd_ptr].command = command;
	cmd_list[cmd_ptr].from = __builtin_return_address(0);

	cmd_ptr = (cmd_ptr + 1) & 7;

	fas216_writeb(info, REG_CMD, command);
}

static void print_debug_list(void)
{
	int i;

	i = ph_ptr;

	printk(KERN_ERR "SCSI IRQ trail\n");
	do {
		printk(" %02x:%02x:%02x:%1x",
			ph_list[i].stat, ph_list[i].ssr,
			ph_list[i].isr, ph_list[i].ph);
		i = (i + 1) & (PH_SIZE - 1);
		if (((i ^ ph_ptr) & 7) == 0)
			printk("\n");
	} while (i != ph_ptr);
	if ((i ^ ph_ptr) & 7)
		printk("\n");

	i = cmd_ptr;
	printk(KERN_ERR "FAS216 commands: ");
	do {
		printk("%02x:%p ", cmd_list[i].command, cmd_list[i].from);
		i = (i + 1) & 7;
	} while (i != cmd_ptr);
	printk("\n");
}

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

/**
 * fas216_get_last_msg - retrive last message from the list
 * @info: interface to search
 * @pos: current fifo position
 *
 * Retrieve a last message from the list, using position in fifo.
 */
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];
	}

	fas216_log(info, LOG_MESSAGES,
		"Message: %04x found at position %02x\n", packed_msg, pos);

	return packed_msg;
}

/**
 * fas216_syncperiod - calculate STP register value
 * @info: state structure for interface connected to device
 * @ns: period in ns (between subsequent bytes)
 *
 * Calculate value to be loaded into the STP register for a given period
 * in ns. Returns a 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;
}

/**
 * fas216_set_sync - setup FAS216 chip for specified transfer period.
 * @info: state structure for interface connected to device
 * @target: target
 *
 * Correctly setup FAS216 chip for specified transfer period.
 * 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)
{
	unsigned int cntl3;

	fas216_writeb(info, REG_SOF, info->device[target].sof);
	fas216_writeb(info, REG_STP, info->device[target].stp);

	cntl3 = info->scsi.cfg[2];
	if (info->device[target].period >= (200 / 4))
		cntl3 = cntl3 & ~CNTL3_FASTSCSI;

	fas216_writeb(info, REG_CNTL3, cntl3);
}

/* 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