ncr53c9x.c

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/* NCR53C9x.c:  Generic SCSI driver code for NCR53C9x chips.
 *
 * Originally esp.c : EnhancedScsiProcessor Sun SCSI driver code.
 *
 * Copyright (C) 1995, 1998 David S. Miller ([e-mail])
 *
 * Most DMA dependencies put in driver specific files by 
 * Jesper Skov ([e-mail])
 *
 * Set up to use esp_read/esp_write (preprocessor macros in NCR53c9x.h) by
 * Tymm Twillman ([e-mail])
 */

/* TODO:
 *
 * 1) Maybe disable parity checking in config register one for SCSI1
 *    targets.  (Gilmore says parity error on the SBus can lock up
 *    old sun4c's)
 * 2) Add support for DMA2 pipelining.
 * 3) Add tagged queueing.
 * 4) Maybe change use of "esp" to something more "NCR"'ish.
 */

#ifdef MODULE
#include <linux/module.h>
#endif

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/malloc.h>
#include <linux/blk.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>

#include "scsi.h"
#include "hosts.h"
#include "NCR53C9x.h"

#include <asm/system.h>
#include <asm/ptrace.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/irq.h>

/* Command phase enumeration. */
enum {
	not_issued    = 0x00,  /* Still in the issue_SC queue.          */

	/* Various forms of selecting a target. */
#define in_slct_mask    0x10
	in_slct_norm  = 0x10,  /* ESP is arbitrating, normal selection  */
	in_slct_stop  = 0x11,  /* ESP will select, then stop with IRQ   */
	in_slct_msg   = 0x12,  /* select, then send a message           */
	in_slct_tag   = 0x13,  /* select and send tagged queue msg      */
	in_slct_sneg  = 0x14,  /* select and acquire sync capabilities  */

	/* Any post selection activity. */
#define in_phases_mask  0x20
	in_datain     = 0x20,  /* Data is transferring from the bus     */
	in_dataout    = 0x21,  /* Data is transferring to the bus       */
	in_data_done  = 0x22,  /* Last DMA data operation done (maybe)  */
	in_msgin      = 0x23,  /* Eating message from target            */
	in_msgincont  = 0x24,  /* Eating more msg bytes from target     */
	in_msgindone  = 0x25,  /* Decide what to do with what we got    */
	in_msgout     = 0x26,  /* Sending message to target             */
	in_msgoutdone = 0x27,  /* Done sending msg out                  */
	in_cmdbegin   = 0x28,  /* Sending cmd after abnormal selection  */
	in_cmdend     = 0x29,  /* Done sending slow cmd                 */
	in_status     = 0x2a,  /* Was in status phase, finishing cmd    */
	in_freeing    = 0x2b,  /* freeing the bus for cmd cmplt or disc */
	in_the_dark   = 0x2c,  /* Don't know what bus phase we are in   */

	/* Special states, ie. not normal bus transitions... */
#define in_spec_mask    0x80
	in_abortone   = 0x80,  /* Aborting one command currently        */
	in_abortall   = 0x81,  /* Blowing away all commands we have     */
	in_resetdev   = 0x82,  /* SCSI target reset in progress         */
	in_resetbus   = 0x83,  /* SCSI bus reset in progress            */
	in_tgterror   = 0x84,  /* Target did something stupid           */
};

enum {
	/* Zero has special meaning, see skipahead[12]. */
/*0*/	do_never,

/*1*/	do_phase_determine,
/*2*/	do_reset_bus,
/*3*/	do_reset_complete,
/*4*/	do_work_bus,
/*5*/	do_intr_end
};

/* The master ring of all esp hosts we are managing in this driver. */
struct NCR_ESP *espchain = 0;
int nesps = 0, esps_in_use = 0, esps_running = 0;

void esp_intr(int irq, void *dev_id, struct pt_regs *pregs);

/* Debugging routines */
struct esp_cmdstrings {
	unchar cmdchar;
	char *text;
} esp_cmd_strings[] = {
	/* Miscellaneous */
	{ ESP_CMD_NULL, "ESP_NOP", },
	{ ESP_CMD_FLUSH, "FIFO_FLUSH", },
	{ ESP_CMD_RC, "RSTESP", },
	{ ESP_CMD_RS, "RSTSCSI", },
	/* Disconnected State Group */
	{ ESP_CMD_RSEL, "RESLCTSEQ", },
	{ ESP_CMD_SEL, "SLCTNATN", },
	{ ESP_CMD_SELA, "SLCTATN", },
	{ ESP_CMD_SELAS, "SLCTATNSTOP", },
	{ ESP_CMD_ESEL, "ENSLCTRESEL", },
	{ ESP_CMD_DSEL, "DISSELRESEL", },
	{ ESP_CMD_SA3, "SLCTATN3", },
	{ ESP_CMD_RSEL3, "RESLCTSEQ", },
	/* Target State Group */
	{ ESP_CMD_SMSG, "SNDMSG", },
	{ ESP_CMD_SSTAT, "SNDSTATUS", },
	{ ESP_CMD_SDATA, "SNDDATA", },
	{ ESP_CMD_DSEQ, "DISCSEQ", },
	{ ESP_CMD_TSEQ, "TERMSEQ", },
	{ ESP_CMD_TCCSEQ, "TRGTCMDCOMPSEQ", },
	{ ESP_CMD_DCNCT, "DISC", },
	{ ESP_CMD_RMSG, "RCVMSG", },
	{ ESP_CMD_RCMD, "RCVCMD", },
	{ ESP_CMD_RDATA, "RCVDATA", },
	{ ESP_CMD_RCSEQ, "RCVCMDSEQ", },
	/* Initiator State Group */
	{ ESP_CMD_TI, "TRANSINFO", },
	{ ESP_CMD_ICCSEQ, "INICMDSEQCOMP", },
	{ ESP_CMD_MOK, "MSGACCEPTED", },
	{ ESP_CMD_TPAD, "TPAD", },
	{ ESP_CMD_SATN, "SATN", },
	{ ESP_CMD_RATN, "RATN", },
};
#define NUM_ESP_COMMANDS  ((sizeof(esp_cmd_strings)) / (sizeof(struct esp_cmdstrings)))

/* Print textual representation of an ESP command */
static inline void esp_print_cmd(unchar espcmd)
{
	unchar dma_bit = espcmd & ESP_CMD_DMA;
	int i;

	espcmd &= ~dma_bit;
	for(i=0; i<NUM_ESP_COMMANDS; i++)
		if(esp_cmd_strings[i].cmdchar == espcmd)
			break;
	if(i==NUM_ESP_COMMANDS)
		printk("ESP_Unknown");
	else
		printk("%s%s", esp_cmd_strings[i].text,
		       ((dma_bit) ? "+DMA" : ""));
}

/* Print the status register's value */
static inline void esp_print_statreg(unchar statreg)
{
	unchar phase;

	printk("STATUS<");
	phase = statreg & ESP_STAT_PMASK;
	printk("%s,", (phase == ESP_DOP ? "DATA-OUT" :
		       (phase == ESP_DIP ? "DATA-IN" :
			(phase == ESP_CMDP ? "COMMAND" :
			 (phase == ESP_STATP ? "STATUS" :
			  (phase == ESP_MOP ? "MSG-OUT" :
			   (phase == ESP_MIP ? "MSG_IN" :
			    "unknown")))))));
	if(statreg & ESP_STAT_TDONE)
		printk("TRANS_DONE,");
	if(statreg & ESP_STAT_TCNT)
		printk("TCOUNT_ZERO,");
	if(statreg & ESP_STAT_PERR)
		printk("P_ERROR,");
	if(statreg & ESP_STAT_SPAM)
		printk("SPAM,");
	if(statreg & ESP_STAT_INTR)
		printk("IRQ,");
	printk(">");
}

/* Print the interrupt register's value */
static inline void esp_print_ireg(unchar intreg)
{
	printk("INTREG< ");
	if(intreg & ESP_INTR_S)
		printk("SLCT_NATN ");
	if(intreg & ESP_INTR_SATN)
		printk("SLCT_ATN ");
	if(intreg & ESP_INTR_RSEL)
		printk("RSLCT ");
	if(intreg & ESP_INTR_FDONE)
		printk("FDONE ");
	if(intreg & ESP_INTR_BSERV)
		printk("BSERV ");
	if(intreg & ESP_INTR_DC)
		printk("DISCNCT ");
	if(intreg & ESP_INTR_IC)
		printk("ILL_CMD ");
	if(intreg & ESP_INTR_SR)
		printk("SCSI_BUS_RESET ");
	printk(">");
}

/* Print the sequence step registers contents */
static inline void esp_print_seqreg(unchar stepreg)
{
	stepreg &= ESP_STEP_VBITS;
	printk("STEP<%s>",
	       (stepreg == ESP_STEP_ASEL ? "SLCT_ARB_CMPLT" :
		(stepreg == ESP_STEP_SID ? "1BYTE_MSG_SENT" :
		 (stepreg == ESP_STEP_NCMD ? "NOT_IN_CMD_PHASE" :
		  (stepreg == ESP_STEP_PPC ? "CMD_BYTES_LOST" :
		   (stepreg == ESP_STEP_FINI4 ? "CMD_SENT_OK" :
		    "UNKNOWN"))))));
}

static char *phase_string(int phase)
{
	switch(phase) {
	case not_issued:
		return "UNISSUED";
	case in_slct_norm:
		return "SLCTNORM";
	case in_slct_stop:
		return "SLCTSTOP";
	case in_slct_msg:
		return "SLCTMSG";
	case in_slct_tag:
		return "SLCTTAG";
	case in_slct_sneg:
		return "SLCTSNEG";
	case in_datain:
		return "DATAIN";
	case in_dataout:
		return "DATAOUT";
	case in_data_done:
		return "DATADONE";
	case in_msgin:
		return "MSGIN";
	case in_msgincont:
		return "MSGINCONT";
	case in_msgindone:
		return "MSGINDONE";
	case in_msgout:
		return "MSGOUT";
	case in_msgoutdone:
		return "MSGOUTDONE";
	case in_cmdbegin:
		return "CMDBEGIN";
	case in_cmdend:
		return "CMDEND";
	case in_status:
		return "STATUS";
	case in_freeing:
		return "FREEING";
	case in_the_dark:
		return "CLUELESS";
	case in_abortone:
		return "ABORTONE";
	case in_abortall:
		return "ABORTALL";
	case in_resetdev:
		return "RESETDEV";
	case in_resetbus:
		return "RESETBUS";
	case in_tgterror:
		return "TGTERROR";
	default:
		return "UNKNOWN";
	};
}

#ifdef DEBUG_STATE_MACHINE
static inline void esp_advance_phase(Scsi_Cmnd *s, int newphase)
{
	ESPLOG(("<%s>", phase_string(newphase)));
	s->SCp.sent_command = s->SCp.phase;
	s->SCp.phase = newphase;
}
#else
#define esp_advance_phase(__s, __newphase) \
	(__s)->SCp.sent_command = (__s)->SCp.phase; \
	(__s)->SCp.phase = (__newphase);
#endif

#ifdef DEBUG_ESP_CMDS
extern inline void esp_cmd(struct NCR_ESP *esp, struct ESP_regs *eregs,
			   unchar cmd)
{
	esp->espcmdlog[esp->espcmdent] = cmd;
	esp->espcmdent = (esp->espcmdent + 1) & 31;
	esp_write(eregs->esp_cmnd, cmd);
}
#else
#define esp_cmd(__esp, __eregs, __cmd)	esp_write((__eregs)->esp_cmnd, (__cmd))
#endif

/* How we use the various Linux SCSI data structures for operation.
 *
 * struct scsi_cmnd:
 *
 *   We keep track of the syncronous capabilities of a target
 *   in the device member, using sync_min_period and
 *   sync_max_offset.  These are the values we directly write
 *   into the ESP registers while running a command.  If offset
 *   is zero the ESP will use asynchronous transfers.
 *   If the borken flag is set we assume we shouldn't even bother
 *   trying to negotiate for synchronous transfer as this target
 *   is really stupid.  If we notice the target is dropping the
 *   bus, and we have been allowing it to disconnect, we clear
 *   the disconnect flag.
 */

/* Manipulation of the ESP command queues.  Thanks to the aha152x driver
 * and its author, Juergen E. Fischer, for the methods used here.
 * Note that these are per-ESP queues, not global queues like
 * the aha152x driver uses.
 */
static inline void append_SC(Scsi_Cmnd **SC, Scsi_Cmnd *new_SC)
{
	Scsi_Cmnd *end;

	new_SC->host_scribble = (unsigned char *) NULL;
	if(!*SC)
		*SC = new_SC;
	else {
		for(end=*SC;end->host_scribble;end=(Scsi_Cmnd *)end->host_scribble)
			;
		end->host_scribble = (unsigned char *) new_SC;
	}
}

static inline void prepend_SC(Scsi_Cmnd **SC, Scsi_Cmnd *new_SC)
{
	new_SC->host_scribble = (unsigned char *) *SC;
	*SC = new_SC;
}

static inline Scsi_Cmnd *remove_first_SC(Scsi_Cmnd **SC)
{
	Scsi_Cmnd *ptr;

	ptr = *SC;
	if(ptr)
		*SC = (Scsi_Cmnd *) (*SC)->host_scribble;
	return ptr;
}

static inline Scsi_Cmnd *remove_SC(Scsi_Cmnd **SC, int target, int lun)
{
	Scsi_Cmnd *ptr, *prev;

	for(ptr = *SC, prev = NULL;
	    ptr && ((ptr->target != target) || (ptr->lun != lun));
	    prev = ptr, ptr = (Scsi_Cmnd *) ptr->host_scribble)
		;
	if(ptr) {
		if(prev)
			prev->host_scribble=ptr->host_scribble;
		else
			*SC=(Scsi_Cmnd *)ptr->host_scribble;
	}
	return ptr;
}

/* Resetting various pieces of the ESP scsi driver chipset */

/* Reset the ESP chip, _not_ the SCSI bus. */
static void esp_reset_esp(struct NCR_ESP *esp, struct ESP_regs *eregs)
{
	int family_code, version, i;
	volatile int trash;

	/* Now reset the ESP chip */
	esp_cmd(esp, eregs, ESP_CMD_RC);
	esp_cmd(esp, eregs, ESP_CMD_NULL | ESP_CMD_DMA);
	if(esp->erev == fast)
		esp_write(eregs->esp_cfg2, ESP_CONFIG2_FENAB);
	esp_cmd(esp, eregs, ESP_CMD_NULL | ESP_CMD_DMA);

	/* This is the only point at which it is reliable to read
	 * the ID-code for a fast ESP chip variant.
	 */
	esp->max_period = ((35 * esp->ccycle) / 1000);
	if(esp->erev == fast) {
		char *erev2string[] = {
			"Emulex FAS236",
			"Emulex FPESP100A",
			"fast",
			"QLogic FAS366",
			"Emulex FAS216",
			"Symbios Logic 53CF9x-2",
			"unknown!"
		};
			
		version = esp_read(eregs->esp_uid);
		family_code = (version & 0xf8) >> 3;
		if(family_code == 0x02) {
		        if ((version & 7) == 2)
			        esp->erev = fas216;	
                        else
			        esp->erev = fas236;
		} else if(family_code == 0x0a)
			esp->erev = fas366; /* Version is usually '5'. */
		else if(family_code == 0x00) {
			if ((version & 7) == 2)
				esp->erev = fas100a; /* NCR53C9X */
			else
				esp->erev = espunknown;
		} else if(family_code == 0x14) {
			if ((version & 7) == 2)
				esp->erev = fsc;
		        else
				esp->erev = espunknown;
		} else if(family_code == 0x00) {
			if ((version & 7) == 2)
				esp->erev = fas100a; /* NCR53C9X */
			else
				esp->erev = espunknown;
		} else
			esp->erev = espunknown;
		ESPLOG(("esp%d: FAST chip is %s (family=%d, version=%d)\n",
			esp->esp_id, erev2string[esp->erev - fas236],
			family_code, (version & 7)));

		esp->min_period = ((4 * esp->ccycle) / 1000);
	} else {
		esp->min_period = ((5 * esp->ccycle) / 1000);
	}

	/* Reload the configuration registers */
	esp_write(eregs->esp_cfact, esp->cfact);
	esp->prev_stp = 0;
	esp_write(eregs->esp_stp, 0);
	esp->prev_soff = 0;
	esp_write(eregs->esp_soff, 0);
	esp_write(eregs->esp_timeo, esp->neg_defp);
	esp->max_period = (esp->max_period + 3)>>2;
	esp->min_period = (esp->min_period + 3)>>2;

	esp_write(eregs->esp_cfg1, esp->config1);
	switch(esp->erev) {
	case esp100:
		/* nothing to do */
		break;
	case esp100a:
		esp_write(eregs->esp_cfg2, esp->config2);
		break;
	case esp236:
		/* Slow 236 */
		esp_write(eregs->esp_cfg2, esp->config2);
		esp->prev_cfg3 = esp->config3[0];
		esp_write(eregs->esp_cfg3, esp->prev_cfg3);
		break;
	case fas366:
		panic("esp: FAS366 support not present, please notify "
		      "[e-mail]");