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date and time created 92/07/13 00:44:05 by torek
[unix-history] / usr / src / sys / sparc / sbus / esp.c
/*
* Copyright (c) 1992 The Regents of the University of California.
* All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* %sccs.include.redist.c%
*
* @(#)esp.c 7.1 (Berkeley) %G%
*
* from: $Header: esp.c,v 1.22 92/06/17 06:59:33 torek Exp $ (LBL)
*
* Loosely derived from Mary Baker's devSCSIC90.c from the Berkeley
* Sprite project, which is:
*
* Copyright 1988 Regents of the University of California
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies. The University of California
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
*
* from /sprite/src/kernel/dev/sun4c.md/RCS/devSCSIC90.c,v 1.4
* 90/12/19 12:37:58 mgbaker Exp $ SPRITE (Berkeley)
*/
/*
* Sbus ESP/DMA driver. A single driver must be used for both devices
* as they are physically tied to each other: The DMA chip can only
* be used to assist ESP SCSI transactions; the ESP interrupt enable is
* in the DMA chip csr.
*
* Since DMA and SCSI interrupts are handled in the same routine, the
* DMA device does not declare itself as an sbus device. This saves
* some space.
*/
#include "sys/param.h"
#include "sys/buf.h"
#include "sys/device.h"
#include "sys/malloc.h"
#include "scsi/scsi.h"
#include "scsi/scsivar.h"
#include "machine/autoconf.h"
#include "machine/cpu.h"
#include "dmareg.h"
#define ESP_PHASE_NAMES
#include "espreg.h"
#include "sbusvar.h"
#ifdef DEBUG
int espdebug = 1;
#endif
/*
* This driver is organized as a collection of state machines. The
* primary machine is the SCSI sequencer:
*
* Given some previous SCSI state (as set up or tracked by us earlier)
* and the interrupt registers provided on the chips (dmacsr, espstat,
* espstep, and espintr), derive an action. In many cases this is
* just a matter of reading the target's phase and following its orders,
* which sets a new state.
*
* This sequencing is done in espact(); the state is primed in espselect().
*
* There will be (update this comment when there is) another state machine
* used to handle transfers that fall afoul of chip limits (16 bit DMA
* counter; 24 bit address counter in 32 bit address field).
*
* Another state bit is used to recover from bus resets:
*
* A single TEST UNIT READY is attempted on each target before any
* real communication begins; this TEST UNIT READY is allowed to
* fail in any way. This is required for the Quantum ProDrive 100
* MB disks, for instance, which respond to their first selection
* with status phase, and for anything that insists on implementing
* the broken SCSI-2 synch transfer initial message.
*
* This is done in espclear() (which calls espselect(); functions that
* call espselect() must check for clearing first).
*
* The state machines actually intermingle, as some SCSI sequences are
* only allowed during clearing.
*/
/* per-DMA variables */
struct dma_softc {
struct device sc_dev; /* base device */
volatile struct dmareg *sc_dma; /* register virtual address */
};
void dmaattach(struct device *, struct device *, void *);
struct cfdriver dmacd =
{ NULL, "dma", matchbyname, dmaattach, DV_DULL, sizeof(struct dma_softc) };
/* per-ESP variables */
struct esp_softc {
/*
* External interfaces.
*/
struct hba_softc sc_hba; /* base device + hba, must be first */
struct sbusdev sc_sd; /* sbus device */
struct intrhand sc_ih; /* interrupt entry */
int sc_interrupts; /* total number of interrupts taken */
struct dma_softc *sc_dsc; /* pointer to corresponding dma sc */
/*
* Addresses mapped to hardware registers.
*/
volatile struct espreg *sc_esp;
volatile struct dmareg *sc_dma;
/*
* Copies of registers cleared/unlatched by reading.
*/
u_long sc_dmacsr;
u_char sc_espstat;
u_char sc_espstep;
u_char sc_espintr;
/* miscellaneous */
int sc_clockfreq; /* clock frequency */
u_char sc_sel_timeout; /* select timeout */
u_char sc_id; /* initiator ID (default = 7) */
u_char sc_needclear; /* uncleared targets (1 bit each) */
u_char sc_esptype; /* 100, 100A, 2xx (see below) */
u_char sc_ccf; /* clock conversion factor */
u_char sc_conf1; /* value for config reg 1 */
u_char sc_conf2; /* value for config reg 2 */
u_char sc_conf3; /* value for config reg 3 */
/*
* Information pertaining to the current transfer,
* including sequencing.
*
* The size of sc_msg is the size of the ESP fifo,
* since we do message-in simply by allowing the fifo to fill.
*/
char sc_probing; /* used during autoconf; see below */
char sc_clearing; /* true => cmd is just to clear targ */
char sc_state; /* SCSI protocol state; see below */
char sc_sentcmd; /* set once we get cmd out */
char sc_dmaactive; /* true => doing dma */
#ifdef notyet
u_char sc_sync; /* synchronous transfer stuff (?) */
#endif
u_char sc_stat[2]; /* status from last `status' phase */
u_char sc_msg[16]; /* message from device */
u_short sc_dmactl; /* control to load into dma csr */
u_long sc_dmaaddr; /* addr to load into dma addr */
int sc_targ; /* the target involved */
int sc_resid; /* count of bytes not xferred */
struct scsi_cdb sc_cdb; /* current command (not in dvma) */
};
/*
* Values for sc_esptype (used to control configuration reset).
* The order is important; see espreset().
*/
#define ESP100 0
#define ESP100A 1
#define ESP2XX 2
/*
* Probe state. 0 means not probing. While looking for each target
* we set this to PROBE_TESTING and do a TEST UNIT READY on unit 0.
* If selection fails, this is changed to PROBE_NO_TARGET; otherwise
* we assume the target exists, regardless of the result of the test.
*/
#define PROBE_TESTING 1
#define PROBE_NO_TARGET 2
/*
* States in sc_state.
*
* Note that S_CMDSVC is rare: normally we load the SCSI command into the
* ESP fifo and get interrupted only when the device has gone to data
* or status phase. If the device wants to play games, though, we end
* up doing things differently.
*/
char *espstates[] = {
#define S_IDLE 0 /* not doing anything */
"idle",
#define S_SEL 1 /* expecting select done interrupt */
"selecting",
#define S_CMDSVC 2 /* expecting service req interrupt */
"waiting for service request after command",
#define S_IOSVC 3 /* expecting service req interrupt */
"waiting for service request after io",
#define S_DI 4 /* expecting data-in done interrupt */
"receiving data",
#define S_DO 5 /* expecting data-out done interrupt */
"sending data",
#define S_STAT 6 /* expecting status done interrupt */
"receiving status",
#define S_MI 7 /* expecting message-in done interrupt */
"receiving message",
#define S_FI 8 /* expecting final disconnect interrupt */
"waiting for disconnect"
};
/*
* Return values from espact().
*/
#define ACT_CONT 0 /* espact() handled everything */
#define ACT_READ 1 /* target said it is sending us data */
#define ACT_WRITE 2 /* target said it is expecting data */
#define ACT_DONE 3 /* handled everything, and op is now done */
#define ACT_ERROR 4 /* an error occurred, op has been trashed */
#define ACT_RESET 5 /* please reset ESP, then do ACT_ERROR */
#define ACT_QUICKINTR 6 /* another interrupt is expected immediately */
/* autoconfiguration driver */
void espattach(struct device *, struct device *, void *);
struct cfdriver espcd =
{ NULL, "esp", matchbyname, espattach, DV_DULL, sizeof(struct esp_softc) };
/* Sbus driver */
void espsbreset(struct device *);
/* interrupt interface */
int espintr(void *);
/* SCSI HBA driver */
int espicmd(struct hba_softc *, int, struct scsi_cdb *, caddr_t, int, int);
int espdump(struct hba_softc *, int, struct scsi_cdb *, caddr_t, int);
void espstart(struct device *, struct sq *, struct buf *,
scdgo_fn, struct device *);
int espgo(struct device *, int, scintr_fn, struct device *,
struct buf *, int);
void esprel(struct device *);
void esphbareset(struct hba_softc *, int);
static struct hbadriver esphbadriver =
{ espicmd, espdump, espstart, espgo, esprel, esphbareset };
/* forward declarations */
static void espdoattach(int unit);
static void espreset(struct esp_softc *);
/*
* The transfer size is limited to 16 bits since the scsi ctrl transfer
* counter is only 2 bytes. A 0 value means the biggest transfer size
* (2 ** 16) == 64k.
*/
#define MAX_TRANSFER_SIZE (64 * 1024)
/* Return true if this transfer will cross a dma boundary */
#define CROSS_DMA(addr, len) \
(((int)(addr) & 0xff000000) != (((int)(addr) + (len) - 1) & 0xff000000))
/*
* Attach a found DMA chip.
* The second argument is really a pointer to an sbus_attach_args.
*/
void
dmaattach(parent, dev, args)
struct device *parent;
struct device *dev;
void *args;
{
register struct dma_softc *dsc = (struct dma_softc *)dev;
register struct sbus_attach_args *sa = args;
register volatile struct dmareg *dma;
register int rev;
struct esp_softc *esc;
if (sa->sa_ra.ra_vaddr)
dma = (volatile struct dmareg *)sa->sa_ra.ra_vaddr;
else
dma = (volatile struct dmareg *)
mapiodev(sa->sa_ra.ra_paddr, sizeof(struct dmareg));
dsc->sc_dma = dma;
switch (rev = DMA_REV(dma->dma_csr)) {
case DMAREV_1:
printf(": rev 1\n");
break;
case DMAREV_2:
printf(": rev 2\n");
break;
default:
printf(": unknown revision %d\n", rev);
break;
}
espdoattach(dsc->sc_dev.dv_unit);
}
/*
* Attach a found ESP chip. Search for targets; attach each one found.
* The latter must be deferred if the corresponding dma chip has not yet
* been configured.
*/
void
espattach(parent, self, args)
struct device *parent;
struct device *self;
void *args;
{
register struct esp_softc *sc = (struct esp_softc *)self;
register struct sbus_attach_args *sa = args;
register volatile struct espreg *esp;
struct dma_softc *dsc;
int node, pri, freq, t;
if (sa->sa_ra.ra_nintr != 1) {
printf(": expected 1 interrupt, got %d\n", sa->sa_ra.ra_nintr);
return;
}
pri = sa->sa_ra.ra_intr[0].int_pri;
printf(" pri %d", pri);
if (sa->sa_ra.ra_vaddr)
esp = (volatile struct espreg *)sa->sa_ra.ra_vaddr;
else
esp = (volatile struct espreg *)
mapiodev(sa->sa_ra.ra_paddr, sizeof(struct espreg));
sc->sc_esp = esp;
node = sa->sa_ra.ra_node;
sc->sc_id = getpropint(node, "initiator-id", 7);
freq = getpropint(node, "clock-frequency", -1);
if (freq < 0)
freq = ((struct sbus_softc *)sc->sc_hba.hba_dev.dv_parent)->sc_clockfreq;
/* MIGHT NEED TO RESET ESP CHIP HERE ...? */
/*
* Find out whether we have a -100, -100A, or -2xx,
* and what speed it runs at.
*/
sc->sc_conf1 = sc->sc_id | ESPCONF1_PARENB;
/* sc->sc_conf2 = 0; */
/* sc->sc_conf3 = 0; */
esp->esp_conf1 = sc->sc_conf1;
esp->esp_conf2 = 0;
esp->esp_conf2 = ESPCONF2_SCSI2 | ESPCONF2_RPE;
if ((esp->esp_conf2 & ~ESPCONF2_RSVD) !=
(ESPCONF2_SCSI2 | ESPCONF2_RPE)) {
printf(": ESP100");
sc->sc_esptype = ESP100;
} else {
esp->esp_conf2 = 0;
esp->esp_conf3 = 0;
esp->esp_conf3 = 5;
if (esp->esp_conf3 != 5) { /* XXX def bits */
printf(": ESP100A");
sc->sc_esptype = ESP100A;
} else {
esp->esp_conf3 = 0;
printf(": ESP2XX");
sc->sc_esptype = ESP2XX;
}
}
printf(", clock = %s MHz, ID = %d\n", clockfreq(freq), sc->sc_id);
/*
* Set clock conversion factor and select timeout.
* N.B.: clock frequency is not actually used in the rest
* of the driver; I calculate it here for completeness only
* (so I can see it when debugging).
*/
sc->sc_clockfreq = freq;
freq = howmany(freq, 1000 * 1000); /* convert to MHz */
t = ESPCCF_FROMMHZ(freq);
if (t < ESPCCF_MIN)
t = ESPCCF_MIN;
sc->sc_ccf = t;
t = ESPTIMO_REGVAL(250, t, freq); /* timeout = 250 ms. */
if (t >= 256)
t = 0;
sc->sc_sel_timeout = t;
/*
* Link into sbus; set interrupt handler.
*/
sc->sc_sd.sd_reset = espsbreset;
sbus_establish(&sc->sc_sd, &sc->sc_hba.hba_dev);
sc->sc_ih.ih_fun = espintr;
sc->sc_ih.ih_arg = sc;
intr_establish(pri, &sc->sc_ih);
espdoattach(sc->sc_hba.hba_dev.dv_unit);
}
/*
* `Final' attach of esp occurs once esp and dma chips have been found
* and assigned virtual addresses. Set up the ESP SCSI data structures
* and probe the SCSI bus.
*/
static void
espdoattach(unit)
int unit;
{
register struct esp_softc *sc;
register struct dma_softc *dsc;
register int targ;
/* make sure we have both */
if (espcd.cd_ndevs <= unit ||
dmacd.cd_ndevs <= unit ||
(sc = espcd.cd_devs[unit]) == NULL ||
(dsc = dmacd.cd_devs[unit]) == NULL)
return;
sc->sc_dsc = dsc;
sc->sc_dma = dsc->sc_dma;
sc->sc_hba.hba_driver = &esphbadriver;
espreset(sc);
/* MAYBE THIS SHOULD BE MOVED TO scsi_subr.c? */
for (targ = 0; targ < 8; targ++) {
if (targ == sc->sc_id)
continue;
sc->sc_probing = PROBE_TESTING;
sc->sc_clearing = 1;
(void) scsi_test_unit_ready(&sc->sc_hba, targ, 0);
if (sc->sc_probing != PROBE_NO_TARGET) {
sc->sc_probing = 0;
sc->sc_clearing = 0;
SCSI_FOUNDTARGET(&sc->sc_hba, targ);
}
}
sc->sc_probing = 0;
sc->sc_clearing = 0;
}
/*
* Internal DMA reset.
*/
static void
dmareset(sc)
struct esp_softc *sc;
{
register volatile struct dmareg *dma = sc->sc_dma;
/* reset DMA chip */
dma->dma_csr |= DMA_RESET;
DELAY(200);
dma->dma_csr &= ~DMA_RESET; /* ??? */
sc->sc_state = S_IDLE;
sc->sc_dmaactive = 0;
dma->dma_csr |= DMA_IE; /* enable interrupts */
DELAY(200);
}
/*
* Reset the chip. N.B.: this causes a SCSI bus reset!
*/
static void
espreset(sc)
register struct esp_softc *sc;
{
register volatile struct espreg *esp = sc->sc_esp;
dmareset(sc);
esp->esp_cmd = ESPCMD_RESET_CHIP;
DELAY(200);
esp->esp_cmd = ESPCMD_NOP;
DELAY(200);
/*
* Reload configuration registers (cleared by RESET_CHIP command).
* Reloading conf2 on an ESP100 goofs it up, so out of paranoia
* we load only the registers that exist.
*/
esp->esp_conf1 = sc->sc_conf1;
if (sc->sc_esptype > ESP100) { /* 100A, 2XX */
esp->esp_conf2 = sc->sc_conf2;
if (sc->sc_esptype > ESP100A) /* 2XX only */
esp->esp_conf3 = sc->sc_conf3;
}
esp->esp_ccf = sc->sc_ccf;
esp->esp_timeout = sc->sc_sel_timeout;
/* We set synch offset later. */
sc->sc_needclear = 0xff;
}
/*
* Reset the SCSI bus and, optionally, all attached targets.
* The chip should retain most of its parameters (including esp_ccf)
* across this kind of reset (see section 3.5 of Emulex documentation).
*/
void
esphbareset(hba, resetunits)
struct hba_softc *hba;
int resetunits;
{
register struct esp_softc *sc = (struct esp_softc *)hba;
register volatile struct espreg *esp = sc->sc_esp;
dmareset(sc);
/* BEGIN ??? */
/* turn off scsi bus reset interrupts and reset scsi bus */
esp->esp_conf1 = sc->sc_conf1 | ESPCONF1_REPORT;
DELAY(200);
esp->esp_cmd = ESPCMD_RESET_BUS;
DELAY(800);
esp->esp_cmd = ESPCMD_NOP;
DELAY(200);
esp->esp_conf1 = sc->sc_conf1;
/* END ??? */
sc->sc_needclear = 0xff;
if (resetunits)
scsi_reset_units(&sc->sc_hba);
}
/*
* Reset the esp, after an Sbus reset.
* Also resets corresponding dma chip.
*
* THIS ROUTINE MIGHT GO AWAY
*/
void
espsbreset(dev)
struct device *dev;
{
struct esp_softc *sc = (struct esp_softc *)dev;
if (sc->sc_dsc) {
printf(" %s %s", sc->sc_dsc->sc_dev.dv_xname,
sc->sc_hba.hba_dev.dv_xname);
esphbareset(&sc->sc_hba, 1);
}
}
static void
esperror(sc, err)
char *err;
register struct esp_softc *sc;
{
printf("%s: %s (target=%d): stat=%b step=%x dmacsr=%b intr=%b\n",
sc->sc_hba.hba_dev.dv_xname, err, sc->sc_targ,
sc->sc_espstat, ESPSTAT_BITS, sc->sc_espstep,
sc->sc_dmacsr, DMA_BITS, sc->sc_espintr, ESPINTR_BITS);
}
/*
* An interrupt has occurred. Sequence through the SCSI state machine.
* Return the action to take.
*
* Most of the work happens here.
*
* There are three interrupt sources:
* -- ESP interrupt request (typically, some device wants something).
* -- DMA memory error.
* -- DMA byte count has reached 0 (we do not often want this one but
* can only turn it off in rev 2 DMA chips, it seems).
* DOES THIS OCCUR AT ALL HERE? THERE IS NOTHING TO HANDLE IT!
*/
static int
espact(sc, esp, dma, cdb)
register struct esp_softc *sc;
register volatile struct espreg *esp;
register volatile struct dmareg *dma;
register struct scsi_cdb *cdb;
{
register char *xname = sc->sc_hba.hba_dev.dv_xname;
register int reg, phase, i;
/* check various error conditions, using as little code as possible */
if (sc->sc_dmacsr & DMA_EP) {
esperror(sc, "DMA error");
dma->dma_csr |= DMA_FLUSH;
return (ACT_ERROR);
}
reg = sc->sc_espstat;
if (reg & ESPSTAT_GE) {
/*
* This often occurs when there is no target.
* (See DSC code below.)
*/
if (sc->sc_espintr & ESPINTR_DSC &&
sc->sc_state == S_SEL && sc->sc_probing) {
sc->sc_probing = PROBE_NO_TARGET;
return (ACT_RESET);
}
esperror(sc, "DIAGNOSTIC: gross error (ignored)");
}
if (reg & ESPSTAT_PE) {
esperror(sc, "parity error");
return (ACT_RESET);
}
reg = sc->sc_espintr;
#define ERR (ESPINTR_SBR|ESPINTR_ILC|ESPINTR_RSL|ESPINTR_SAT|ESPINTR_SEL)
if (reg & ERR) {
if (reg & ESPINTR_SBR)
esperror(sc, "scsi bus reset");
else if (reg & ESPINTR_ILC)
esperror(sc, "illegal command (driver bug)");
else {
printf("%s: target %d", xname, sc->sc_targ);
if (reg & ESPINTR_RSL)
printf(" tried to reselect;");
if (reg & ESPINTR_SAT)
printf(" selected with ATN;");
if (reg & ESPINTR_SEL)
printf(" selected us as target;");
printf("we do not allow this yet\n");
}
return (ACT_ERROR);
}
#undef ERR
/*
* Disconnect currently only allowed in `final interrupt' states.
*/
if (reg & ESPINTR_DSC) {
if (sc->sc_state == S_FI)
return (ACT_DONE);
/*
* If we were doing a select just to test the existence
* of the target, note that it did not respond; otherwise
* gripe.
*/
if (sc->sc_state == S_SEL) {
if (sc->sc_probing) {
sc->sc_probing = PROBE_NO_TARGET;
return (ACT_RESET);
}
}
/* flush fifo, in case we were selecting or sending data */
esp->esp_cmd = ESPCMD_FLUSH_FIFO;
printf("%s: target %d not responding\n",
xname, sc->sc_targ);
return (ACT_ERROR);
}
/*
* Okay, things are moving along.
* What were we doing the last time we did something,
* and did it complete normally?
*/
phase = sc->sc_espstat & ESPSTAT_PHASE;
switch (sc->sc_state) {
case S_SEL:
/*
* We were selecting. Arbitration and select are
* complete (because ESPINTR_DSC was not set), but
* there is no guarantee the command went out.
*/
if ((reg & (ESPINTR_SVC|ESPINTR_CMP)) !=
(ESPINTR_SVC|ESPINTR_CMP)) {
esperror(sc, "selection failed");
return (ACT_RESET);
}
if (sc->sc_espstep == ESPSTEP_DONE) {
sc->sc_sentcmd = 1;
break;
}
if (sc->sc_espstep == 2) {
/*
* We got something other than command phase.
* Just pretend things are normal; the
* device will ask for the command later.
*/
esperror(sc, "DIAGNOSTIC: esp step 2");
} else if (sc->sc_espstep == 3) {
/*
* Device entered command phase and then exited it
* before we finished handing out the command.
* Let this happen iff we are trying to clear the
* target state.
*/
esperror(sc, "DIAGNOSTIC: esp step 3");
if (!sc->sc_clearing)
return (ACT_RESET);
} else {
printf("%s: mysterious esp step %d\n",
xname, sc->sc_espstep);
return (ACT_RESET);
}
/*
* Part of the command may still be lodged in the FIFO.
*/
esp->esp_cmd = ESPCMD_FLUSH_FIFO;
break;
case S_CMDSVC:
/*
* We were waiting for phase change after stuffing the command
* into the FIFO. Make sure it got out.
*/
reg = ESP_NFIFO(esp);
if (reg) {
esperror(sc, "DIAGNOSTIC: CMDSVC, fifo not empty");
printf("\tfifo count = %x\n", reg);
esp->esp_cmd = ESPCMD_FLUSH_FIFO;
} else
sc->sc_sentcmd = 1;
break;
case S_IOSVC:
/*
* We were waiting for phase change after I/O.
*/
break;
case S_DI:
/*
* We were doing DMA data in, and expecting a
* transfer-count-zero interrupt or a phase change.
* We got that; drain the pack register and
* handle as for data out.
*/
dma->dma_csr |= DMA_DRAIN;
reg = 0; /* FIFO auto flushed? */
goto dma_data_done;
case S_DO:
/*
* We were doing DMA data out. If there is data in the
* FIFO, it is stuff that got DMAed out but never made
* it to the device, so it counts as residual.
*
* XXX handle DMA IO with large count or address
* boundary condition by resuming here, or below?
*/
if ((reg = ESP_NFIFO(esp)) != 0)
esp->esp_cmd = ESPCMD_FLUSH_FIFO;
dma_data_done:
if (sc->sc_dmaactive == 0) {
printf("%s: dma done while %s, dmaactive==0\n",
xname, espstates[sc->sc_state]);
panic("espact");
}
sc->sc_dmaactive = 0;
reg += esp->esp_tcl | (esp->esp_tch << 8);
if (reg == 0 && (sc->sc_espstat & ESPSTAT_TC) == 0)
reg = 65536;
if (reg > sc->sc_resid) {
printf("%s: xfer resid (%d) > xfer req (%d)\n",
xname, reg, sc->sc_resid);
reg = sc->sc_resid;
}
/*
* If data came in we must flush cache.
*/
if (sc->sc_state == S_DI)
cache_flush(sc->sc_dmaaddr, sc->sc_resid - reg);
sc->sc_resid = reg;
if ((sc->sc_espintr & ESPINTR_SVC) == 0) {
printf("%s: no bus service req\n", xname);
return (ACT_RESET);
}
break;
case S_STAT:
/*
* The last thing we did was tell it `initiator complete'
* and so we expect to have gotten both the status byte
* and the final message byte. It is possible that we
* got something else....
*
* Apparently, BUS SERVICE is set if we got just status,
* while FUNCTION COMPLETE is set if we got both.
*/
if ((reg & (ESPINTR_SVC|ESPINTR_CMP)) != ESPINTR_CMP) {
esperror(sc, "bad status interrupt state");
return (ACT_RESET);
}
reg = ESP_NFIFO(esp);
if (reg < 2) {
printf(
"%s: command done but fifo count = %d; must be >= 2\n", xname,
reg);
return (ACT_RESET);
}
/*
* Read the status and the first msg byte.
* It should be CMD_COMPLETE. Eventually we
* may handle IDENTIFY, DISCONNECT, etc., as well.
*/
sc->sc_stat[0] = esp->esp_fifo;
sc->sc_msg[0] = reg = esp->esp_fifo;
esp->esp_cmd = ESPCMD_MSG_ACCEPT;
if (reg == MSG_CMD_COMPLETE) {
sc->sc_state = S_FI;
return (ACT_CONT);
}
if (SCSIMSGLEN(reg) != 1) {
printf("%s: target %d is naughty\n",
xname, sc->sc_targ);
return (ACT_RESET);
}
printf("%s: warning: target %d returned msg 0x%x\n",
xname, sc->sc_targ, reg);
sc->sc_state = S_FI;
return (ACT_CONT);
case S_MI:
if ((reg & ESPINTR_SVC) == 0) {
esperror(sc, "missing phase after msg in");
return (ACT_RESET);
}
reg = ESP_NFIFO(esp);
for (i = 0; i < reg; i++)
sc->sc_msg[i] = esp->esp_fifo;
break;
case S_FI:
esperror(sc, "target did not disconnect");
return (ACT_RESET);
}
/*
* Things are still moving along. The phase tells us
* what the device wants next. Do it.
*/
switch (phase) {
case ESPPHASE_DATA_OUT:
if (!sc->sc_sentcmd) esperror(sc, "DIAGNOSTIC: data out without command");
sc->sc_state = S_DO;
return (ACT_WRITE);
case ESPPHASE_DATA_IN:
if (!sc->sc_sentcmd) esperror(sc, "DIAGNOSTIC: data in without command");
sc->sc_state = S_DI;
return (ACT_READ);
case ESPPHASE_CMD:
/*
* Silly thing wants the command again.
* Load it into the FIFO and go to CMDSVC state.
*/
printf("%s: redoing command\n", xname);
reg = SCSICMDLEN(cdb->cdb_bytes[0]);
for (i = 0; i < reg; i++)
esp->esp_fifo = cdb->cdb_bytes[i];
sc->sc_state = S_CMDSVC;
esp->esp_cmd = ESPCMD_XFER_INFO;
return (ACT_CONT);
case ESPPHASE_STATUS:
sc->sc_state = S_STAT;
esp->esp_cmd = ESPCMD_INIT_COMP;
return (ACT_CONT);
case ESPPHASE_MSG_IN:
printf("%s: accepting (& ignoring) msg from target %d\n", xname, sc->sc_targ);
sc->sc_state = S_MI;
esp->esp_cmd = ESPCMD_MSG_ACCEPT;
return (ACT_CONT);
default:
printf("%s: target %d asked for strange phase (%s)\n",
xname, sc->sc_targ, espphases[phase]);
return (ACT_RESET);
}
/* NOTREACHED */
}
/*
* Issue a select, loading command into the FIFO.
* Return nonzero on error, 0 if OK.
* Sets state to `selecting'; espact() will sequence state FSM.
*/
void
espselect(sc, esp, targ, cdb)
register struct esp_softc *sc;
register volatile struct espreg *esp;
register int targ;
register struct scsi_cdb *cdb;
{
register int i, cmdlen = SCSICMDLEN(cdb->cdb_bytes[0]);
sc->sc_targ = targ;
sc->sc_state = S_SEL;
sc->sc_sentcmd = 0;
sc->sc_stat[0] = 0xff; /* ??? */
sc->sc_msg[0] = 0xff; /* ??? */
/*
* Try to talk to target.
* Synch offset 0 => asynchronous transfer.
*/
esp->esp_id = targ;
esp->esp_syncoff = 0;
/*
* Stuff the command bytes into the fifo.
* Select without attention since we do not do disconnect yet.
*/
for (i = 0; i < cmdlen; i++)
esp->esp_fifo = cdb->cdb_bytes[i];
esp->esp_cmd = ESPCMD_SEL_NATN;
/* the rest is done elsewhere */
}
/*
* THIS SHOULD BE ADJUSTABLE
*/
/* name howlong purpose */
#define SELECT_WAIT 300000 /* wait for select to complete */
#define CMD_WAIT 1000 /* wait for next phase, generic */
#define IO_WAIT 1000000 /* time to xfer data in/out */
#define POSTDATA_WAIT 10000000 /* wait for next phase, after dataio */
/*
* Transfer data out via polling. Return success (0) iff all
* the bytes were sent and we got an interrupt.
*
* This returns -1 on timeout, resid count on early interrupt,
* but no one really cares....
*/
static int
espixfer_out(sc, esp, dma, buf, len)
register struct esp_softc *sc;
register volatile struct espreg *esp;
register volatile struct dmareg *dma;
register caddr_t buf;
register int len;
{
register int wait, n;
if (CROSS_DMA(buf, len))
panic("espixfer_out: 16MB boundary");
/* set dma address and transfer count */
dma->dma_addr = (int)buf;
esp->esp_tch = len >> 8;
esp->esp_tcl = len;
/* load count into counter via DMA NOP */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_NOP;
/* enable dma (but not interrupts) */
dma->dma_csr = DMA_ENA;
/* and go */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_XFER_INFO;
/* wait for completion */
for (wait = IO_WAIT; wait > 0; --wait) {
n = dma->dma_csr;
if (DMA_INTR(n)) {
sc->sc_espstat = esp->esp_stat;
sc->sc_espstep = esp->esp_step & ESPSTEP_MASK;
sc->sc_espintr = esp->esp_intr;
sc->sc_dmacsr = n;
n = esp->esp_tcl | (esp->esp_tch << 8);
if (n == 0 && (sc->sc_espstat & ESPSTAT_TC) == 0)
n = 65536;
return (n);
}
DELAY(1);
}
return (-1);
}
/*
* Transfer data in via polling.
* Return resid count on interrupt, -1 if timed out.
*/
static int
espixfer_in(sc, esp, dma, buf, len)
register struct esp_softc *sc;
register volatile struct espreg *esp;
register volatile struct dmareg *dma;
register caddr_t buf;
register int len;
{
register int wait, n;
if (CROSS_DMA(buf, len))
panic("espixfer_in: 16MB boundary");
/* set dma address and transfer count */
dma->dma_addr = (int)buf;
esp->esp_tch = len >> 8;
esp->esp_tcl = len;
/* load count into counter via DMA NOP */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_NOP;
/* enable dma (but not interrupts) */
dma->dma_csr = DMA_ENA | DMA_READ;
/* and go */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_XFER_INFO;
/* wait for completion */
for (wait = IO_WAIT; wait > 0; --wait) {
n = dma->dma_csr;
if (DMA_INTR(n)) {
sc->sc_espstat = esp->esp_stat;
sc->sc_espstep = esp->esp_step & ESPSTEP_MASK;
sc->sc_espintr = esp->esp_intr;
dma->dma_csr |= DMA_DRAIN;
sc->sc_dmacsr = n;
n = esp->esp_tcl | (esp->esp_tch << 8);
if (n == 0 && (sc->sc_espstat & ESPSTAT_TC) == 0)
n = 65536;
cache_flush(buf, (u_int)len - n);
return (n);
}
DELAY(1);
}
return (-1);
}
/*
* Clear out target state by doing a special TEST UNIT READY.
* Note that this calls espicmd (possibly recursively).
*/
void
espclear(sc, targ)
register struct esp_softc *sc;
register int targ;
{
/* turn off needclear immediately since this calls espicmd() again */
sc->sc_needclear &= ~(1 << targ);
sc->sc_clearing = 1;
(void) scsi_test_unit_ready(&sc->sc_hba, targ, 0);
sc->sc_clearing = 0;
}
/*
* Send an `immediate' command, i.e., poll until the whole thing is done.
* Return the status byte from the device, or -1 if we timed out.
*/
int
espicmd(hba, targ, cdb, buf, len, rw)
register struct hba_softc *hba;
int targ;
register struct scsi_cdb *cdb;
caddr_t buf;
register int len;
int rw;
{
register struct esp_softc *sc = (struct esp_softc *)hba;
register volatile struct espreg *esp = sc->sc_esp;
register volatile struct dmareg *dma = sc->sc_dma;
register int r, wait;
char *msg;
if ((unsigned)len > MAX_TRANSFER_SIZE) {
printf("%s: bad length %d\n", sc->sc_hba.hba_dev.dv_xname, len);
panic("espicmd");
}
/*
* Clear the target if necessary.
*/
if (sc->sc_needclear & (1 << targ) && !sc->sc_probing)
espclear(sc, targ);
/*
* Disable hardware interrupts, start select sequence.
* Wait for interrupt-pending bit, then call espact() to
* sequence the state machine. When it tells us to do
* data transfer, we do programmed I/O.
* In any case, we loop calling espact() until done.
*/
dma->dma_csr = 0; /* disable hardware interrupts */
espselect(sc, esp, targ, cdb);
wait = SELECT_WAIT;
loop:
for (;;) {
r = dma->dma_csr;
if (!DMA_INTR(r)) {
if (--wait < 0) {
msg = "timeout waiting for phase change";
goto err;
}
DELAY(1);
continue;
}
break;
}
sc->sc_espstat = esp->esp_stat;
sc->sc_espstep = esp->esp_step & ESPSTEP_MASK;
sc->sc_espintr = esp->esp_intr;
sc->sc_dmacsr = r;
/*
* The action happens `twice around' for read and write.
* All the rest `goto loop' or return or some such.
*/
wait = CMD_WAIT;
for (;;) {
switch (r = espact(sc, esp, dma, cdb)) {
case ACT_CONT:
case ACT_QUICKINTR:
goto loop;
case ACT_READ:
if (len == 0 || (rw & B_READ) == 0) {
msg = "wrong phase";
goto err;
}
r = espixfer_in(sc, esp, dma, buf, len);
if (r < 0) {
msg = "timeout reading from device";
goto err;
}
buf += len - r;
len = r;
/* we did the io, expecting `generic service' */
sc->sc_state = S_IOSVC;
wait = POSTDATA_WAIT;
break;
case ACT_WRITE:
if (len == 0 || rw & B_READ) {
msg = "wrong phase";
goto err;
}
if (espixfer_out(sc, esp, dma, buf, len)) {
msg = "timeout writing to device";
goto err;
}
sc->sc_state = S_IOSVC;
wait = POSTDATA_WAIT;
break;
case ACT_RESET:
sc->sc_state = S_IDLE;
goto reset;
case ACT_DONE:
sc->sc_state = S_IDLE;
return (sc->sc_stat[0]);
case ACT_ERROR:
sc->sc_state = S_IDLE;
return (-1);
default:
panic("espicmd action");
}
}
err:
printf("%s: target %d: %s (phase = %s)\n",
sc->sc_hba.hba_dev.dv_xname, targ, msg,
espphases[sc->sc_espstat & ESPSTAT_PHASE]);
reset:
espreset(sc); /* ??? */
return (-1);
}
/*
* Dump (write memory, possibly physmem).
* SPARC higher-level dump code always provides virtual addresses,
* so we need not do any I/O mapping here.
*/
int
espdump(hba, targ, cdb, buf, len)
register struct hba_softc *hba;
int targ;
register struct scsi_cdb *cdb;
caddr_t buf;
register int len;
{
return (espicmd(hba, targ, cdb, buf, len, B_WRITE));
}
/*
* Allocate resources (SCSI bus and DVMA space) for the given transfer.
* Must be called at splbio().
*
* THIS SHOULD RETURN SUCCESS/FAIL INDICATION
*/
void
espstart(self, sq, bp, dgo, dev)
struct device *self;
register struct sq *sq;
struct buf *bp;
scdgo_fn dgo;
struct device *dev;
{
register struct esp_softc *sc = (struct esp_softc *)self;
if (sc->sc_hba.hba_busy == 0) {
/*
* Bus not busy, nothing to do here, just tell
* this target or unit that it has the SCSI bus.
*/
sc->sc_hba.hba_busy = 1;
(*dgo)(dev, &sc->sc_cdb);
} else {
/*
* Bus is busy; just enqueue.
*/
sq->sq_dgo = dgo;
sq->sq_dev = dev;
sq->sq_forw = NULL;
if (sc->sc_hba.hba_head == NULL)
sc->sc_hba.hba_head = sq;
else
sc->sc_hba.hba_tail->sq_forw = sq;
sc->sc_hba.hba_tail = sq;
}
}
/*
* Send a `dma' command, i.e., send the cdb and use DMA to send the data.
* Return 0 on success, 1 on failure.
*/
int
espgo(self, targ, intr, dev, bp, pad)
struct device *self;
int targ;
scintr_fn intr;
struct device *dev;
register struct buf *bp;
int pad;
{
register struct esp_softc *sc = (struct esp_softc *)self;
register int len = bp->b_bcount;
register u_long addr;
if ((unsigned)len > MAX_TRANSFER_SIZE) {
printf("%s: %s\n", sc->sc_hba.hba_dev.dv_xname,
len < 0 ? "negative length" : "transfer too big");
return (1);
}
if (sc->sc_needclear & (1 << targ))
espclear(sc, targ);
/*
* Set dma registers later, on data transfer,
* but compute the contents now.
* COULD JUST REMEMBER bp HERE...?
*
* The DMA chip cannot cross a 16 MB address boundary.
* We should do this as multiple DMA transactions on a
* single SCSI command, but I have not written that yet.
*/
sc->sc_dmactl = bp->b_flags & B_READ ? DMA_ENA | DMA_READ | DMA_IE :
DMA_ENA | DMA_IE;
addr = (u_long)bp->b_un.b_addr;
/* dma chip cannot cross 16MB boundary XXX */
if (CROSS_DMA(addr, len))
panic("dma crosses 16MB boundary: fix esp.c");
sc->sc_dmaaddr = addr;
sc->sc_resid = len;
/*
* Enable interrupts and start selection.
* The rest is done in our interrupt handler.
*/
sc->sc_hba.hba_intr = intr; /* remember dev done function */
sc->sc_hba.hba_intrdev = dev; /* and its first arg */
sc->sc_dma->dma_csr = DMA_IE;
espselect(sc, sc->sc_esp, targ, &sc->sc_cdb);
return (0);
}
/*
* Handle interrupt. Return 1 if taken.
*/
int
espintr(sc0)
void *sc0;
{
register struct esp_softc *sc = (struct esp_softc *)sc0;
register volatile struct espreg *esp = sc->sc_esp;
register volatile struct dmareg *dma = sc->sc_dma;
register int r, wait;
register struct sq *sq;
r = dma->dma_csr;
if (!DMA_INTR(r))
return (0); /* not ours */
sc->sc_interrupts++;
again:
sc->sc_espstat = esp->esp_stat;
sc->sc_espstep = esp->esp_step & ESPSTEP_MASK;
sc->sc_espintr = esp->esp_intr;
sc->sc_dmacsr = r;
if (sc->sc_state == S_IDLE) {
printf("%s: stray interrupt\n", sc->sc_hba.hba_dev.dv_xname);
dma->dma_csr &= ~DMA_IE; /* ??? */
return (1);
}
switch (r = espact(sc, esp, dma, &sc->sc_cdb)) {
case ACT_CONT: /* just return */
break;
case ACT_READ:
case ACT_WRITE:
/*
* We have to do this ourselves since another
* user of espact() wants to do programmed I/O.
* If we already did dma, and are done, stop.
*/
if (sc->sc_resid == 0) {
printf("%s: target %d sent too much data\n",
sc->sc_hba.hba_dev.dv_xname, sc->sc_targ);
goto reset;
}
sc->sc_dmaactive = 1;
dma->dma_addr = sc->sc_dmaaddr;
esp->esp_tch = sc->sc_resid >> 8;
esp->esp_tcl = sc->sc_resid;
/* load count into counter via DMA NOP */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_NOP;
/* enable dma */
dma->dma_csr = sc->sc_dmactl;
/* and go */
esp->esp_cmd = ESPCMD_DMA | ESPCMD_XFER_INFO;
break;
case ACT_RESET: /* please reset esp */
reset:
espreset(sc); /* ??? */
/* FALLTHROUGH */
case ACT_DONE: /* this one is done, successfully */
case ACT_ERROR: /* this one is done due to `severe' error */
sc->sc_state = S_IDLE;
if (!sc->sc_hba.hba_busy)
panic("espintr sq");
/*
* This transaction is done.
* Call the driver's intr routine,
* then start the next guy if any.
*/
(*sc->sc_hba.hba_intr)(sc->sc_hba.hba_intrdev,
r == ACT_DONE ? sc->sc_stat[0] : -1, sc->sc_resid);
if ((sq = sc->sc_hba.hba_head) != NULL) {
sc->sc_hba.hba_head = sq->sq_forw;
(*sq->sq_dgo)(sq->sq_dev, &sc->sc_cdb);
} else
sc->sc_hba.hba_busy = 0;
break;
case ACT_QUICKINTR: /* wait a short while for another interrupt */
printf("%s: quickintr: ", sc->sc_hba.hba_dev.dv_xname);
wait = 100;
do {
r = dma->dma_csr;
if (DMA_INTR(r)) {
printf("got one, wait=%d\n", wait);
goto again;
}
} while (--wait > 0);
printf("did not get one\n");
break;
default:
panic("espintr action");
}
return (1);
}
/*
* Target or unit decided to let go of the bus early.
*/
void
esprel(self)
struct device *self;
{
register struct esp_softc *sc = (struct esp_softc *)self;
register struct sq *sq;
/* if there is someone else waiting, give them a crack at it */
if ((sq = sc->sc_hba.hba_head) != NULL)
(*sq->sq_dgo)(sq->sq_dev, &sc->sc_cdb);
else
sc->sc_hba.hba_busy = 0;
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.