freebsd-dev/sys/dev/ata/atapi-cam.c

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/*-
* Copyright (c) 2001,2002 Thomas Quinot <thomas@cuivre.fr.eu.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification, immediately at the beginning of the file.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/ata.h>
#include <machine/bus.h>
#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_periph.h>
#include <cam/cam_sim.h>
#include <cam/cam_xpt_sim.h>
#include <cam/cam_debug.h>
#include <cam/scsi/scsi_all.h>
#include <dev/ata/ata-all.h>
#include <dev/ata/atapi-all.h>
/* hardware command descriptor block */
struct atapi_hcb {
struct atapi_xpt_softc *softc;
int unit;
int bus;
int target;
int lun;
union ccb *ccb;
u_int8_t cmd[CAM_MAX_CDBLEN];
2002-08-19 18:47:51 +00:00
int flags;
#define DOING_AUTOSENSE 1
char *dxfer_alloc;
TAILQ_ENTRY(atapi_hcb) chain;
};
/* private data associated with an ATA bus */
struct atapi_xpt_softc {
struct ata_channel *ata_ch;
struct cam_path *path;
struct cam_sim *sim;
int flags;
#define BUS_REGISTERED 0x01
#define RESOURCE_SHORTAGE 0x02
TAILQ_HEAD(,atapi_hcb) pending_hcbs;
LIST_ENTRY(atapi_xpt_softc) chain;
};
enum reinit_reason { BOOT_ATTACH, ATTACH, RESET };
static LIST_HEAD(,atapi_xpt_softc) all_buses = LIST_HEAD_INITIALIZER(all_buses);
/* CAM XPT methods */
static void atapi_action(struct cam_sim *, union ccb *);
static void atapi_poll(struct cam_sim *);
static void atapi_async(void *, u_int32_t, struct cam_path *, void *);
static void atapi_async1(void *, u_int32_t, struct cam_path *, void *);
static int atapi_cb(struct atapi_request *);
/* internal functions */
static void reinit_bus(struct atapi_xpt_softc *scp, enum reinit_reason reason);
static void setup_dev(struct atapi_xpt_softc *, struct ata_device *);
static void setup_async_cb(struct atapi_xpt_softc *, uint32_t);
static void cam_rescan_callback(struct cam_periph *, union ccb *);
static void cam_rescan(struct cam_sim *);
static void free_hcb_and_ccb_done(struct atapi_hcb *, u_int32_t);
static struct atapi_hcb *allocate_hcb(struct atapi_xpt_softc *, int, int, union ccb *);
static void free_hcb(struct atapi_hcb *hcb);
static void free_softc(struct atapi_xpt_softc *scp);
static struct atapi_xpt_softc *get_softc(struct ata_channel *ata_ch);
static struct ata_device *get_ata_device(struct atapi_xpt_softc *scp, int id);
static MALLOC_DEFINE(M_ATACAM, "ATA CAM transport", "ATA driver CAM-XPT layer");
void
atapi_cam_attach_bus(struct ata_channel *ata_ch)
{
struct atapi_xpt_softc *scp = NULL;
struct cam_devq *devq = NULL;
struct cam_sim *sim = NULL;
struct cam_path *path = NULL;
int unit;
LIST_FOREACH(scp, &all_buses, chain) {
if (scp->ata_ch == ata_ch)
return;
}
if ((scp = malloc(sizeof(struct atapi_xpt_softc),
M_ATACAM, M_NOWAIT | M_ZERO)) == NULL)
goto error;
scp->ata_ch = ata_ch;
TAILQ_INIT(&scp->pending_hcbs);
LIST_INSERT_HEAD(&all_buses, scp, chain);
unit = device_get_unit(ata_ch->dev);
if ((devq = cam_simq_alloc(16)) == NULL)
goto error;
if ((sim = cam_sim_alloc(atapi_action, atapi_poll, "ata",
(void *)scp, unit, 1, 1, devq)) == NULL) {
cam_simq_free(devq);
goto error;
}
scp->sim = sim;
if (xpt_bus_register(sim, 0) != CAM_SUCCESS) {
goto error;
}
scp->flags |= BUS_REGISTERED;
if (xpt_create_path(&path, /*periph*/ NULL,
cam_sim_path(sim), CAM_TARGET_WILDCARD,
CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
goto error;
}
scp->path = path;
CAM_DEBUG(path, CAM_DEBUG_TRACE, ("Registered SIM for ata%d\n", unit));
setup_async_cb(scp, AC_LOST_DEVICE);
reinit_bus(scp, cold ? BOOT_ATTACH : ATTACH);
return;
error:
free_softc(scp);
}
void
atapi_cam_detach_bus(struct ata_channel *ata_ch)
{
struct atapi_xpt_softc *scp = get_softc(ata_ch);
free_softc(scp);
}
void
atapi_cam_reinit_bus(struct ata_channel *ata_ch) {
struct atapi_xpt_softc *scp = get_softc(ata_ch);
/*
* scp might be null if the bus is being reinitialised during
* the boot-up sequence, before the ATAPI bus is registered.
*/
if (scp != NULL)
reinit_bus(scp, RESET);
}
static void
reinit_bus(struct atapi_xpt_softc *scp, enum reinit_reason reason) {
if (scp->ata_ch->devices & ATA_ATAPI_MASTER)
setup_dev(scp, &scp->ata_ch->device[MASTER]);
if (scp->ata_ch->devices & ATA_ATAPI_SLAVE)
setup_dev(scp, &scp->ata_ch->device[SLAVE]);
switch (reason) {
case BOOT_ATTACH:
break;
case RESET:
xpt_async(AC_BUS_RESET, scp->path, NULL);
/*FALLTHROUGH*/
case ATTACH:
cam_rescan(scp->sim);
break;
}
}
static void
setup_dev(struct atapi_xpt_softc *scp, struct ata_device *atp)
{
if (atp->driver == NULL) {
ata_set_name(atp, "atapicam",
2 * device_get_unit(atp->channel->dev) +
(atp->unit == ATA_MASTER) ? 0 : 1);
atp->driver = (void *)scp;
}
}
static void
setup_async_cb(struct atapi_xpt_softc *scp, uint32_t events)
{
struct ccb_setasync csa;
xpt_setup_ccb(&csa.ccb_h, scp->path, /*priority*/ 5);
csa.ccb_h.func_code = XPT_SASYNC_CB;
csa.event_enable = events;
csa.callback = &atapi_async;
csa.callback_arg = scp->sim;
xpt_action((union ccb *) &csa);
}
static void
atapi_action(struct cam_sim *sim, union ccb *ccb)
{
struct atapi_xpt_softc *softc = (struct atapi_xpt_softc*)cam_sim_softc(sim);
struct ccb_hdr *ccb_h = &ccb->ccb_h;
struct atapi_hcb *hcb = NULL;
int unit = cam_sim_unit(sim);
int bus = cam_sim_bus(sim);
int len, s;
char *buf;
switch (ccb_h->func_code) {
case XPT_PATH_INQ: {
struct ccb_pathinq *cpi = &ccb->cpi;
cpi->version_num = 1;
cpi->hba_inquiry = 0;
cpi->target_sprt = 0;
cpi->hba_misc = 0;
cpi->hba_eng_cnt = 0;
bzero(cpi->vuhba_flags, sizeof(cpi->vuhba_flags));
cpi->max_target = 1;
cpi->max_lun = 0;
cpi->async_flags = 0;
cpi->hpath_id = 0;
cpi->initiator_id = 7;
strncpy(cpi->sim_vid, "FreeBSD", sizeof(cpi->sim_vid));
strncpy(cpi->hba_vid, "ATAPI", sizeof(cpi->hba_vid));
strncpy(cpi->dev_name, cam_sim_name(sim), sizeof cpi->dev_name);
cpi->unit_number = cam_sim_unit(sim);
cpi->bus_id = cam_sim_bus(sim);
if (softc->ata_ch && ccb_h->target_id >= 0) {
switch (softc->ata_ch->device[ccb_h->target_id].mode) {
case ATA_PIO1:
cpi->base_transfer_speed = 5200;
break;
case ATA_PIO2:
cpi->base_transfer_speed = 7000;
break;
case ATA_PIO3:
cpi->base_transfer_speed = 11000;
break;
case ATA_PIO4:
case ATA_DMA:
case ATA_WDMA2:
cpi->base_transfer_speed = 16000;
break;
case ATA_UDMA2:
cpi->base_transfer_speed = 33000;
break;
case ATA_UDMA4:
cpi->base_transfer_speed = 66000;
break;
case ATA_UDMA5:
cpi->base_transfer_speed = 100000;
break;
case ATA_UDMA6:
cpi->base_transfer_speed = 133000;
break;
default: cpi->base_transfer_speed = 3300;
}
}
ccb->ccb_h.status = CAM_REQ_CMP;
xpt_done(ccb);
return;
}
case XPT_RESET_DEV: {
int tid = ccb_h->target_id;
struct ata_device *dev = get_ata_device(softc, tid);
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_SUBTRACE, ("dev reset\n"));
atapi_reinit(dev);
ccb->ccb_h.status = CAM_REQ_CMP;
xpt_done(ccb);
return;
}
case XPT_RESET_BUS:
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_SUBTRACE, ("bus reset\n"));
ata_reinit(softc->ata_ch);
ccb->ccb_h.status = CAM_REQ_CMP;
xpt_done(ccb);
return;
case XPT_SET_TRAN_SETTINGS:
/* ignore these, we're not doing SCSI here */
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_SUBTRACE,
("SET_TRAN_SETTINGS not supported\n"));
ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
xpt_done(ccb);
return;
case XPT_GET_TRAN_SETTINGS: {
struct ccb_trans_settings *cts = &ccb->cts;
/*
* XXX The default CAM transport code is very scsi specific and
* doesn't understand IDE speeds very well. Be silent about it
* here and let it default to what is set in XPT_PATH_INQ
*/
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_SUBTRACE, ("GET_TRAN_SETTINGS\n"));
cts->valid = (CCB_TRANS_DISC_VALID | CCB_TRANS_TQ_VALID);
cts->flags &= ~(CCB_TRANS_DISC_ENB | CCB_TRANS_TAG_ENB);
ccb->ccb_h.status = CAM_REQ_CMP;
xpt_done(ccb);
return;
}
case XPT_CALC_GEOMETRY: {
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_SUBTRACE, ("CALC_GEOMETRY\n"));
cam_calc_geometry(&ccb->ccg, /*extended*/1);
xpt_done(ccb);
return;
}
case XPT_SCSI_IO: {
struct ccb_scsiio *csio = &ccb->csio;
int tid = ccb_h->target_id, lid = ccb_h->target_lun;
struct ata_device *dev = get_ata_device(softc, tid);
CAM_DEBUG(ccb_h->path, CAM_DEBUG_SUBTRACE, ("XPT_SCSI_IO\n"));
/* check that this request was not aborted already */
if ((ccb_h->status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
printf("XPT_SCSI_IO received but already in progress?\n");
xpt_done(ccb);
return;
}
if (dev == NULL) {
CAM_DEBUG(ccb_h->path, CAM_DEBUG_SUBTRACE,
("SCSI IO received for invalid device\n"));
ccb_h->status = CAM_TID_INVALID;
xpt_done(ccb);
return;
}
if (lid > 0) {
CAM_DEBUG(ccb_h->path, CAM_DEBUG_SUBTRACE,
("SCSI IO received for invalid lun %d\n", lid));
ccb_h->status = CAM_LUN_INVALID;
xpt_done(ccb);
return;
}
if ((ccb_h->flags & CAM_SCATTER_VALID)) {
/* scatter-gather not supported */
xpt_print_path(ccb_h->path);
printf("ATAPI-CAM does not support scatter-gather yet!\n");
break;
}
if ((hcb = allocate_hcb(softc, unit, bus, ccb)) == NULL)
goto action_oom;
ccb_h->status |= CAM_SIM_QUEUED;
bcopy((ccb_h->flags & CAM_CDB_POINTER) ?
csio->cdb_io.cdb_ptr : csio->cdb_io.cdb_bytes,
hcb->cmd, csio->cdb_len);
#ifdef CAMDEBUG
if (CAM_DEBUGGED(ccb_h->path, CAM_DEBUG_CDB)) {
char cdb_str[(SCSI_MAX_CDBLEN * 3) + 1];
printf("atapi_action: hcb@%p: %s\n", hcb,
scsi_cdb_string(hcb->cmd, cdb_str, sizeof(cdb_str)));
}
#endif
len = csio->dxfer_len;
buf = csio->data_ptr;
/* some SCSI commands require special processing */
switch (hcb->cmd[0]) {
case INQUIRY: {
/*
* many ATAPI devices seem to report more than
* SHORT_INQUIRY_LENGTH bytes of available INQUIRY
* information, but respond with some incorrect condition
* when actually asked for it, so we are going to pretend
* that only SHORT_INQUIRY_LENGTH are expected, anyway.
*/
struct scsi_inquiry *inq = (struct scsi_inquiry *) &hcb->cmd[0];
if (inq->byte2 == 0 && inq->page_code == 0 &&
inq->length > SHORT_INQUIRY_LENGTH) {
bzero(buf, len);
len = inq->length = SHORT_INQUIRY_LENGTH;
}
break;
}
case READ_6:
/* FALLTHROUGH */
case WRITE_6:
CAM_DEBUG(ccb_h->path, CAM_DEBUG_SUBTRACE,
("Translating %s into _10 equivalent\n",
(hcb->cmd[0] == READ_6) ? "READ_6" : "WRITE_6"));
hcb->cmd[0] |= 0x20;
hcb->cmd[9] = hcb->cmd[5];
hcb->cmd[8] = hcb->cmd[4];
hcb->cmd[7] = 0;
hcb->cmd[6] = 0;
hcb->cmd[5] = hcb->cmd[3];
hcb->cmd[4] = hcb->cmd[2];
hcb->cmd[3] = hcb->cmd[1] & 0x1f;
hcb->cmd[2] = 0;
hcb->cmd[1] = 0;
break;
}
if ((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_IN && (len & 1)) {
/* ATA always transfers an even number of bytes */
if (!(buf = hcb->dxfer_alloc = malloc(++len, M_ATACAM,
M_NOWAIT | M_ZERO)))
goto action_oom;
}
s = splbio();
TAILQ_INSERT_TAIL(&softc->pending_hcbs, hcb, chain);
splx(s);
if (atapi_queue_cmd(dev, hcb->cmd, buf, len,
(((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_IN) ?
ATPR_F_READ : 0) | ATPR_F_QUIET,
ccb_h->timeout, atapi_cb, (void *)hcb) == 0)
return;
break;
}
default:
CAM_DEBUG(ccb_h->path, CAM_DEBUG_SUBTRACE,
("unsupported function code 0x%02x\n", ccb_h->func_code));
ccb_h->status = CAM_REQ_INVALID;
xpt_done(ccb);
return;
}
action_oom:
if (hcb != NULL)
free_hcb(hcb);
xpt_print_path(ccb_h->path);
printf("out of memory, freezing queue.\n");
softc->flags |= RESOURCE_SHORTAGE;
xpt_freeze_simq(sim, /*count*/ 1);
ccb_h->status = CAM_REQUEUE_REQ;
xpt_done(ccb);
}
static void
atapi_poll(struct cam_sim *sim)
{
/* do nothing - we do not actually service any interrupts */
printf("atapi_poll called!\n");
}
static int
atapi_cb(struct atapi_request *req)
{
struct atapi_hcb *hcb = (struct atapi_hcb *) req->driver;
struct ccb_scsiio *csio = &hcb->ccb->csio;
int hcb_status = req->result;
int s = splbio();
#ifdef CAMDEBUG
if (CAM_DEBUGGED(csio->ccb_h.path, CAM_DEBUG_CDB)) {
printf("atapi_cb: hcb@%p status = %02x: (sk = %02x%s%s%s)\n",
hcb, hcb_status, hcb_status >> 4,
(hcb_status & 4) ? " ABRT" : "",
(hcb_status & 2) ? " EOM" : "",
(hcb_status & 1) ? " ILI" : "");
printf(" %s: cmd %02x - sk=%02x asc=%02x ascq=%02x\n",
req->device->name, req->ccb[0], req->sense.sense_key,
req->sense.asc, req->sense.ascq);
}
#endif
if (hcb_status != 0) {
csio->scsi_status = SCSI_STATUS_CHECK_COND;
if ((csio->ccb_h.flags & CAM_DIS_AUTOSENSE) == 0) {
csio->ccb_h.status |= CAM_AUTOSNS_VALID;
bcopy((void *)&req->sense, (void *)&csio->sense_data,
sizeof(struct atapi_reqsense));
}
free_hcb_and_ccb_done(hcb, CAM_SCSI_STATUS_ERROR);
}
else {
if (((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) &&
hcb->dxfer_alloc != NULL)
bcopy(hcb->dxfer_alloc, csio->data_ptr, csio->dxfer_len);
csio->scsi_status = SCSI_STATUS_OK;
free_hcb_and_ccb_done(hcb, CAM_REQ_CMP);
}
splx(s);
return 0;
}
static void
free_hcb_and_ccb_done(struct atapi_hcb *hcb, u_int32_t status)
{
struct atapi_xpt_softc *softc = hcb->softc;
union ccb *ccb = hcb->ccb;
if (hcb != NULL) {
/* we're about to free a hcb, so the shortage has ended */
if (softc->flags & RESOURCE_SHORTAGE) {
softc->flags &= ~RESOURCE_SHORTAGE;
status |= CAM_RELEASE_SIMQ;
}
free_hcb(hcb);
}
ccb->ccb_h.status =
status | (ccb->ccb_h.status & ~(CAM_STATUS_MASK | CAM_SIM_QUEUED));
xpt_done(ccb);
}
static void
atapi_async(void *callback_arg, u_int32_t code,
struct cam_path *path, void *arg)
{
int s = splbio();
atapi_async1(callback_arg, code, path, arg);
splx(s);
}
static void
atapi_async1(void *callback_arg, u_int32_t code,
struct cam_path* path, void *arg)
{
struct atapi_xpt_softc *softc;
struct cam_sim *sim;
int targ;
sim = (struct cam_sim *) callback_arg;
softc = (struct atapi_xpt_softc *) cam_sim_softc(sim);
switch (code) {
case AC_LOST_DEVICE:
targ = xpt_path_target_id(path);
xpt_print_path(path);
if (targ == -1)
printf("Lost host adapter\n");
else
printf("Lost target %d???\n", targ);
break;
default:
break;
}
}
static void
cam_rescan_callback(struct cam_periph *periph, union ccb *ccb)
{
if (ccb->ccb_h.status != CAM_REQ_CMP) {
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE,
("Rescan failed, 0x%04x\n", ccb->ccb_h.status));
} else {
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE,
("Rescan succeeded\n"));
}
xpt_free_path(ccb->ccb_h.path);
free(ccb, M_ATACAM);
}
static void
cam_rescan(struct cam_sim *sim)
{
struct cam_path *path;
union ccb *ccb = malloc(sizeof(union ccb), M_ATACAM, M_WAITOK | M_ZERO);
if (xpt_create_path(&path, xpt_periph, cam_sim_path(sim),
CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD) != CAM_REQ_CMP)
return;
2002-08-12 20:08:00 +00:00
CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE, ("Rescanning ATAPI bus.\n"));
xpt_setup_ccb(&ccb->ccb_h, path, 5/*priority (low)*/);
ccb->ccb_h.func_code = XPT_SCAN_BUS;
ccb->ccb_h.cbfcnp = cam_rescan_callback;
ccb->crcn.flags = CAM_FLAG_NONE;
xpt_action(ccb);
/* scan is in progress now */
}
static struct atapi_hcb *
allocate_hcb(struct atapi_xpt_softc *softc, int unit, int bus, union ccb *ccb)
{
struct atapi_hcb *hcb = (struct atapi_hcb *)
malloc(sizeof(struct atapi_hcb), M_ATACAM, M_NOWAIT | M_ZERO);
if (hcb != NULL) {
hcb->softc = softc;
hcb->unit = unit;
hcb->bus = bus;
hcb->ccb = ccb;
}
return hcb;
}
static void
free_hcb(struct atapi_hcb *hcb)
{
TAILQ_REMOVE(&hcb->softc->pending_hcbs, hcb, chain);
if (hcb->dxfer_alloc != NULL)
free(hcb->dxfer_alloc, M_ATACAM);
free(hcb, M_ATACAM);
}
static void
free_softc(struct atapi_xpt_softc *scp)
{
struct atapi_hcb *hcb;
if (scp != NULL) {
TAILQ_FOREACH(hcb, &scp->pending_hcbs, chain) {
free_hcb_and_ccb_done(hcb, CAM_UNREC_HBA_ERROR);
}
if (scp->path != NULL) {
setup_async_cb(scp, 0);
xpt_free_path(scp->path);
}
if ((scp->flags & BUS_REGISTERED) != 0) {
if (xpt_bus_deregister(cam_sim_path(scp->sim)) == CAM_REQ_CMP)
scp->flags &= ~BUS_REGISTERED;
}
if (scp->sim != NULL) {
if ((scp->flags & BUS_REGISTERED) == 0)
cam_sim_free(scp->sim, /*free_devq*/TRUE);
else
printf("Can't free %s SIM (still registered)\n",
cam_sim_name(scp->sim));
}
LIST_REMOVE(scp, chain);
free(scp, M_ATACAM);
}
}
static struct atapi_xpt_softc *
get_softc(struct ata_channel *ata_ch) {
struct atapi_xpt_softc *scp;
LIST_FOREACH(scp, &all_buses, chain) {
if (scp->ata_ch == ata_ch)
return scp;
}
return NULL;
}
static struct ata_device *
get_ata_device(struct atapi_xpt_softc *scp, int id)
{
int role = ATA_ATAPI_MASTER;
switch (id) {
case 1:
role = ATA_ATAPI_SLAVE;
/* FALLTHROUGH */
case 0:
if (scp->ata_ch->devices & role)
return &scp->ata_ch->device[id];
/* FALLTHROUGH */
default:
return NULL;
}
}