1 /*        $NetBSD: pcscp.c,v 1.50 2023/05/17 18:20:30 tsutsui Exp $   */
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center; Izumi Tsutsui.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * pcscp.c: device dependent code for AMD Am53c974 (PCscsi-PCI)
35  * written by Izumi Tsutsui <tsutsui@NetBSD.org>
36  *
37  * Technical manual available at
38  * https://www.amd.com/system/files/TechDocs/19113.pdf
39  */
40 
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: pcscp.c,v 1.50 2023/05/17 18:20:30 tsutsui Exp $");
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/device.h>
47 #include <sys/buf.h>
48 
49 #include <sys/bus.h>
50 #include <sys/intr.h>
51 
52 #include <dev/scsipi/scsipi_all.h>
53 #include <dev/scsipi/scsi_all.h>
54 #include <dev/scsipi/scsiconf.h>
55 
56 #include <dev/pci/pcireg.h>
57 #include <dev/pci/pcivar.h>
58 #include <dev/pci/pcidevs.h>
59 
60 #include <dev/ic/ncr53c9xreg.h>
61 #include <dev/ic/ncr53c9xvar.h>
62 
63 #include <dev/pci/pcscpreg.h>
64 
65 #define IO_MAP_REG  0x10
66 
67 struct pcscp_softc {
68           struct ncr53c9x_softc sc_ncr53c9x;      /* glue to MI code */
69 
70           bus_space_tag_t sc_st;                  /* bus space tag */
71           bus_space_handle_t sc_sh;     /* bus space handle */
72           void *sc_ih;                            /* interrupt cookie */
73 
74           bus_dma_tag_t sc_dmat;                  /* DMA tag */
75 
76           bus_dmamap_t sc_xfermap;      /* DMA map for transfers */
77 
78           uint32_t *sc_mdladdr;                   /* MDL array */
79           bus_dmamap_t sc_mdldmap;      /* MDL DMA map */
80 
81           int       sc_active;                    /* DMA state */
82           int       sc_datain;                    /* DMA Data Direction */
83           size_t    sc_dmasize;                   /* DMA size */
84           uint8_t   **sc_dmaaddr;                 /* DMA address */
85           size_t    *sc_dmalen;                   /* DMA length */
86 };
87 
88 #define   READ_DMAREG(sc, reg) \
89           bus_space_read_4((sc)->sc_st, (sc)->sc_sh, (reg))
90 #define   WRITE_DMAREG(sc, reg, var) \
91           bus_space_write_4((sc)->sc_st, (sc)->sc_sh, (reg), (var))
92 
93 #define   PCSCP_READ_REG(sc, reg)       \
94           bus_space_read_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2)
95 #define   PCSCP_WRITE_REG(sc, reg, val) \
96           bus_space_write_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2, (val))
97 
98 
99 static int pcscp_match(device_t, cfdata_t, void *);
100 static void pcscp_attach(device_t, device_t, void *);
101 
102 CFATTACH_DECL_NEW(pcscp, sizeof(struct pcscp_softc),
103     pcscp_match, pcscp_attach, NULL, NULL);
104 
105 /*
106  * Functions and the switch for the MI code.
107  */
108 
109 static uint8_t      pcscp_read_reg(struct ncr53c9x_softc *, int);
110 static void         pcscp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
111 static int          pcscp_dma_isintr(struct ncr53c9x_softc *);
112 static void         pcscp_dma_reset(struct ncr53c9x_softc *);
113 static int          pcscp_dma_intr(struct ncr53c9x_softc *);
114 static int          pcscp_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *,
115                         int, size_t *);
116 static void         pcscp_dma_go(struct ncr53c9x_softc *);
117 static void         pcscp_dma_stop(struct ncr53c9x_softc *);
118 static int          pcscp_dma_isactive(struct ncr53c9x_softc *);
119 
120 static struct ncr53c9x_glue pcscp_glue = {
121           pcscp_read_reg,
122           pcscp_write_reg,
123           pcscp_dma_isintr,
124           pcscp_dma_reset,
125           pcscp_dma_intr,
126           pcscp_dma_setup,
127           pcscp_dma_go,
128           pcscp_dma_stop,
129           pcscp_dma_isactive,
130           NULL,                         /* gl_clear_latched_intr */
131 };
132 
133 static int
pcscp_match(device_t parent,cfdata_t cf,void * aux)134 pcscp_match(device_t parent, cfdata_t cf, void *aux)
135 {
136           struct pci_attach_args *pa = aux;
137 
138           if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_AMD)
139                     return 0;
140 
141           switch (PCI_PRODUCT(pa->pa_id)) {
142           case PCI_PRODUCT_AMD_PCSCSI_PCI:
143                     return 1;
144           }
145           return 0;
146 }
147 
148 /*
149  * Attach this instance, and then all the sub-devices
150  */
151 static void
pcscp_attach(device_t parent,device_t self,void * aux)152 pcscp_attach(device_t parent, device_t self, void *aux)
153 {
154           struct pcscp_softc *esc = device_private(self);
155           struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
156           struct pci_attach_args *pa = aux;
157           bus_space_tag_t iot;
158           bus_space_handle_t ioh;
159           pci_intr_handle_t ih;
160           const char *intrstr;
161           pcireg_t csr;
162           bus_dma_segment_t seg;
163           int error, rseg;
164           char intrbuf[PCI_INTRSTR_LEN];
165 
166           sc->sc_dev = self;
167           pci_aprint_devinfo(pa, NULL);
168           aprint_normal("%s", device_xname(sc->sc_dev));
169 
170           if (pci_mapreg_map(pa, IO_MAP_REG, PCI_MAPREG_TYPE_IO, 0,
171               &iot, &ioh, NULL, NULL)) {
172                     aprint_error(": unable to map registers\n");
173                     return;
174           }
175 
176           sc->sc_glue = &pcscp_glue;
177 
178           esc->sc_st = iot;
179           esc->sc_sh = ioh;
180           esc->sc_dmat = pa->pa_dmat;
181 
182           csr = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG);
183           pci_conf_write(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG,
184               csr | PCI_COMMAND_MASTER_ENABLE | PCI_COMMAND_IO_ENABLE);
185 
186           /*
187            * XXX More of this should be in ncr53c9x_attach(), but
188            * XXX should we really poke around the chip that much in
189            * XXX the MI code?  Think about this more...
190            */
191 
192           /*
193            * Set up static configuration info.
194            */
195 
196           /*
197            * XXX should read configuration from EEPROM?
198            *
199            * MI ncr53c9x driver does not support configuration
200            * per each target device, though...
201            */
202           sc->sc_id = 7;
203           sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
204           sc->sc_cfg2 = NCRCFG2_SCSI2 | NCRCFG2_FE;
205           sc->sc_cfg3 = NCRAMDCFG3_IDM | NCRAMDCFG3_FCLK;
206           sc->sc_cfg4 = NCRAMDCFG4_GE12NS | NCRAMDCFG4_RADE;
207           sc->sc_rev = NCR_VARIANT_AM53C974;
208           sc->sc_features = NCR_F_FASTSCSI;
209           sc->sc_cfg3_fscsi = NCRAMDCFG3_FSCSI;
210           sc->sc_freq = 40; /* MHz */
211 
212           /*
213            * XXX minsync and maxxfer _should_ be set up in MI code,
214            * XXX but it appears to have some dependency on what sort
215            * XXX of DMA we're hooked up to, etc.
216            */
217 
218           /*
219            * This is the value used to start sync negotiations
220            * Note that the NCR register "SYNCTP" is programmed
221            * in "clocks per byte", and has a minimum value of 4.
222            * The SCSI period used in negotiation is one-fourth
223            * of the time (in nanoseconds) needed to transfer one byte.
224            * Since the chip's clock is given in MHz, we have the following
225            * formula: 4 * period = (1000 / freq) * 4
226            */
227 
228           sc->sc_minsync = 1000 / sc->sc_freq;
229 
230           /* Really no limit, but since we want to fit into the TCR... */
231           sc->sc_maxxfer = 16 * 1024 * 1024;
232 
233           /*
234            * Create the DMA maps for the data transfers.
235            */
236 
237 #define MDL_SEG_SIZE          0x1000 /* 4kbyte per segment */
238 #define MDL_SEG_OFFSET        0x0FFF
239 #define MDL_SIZE    (MAXPHYS / MDL_SEG_SIZE + 1) /* no hardware limit? */
240 
241           if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MDL_SEG_SIZE,
242               MDL_SEG_SIZE, BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
243                     aprint_error(": can't create DMA maps\n");
244                     return;
245           }
246 
247           /*
248            * Allocate and map memory for the MDL.
249            */
250 
251           if ((error = bus_dmamem_alloc(esc->sc_dmat,
252               sizeof(uint32_t) * MDL_SIZE, PAGE_SIZE, 0, &seg, 1, &rseg,
253               BUS_DMA_NOWAIT)) != 0) {
254                     aprint_error(": unable to allocate memory for the MDL,"
255                         " error = %d\n", error);
256                     goto fail_0;
257           }
258           if ((error = bus_dmamem_map(esc->sc_dmat, &seg, rseg,
259               sizeof(uint32_t) * MDL_SIZE , (void **)&esc->sc_mdladdr,
260               BUS_DMA_NOWAIT|BUS_DMA_COHERENT)) != 0) {
261                     aprint_error(": unable to map the MDL memory, error = %d\n",
262                         error);
263                     goto fail_1;
264           }
265           if ((error = bus_dmamap_create(esc->sc_dmat,
266               sizeof(uint32_t) * MDL_SIZE, 1, sizeof(uint32_t) * MDL_SIZE,
267               0, BUS_DMA_NOWAIT, &esc->sc_mdldmap)) != 0) {
268                     aprint_error(": unable to map_create for the MDL, error = %d\n",
269                         error);
270                     goto fail_2;
271           }
272           if ((error = bus_dmamap_load(esc->sc_dmat, esc->sc_mdldmap,
273                esc->sc_mdladdr, sizeof(uint32_t) * MDL_SIZE,
274                NULL, BUS_DMA_NOWAIT)) != 0) {
275                     aprint_error(": unable to load for the MDL, error = %d\n",
276                         error);
277                     goto fail_3;
278           }
279 
280           /* map and establish interrupt */
281           if (pci_intr_map(pa, &ih)) {
282                     aprint_error(": couldn't map interrupt\n");
283                     goto fail_4;
284           }
285 
286           intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf, sizeof(intrbuf));
287           esc->sc_ih = pci_intr_establish_xname(pa->pa_pc, ih, IPL_BIO,
288               ncr53c9x_intr, esc, device_xname(self));
289           if (esc->sc_ih == NULL) {
290                     aprint_error(": couldn't establish interrupt");
291                     if (intrstr != NULL)
292                               aprint_error(" at %s", intrstr);
293                     aprint_error("\n");
294                     goto fail_4;
295           }
296           if (intrstr != NULL) {
297                     aprint_normal(": interrupting at %s\n", intrstr);
298                     aprint_normal("%s", device_xname(sc->sc_dev));
299           }
300 
301           /* Do the common parts of attachment. */
302           sc->sc_adapter.adapt_minphys = minphys;
303           sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
304           ncr53c9x_attach(sc);
305 
306           /* Turn on target selection using the `DMA' method */
307           sc->sc_features |= NCR_F_DMASELECT;
308 
309           return;
310 
311  fail_4:
312           bus_dmamap_unload(esc->sc_dmat, esc->sc_mdldmap);
313  fail_3:
314           bus_dmamap_destroy(esc->sc_dmat, esc->sc_mdldmap);
315  fail_2:
316           bus_dmamem_unmap(esc->sc_dmat, (void *)esc->sc_mdldmap,
317               sizeof(uint32_t) * MDL_SIZE);
318  fail_1:
319           bus_dmamem_free(esc->sc_dmat, &seg, rseg);
320  fail_0:
321           bus_dmamap_destroy(esc->sc_dmat, esc->sc_xfermap);
322 }
323 
324 /*
325  * Glue functions.
326  */
327 
328 static uint8_t
pcscp_read_reg(struct ncr53c9x_softc * sc,int reg)329 pcscp_read_reg(struct ncr53c9x_softc *sc, int reg)
330 {
331           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
332 
333           return PCSCP_READ_REG(esc, reg);
334 }
335 
336 static void
pcscp_write_reg(struct ncr53c9x_softc * sc,int reg,uint8_t v)337 pcscp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t v)
338 {
339           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
340 
341           PCSCP_WRITE_REG(esc, reg, v);
342 }
343 
344 static int
pcscp_dma_isintr(struct ncr53c9x_softc * sc)345 pcscp_dma_isintr(struct ncr53c9x_softc *sc)
346 {
347           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
348 
349           return (PCSCP_READ_REG(esc, NCR_STAT) & NCRSTAT_INT) != 0;
350 }
351 
352 static void
pcscp_dma_reset(struct ncr53c9x_softc * sc)353 pcscp_dma_reset(struct ncr53c9x_softc *sc)
354 {
355           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
356 
357           WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE);
358 
359           esc->sc_active = 0;
360 }
361 
362 static int
pcscp_dma_intr(struct ncr53c9x_softc * sc)363 pcscp_dma_intr(struct ncr53c9x_softc *sc)
364 {
365           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
366           int trans, resid, i;
367           bus_dmamap_t dmap = esc->sc_xfermap;
368           int datain = esc->sc_datain;
369           uint32_t dmastat;
370           uint8_t *p = NULL;
371 
372           dmastat = READ_DMAREG(esc, DMA_STAT);
373 
374           if (dmastat & DMASTAT_ERR) {
375                     /* XXX not tested... */
376                     WRITE_DMAREG(esc, DMA_CMD,
377                         DMACMD_ABORT | (datain ? DMACMD_DIR : 0));
378 
379                     printf("%s: error: DMA error detected; Aborting.\n",
380                         device_xname(sc->sc_dev));
381                     bus_dmamap_unload(esc->sc_dmat, dmap);
382                     return -1;
383           }
384 
385           if (dmastat & DMASTAT_ABT) {
386                     /* XXX What should be done? */
387                     printf("%s: %s: DMA aborted.\n",
388                         device_xname(sc->sc_dev), __func__);
389                     WRITE_DMAREG(esc, DMA_CMD,
390                         DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
391                     esc->sc_active = 0;
392                     return 0;
393           }
394 
395 #ifdef DIAGNOSTIC
396           /* This is an "assertion" :) */
397           if (esc->sc_active == 0)
398                     panic("%s: %s: DMA wasn't active",
399                         device_xname(sc->sc_dev), __func__);
400 #endif
401 
402           /* DMA has stopped */
403 
404           esc->sc_active = 0;
405 
406           if (esc->sc_dmasize == 0) {
407                     /* A "Transfer Pad" operation completed */
408                     NCR_DMA(("%s: discarded %d bytes (tcl=%d, tcm=%d)\n",
409                         __func__,
410                         PCSCP_READ_REG(esc, NCR_TCL) |
411                         (PCSCP_READ_REG(esc, NCR_TCM) << 8),
412                         PCSCP_READ_REG(esc, NCR_TCL),
413                         PCSCP_READ_REG(esc, NCR_TCM)));
414                     return 0;
415           }
416 
417           resid = 0;
418           /*
419            * If a transfer onto the SCSI bus gets interrupted by the device
420            * (e.g. for a SAVEPOINTER message), the data in the FIFO counts
421            * as residual since the ESP counter registers get decremented as
422            * bytes are clocked into the FIFO.
423            */
424           if (!datain &&
425               (resid = (PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
426                     NCR_DMA(("%s: empty esp FIFO of %d ", __func__, resid));
427           }
428 
429           if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
430                     /*
431                      * `Terminal count' is off, so read the residue
432                      * out of the ESP counter registers.
433                      */
434                     if (datain) {
435                               resid = PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
436                               while (resid > 1)
437                                         resid =
438                                             PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
439                               WRITE_DMAREG(esc, DMA_CMD, DMACMD_BLAST | DMACMD_MDL |
440                                   (datain ? DMACMD_DIR : 0));
441 
442                               for (i = 0; i < 1000; i++) { /* XXX */
443                                         if (READ_DMAREG(esc, DMA_STAT) & DMASTAT_BCMP)
444                                                   break;
445                                         DELAY(1);
446                               }
447 
448                               /* See the below comments... */
449                               if (resid)
450                                         p = *esc->sc_dmaaddr;
451                     }
452 
453                     resid += PCSCP_READ_REG(esc, NCR_TCL) |
454                         (PCSCP_READ_REG(esc, NCR_TCM) << 8) |
455                         (PCSCP_READ_REG(esc, NCR_TCH) << 16);
456           } else {
457                     while ((dmastat & DMASTAT_DONE) == 0)
458                               dmastat = READ_DMAREG(esc, DMA_STAT);
459           }
460 
461           WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
462 
463           /* sync MDL */
464           bus_dmamap_sync(esc->sc_dmat, esc->sc_mdldmap,
465               0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_POSTWRITE);
466           /* sync transfer buffer */
467           bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
468               datain ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
469           bus_dmamap_unload(esc->sc_dmat, dmap);
470 
471           trans = esc->sc_dmasize - resid;
472 
473           /*
474            * From the technical manual notes:
475            *
476            * `In some odd byte conditions, one residual byte will be left
477            *  in the SCSI FIFO, and the FIFO flags will never count to 0.
478            *  When this happens, the residual byte should be retrieved
479            *  via PIO following completion of the BLAST operation.'
480            */
481 
482           if (p) {
483                     p += trans;
484                     *p = PCSCP_READ_REG(esc, NCR_FIFO);
485                     trans++;
486           }
487 
488           if (trans < 0) {                        /* transferred < 0 ? */
489 #if 0
490                     /*
491                      * This situation can happen in perfectly normal operation
492                      * if the ESP is reselected while using DMA to select
493                      * another target.  As such, don't print the warning.
494                      */
495                     printf("%s: xfer (%d) > req (%d)\n",
496                         device_xname(sc->sc_dev), trans, esc->sc_dmasize);
497 #endif
498                     trans = esc->sc_dmasize;
499           }
500 
501           NCR_DMA(("%s: tcl=%d, tcm=%d, tch=%d; trans=%d, resid=%d\n",
502               __func__,
503               PCSCP_READ_REG(esc, NCR_TCL),
504               PCSCP_READ_REG(esc, NCR_TCM),
505               PCSCP_READ_REG(esc, NCR_TCH),
506               trans, resid));
507 
508           *esc->sc_dmalen -= trans;
509           *esc->sc_dmaaddr += trans;
510 
511           return 0;
512 }
513 
514 static int
pcscp_dma_setup(struct ncr53c9x_softc * sc,uint8_t ** addr,size_t * len,int datain,size_t * dmasize)515 pcscp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
516     int datain, size_t *dmasize)
517 {
518           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
519           bus_dmamap_t dmap = esc->sc_xfermap;
520           uint32_t *mdl;
521           int error, nseg, seg;
522           bus_addr_t s_offset, s_addr;
523 
524           WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
525 
526           esc->sc_dmaaddr = addr;
527           esc->sc_dmalen = len;
528           esc->sc_dmasize = *dmasize;
529           esc->sc_datain = datain;
530 
531 #ifdef DIAGNOSTIC
532           if ((*dmasize / MDL_SEG_SIZE) > MDL_SIZE)
533                     panic("%s: transfer size too large", device_xname(sc->sc_dev));
534 #endif
535 
536           /*
537            * No need to set up DMA in `Transfer Pad' operation.
538            * (case of *dmasize == 0)
539            */
540           if (*dmasize == 0)
541                     return 0;
542 
543           error = bus_dmamap_load(esc->sc_dmat, dmap, *esc->sc_dmaaddr,
544               *esc->sc_dmalen, NULL,
545               ((sc->sc_nexus->xs->xs_control & XS_CTL_NOSLEEP) ?
546               BUS_DMA_NOWAIT : BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
547               ((sc->sc_nexus->xs->xs_control & XS_CTL_DATA_IN) ?
548                BUS_DMA_READ : BUS_DMA_WRITE));
549           if (error) {
550                     printf("%s: unable to load dmamap, error = %d\n",
551                         device_xname(sc->sc_dev), error);
552                     return error;
553           }
554 
555           /* set transfer length */
556           WRITE_DMAREG(esc, DMA_STC, *dmasize);
557 
558           /* set up MDL */
559           mdl = esc->sc_mdladdr;
560           nseg = dmap->dm_nsegs;
561 
562           /* the first segment is possibly not aligned with 4k MDL boundary */
563           s_addr = dmap->dm_segs[0].ds_addr;
564           s_offset = s_addr & MDL_SEG_OFFSET;
565           s_addr -= s_offset;
566 
567           /* set the first MDL and offset */
568           WRITE_DMAREG(esc, DMA_SPA, s_offset);
569           *mdl++ = htole32(s_addr);
570 
571           /* the rest dmamap segments are aligned with 4k boundary */
572           for (seg = 1; seg < nseg; seg++)
573                     *mdl++ = htole32(dmap->dm_segs[seg].ds_addr);
574 
575           return 0;
576 }
577 
578 static void
pcscp_dma_go(struct ncr53c9x_softc * sc)579 pcscp_dma_go(struct ncr53c9x_softc *sc)
580 {
581           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
582           bus_dmamap_t dmap = esc->sc_xfermap, mdldmap = esc->sc_mdldmap;
583           int datain = esc->sc_datain;
584 
585           /* No DMA transfer in Transfer Pad operation */
586           if (esc->sc_dmasize == 0)
587                     return;
588 
589           /* sync transfer buffer */
590           bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
591               datain ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
592 
593           /* sync MDL */
594           bus_dmamap_sync(esc->sc_dmat, mdldmap,
595               0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_PREWRITE);
596 
597           /* set Starting MDL Address */
598           WRITE_DMAREG(esc, DMA_SMDLA, mdldmap->dm_segs[0].ds_addr);
599 
600           /* set DMA command register bits */
601           /* XXX DMA Transfer Interrupt Enable bit is broken? */
602           WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | DMACMD_MDL |
603               /* DMACMD_INTE | */
604               (datain ? DMACMD_DIR : 0));
605 
606           /* issue DMA start command */
607           WRITE_DMAREG(esc, DMA_CMD, DMACMD_START | DMACMD_MDL |
608               /* DMACMD_INTE | */
609               (datain ? DMACMD_DIR : 0));
610 
611           esc->sc_active = 1;
612 }
613 
614 static void
pcscp_dma_stop(struct ncr53c9x_softc * sc)615 pcscp_dma_stop(struct ncr53c9x_softc *sc)
616 {
617           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
618 
619           /* DMA stop */
620           /* XXX What should we do here ? */
621           WRITE_DMAREG(esc, DMA_CMD,
622               DMACMD_ABORT | (esc->sc_datain ? DMACMD_DIR : 0));
623           bus_dmamap_unload(esc->sc_dmat, esc->sc_xfermap);
624 
625           esc->sc_active = 0;
626 }
627 
628 static int
pcscp_dma_isactive(struct ncr53c9x_softc * sc)629 pcscp_dma_isactive(struct ncr53c9x_softc *sc)
630 {
631           struct pcscp_softc *esc = (struct pcscp_softc *)sc;
632 
633           /* XXX should check esc->sc_active? */
634           if ((READ_DMAREG(esc, DMA_CMD) & DMACMD_CMD) != DMACMD_IDLE)
635                     return 1;
636           return 0;
637 }
638