The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_bus_dma.c

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    1 /*-
    2  * Copyright (c) 2012 EMC Corp.
    3  * All rights reserved.
    4  *
    5  * Copyright (c) 1997, 1998 Justin T. Gibbs.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD$");
   32 
   33 #include "opt_bus.h"
   34 
   35 #include <sys/param.h>
   36 #include <sys/conf.h>
   37 #include <sys/systm.h>
   38 #include <sys/bio.h>
   39 #include <sys/bus.h>
   40 #include <sys/callout.h>
   41 #include <sys/mbuf.h>
   42 #include <sys/memdesc.h>
   43 #include <sys/proc.h>
   44 #include <sys/uio.h>
   45 
   46 #include <vm/vm.h>
   47 #include <vm/vm_page.h>
   48 #include <vm/vm_map.h>
   49 #include <vm/pmap.h>
   50 
   51 #include <cam/cam.h>
   52 #include <cam/cam_ccb.h>
   53 
   54 #include <machine/bus.h>
   55 
   56 /*
   57  * Load up data starting at offset within a region specified by a
   58  * list of virtual address ranges until either length or the region
   59  * are exhausted.
   60  */
   61 static int
   62 _bus_dmamap_load_vlist(bus_dma_tag_t dmat, bus_dmamap_t map,
   63     bus_dma_segment_t *list, int sglist_cnt, struct pmap *pmap, int *nsegs,
   64     int flags, size_t offset, size_t length)
   65 {
   66         int error;
   67 
   68         error = 0;
   69         for (; sglist_cnt > 0 && length != 0; sglist_cnt--, list++) {
   70                 char *addr;
   71                 size_t ds_len;
   72 
   73                 KASSERT((offset < list->ds_len),
   74                     ("Invalid mid-segment offset"));
   75                 addr = (char *)(uintptr_t)list->ds_addr + offset;
   76                 ds_len = list->ds_len - offset;
   77                 offset = 0;
   78                 if (ds_len > length)
   79                         ds_len = length;
   80                 length -= ds_len;
   81                 KASSERT((ds_len != 0), ("Segment length is zero"));
   82                 error = _bus_dmamap_load_buffer(dmat, map, addr, ds_len, pmap,
   83                     flags, NULL, nsegs);
   84                 if (error)
   85                         break;
   86         }
   87         return (error);
   88 }
   89 
   90 /*
   91  * Load a list of physical addresses.
   92  */
   93 static int
   94 _bus_dmamap_load_plist(bus_dma_tag_t dmat, bus_dmamap_t map,
   95     bus_dma_segment_t *list, int sglist_cnt, int *nsegs, int flags)
   96 {
   97         int error;
   98 
   99         error = 0;
  100         for (; sglist_cnt > 0; sglist_cnt--, list++) {
  101                 error = _bus_dmamap_load_phys(dmat, map,
  102                     (vm_paddr_t)list->ds_addr, list->ds_len, flags, NULL,
  103                     nsegs);
  104                 if (error)
  105                         break;
  106         }
  107         return (error);
  108 }
  109 
  110 /*
  111  * Load an mbuf chain.
  112  */
  113 static int
  114 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
  115     struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, int flags)
  116 {
  117         struct mbuf *m;
  118         int error;
  119 
  120         error = 0;
  121         for (m = m0; m != NULL && error == 0; m = m->m_next) {
  122                 if (m->m_len > 0) {
  123                         error = _bus_dmamap_load_buffer(dmat, map, m->m_data,
  124                             m->m_len, kernel_pmap, flags | BUS_DMA_LOAD_MBUF,
  125                             segs, nsegs);
  126                 }
  127         }
  128         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  129             __func__, dmat, flags, error, *nsegs);
  130         return (error);
  131 }
  132 
  133 /*
  134  * Load tlen data starting at offset within a region specified by a list of
  135  * physical pages.
  136  */
  137 static int
  138 _bus_dmamap_load_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
  139     vm_page_t *pages, bus_size_t tlen, int offset, int *nsegs, int flags)
  140 {
  141         vm_paddr_t paddr;
  142         bus_size_t len;
  143         int error, i;
  144  
  145         for (i = 0, error = 0; error == 0 && tlen > 0; i++, tlen -= len) {
  146                 len = min(PAGE_SIZE - offset, tlen);
  147                 paddr = VM_PAGE_TO_PHYS(pages[i]) + offset;
  148                 error = _bus_dmamap_load_phys(dmat, map, paddr, len,
  149                     flags, NULL, nsegs);
  150                 offset = 0;
  151         }
  152         return (error);
  153 }
  154  
  155 /*
  156  * Load from block io.
  157  */
  158 static int
  159 _bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
  160     int *nsegs, int flags)
  161 {
  162 
  163         if ((bio->bio_flags & BIO_VLIST) != 0) {
  164                 bus_dma_segment_t *segs = (bus_dma_segment_t *)bio->bio_data;
  165                 return (_bus_dmamap_load_vlist(dmat, map, segs, bio->bio_ma_n,
  166                     kernel_pmap, nsegs, flags, bio->bio_ma_offset,
  167                     bio->bio_bcount));
  168         }
  169 
  170         if ((bio->bio_flags & BIO_UNMAPPED) != 0)
  171                 return (_bus_dmamap_load_pages(dmat, map, bio->bio_ma,
  172                     bio->bio_bcount, bio->bio_ma_offset, nsegs, flags));
  173 
  174         return (_bus_dmamap_load_buffer(dmat, map, bio->bio_data,
  175             bio->bio_bcount, kernel_pmap, flags, NULL, nsegs));
  176 }
  177 
  178 int
  179 bus_dmamap_load_ma_triv(bus_dma_tag_t dmat, bus_dmamap_t map,
  180     struct vm_page **ma, bus_size_t tlen, int ma_offs, int flags,
  181     bus_dma_segment_t *segs, int *segp)
  182 {
  183         vm_paddr_t paddr;
  184         bus_size_t len;
  185         int error, i;
  186 
  187         error = 0;
  188         for (i = 0; tlen > 0; i++, tlen -= len) {
  189                 len = min(PAGE_SIZE - ma_offs, tlen);
  190                 paddr = VM_PAGE_TO_PHYS(ma[i]) + ma_offs;
  191                 error = _bus_dmamap_load_phys(dmat, map, paddr, len,
  192                     flags, segs, segp);
  193                 if (error != 0)
  194                         break;
  195                 ma_offs = 0;
  196         }
  197         return (error);
  198 }
  199 
  200 /*
  201  * Load a cam control block.
  202  */
  203 static int
  204 _bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
  205                     int *nsegs, int flags)
  206 {
  207         struct ccb_hdr *ccb_h;
  208         void *data_ptr;
  209         int error;
  210         uint32_t dxfer_len;
  211         uint16_t sglist_cnt;
  212 
  213         error = 0;
  214         ccb_h = &ccb->ccb_h;
  215         switch (ccb_h->func_code) {
  216         case XPT_SCSI_IO: {
  217                 struct ccb_scsiio *csio;
  218 
  219                 csio = &ccb->csio;
  220                 data_ptr = csio->data_ptr;
  221                 dxfer_len = csio->dxfer_len;
  222                 sglist_cnt = csio->sglist_cnt;
  223                 break;
  224         }
  225         case XPT_CONT_TARGET_IO: {
  226                 struct ccb_scsiio *ctio;
  227 
  228                 ctio = &ccb->ctio;
  229                 data_ptr = ctio->data_ptr;
  230                 dxfer_len = ctio->dxfer_len;
  231                 sglist_cnt = ctio->sglist_cnt;
  232                 break;
  233         }
  234         case XPT_ATA_IO: {
  235                 struct ccb_ataio *ataio;
  236 
  237                 ataio = &ccb->ataio;
  238                 data_ptr = ataio->data_ptr;
  239                 dxfer_len = ataio->dxfer_len;
  240                 sglist_cnt = 0;
  241                 break;
  242         }
  243         default:
  244                 panic("_bus_dmamap_load_ccb: Unsupported func code %d",
  245                     ccb_h->func_code);
  246         }
  247 
  248         switch ((ccb_h->flags & CAM_DATA_MASK)) {
  249         case CAM_DATA_VADDR:
  250                 error = _bus_dmamap_load_buffer(dmat, map, data_ptr, dxfer_len,
  251                     kernel_pmap, flags, NULL, nsegs);
  252                 break;
  253         case CAM_DATA_PADDR:
  254                 error = _bus_dmamap_load_phys(dmat, map,
  255                     (vm_paddr_t)(uintptr_t)data_ptr, dxfer_len, flags, NULL,
  256                     nsegs);
  257                 break;
  258         case CAM_DATA_SG:
  259                 error = _bus_dmamap_load_vlist(dmat, map,
  260                     (bus_dma_segment_t *)data_ptr, sglist_cnt, kernel_pmap,
  261                     nsegs, flags, 0, dxfer_len);
  262                 break;
  263         case CAM_DATA_SG_PADDR:
  264                 error = _bus_dmamap_load_plist(dmat, map,
  265                     (bus_dma_segment_t *)data_ptr, sglist_cnt, nsegs, flags);
  266                 break;
  267         case CAM_DATA_BIO:
  268                 error = _bus_dmamap_load_bio(dmat, map, (struct bio *)data_ptr,
  269                     nsegs, flags);
  270                 break;
  271         default:
  272                 panic("_bus_dmamap_load_ccb: flags 0x%X unimplemented",
  273                     ccb_h->flags);
  274         }
  275         return (error);
  276 }
  277 
  278 /*
  279  * Load a uio.
  280  */
  281 static int
  282 _bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
  283     int *nsegs, int flags)
  284 {
  285         bus_size_t resid;
  286         bus_size_t minlen;
  287         struct iovec *iov;
  288         pmap_t pmap;
  289         caddr_t addr;
  290         int error, i;
  291 
  292         if (uio->uio_segflg == UIO_USERSPACE) {
  293                 KASSERT(uio->uio_td != NULL,
  294                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
  295                 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
  296         } else
  297                 pmap = kernel_pmap;
  298         resid = uio->uio_resid;
  299         iov = uio->uio_iov;
  300         error = 0;
  301 
  302         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
  303                 /*
  304                  * Now at the first iovec to load.  Load each iovec
  305                  * until we have exhausted the residual count.
  306                  */
  307 
  308                 addr = (caddr_t) iov[i].iov_base;
  309                 minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
  310                 if (minlen > 0) {
  311                         error = _bus_dmamap_load_buffer(dmat, map, addr,
  312                             minlen, pmap, flags, NULL, nsegs);
  313                         resid -= minlen;
  314                 }
  315         }
  316 
  317         return (error);
  318 }
  319 
  320 /*
  321  * Map the buffer buf into bus space using the dmamap map.
  322  */
  323 int
  324 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
  325     bus_size_t buflen, bus_dmamap_callback_t *callback,
  326     void *callback_arg, int flags)
  327 {
  328         bus_dma_segment_t *segs;
  329         struct memdesc mem;
  330         int error;
  331         int nsegs;
  332 
  333         if ((flags & BUS_DMA_NOWAIT) == 0) {
  334                 mem = memdesc_vaddr(buf, buflen);
  335                 _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  336         }
  337 
  338         nsegs = -1;
  339         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, kernel_pmap,
  340             flags, NULL, &nsegs);
  341         nsegs++;
  342 
  343         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  344             __func__, dmat, flags, error, nsegs);
  345 
  346         if (error == EINPROGRESS)
  347                 return (error);
  348 
  349         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  350         if (error)
  351                 (*callback)(callback_arg, segs, 0, error);
  352         else
  353                 (*callback)(callback_arg, segs, nsegs, 0);
  354 
  355         /*
  356          * Return ENOMEM to the caller so that it can pass it up the stack.
  357          * This error only happens when NOWAIT is set, so deferral is disabled.
  358          */
  359         if (error == ENOMEM)
  360                 return (error);
  361 
  362         return (0);
  363 }
  364 
  365 int
  366 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
  367     bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
  368 {
  369         bus_dma_segment_t *segs;
  370         int nsegs, error;
  371 
  372         M_ASSERTPKTHDR(m0);
  373 
  374         flags |= BUS_DMA_NOWAIT;
  375         nsegs = -1;
  376         error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, NULL, &nsegs, flags);
  377         ++nsegs;
  378 
  379         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  380         if (error)
  381                 (*callback)(callback_arg, segs, 0, 0, error);
  382         else
  383                 (*callback)(callback_arg, segs, nsegs, m0->m_pkthdr.len, error);
  384 
  385         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  386             __func__, dmat, flags, error, nsegs);
  387         return (error);
  388 }
  389 
  390 int
  391 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
  392     bus_dma_segment_t *segs, int *nsegs, int flags)
  393 {
  394         int error;
  395 
  396         flags |= BUS_DMA_NOWAIT;
  397         *nsegs = -1;
  398         error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags);
  399         ++*nsegs;
  400         _bus_dmamap_complete(dmat, map, segs, *nsegs, error);
  401         return (error);
  402 }
  403 
  404 int
  405 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
  406     bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
  407 {
  408         bus_dma_segment_t *segs;
  409         int nsegs, error;
  410 
  411         flags |= BUS_DMA_NOWAIT;
  412         nsegs = -1;
  413         error = _bus_dmamap_load_uio(dmat, map, uio, &nsegs, flags);
  414         nsegs++;
  415 
  416         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  417         if (error)
  418                 (*callback)(callback_arg, segs, 0, 0, error);
  419         else
  420                 (*callback)(callback_arg, segs, nsegs, uio->uio_resid, error);
  421 
  422         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  423             __func__, dmat, flags, error, nsegs);
  424         return (error);
  425 }
  426 
  427 int
  428 bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
  429                     bus_dmamap_callback_t *callback, void *callback_arg,
  430                     int flags)
  431 {
  432         bus_dma_segment_t *segs;
  433         struct ccb_hdr *ccb_h;
  434         struct memdesc mem;
  435         int error;
  436         int nsegs;
  437 
  438         ccb_h = &ccb->ccb_h;
  439         if ((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_NONE) {
  440                 callback(callback_arg, NULL, 0, 0);
  441                 return (0);
  442         }
  443         if ((flags & BUS_DMA_NOWAIT) == 0) {
  444                 mem = memdesc_ccb(ccb);
  445                 _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  446         }
  447         nsegs = -1;
  448         error = _bus_dmamap_load_ccb(dmat, map, ccb, &nsegs, flags);
  449         nsegs++;
  450 
  451         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  452             __func__, dmat, flags, error, nsegs);
  453 
  454         if (error == EINPROGRESS)
  455                 return (error);
  456 
  457         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  458         if (error)
  459                 (*callback)(callback_arg, segs, 0, error);
  460         else
  461                 (*callback)(callback_arg, segs, nsegs, error);
  462         /*
  463          * Return ENOMEM to the caller so that it can pass it up the stack.
  464          * This error only happens when NOWAIT is set, so deferral is disabled.
  465          */
  466         if (error == ENOMEM)
  467                 return (error);
  468 
  469         return (0);
  470 }
  471 
  472 int
  473 bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
  474                     bus_dmamap_callback_t *callback, void *callback_arg,
  475                     int flags)
  476 {
  477         bus_dma_segment_t *segs;
  478         struct memdesc mem;
  479         int error;
  480         int nsegs;
  481 
  482         if ((flags & BUS_DMA_NOWAIT) == 0) {
  483                 mem = memdesc_bio(bio);
  484                 _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  485         }
  486         nsegs = -1;
  487         error = _bus_dmamap_load_bio(dmat, map, bio, &nsegs, flags);
  488         nsegs++;
  489 
  490         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  491             __func__, dmat, flags, error, nsegs);
  492 
  493         if (error == EINPROGRESS)
  494                 return (error);
  495 
  496         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  497         if (error)
  498                 (*callback)(callback_arg, segs, 0, error);
  499         else
  500                 (*callback)(callback_arg, segs, nsegs, error);
  501         /*
  502          * Return ENOMEM to the caller so that it can pass it up the stack.
  503          * This error only happens when NOWAIT is set, so deferral is disabled.
  504          */
  505         if (error == ENOMEM)
  506                 return (error);
  507 
  508         return (0);
  509 }
  510 
  511 int
  512 bus_dmamap_load_mem(bus_dma_tag_t dmat, bus_dmamap_t map,
  513     struct memdesc *mem, bus_dmamap_callback_t *callback,
  514     void *callback_arg, int flags)
  515 {
  516         bus_dma_segment_t *segs;
  517         int error;
  518         int nsegs;
  519 
  520         if ((flags & BUS_DMA_NOWAIT) == 0)
  521                 _bus_dmamap_waitok(dmat, map, mem, callback, callback_arg);
  522 
  523         nsegs = -1;
  524         error = 0;
  525         switch (mem->md_type) {
  526         case MEMDESC_VADDR:
  527                 error = _bus_dmamap_load_buffer(dmat, map, mem->u.md_vaddr,
  528                     mem->md_opaque, kernel_pmap, flags, NULL, &nsegs);
  529                 break;
  530         case MEMDESC_PADDR:
  531                 error = _bus_dmamap_load_phys(dmat, map, mem->u.md_paddr,
  532                     mem->md_opaque, flags, NULL, &nsegs);
  533                 break;
  534         case MEMDESC_VLIST:
  535                 error = _bus_dmamap_load_vlist(dmat, map, mem->u.md_list,
  536                     mem->md_opaque, kernel_pmap, &nsegs, flags, 0, SIZE_T_MAX);
  537                 break;
  538         case MEMDESC_PLIST:
  539                 error = _bus_dmamap_load_plist(dmat, map, mem->u.md_list,
  540                     mem->md_opaque, &nsegs, flags);
  541                 break;
  542         case MEMDESC_BIO:
  543                 error = _bus_dmamap_load_bio(dmat, map, mem->u.md_bio,
  544                     &nsegs, flags);
  545                 break;
  546         case MEMDESC_UIO:
  547                 error = _bus_dmamap_load_uio(dmat, map, mem->u.md_uio,
  548                     &nsegs, flags);
  549                 break;
  550         case MEMDESC_MBUF:
  551                 error = _bus_dmamap_load_mbuf_sg(dmat, map, mem->u.md_mbuf,
  552                     NULL, &nsegs, flags);
  553                 break;
  554         case MEMDESC_CCB:
  555                 error = _bus_dmamap_load_ccb(dmat, map, mem->u.md_ccb, &nsegs,
  556                     flags);
  557                 break;
  558         }
  559         nsegs++;
  560 
  561         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  562             __func__, dmat, flags, error, nsegs);
  563 
  564         if (error == EINPROGRESS)
  565                 return (error);
  566 
  567         segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  568         if (error)
  569                 (*callback)(callback_arg, segs, 0, error);
  570         else
  571                 (*callback)(callback_arg, segs, nsegs, 0);
  572 
  573         /*
  574          * Return ENOMEM to the caller so that it can pass it up the stack.
  575          * This error only happens when NOWAIT is set, so deferral is disabled.
  576          */
  577         if (error == ENOMEM)
  578                 return (error);
  579 
  580         return (0);
  581 }

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