subr_bus_dma.c

Go to the documentation of this file.

/*-
 * Copyright (c) 2012 EMC Corp.
 * All rights reserved.
 *
 * Copyright (c) 1997, 1998 Justin T. Gibbs.
 * 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.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 */

#include <sys/cdefs.h>
__FBSDID("$BSDSUniX$");

#include "opt_bus.h"

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/bus.h>
#include <sys/callout.h>
#include <sys/mbuf.h>
#include <sys/memdesc.h>
#include <sys/proc.h>
#include <sys/uio.h>

#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/pmap.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>

#include <machine/bus.h>

/*
 * Load a list of virtual addresses.
 */
static int
_bus_dmamap_load_vlist(bus_dma_tag_t dmat, bus_dmamap_t map,
    bus_dma_segment_t *list, int sglist_cnt, struct pmap *pmap, int *nsegs,
    int flags)
{
        int error;

        error = 0;
        for (; sglist_cnt > 0; sglist_cnt--, list++) {
                error = _bus_dmamap_load_buffer(dmat, map,
                    (void *)(uintptr_t)list->ds_addr, list->ds_len, pmap,
                    flags, NULL, nsegs);
                if (error)
                        break;
        }
        return (error);
}

/*
 * Load a list of physical addresses.
 */
static int
_bus_dmamap_load_plist(bus_dma_tag_t dmat, bus_dmamap_t map,
    bus_dma_segment_t *list, int sglist_cnt, int *nsegs, int flags)
{
        int error;

        error = 0;
        for (; sglist_cnt > 0; sglist_cnt--, list++) {
                error = _bus_dmamap_load_phys(dmat, map,
                    (vm_paddr_t)list->ds_addr, list->ds_len, flags, NULL,
                    nsegs);
                if (error)
                        break;
        }
        return (error);
}

/*
 * Load an mbuf chain.
 */
static int
_bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
    struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, int flags)
{
        struct mbuf *m;
        int error;

        error = 0;
        for (m = m0; m != NULL && error == 0; m = m->m_next) {
                if (m->m_len > 0) {
                        error = _bus_dmamap_load_buffer(dmat, map, m->m_data,
                            m->m_len, kernel_pmap, flags | BUS_DMA_LOAD_MBUF,
                            segs, nsegs);
                }
        }
        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, *nsegs);
        return (error);
}

/*
 * Load from block io.
 */
static int
_bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
    int *nsegs, int flags)
{
        vm_paddr_t paddr;
        bus_size_t len, tlen;
        int error, i, ma_offs;

        if ((bio->bio_flags & BIO_UNMAPPED) == 0) {
                error = _bus_dmamap_load_buffer(dmat, map, bio->bio_data,
                    bio->bio_bcount, kernel_pmap, flags, NULL, nsegs);
                return (error);
        }

        error = 0;
        tlen = bio->bio_bcount;
        ma_offs = bio->bio_ma_offset;
        for (i = 0; tlen > 0; i++, tlen -= len) {
                len = min(PAGE_SIZE - ma_offs, tlen);
                paddr = VM_PAGE_TO_PHYS(bio->bio_ma[i]) + ma_offs;
                error = _bus_dmamap_load_phys(dmat, map, paddr, len,
                    flags, NULL, nsegs);
                if (error != 0)
                        break;
                ma_offs = 0;
        }
        return (error);
}

/*
 * Load a cam control block.
 */
static int
_bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
                    int *nsegs, int flags)
{
        struct ccb_hdr *ccb_h;
        void *data_ptr;
        int error;
        uint32_t dxfer_len;
        uint16_t sglist_cnt;

        error = 0;
        ccb_h = &ccb->ccb_h;
        switch (ccb_h->func_code) {
        case XPT_SCSI_IO: {
                struct ccb_scsiio *csio;

                csio = &ccb->csio;
                data_ptr = csio->data_ptr;
                dxfer_len = csio->dxfer_len;
                sglist_cnt = csio->sglist_cnt;
                break;
        }
        case XPT_CONT_TARGET_IO: {
                struct ccb_scsiio *ctio;

                ctio = &ccb->ctio;
                data_ptr = ctio->data_ptr;
                dxfer_len = ctio->dxfer_len;
                sglist_cnt = ctio->sglist_cnt;
                break;
        }
        case XPT_ATA_IO: {
                struct ccb_ataio *ataio;

                ataio = &ccb->ataio;
                data_ptr = ataio->data_ptr;
                dxfer_len = ataio->dxfer_len;
                sglist_cnt = 0;
                break;
        }
        default:
                panic("_bus_dmamap_load_ccb: Unsupported func code %d",
                    ccb_h->func_code);
        }

        switch ((ccb_h->flags & CAM_DATA_MASK)) {
        case CAM_DATA_VADDR:
                error = _bus_dmamap_load_buffer(dmat, map, data_ptr, dxfer_len,
                    kernel_pmap, flags, NULL, nsegs);
                break;
        case CAM_DATA_PADDR:
                error = _bus_dmamap_load_phys(dmat, map,
                    (vm_paddr_t)(uintptr_t)data_ptr, dxfer_len, flags, NULL,
                    nsegs);
                break;
        case CAM_DATA_SG:
                error = _bus_dmamap_load_vlist(dmat, map,
                    (bus_dma_segment_t *)data_ptr, sglist_cnt, kernel_pmap,
                    nsegs, flags);
                break;
        case CAM_DATA_SG_PADDR:
                error = _bus_dmamap_load_plist(dmat, map,
                    (bus_dma_segment_t *)data_ptr, sglist_cnt, nsegs, flags);
                break;
        case CAM_DATA_BIO:
                error = _bus_dmamap_load_bio(dmat, map, (struct bio *)data_ptr,
                    nsegs, flags);
                break;
        default:
                panic("_bus_dmamap_load_ccb: flags 0x%X unimplemented",
                    ccb_h->flags);
        }
        return (error);
}

/*
 * Load a uio.
 */
static int
_bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
    int *nsegs, int flags)
{
        bus_size_t resid;
        bus_size_t minlen;
        struct iovec *iov;
        pmap_t pmap;
        caddr_t addr;
        int error, i;

        if (uio->uio_segflg == UIO_USERSPACE) {
                KASSERT(uio->uio_td != NULL,
                        ("bus_dmamap_load_uio: USERSPACE but no proc"));
                pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
        } else
                pmap = kernel_pmap;
        resid = uio->uio_resid;
        iov = uio->uio_iov;
        error = 0;

        for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
                /*
                 * Now at the first iovec to load.  Load each iovec
                 * until we have exhausted the residual count.
                 */

                addr = (caddr_t) iov[i].iov_base;
                minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
                if (minlen > 0) {
                        error = _bus_dmamap_load_buffer(dmat, map, addr,
                            minlen, pmap, flags, NULL, nsegs);
                        resid -= minlen;
                }
        }

        return (error);
}

/*
 * Map the buffer buf into bus space using the dmamap map.
 */
int
bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
    bus_size_t buflen, bus_dmamap_callback_t *callback,
    void *callback_arg, int flags)
{
        bus_dma_segment_t *segs;
        struct memdesc mem;
        int error;
        int nsegs;

        if ((flags & BUS_DMA_NOWAIT) == 0) {
                mem = memdesc_vaddr(buf, buflen);
                _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
        }

        nsegs = -1;
        error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, kernel_pmap,
            flags, NULL, &nsegs);
        nsegs++;

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);

        if (error == EINPROGRESS)
                return (error);

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, 0);

        /*
         * Return ENOMEM to the caller so that it can pass it up the stack.
         * This error only happens when NOWAIT is set, so deferral is disabled.
         */
        if (error == ENOMEM)
                return (error);

        return (0);
}

int
bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
    bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
{
        bus_dma_segment_t *segs;
        int nsegs, error;

        M_ASSERTPKTHDR(m0);

        flags |= BUS_DMA_NOWAIT;
        nsegs = -1;
        error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, NULL, &nsegs, flags);
        ++nsegs;

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, m0->m_pkthdr.len, error);

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);
        return (error);
}

int
bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
    bus_dma_segment_t *segs, int *nsegs, int flags)
{
        int error;

        flags |= BUS_DMA_NOWAIT;
        *nsegs = -1;
        error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags);
        ++*nsegs;
        _bus_dmamap_complete(dmat, map, segs, *nsegs, error);
        return (error);
}

int
bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
    bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
{
        bus_dma_segment_t *segs;
        int nsegs, error;

        flags |= BUS_DMA_NOWAIT;
        nsegs = -1;
        error = _bus_dmamap_load_uio(dmat, map, uio, &nsegs, flags);
        nsegs++;

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, uio->uio_resid, error);

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);
        return (error);
}

int
bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
                    bus_dmamap_callback_t *callback, void *callback_arg,
                    int flags)
{
        bus_dma_segment_t *segs;
        struct ccb_hdr *ccb_h;
        struct memdesc mem;
        int error;
        int nsegs;

        ccb_h = &ccb->ccb_h;
        if ((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_NONE) {
                callback(callback_arg, NULL, 0, 0);
                return (0);
        }
        if ((flags & BUS_DMA_NOWAIT) == 0) {
                mem = memdesc_ccb(ccb);
                _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
        }
        nsegs = -1;
        error = _bus_dmamap_load_ccb(dmat, map, ccb, &nsegs, flags);
        nsegs++;

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);

        if (error == EINPROGRESS)
                return (error);

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, error);
        /*
         * Return ENOMEM to the caller so that it can pass it up the stack.
         * This error only happens when NOWAIT is set, so deferral is disabled.
         */
        if (error == ENOMEM)
                return (error);

        return (0);
}

int
bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
                    bus_dmamap_callback_t *callback, void *callback_arg,
                    int flags)
{
        bus_dma_segment_t *segs;
        struct memdesc mem;
        int error;
        int nsegs;

        if ((flags & BUS_DMA_NOWAIT) == 0) {
                mem = memdesc_bio(bio);
                _bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
        }
        nsegs = -1;
        error = _bus_dmamap_load_bio(dmat, map, bio, &nsegs, flags);
        nsegs++;

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);

        if (error == EINPROGRESS)
                return (error);

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, error);
        /*
         * Return ENOMEM to the caller so that it can pass it up the stack.
         * This error only happens when NOWAIT is set, so deferral is disabled.
         */
        if (error == ENOMEM)
                return (error);

        return (0);
}

int
bus_dmamap_load_mem(bus_dma_tag_t dmat, bus_dmamap_t map,
    struct memdesc *mem, bus_dmamap_callback_t *callback,
    void *callback_arg, int flags)
{
        bus_dma_segment_t *segs;
        int error;
        int nsegs;

        if ((flags & BUS_DMA_NOWAIT) == 0)
                _bus_dmamap_waitok(dmat, map, mem, callback, callback_arg);

        nsegs = -1;
        error = 0;
        switch (mem->md_type) {
        case MEMDESC_VADDR:
                error = _bus_dmamap_load_buffer(dmat, map, mem->u.md_vaddr,
                    mem->md_opaque, kernel_pmap, flags, NULL, &nsegs);
                break;
        case MEMDESC_PADDR:
                error = _bus_dmamap_load_phys(dmat, map, mem->u.md_paddr,
                    mem->md_opaque, flags, NULL, &nsegs);
                break;
        case MEMDESC_VLIST:
                error = _bus_dmamap_load_vlist(dmat, map, mem->u.md_list,
                    mem->md_opaque, kernel_pmap, &nsegs, flags);
                break;
        case MEMDESC_PLIST:
                error = _bus_dmamap_load_plist(dmat, map, mem->u.md_list,
                    mem->md_opaque, &nsegs, flags);
                break;
        case MEMDESC_BIO:
                error = _bus_dmamap_load_bio(dmat, map, mem->u.md_bio,
                    &nsegs, flags);
                break;
        case MEMDESC_UIO:
                error = _bus_dmamap_load_uio(dmat, map, mem->u.md_uio,
                    &nsegs, flags);
                break;
        case MEMDESC_MBUF:
                error = _bus_dmamap_load_mbuf_sg(dmat, map, mem->u.md_mbuf,
                    NULL, &nsegs, flags);
                break;
        case MEMDESC_CCB:
                error = _bus_dmamap_load_ccb(dmat, map, mem->u.md_ccb, &nsegs,
                    flags);
                break;
        }
        nsegs++;

        CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
            __func__, dmat, flags, error, nsegs);

        if (error == EINPROGRESS)
                return (error);

        segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
        if (error)
                (*callback)(callback_arg, segs, 0, error);
        else
                (*callback)(callback_arg, segs, nsegs, 0);

        /*
         * Return ENOMEM to the caller so that it can pass it up the stack.
         * This error only happens when NOWAIT is set, so deferral is disabled.
         */
        if (error == ENOMEM)
                return (error);

        return (0);
}