9dc7c250b8
Investigation of iSCSI target data corruption reports brought me to discovery that cxgb(4) expects mbufs to be physically contiguous, that is not true after I've started using m_extaddref() in software iSCSI for large zero-copy transmissions. In case of fragmented memory the driver transmitted garbage from pages following the first one due to simple use of pmap_kextract() for the first pointer instead of proper bus_dmamap_load_mbuf_sg(). Seems like it was done as some optimization many years ago, and at very least it is wrong in a world of IOMMUs. This patch just removes that optimization, plus limits packet coalescing for mbufs crossing page boundary, also depending on assumption of one segment per packet. MFC after: 3 days Sponsored by: iXsystems, Inc. Reviewed by: mmacy, np Differential revision: https://reviews.freebsd.org/D28428
107 lines
3.0 KiB
C
107 lines
3.0 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
*
|
|
* Copyright (c) 2007-2008 Kip Macy <kmacy@freebsd.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.
|
|
* 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("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/ktr.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/pmap.h>
|
|
|
|
#include <machine/bus.h>
|
|
|
|
#include <cxgb_include.h>
|
|
#include <sys/mvec.h>
|
|
|
|
#ifdef INVARIANTS
|
|
#define M_SANITY m_sanity
|
|
#else
|
|
#define M_SANITY(a, b)
|
|
#endif
|
|
|
|
int
|
|
busdma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
|
|
struct mbuf **m, bus_dma_segment_t *segs, int *nsegs)
|
|
{
|
|
struct mbuf *n = *m;
|
|
int seg_count, defragged = 0, err = 0;
|
|
bus_dma_segment_t *psegs;
|
|
|
|
KASSERT(n->m_pkthdr.len, ("packet has zero header len"));
|
|
if (n->m_pkthdr.len <= PIO_LEN)
|
|
return (0);
|
|
retry:
|
|
psegs = segs;
|
|
seg_count = 0;
|
|
err = bus_dmamap_load_mbuf_sg(tag, map, *m, segs, &seg_count, 0);
|
|
if (seg_count == 0) {
|
|
if (cxgb_debug)
|
|
printf("empty segment chain\n");
|
|
err = EFBIG;
|
|
goto err_out;
|
|
} else if (err == EFBIG || seg_count >= TX_MAX_SEGS) {
|
|
if (cxgb_debug)
|
|
printf("mbuf chain too long: %d max allowed %d\n",
|
|
seg_count, TX_MAX_SEGS);
|
|
if (!defragged) {
|
|
n = m_defrag(*m, M_NOWAIT);
|
|
if (n == NULL) {
|
|
err = ENOBUFS;
|
|
goto err_out;
|
|
}
|
|
*m = n;
|
|
defragged = 1;
|
|
goto retry;
|
|
}
|
|
err = EFBIG;
|
|
goto err_out;
|
|
}
|
|
|
|
*nsegs = seg_count;
|
|
err_out:
|
|
return (err);
|
|
}
|
|
|
|
void
|
|
busdma_map_sg_vec(bus_dma_tag_t tag, bus_dmamap_t map,
|
|
struct mbuf *m, bus_dma_segment_t *segs, int *nsegs)
|
|
{
|
|
int n = 0;
|
|
|
|
for (*nsegs = 0; m != NULL; segs += n, *nsegs += n, m = m->m_nextpkt)
|
|
bus_dmamap_load_mbuf_sg(tag, map, m, segs, &n, 0);
|
|
}
|
|
|