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iflib: Support to padding Ethernet frames to a min size

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Some bnxt devices do not correctly send frames smaller than
52 bytes (without CRC), so add a quirk that will pad frames to an
arbitrary size before passing off to the encap routine.

Reported by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D13269
This commit is contained in:
Stephen Hurd 2017-12-05 21:00:31 +00:00
parent fe1bcada9b
commit d14c853ba3
4 changed files with 52 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/dev/bnxt/bnxt.h
View File

@ -236,6 +236,8 @@ __FBSDID("$FreeBSD$");
ifmedia_add(softc->media, IFM_ETHER | (ifm_speed), 0, NULL); \
} while(0)
#define BNXT_MIN_FRAME_SIZE 52 /* Frames must be padded to this size for some A0 chips */
/* NVRAM access */
enum bnxt_nvm_directory_type {
BNX_DIR_TYPE_UNUSED = 0,

3
sys/dev/bnxt/if_bnxt.c
View File

@ -298,7 +298,7 @@ static struct if_shared_ctx bnxt_sctx_init = {
.isc_magic = IFLIB_MAGIC,
.isc_driver = &bnxt_iflib_driver,
.isc_nfl = 2, // Number of Free Lists
.isc_flags = IFLIB_HAS_RXCQ | IFLIB_HAS_TXCQ,
.isc_flags = IFLIB_HAS_RXCQ | IFLIB_HAS_TXCQ | IFLIB_NEED_ETHER_PAD,
.isc_q_align = PAGE_SIZE,
.isc_tx_maxsize = BNXT_TSO_SIZE,
.isc_tx_maxsegsize = BNXT_TSO_SIZE,
@ -793,6 +793,7 @@ bnxt_attach_pre(if_ctx_t ctx)
scctx->isc_tx_tso_size_max = BNXT_TSO_SIZE;
scctx->isc_tx_tso_segsize_max = BNXT_TSO_SIZE;
scctx->isc_vectors = softc->func.max_cp_rings;
scctx->isc_min_frame_size = BNXT_MIN_FRAME_SIZE;
scctx->isc_txrx = &bnxt_txrx;
if (scctx->isc_nrxd[0] <

45
sys/net/iflib.c
View File

@ -627,11 +627,14 @@ SYSCTL_INT(_net_iflib, OID_AUTO, txq_drain_encapfail, CTLFLAG_RD,
static int iflib_encap_load_mbuf_fail;
static int iflib_encap_pad_mbuf_fail;
static int iflib_encap_txq_avail_fail;
static int iflib_encap_txd_encap_fail;
SYSCTL_INT(_net_iflib, OID_AUTO, encap_load_mbuf_fail, CTLFLAG_RD,
&iflib_encap_load_mbuf_fail, 0, "# busdma load failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_pad_mbuf_fail, CTLFLAG_RD,
&iflib_encap_pad_mbuf_fail, 0, "# runt frame pad failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_txq_avail_fail, CTLFLAG_RD,
&iflib_encap_txq_avail_fail, 0, "# txq avail failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_txd_encap_fail, CTLFLAG_RD,
@ -684,9 +687,10 @@ iflib_debug_reset(void)
iflib_fl_refills = iflib_fl_refills_large = iflib_tx_frees =
iflib_txq_drain_flushing = iflib_txq_drain_oactive =
iflib_txq_drain_notready = iflib_txq_drain_encapfail =
iflib_encap_load_mbuf_fail = iflib_encap_txq_avail_fail =
iflib_encap_txd_encap_fail = iflib_task_fn_rxs = iflib_rx_intr_enables =
iflib_fast_intrs = iflib_intr_link = iflib_intr_msix = iflib_rx_unavail =
iflib_encap_load_mbuf_fail = iflib_encap_pad_mbuf_fail =
iflib_encap_txq_avail_fail = iflib_encap_txd_encap_fail =
iflib_task_fn_rxs = iflib_rx_intr_enables = iflib_fast_intrs =
iflib_intr_link = iflib_intr_msix = iflib_rx_unavail =
iflib_rx_ctx_inactive = iflib_rx_zero_len = iflib_rx_if_input =
iflib_rx_mbuf_null = iflib_rxd_flush = 0;
}
@ -3103,6 +3107,35 @@ calc_next_txd(iflib_txq_t txq, int cidx, uint8_t qid)
return (next < end ? next : start);
}
/*
* Pad an mbuf to ensure a minimum ethernet frame size.
* min_frame_size is the frame size (less CRC) to pad the mbuf to
*/
static __noinline int
iflib_ether_pad(device_t dev, struct mbuf *m_head, uint16_t min_frame_size)
{
/*
* 18 is enough bytes to pad an ARP packet to 46 bytes, and
* and ARP message is the smallest common payload I can think of
*/
static char pad[18]; /* just zeros */
int n;
for (n = min_frame_size - m_head->m_pkthdr.len;
n > 0; n -= sizeof(pad))
if (!m_append(m_head, min(n, sizeof(pad)), pad))
break;
if (n > 0) {
m_freem(m_head);
device_printf(dev, "cannot pad short frame\n");
DBG_COUNTER_INC(encap_pad_mbuf_fail);
return (ENOBUFS);
}
return 0;
}
static int
iflib_encap(iflib_txq_t txq, struct mbuf **m_headp)
{
@ -3157,6 +3190,12 @@ iflib_encap(iflib_txq_t txq, struct mbuf **m_headp)
max_segs = scctx->isc_tx_nsegments;
}
m_head = *m_headp;
if ((sctx->isc_flags & IFLIB_NEED_ETHER_PAD) &&
__predict_false(m_head->m_pkthdr.len < scctx->isc_min_frame_size)) {
err = iflib_ether_pad(ctx->ifc_dev, m_head, scctx->isc_min_frame_size);
if (err)
return err;
}
pkt_info_zero(&pi);
pi.ipi_mflags = (m_head->m_flags & (M_VLANTAG|M_BCAST|M_MCAST));

6
sys/net/iflib.h
View File

@ -217,6 +217,8 @@ typedef struct if_softc_ctx {
iflib_intr_mode_t isc_intr;
uint16_t isc_max_frame_size; /* set at init time by driver */
uint16_t isc_min_frame_size; /* set at init time by driver, only used if
IFLIB_NEED_ETHER_PAD is set. */
uint32_t isc_pause_frames; /* set by driver for iflib_timer to detect */
pci_vendor_info_t isc_vendor_info; /* set by iflib prior to attach_pre */
int isc_disable_msix;
@ -314,6 +316,10 @@ typedef enum {
* Driver needs csum zeroed for offloading
*/
#define IFLIB_NEED_ZERO_CSUM 0x80
/*
* Driver needs frames padded to some minimum length
*/
#define IFLIB_NEED_ETHER_PAD 0x100