From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: [PATCH net-next 11/11] sfc: Avoid generating over-length MC_CMD_FLUSH_RX_QUEUES request Date: Wed, 19 Sep 2012 20:18:49 +0100 Message-ID: <1348082329.2636.26.camel@bwh-desktop.uk.solarflarecom.com> References: <1348081775.2636.15.camel@bwh-desktop.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , To: David Miller Return-path: Received: from webmail.solarflare.com ([12.187.104.25]:20258 "EHLO ocex02.SolarFlarecom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932495Ab2ISTSw (ORCPT ); Wed, 19 Sep 2012 15:18:52 -0400 In-Reply-To: <1348081775.2636.15.camel@bwh-desktop.uk.solarflarecom.com> Sender: netdev-owner@vger.kernel.org List-ID: MCDI supports requests up to 252 bytes long, which is only enough to pass 63 RX queue IDs to MC_CMD_FLUSH_RX_QUEUES. However a VF may have up to 64 RX queues, and if we try to flush them all we will generate an over-length request and BUG() in efx_mcdi_copyin(). Currently all VF drivers limit themselves to 32 RX queues, so reducing the limit to 63 does no harm. Also add a BUILD_BUG_ON in efx_mcdi_flush_rxqs() so we remember to deal with the same problem there if EFX_MAX_CHANNELS is increased. Signed-off-by: Ben Hutchings --- drivers/net/ethernet/sfc/mcdi.c | 3 +++ drivers/net/ethernet/sfc/siena_sriov.c | 7 +++++++ 2 files changed, 10 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c index e855f4c..aea43cb 100644 --- a/drivers/net/ethernet/sfc/mcdi.c +++ b/drivers/net/ethernet/sfc/mcdi.c @@ -1195,6 +1195,9 @@ int efx_mcdi_flush_rxqs(struct efx_nic *efx) __le32 *qid; int rc, count; + BUILD_BUG_ON(EFX_MAX_CHANNELS > + MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM); + qid = kmalloc(EFX_MAX_CHANNELS * sizeof(*qid), GFP_KERNEL); if (qid == NULL) return -ENOMEM; diff --git a/drivers/net/ethernet/sfc/siena_sriov.c b/drivers/net/ethernet/sfc/siena_sriov.c index 9cb3b84..a8f48a4 100644 --- a/drivers/net/ethernet/sfc/siena_sriov.c +++ b/drivers/net/ethernet/sfc/siena_sriov.c @@ -21,6 +21,9 @@ /* Number of longs required to track all the VIs in a VF */ #define VI_MASK_LENGTH BITS_TO_LONGS(1 << EFX_VI_SCALE_MAX) +/* Maximum number of RX queues supported */ +#define VF_MAX_RX_QUEUES 63 + /** * enum efx_vf_tx_filter_mode - TX MAC filtering behaviour * @VF_TX_FILTER_OFF: Disabled @@ -578,6 +581,7 @@ static int efx_vfdi_init_rxq(struct efx_vf *vf) efx_oword_t reg; if (bad_vf_index(efx, vf_evq) || bad_vf_index(efx, vf_rxq) || + vf_rxq >= VF_MAX_RX_QUEUES || bad_buf_count(buf_count, EFX_MAX_DMAQ_SIZE)) { if (net_ratelimit()) netif_err(efx, hw, efx->net_dev, @@ -683,6 +687,9 @@ static int efx_vfdi_fini_all_queues(struct efx_vf *vf) __le32 *rxqs; int rc; + BUILD_BUG_ON(VF_MAX_RX_QUEUES > + MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM); + rxqs = kmalloc(count * sizeof(*rxqs), GFP_KERNEL); if (rxqs == NULL) return VFDI_RC_ENOMEM; -- 1.7.7.6 -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.