From: David S. Miller Date: Fri, 12 Oct 2007 01:08:29 +0000 (-0700) Subject: [NET]: Fix NAPI completion handling in some drivers. X-Git-Tag: v2.6.24-rc1~1454^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6f535763165331bb91277d7519b507fed22034e5;p=linux-2.6 [NET]: Fix NAPI completion handling in some drivers. In order for the list handling in net_rx_action() to be correct, drivers must follow certain rules as stated by this comment in net_rx_action(): /* Drivers must not modify the NAPI state if they * consume the entire weight. In such cases this code * still "owns" the NAPI instance and therefore can * move the instance around on the list at-will. */ A few drivers do not do this because they mix the budget checks with reading hardware state, resulting in crashes like the one reported by takano@axe-inc.co.jp. BNX2 and TG3 are taken care of here, SKY2 fix is from Stephen Hemminger. Signed-off-by: David S. Miller --- diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c index bbfbdafb4a..d68accea38 100644 --- a/drivers/net/bnx2.c +++ b/drivers/net/bnx2.c @@ -2633,15 +2633,11 @@ bnx2_has_work(struct bnx2 *bp) return 0; } -static int -bnx2_poll(struct napi_struct *napi, int budget) +static int bnx2_poll_work(struct bnx2 *bp, int work_done, int budget) { - struct bnx2 *bp = container_of(napi, struct bnx2, napi); - struct net_device *dev = bp->dev; struct status_block *sblk = bp->status_blk; u32 status_attn_bits = sblk->status_attn_bits; u32 status_attn_bits_ack = sblk->status_attn_bits_ack; - int work_done = 0; if ((status_attn_bits & STATUS_ATTN_EVENTS) != (status_attn_bits_ack & STATUS_ATTN_EVENTS)) { @@ -2660,27 +2656,43 @@ bnx2_poll(struct napi_struct *napi, int budget) bnx2_tx_int(bp); if (bp->status_blk->status_rx_quick_consumer_index0 != bp->hw_rx_cons) - work_done = bnx2_rx_int(bp, budget); + work_done += bnx2_rx_int(bp, budget - work_done); - bp->last_status_idx = bp->status_blk->status_idx; - rmb(); + return work_done; +} + +static int bnx2_poll(struct napi_struct *napi, int budget) +{ + struct bnx2 *bp = container_of(napi, struct bnx2, napi); + int work_done = 0; + + while (1) { + work_done = bnx2_poll_work(bp, work_done, budget); - if (!bnx2_has_work(bp)) { - netif_rx_complete(dev, napi); - if (likely(bp->flags & USING_MSI_FLAG)) { + if (unlikely(work_done >= budget)) + break; + + if (likely(!bnx2_has_work(bp))) { + bp->last_status_idx = bp->status_blk->status_idx; + rmb(); + + netif_rx_complete(bp->dev, napi); + if (likely(bp->flags & USING_MSI_FLAG)) { + REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD, + BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID | + bp->last_status_idx); + return 0; + } REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD, BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID | + BNX2_PCICFG_INT_ACK_CMD_MASK_INT | bp->last_status_idx); - return 0; - } - REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD, - BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID | - BNX2_PCICFG_INT_ACK_CMD_MASK_INT | - bp->last_status_idx); - REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD, - BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID | - bp->last_status_idx); + REG_WR(bp, BNX2_PCICFG_INT_ACK_CMD, + BNX2_PCICFG_INT_ACK_CMD_INDEX_VALID | + bp->last_status_idx); + break; + } } return work_done; diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index fe0e7560d2..4e569fa0f9 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -2606,7 +2606,7 @@ static int sky2_poll(struct napi_struct *napi, int work_limit) { struct sky2_hw *hw = container_of(napi, struct sky2_hw, napi); u32 status = sky2_read32(hw, B0_Y2_SP_EISR); - int work_done; + int work_done = 0; if (unlikely(status & Y2_IS_ERROR)) sky2_err_intr(hw, status); @@ -2617,10 +2617,16 @@ static int sky2_poll(struct napi_struct *napi, int work_limit) if (status & Y2_IS_IRQ_PHY2) sky2_phy_intr(hw, 1); - work_done = sky2_status_intr(hw, work_limit); + for(;;) { + work_done += sky2_status_intr(hw, work_limit); + + if (work_done >= work_limit) + break; + + /* More work? */ + if (hw->st_idx != sky2_read16(hw, STAT_PUT_IDX)) + continue; - /* More work? */ - if (hw->st_idx == sky2_read16(hw, STAT_PUT_IDX)) { /* Bug/Errata workaround? * Need to kick the TX irq moderation timer. */ @@ -2631,7 +2637,10 @@ static int sky2_poll(struct napi_struct *napi, int work_limit) napi_complete(napi); sky2_read32(hw, B0_Y2_SP_LISR); + break; + } + return work_done; } diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index d2b30fb0b3..a402b5c018 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -3555,12 +3555,9 @@ next_pkt_nopost: return received; } -static int tg3_poll(struct napi_struct *napi, int budget) +static int tg3_poll_work(struct tg3 *tp, int work_done, int budget) { - struct tg3 *tp = container_of(napi, struct tg3, napi); - struct net_device *netdev = tp->dev; struct tg3_hw_status *sblk = tp->hw_status; - int work_done = 0; /* handle link change and other phy events */ if (!(tp->tg3_flags & @@ -3578,11 +3575,8 @@ static int tg3_poll(struct napi_struct *napi, int budget) /* run TX completion thread */ if (sblk->idx[0].tx_consumer != tp->tx_cons) { tg3_tx(tp); - if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) { - netif_rx_complete(netdev, napi); - schedule_work(&tp->reset_task); + if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) return 0; - } } /* run RX thread, within the bounds set by NAPI. @@ -3590,21 +3584,46 @@ static int tg3_poll(struct napi_struct *napi, int budget) * code synchronizes with tg3->napi.poll() */ if (sblk->idx[0].rx_producer != tp->rx_rcb_ptr) - work_done = tg3_rx(tp, budget); + work_done += tg3_rx(tp, budget - work_done); - if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) { - tp->last_tag = sblk->status_tag; - rmb(); - } else - sblk->status &= ~SD_STATUS_UPDATED; + return work_done; +} - /* if no more work, tell net stack and NIC we're done */ - if (!tg3_has_work(tp)) { - netif_rx_complete(netdev, napi); - tg3_restart_ints(tp); +static int tg3_poll(struct napi_struct *napi, int budget) +{ + struct tg3 *tp = container_of(napi, struct tg3, napi); + int work_done = 0; + + while (1) { + work_done = tg3_poll_work(tp, work_done, budget); + + if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) + goto tx_recovery; + + if (unlikely(work_done >= budget)) + break; + + if (likely(!tg3_has_work(tp))) { + struct tg3_hw_status *sblk = tp->hw_status; + + if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) { + tp->last_tag = sblk->status_tag; + rmb(); + } else + sblk->status &= ~SD_STATUS_UPDATED; + + netif_rx_complete(tp->dev, napi); + tg3_restart_ints(tp); + break; + } } return work_done; + +tx_recovery: + netif_rx_complete(tp->dev, napi); + schedule_work(&tp->reset_task); + return 0; } static void tg3_irq_quiesce(struct tg3 *tp)