From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sonny Rao Subject: [PATCHv2] Add missing memory barriers to clean_rx_irq functions in Intel Drivers Date: Tue, 27 Jul 2010 17:44:34 -0500 Message-ID: <20100727224434.GN17248@us.ibm.com> References: <20100727223452.GM17248@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: e1000-devel@lists.sf.net, Jeff Kirsher To: netdev@vger.kernel.org Return-path: Received: from e7.ny.us.ibm.com ([32.97.182.137]:60481 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751408Ab0G0WnQ (ORCPT ); Tue, 27 Jul 2010 18:43:16 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e7.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o6RMUJcY016126 for ; Tue, 27 Jul 2010 18:30:19 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o6RMhFOw133778 for ; Tue, 27 Jul 2010 18:43:15 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o6RMhEF7031200 for ; Tue, 27 Jul 2010 18:43:15 -0400 Content-Disposition: inline In-Reply-To: <20100727223452.GM17248@us.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: Add missing memory barriers to clean_rx_irq functions in Intel Drivers This patch is similar to what was fixed in ixgbe in this patch: http://marc.info/?l=e1000-devel&m=126593062701537&w=3 We should add read memory barriers to all the similar cases across the Intel ethernet driver family. In the case of ixgbevf I've also added a missing barrier to the clean_tx_irq path because I missed it in my last patch. Without the barrier a processor can speculate a load ahead of the load which looks at the status bit and get stale information causing a number of different issues including invalid packet length, NULL pointers, or bad data since checksumming was assumed to be done in hardware. v2: I missed the e100 the first time Signed-off-by: Milton Miller Signed-off-by: Sonny Rao cc: stable Index: linux-2.6.35-rc5/drivers/net/e1000/e1000_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/e1000/e1000_main.c 2010-07-27 16:15:18.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/e1000/e1000_main.c 2010-07-27 16:22:21.000000000 -0500 @@ -3638,6 +3638,7 @@ static bool e1000_clean_jumbo_rx_irq(str if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; @@ -3844,6 +3845,7 @@ static bool e1000_clean_rx_irq(struct e1 if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; Index: linux-2.6.35-rc5/drivers/net/e1000e/netdev.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/e1000e/netdev.c 2010-07-27 16:22:38.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/e1000e/netdev.c 2010-07-27 16:25:23.000000000 -0500 @@ -774,6 +774,7 @@ static bool e1000_clean_rx_irq(struct e1 if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; @@ -1081,6 +1082,7 @@ static bool e1000_clean_rx_irq_ps(struct break; (*work_done)++; skb = buffer_info->skb; + rmb(); /* read descriptor and rx_buffer_info after status DD */ /* in the packet split case this is header only */ prefetch(skb->data - NET_IP_ALIGN); @@ -1280,6 +1282,7 @@ static bool e1000_clean_jumbo_rx_irq(str if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; Index: linux-2.6.35-rc5/drivers/net/ixgb/ixgb_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/ixgb/ixgb_main.c 2010-07-27 16:27:23.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/ixgb/ixgb_main.c 2010-07-27 16:41:57.000000000 -0500 @@ -1977,6 +1977,7 @@ ixgb_clean_rx_irq(struct ixgb_adapter *a break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; buffer_info->skb = NULL; Index: linux-2.6.35-rc5/drivers/net/ixgbevf/ixgbevf_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/ixgbevf/ixgbevf_main.c 2010-07-27 16:30:51.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/ixgbevf/ixgbevf_main.c 2010-07-27 16:40:19.000000000 -0500 @@ -231,6 +231,7 @@ static bool ixgbevf_clean_tx_irq(struct while ((eop_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)) && (count < tx_ring->work_limit)) { bool cleaned = false; + rmb(); /* read buffer_info after eop_desc */ for ( ; !cleaned; count++) { struct sk_buff *skb; tx_desc = IXGBE_TX_DESC_ADV(*tx_ring, i); @@ -518,6 +519,7 @@ static bool ixgbevf_clean_rx_irq(struct break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ if (adapter->flags & IXGBE_FLAG_RX_PS_ENABLED) { hdr_info = le16_to_cpu(ixgbevf_get_hdr_info(rx_desc)); len = (hdr_info & IXGBE_RXDADV_HDRBUFLEN_MASK) >> Index: linux-2.6.35-rc5/drivers/net/e100.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/e100.c 2010-07-27 17:36:44.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/e100.c 2010-07-27 17:41:38.000000000 -0500 @@ -1928,6 +1928,7 @@ static int e100_rx_indicate(struct nic * netif_printk(nic, rx_status, KERN_DEBUG, nic->netdev, "status=0x%04X\n", rfd_status); + rmb(); /* read size after status bit */ /* If data isn't ready, nothing to indicate */ if (unlikely(!(rfd_status & cb_complete))) {