From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757632AbZBKS07 (ORCPT ); Wed, 11 Feb 2009 13:26:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756728AbZBKS0v (ORCPT ); Wed, 11 Feb 2009 13:26:51 -0500 Received: from mga03.intel.com ([143.182.124.21]:52023 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755758AbZBKS0u (ORCPT ); Wed, 11 Feb 2009 13:26:50 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,193,1233561600"; d="scan'208";a="109650733" Date: Wed, 11 Feb 2009 10:26:48 -0800 From: Fenghua Yu To: David Woodhouse , Ingo Molnar , Stephen Rothwell , Andrew Morton , Johannes Berg , Emmanuel Grumbach , Tomas Winkler , Zhu Yi , Chris Wright Cc: LKML , iommu@lists.linux-foundation.org Subject: [PATCH]iwlan dma mapping read and write changes Message-ID: <20090211182648.GA1661@linux-os.sc.intel.com> References: <20081001165606.GA21279@linux-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081001165606.GA21279@linux-os.sc.intel.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When iwlan runs on IOMMU, IOMMU generates a lot of PTE write faults because PTE write bit is not set on some of PTE's. This is because iwlan driver calls DMA mapping with PCI_DMA_TODEVICE which is read only in mapping PTE. But iwlan device actually writes to the mapped page to update its contents. This issue is not exposed in swiotlb. But VT-d hardware can capture this fault and stop the fault transaction. The following patch fixes the issue. Signed-off-by: Fenghua Yu --- iwl-tx.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) --- a/drivers/net/wireless/iwlwifi/iwl-tx.c.orig 2009-02-10 21:28:45.000000000 -0800 +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c 2009-02-10 21:41:02.000000000 -0800 @@ -148,7 +148,7 @@ static void iwl_hw_txq_free_tfd(struct i pci_unmap_single(dev, pci_unmap_addr(&txq->cmd[index]->meta, mapping), pci_unmap_len(&txq->cmd[index]->meta, len), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); /* Unmap chunks, if any. */ for (i = 1; i < num_tbs; i++) { @@ -964,7 +964,7 @@ int iwl_tx_skb(struct iwl_priv *priv, st * within command buffer array. */ txcmd_phys = pci_map_single(priv->pci_dev, out_cmd, sizeof(struct iwl_cmd), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); pci_unmap_addr_set(&out_cmd->meta, mapping, txcmd_phys); pci_unmap_len_set(&out_cmd->meta, len, sizeof(struct iwl_cmd)); /* Add buffer containing Tx command and MAC(!) header to TFD's @@ -1115,7 +1115,7 @@ int iwl_enqueue_hcmd(struct iwl_priv *pr IWL_MAX_SCAN_SIZE : sizeof(struct iwl_cmd); phys_addr = pci_map_single(priv->pci_dev, out_cmd, - len, PCI_DMA_TODEVICE); + len, PCI_DMA_BIDIRECTIONAL); pci_unmap_addr_set(&out_cmd->meta, mapping, phys_addr); pci_unmap_len_set(&out_cmd->meta, len, len); phys_addr += offsetof(struct iwl_cmd, hdr); @@ -1212,7 +1212,7 @@ static void iwl_hcmd_queue_reclaim(struc pci_unmap_single(priv->pci_dev, pci_unmap_addr(&txq->cmd[cmd_idx]->meta, mapping), pci_unmap_len(&txq->cmd[cmd_idx]->meta, len), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); for (idx = iwl_queue_inc_wrap(idx, q->n_bd); q->read_ptr != idx; q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {