Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752334Ab2EHJKS (ORCPT ); Tue, 8 May 2012 05:10:18 -0400 Received: from mga03.intel.com ([143.182.124.21]:10084 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751646Ab2EHJJ7 convert rfc822-to-8bit (ORCPT ); Tue, 8 May 2012 05:09:59 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="140239559" From: "Hao, Xudong" To: Bjorn Helgaas , Xudong Hao CC: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Zhang, Xiantao" Subject: RE: [PATCH] PCI: save/restore max Latency Value for device LTR Thread-Topic: [PATCH] PCI: save/restore max Latency Value for device LTR Thread-Index: AQHNK5ooOWnCSqF+oUGdV+xQne+W6Za9/2QAgAGc3NA= Date: Tue, 8 May 2012 09:09:56 +0000 Message-ID: <403610A45A2B5242BD291EDAE8B37D300FDBDA97@SHSMSX102.ccr.corp.intel.com> References: <20120506151156.GA13805@hp-xd.sh.intel.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2787 Lines: 100 > -----Original Message----- > From: Bjorn Helgaas [mailto:bhelgaas@google.com] > > ?} > > > > This doesn't make any sense to me. "pos" is the offset of the PCI > Express Capability (identifier 10h). LTR is a separate extended > capability (identifier 18h), so you at least have to look up its > offset. > Sorry paste a wrong patch... How about this patch, not a formal patch. diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 111569c..eced407 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -910,6 +910,45 @@ static void pci_restore_pcie_state(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]); } +static int pci_save_ltr_value(struct pci_dev *dev) +{ + int i = 0, pos; + struct pci_cap_saved_state *save_state; + u16 *cap; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!pos) + return -ENOTSUPP; + + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state) { + dev_err(&dev->dev, "buffer not found in %s\n", __func__); + return -ENOMEM; + } + cap = (u16 *)&save_state->cap.ltr_data[0]; + + pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, &cap[i++]); + pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, &cap[i++]); +} + +static void pci_restore_ltr_value(struct pci_dev *dev) +{ + int i = 0, pos; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_ltr_supported(dev)) + return; + + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state || !pos) + return; + cap = (u16 *)&save_state->cap.ltr_data[0]; + + pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, cap[i++]); + pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, cap[i++]); +} static int pci_save_pcix_state(struct pci_dev *dev) { @@ -964,6 +1003,10 @@ pci_save_state(struct pci_dev *dev) return i; if ((i = pci_save_pcix_state(dev)) != 0) return i; + + if (pci_ltr_supported(dev)) + return pci_save_ltr_value(dev); + return 0; } @@ -1032,6 +1075,7 @@ void pci_restore_state(struct pci_dev *dev) pci_restore_pcix_state(dev); pci_restore_msi_state(dev); pci_restore_iov_state(dev); + pci_restore_ltr_value(dev); dev->state_saved = false; } diff --git a/include/linux/pci.h b/include/linux/pci.h index e444f5b..6343aeb 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -220,6 +220,7 @@ struct pci_cap_saved_data { char cap_nr; unsigned int size; u32 data[0]; + u32 ltr_data[0]; }; struct pci_cap_saved_state { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/