From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756235AbYESEtF (ORCPT ); Mon, 19 May 2008 00:49:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751388AbYESEs4 (ORCPT ); Mon, 19 May 2008 00:48:56 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:55626 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbYESEsy (ORCPT ); Mon, 19 May 2008 00:48:54 -0400 Message-ID: <48310691.9050706@jp.fujitsu.com> Date: Mon, 19 May 2008 13:48:17 +0900 From: Hidetoshi Seto User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: Jesse Barnes CC: Arnaldo Carvalho de Melo , Matthew Wilcox , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: [PATCH] msi: skip calling pci_find_capability from msi_set_mask_bits References: <20080515160426.GD14846@ghostprotocols.net> <20080515170407.GM9921@parisc-linux.org> <20080515171003.GF14846@ghostprotocols.net> <200805161044.34938.jbarnes@virtuousgeek.org> In-Reply-To: <200805161044.34938.jbarnes@virtuousgeek.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jesse Barnes wrote: > Since we know MSI is a problem, let's just go with fixing that for now. If we > find that other caps are also causing problems we can revisit caching all of > them; the patch is simple enough. Humm... I suppose it can be more simple. How about this patch? > everytime handle_edge_irq is called it needs to mask and unmask MSI, and > that leads to a series of very expensive calls to pci_find_capability The position of MSI capability is already cached in the msi_desc when we enter the msi_set_mask_bits(). Use it instead. Signed-off-by: Hidetoshi Seto --- drivers/pci/msi.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 8c61304..ccb1974 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -70,12 +70,10 @@ arch_teardown_msi_irqs(struct pci_dev *dev) } } -static void msi_set_enable(struct pci_dev *dev, int enable) +static void __msi_set_enable(struct pci_dev *dev, int pos, int enable) { - int pos; u16 control; - pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (pos) { pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); control &= ~PCI_MSI_FLAGS_ENABLE; @@ -85,6 +83,11 @@ static void msi_set_enable(struct pci_dev *dev, int enable) } } +static void msi_set_enable(struct pci_dev *dev, int enable) +{ + __msi_set_enable(dev, pci_find_capability(dev, PCI_CAP_ID_MSI), enable); +} + static void msix_set_enable(struct pci_dev *dev, int enable) { int pos; @@ -141,7 +144,8 @@ static void msi_set_mask_bits(unsigned int irq, u32 mask, u32 flag) mask_bits |= flag & mask; pci_write_config_dword(entry->dev, pos, mask_bits); } else { - msi_set_enable(entry->dev, !flag); + __msi_set_enable(entry->dev, entry->msi_attrib.pos, + !flag); } break; case PCI_CAP_ID_MSIX: -- 1.5.4.3