From patchwork Tue Apr 7 01:33:29 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Zhao X-Patchwork-Id: 16701 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n371WNYm001059 for ; Tue, 7 Apr 2009 01:32:24 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753557AbZDGBcY (ORCPT ); Mon, 6 Apr 2009 21:32:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752718AbZDGBcX (ORCPT ); Mon, 6 Apr 2009 21:32:23 -0400 Received: from mga09.intel.com ([134.134.136.24]:22685 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752226AbZDGBcW (ORCPT ); Mon, 6 Apr 2009 21:32:22 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 06 Apr 2009 18:23:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.39,333,1235980800"; d="scan'208";a="400902693" Received: from yzhao-otc.sh.intel.com ([10.239.48.165]) by orsmga002.jf.intel.com with ESMTP; 06 Apr 2009 18:40:31 -0700 From: Yu Zhao To: linux-pci@vger.kernel.org Cc: kvm@vger.kernel.org, matthew@wil.cx, Yu Zhao Subject: [RFC PATCH 1/3] PCI: rewrite Function Level Reset Date: Tue, 7 Apr 2009 09:33:29 +0800 Message-Id: <1239068011-15164-1-git-send-email-yu.zhao@intel.com> X-Mailer: git-send-email 1.6.1 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Changes: 1) remove disable_irq() so the shared IRQ won't be disabled. 2) replace the 1s wait with 100, 200 and 400ms wait intervals for the Pending Transaction. 3) replace mdelay() with msleep(). 4) add might_sleep(). 5) lock the device to prevent PM suspend from accessing the CSRs during the reset. 6) coding style fixes. Signed-off-by: Yu Zhao --- drivers/pci/pci.c | 166 ++++++++++++++++++++++++++------------------------- include/linux/pci.h | 2 +- 2 files changed, 85 insertions(+), 83 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index af4db4e..46ae997 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2008,111 +2008,112 @@ int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask) EXPORT_SYMBOL(pci_set_dma_seg_boundary); #endif -static int __pcie_flr(struct pci_dev *dev, int probe) +static int pcie_flr(struct pci_dev *dev, int probe) { - u16 status; + int i; + int pos; u32 cap; - int exppos = pci_find_capability(dev, PCI_CAP_ID_EXP); + u16 status; - if (!exppos) + pos = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (!pos) return -ENOTTY; - pci_read_config_dword(dev, exppos + PCI_EXP_DEVCAP, &cap); + + pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap); if (!(cap & PCI_EXP_DEVCAP_FLR)) return -ENOTTY; if (probe) return 0; - pci_block_user_cfg_access(dev); - /* Wait for Transaction Pending bit clean */ - pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status); - if (!(status & PCI_EXP_DEVSTA_TRPND)) - goto transaction_done; + for (i = 0; i < 4; i++) { + if (i) + msleep((1 << (i - 1)) * 100); - msleep(100); - pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status); - if (!(status & PCI_EXP_DEVSTA_TRPND)) - goto transaction_done; - - dev_info(&dev->dev, "Busy after 100ms while trying to reset; " - "sleeping for 1 second\n"); - ssleep(1); - pci_read_config_word(dev, exppos + PCI_EXP_DEVSTA, &status); - if (status & PCI_EXP_DEVSTA_TRPND) - dev_info(&dev->dev, "Still busy after 1s; " - "proceeding with reset anyway\n"); - -transaction_done: - pci_write_config_word(dev, exppos + PCI_EXP_DEVCTL, + pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &status); + if (!(status & PCI_EXP_DEVSTA_TRPND)) + goto clear; + } + + dev_err(&dev->dev, "transaction is not cleared; " + "proceeding with reset anyway\n"); + +clear: + pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); - mdelay(100); + msleep(100); - pci_unblock_user_cfg_access(dev); return 0; } -static int __pci_af_flr(struct pci_dev *dev, int probe) +static int pci_af_flr(struct pci_dev *dev, int probe) { - int cappos = pci_find_capability(dev, PCI_CAP_ID_AF); - u8 status; + int i; + int pos; u8 cap; + u8 status; - if (!cappos) + pos = pci_find_capability(dev, PCI_CAP_ID_AF); + if (!pos) return -ENOTTY; - pci_read_config_byte(dev, cappos + PCI_AF_CAP, &cap); + + pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap); if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) return -ENOTTY; if (probe) return 0; - pci_block_user_cfg_access(dev); - /* Wait for Transaction Pending bit clean */ - pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status); - if (!(status & PCI_AF_STATUS_TP)) - goto transaction_done; + for (i = 0; i < 4; i++) { + if (i) + msleep((1 << (i - 1)) * 100); + + pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status); + if (!(status & PCI_AF_STATUS_TP)) + goto clear; + } + + dev_err(&dev->dev, "transaction is not cleared; " + "proceeding with reset anyway\n"); +clear: + pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR); msleep(100); - pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status); - if (!(status & PCI_AF_STATUS_TP)) - goto transaction_done; - - dev_info(&dev->dev, "Busy after 100ms while trying to" - " reset; sleeping for 1 second\n"); - ssleep(1); - pci_read_config_byte(dev, cappos + PCI_AF_STATUS, &status); - if (status & PCI_AF_STATUS_TP) - dev_info(&dev->dev, "Still busy after 1s; " - "proceeding with reset anyway\n"); - -transaction_done: - pci_write_config_byte(dev, cappos + PCI_AF_CTRL, PCI_AF_CTRL_FLR); - mdelay(100); - - pci_unblock_user_cfg_access(dev); + return 0; } -static int __pci_reset_function(struct pci_dev *pdev, int probe) +static int pci_dev_reset(struct pci_dev *dev, int probe) { - int res; + int rc; + + might_sleep(); + + if (!probe) + pci_block_user_cfg_access(dev); - res = __pcie_flr(pdev, probe); - if (res != -ENOTTY) - return res; + /* block PM suspend, driver probe, etc. */ + down(&dev->dev.sem); - res = __pci_af_flr(pdev, probe); - if (res != -ENOTTY) - return res; + rc = pcie_flr(dev, probe); + if (rc != -ENOTTY) + goto done; - return res; + rc = pci_af_flr(dev, probe); +done: + up(&dev->dev.sem); + + if (!probe) + pci_unblock_user_cfg_access(dev); + + return rc; } /** - * pci_execute_reset_function() - Reset a PCI device function - * @dev: Device function to reset + * __pci_reset_function - reset a PCI device function + * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive @@ -2124,18 +2125,18 @@ static int __pci_reset_function(struct pci_dev *pdev, int probe) * device including MSI, bus mastering, BARs, decoding IO and memory spaces, * etc. * - * Returns 0 if the device function was successfully reset or -ENOTTY if the + * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ -int pci_execute_reset_function(struct pci_dev *dev) +int __pci_reset_function(struct pci_dev *dev) { - return __pci_reset_function(dev, 0); + return pci_dev_reset(dev, 0); } -EXPORT_SYMBOL_GPL(pci_execute_reset_function); +EXPORT_SYMBOL_GPL(__pci_reset_function); /** - * pci_reset_function() - quiesce and reset a PCI device function - * @dev: Device function to reset + * pci_reset_function - quiesce and reset a PCI device function + * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive @@ -2143,32 +2144,33 @@ EXPORT_SYMBOL_GPL(pci_execute_reset_function); * * This function does not just reset the PCI portion of a device, but * clears all the state associated with the device. This function differs - * from pci_execute_reset_function in that it saves and restores device state + * from __pci_reset_function in that it saves and restores device state * over the reset. * - * Returns 0 if the device function was successfully reset or -ENOTTY if the + * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ int pci_reset_function(struct pci_dev *dev) { - int r = __pci_reset_function(dev, 1); + int rc; - if (r < 0) - return r; + rc = pci_dev_reset(dev, 1); + if (rc) + return rc; - if (!dev->msi_enabled && !dev->msix_enabled && dev->irq != 0) - disable_irq(dev->irq); pci_save_state(dev); + /* + * both INTx and MSI are disabled after the Interrupt Disable bit + * is set and the Bus Master bit is cleared. + */ pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); - r = pci_execute_reset_function(dev); + rc = pci_dev_reset(dev, 0); pci_restore_state(dev); - if (!dev->msi_enabled && !dev->msix_enabled && dev->irq != 0) - enable_irq(dev->irq); - return r; + return rc; } EXPORT_SYMBOL_GPL(pci_reset_function); diff --git a/include/linux/pci.h b/include/linux/pci.h index a7fe4bb..597391a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -698,8 +698,8 @@ int pcix_get_mmrbc(struct pci_dev *dev); int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc); int pcie_get_readrq(struct pci_dev *dev); int pcie_set_readrq(struct pci_dev *dev, int rq); +int __pci_reset_function(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); -int pci_execute_reset_function(struct pci_dev *dev); void pci_update_resource(struct pci_dev *dev, int resno); int __must_check pci_assign_resource(struct pci_dev *dev, int i); int pci_select_bars(struct pci_dev *dev, unsigned long flags);