Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754050AbdHOBZq (ORCPT ); Mon, 14 Aug 2017 21:25:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57484 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753823AbdHOBU2 (ORCPT ); Mon, 14 Aug 2017 21:20:28 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Marc Zyngier , Bjorn Helgaas Subject: [PATCH 4.12 50/65] PCI: Add pci_reset_function_locked() Date: Mon, 14 Aug 2017 18:19:41 -0700 Message-Id: <20170815011944.375697602@linuxfoundation.org> X-Mailer: git-send-email 2.14.0 In-Reply-To: <20170815011942.395714306@linuxfoundation.org> References: <20170815011942.395714306@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2904 Lines: 84 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit a477b9cd37aa81a490dfa3265b7ff4f2c5a92463 upstream. The implementation of PCI workarounds may require that the device is reset from its probe function. This implies that the PCI device lock is already held, and makes calling pci_reset_function() impossible (since it will itself try to take that lock). Add pci_reset_function_locked(), which is the equivalent of pci_reset_function(), except that it requires the PCI device lock to be already held by the caller. Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier [bhelgaas: folded in fix for conflict with 52354b9d1f46 ("PCI: Remove __pci_dev_reset() and pci_dev_reset()")] Signed-off-by: Bjorn Helgaas Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 36 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4291,6 +4291,41 @@ int pci_reset_function(struct pci_dev *d EXPORT_SYMBOL_GPL(pci_reset_function); /** + * pci_reset_function_locked - 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 + * to PCI config space in order to use this 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_reset_function() in that it saves and restores device state + * over the reset. It also differs from pci_reset_function() in that it + * requires the PCI device lock to be held. + * + * 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_locked(struct pci_dev *dev) +{ + int rc; + + rc = pci_probe_reset_function(dev); + if (rc) + return rc; + + pci_dev_save_and_disable(dev); + + rc = __pci_reset_function_locked(dev); + + pci_dev_restore(dev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_function_locked); + +/** * pci_try_reset_function - quiesce and reset a PCI device function * @dev: PCI device to reset * --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1049,6 +1049,7 @@ void pcie_flr(struct pci_dev *dev); int __pci_reset_function(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); +int pci_reset_function_locked(struct pci_dev *dev); int pci_try_reset_function(struct pci_dev *dev); int pci_probe_reset_slot(struct pci_slot *slot); int pci_reset_slot(struct pci_slot *slot);