Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752520AbdHRVcP (ORCPT ); Fri, 18 Aug 2017 17:32:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:52872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752440AbdHRVcM (ORCPT ); Fri, 18 Aug 2017 17:32:12 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05A18218F7 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Subject: [PATCH v11 2/4] PCI: Factor out pci_bus_wait_crs() From: Bjorn Helgaas To: Sinan Kaya Cc: linux-pci@vger.kernel.org, Timur Tabi , linux-kernel@vger.kernel.org, Alex Williamson , linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Date: Fri, 18 Aug 2017 16:32:10 -0500 Message-ID: <20170818213210.15145.15340.stgit@bhelgaas-glaptop.roam.corp.google.com> In-Reply-To: <20170818212310.15145.21732.stgit@bhelgaas-glaptop.roam.corp.google.com> References: <20170818212310.15145.21732.stgit@bhelgaas-glaptop.roam.corp.google.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3301 Lines: 99 From: Sinan Kaya Configuration Request Retry Status (CRS) was previously hidden inside pci_bus_read_dev_vendor_id(). We want to add support for CRS in other situations, such as waiting for a device to become ready after a Function Level Reset. Move CRS handling into pci_bus_wait_crs() so it can be called from other places. Signed-off-by: Sinan Kaya [bhelgaas: move CRS reserved Vendor ID test into pci_bus_wait_crs(), remove EXPORT_SYMBOL] Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.h | 1 + drivers/pci/probe.c | 39 +++++++++++++++++++++++---------------- 2 files changed, 24 insertions(+), 16 deletions(-) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 22e061738c6f..b0857052c04a 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -235,6 +235,7 @@ enum pci_bar_type { pci_bar_mem64, /* A 64-bit memory BAR */ }; +bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, int timeout); bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, int crs_timeout); int pci_setup_device(struct pci_dev *dev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 08ea844ac4ba..342a86640c6b 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1824,33 +1824,26 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus) } EXPORT_SYMBOL(pci_alloc_dev); -bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, - int crs_timeout) +bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, int timeout) { int delay = 1; - if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) - return false; + if ((*l & 0xffff) != 0x0001) + return true; /* not a CRS completion */ - /* some broken boards return 0 or ~0 if a slot is empty: */ - if (*l == 0xffffffff || *l == 0x00000000 || - *l == 0x0000ffff || *l == 0xffff0000) - return false; + if (!timeout) + return false; /* CRS, but caller doesn't want to wait */ /* - * Configuration Request Retry Status. Some root ports return the - * actual device ID instead of the synthetic ID (0xFFFF) required - * by the PCIe spec. Ignore the device ID and only check for - * (vendor id == 1). + * We got the reserved Vendor ID that indicates a completion with + * Configuration Request Retry Status (CRS). Retry until we get a + * valid Vendor ID or we time out. */ while ((*l & 0xffff) == 0x0001) { - if (!crs_timeout) - return false; - msleep(delay); delay *= 2; - if (delay > crs_timeout) { + if (delay > timeout) { printk(KERN_WARNING "pci %04x:%02x:%02x.%d: not responding\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn)); @@ -1863,6 +1856,20 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, return true; } + +bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, + int timeout) +{ + if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) + return false; + + /* some broken boards return 0 or ~0 if a slot is empty: */ + if (*l == 0xffffffff || *l == 0x00000000 || + *l == 0x0000ffff || *l == 0xffff0000) + return false; + + return pci_bus_wait_crs(bus, devfn, l, timeout); +} EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); /*