Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751513AbdH0Rlq (ORCPT ); Sun, 27 Aug 2017 13:41:46 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:42596 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751263AbdH0RlD (ORCPT ); Sun, 27 Aug 2017 13:41:03 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4443860722 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: linux-pci@vger.kernel.org, timur@codeaurora.org, alex.williamson@redhat.com Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Bjorn Helgaas , linux-kernel@vger.kernel.org Subject: [PATCH V13 2/4] PCI: Factor out pci_bus_wait_crs() Date: Sun, 27 Aug 2017 13:40:49 -0400 Message-Id: <1503855651-17409-2-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1503855651-17409-1-git-send-email-okaya@codeaurora.org> References: <1503855651-17409-1-git-send-email-okaya@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3097 Lines: 98 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 and also introduce pci_bus_crs_visibility_pending() to determine when we should wait. Signed-off-by: Sinan Kaya --- drivers/pci/probe.c | 52 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 34 insertions(+), 18 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 2849e0e..d834a20 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1824,30 +1824,29 @@ 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) +static inline bool pci_bus_crs_visibility_pending(u32 l) +{ + return (l & 0xffff) == 0x0001; +} + +static 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; - - if (delay > crs_timeout) { + while ((l & 0xffff) == 0x0001) { + 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)); @@ -1857,12 +1856,29 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, msleep(delay); delay *= 2; - if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) + if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l)) return false; } 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; + + if (pci_bus_crs_visibility_pending(*l)) + return pci_bus_wait_crs(bus, devfn, *l, timeout); + + return true; +} EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); /* -- 1.9.1