From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jayachandran C Subject: [PATCH v6 2/5] PCI: Handle ACPI companion and domain number Date: Thu, 14 Jan 2016 13:02:38 +0530 Message-ID: <1452756761-29584-3-git-send-email-jchandra__35732.1287774996$1452755726$gmane$org@broadcom.com> References: <1452756761-29584-1-git-send-email-jchandra@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aJc1I-0000hd-7S for xen-devel@lists.xenproject.org; Thu, 14 Jan 2016 07:08:32 +0000 In-Reply-To: <1452756761-29584-1-git-send-email-jchandra@broadcom.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: linux-pci@vger.kernel.org, Bjorn Helgaas , linux-acpi@vger.kernel.org, Arnd Bergmann , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" Cc: Tomasz Nowicki , Lorenzo Pieralisi , Jayachandran C , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org pci_create_root_bus is called with NULL as parent in ACPI. This ends up calling pci_bus_assign_domain_nr with a NULL parent, which crashes when dereferencing parent. Fix this by providing a way to set the ACPI domain number and ACPI companion in PCI code. We define pci_acpi_set_companion() to set the ACPI companion pointer and acpi_pci_get_segment() and to get the PCI domain number. This is just defined for the generic ACPI PCI controller, using the corresponding sysdata. pci_bus_assign_domain_nr is updated to call acpi_pci_get_segment() to get the domain number to set on the root bus, in case of ACPI. Signed-off-by: Jayachandran C --- drivers/pci/pci.c | 15 ++++++++++++++- drivers/pci/probe.c | 2 ++ include/linux/pci-acpi.h | 28 +++++++++++++++++++++++++++- 3 files changed, 43 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 314db8c..39d2bcc 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -4772,9 +4773,21 @@ int pci_get_new_domain_nr(void) void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) { static int use_dt_domains = -1; - int domain = of_get_pci_domain_nr(parent->of_node); + int domain; /* + * Handle ACPI early + * + * The companion is not set at this point, and ACPI sets parent to + * NULL, we have to try to get the segment from acpi root info. + */ + if (!parent || !parent->of_node) { + bus->domain_nr = acpi_pci_get_segment(bus->sysdata); + return; + } + + domain = of_get_pci_domain_nr(parent->of_node); + /* * Check DT domain and use_dt_domains values. * * If DT domain property is valid (domain >= 0) and diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index edb1984..5af66496 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -2105,6 +2106,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, bridge->dev.parent = parent; bridge->dev.release = pci_release_host_bridge_dev; dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); + pci_acpi_set_companion(bridge); error = pcibios_root_bridge_prepare(bridge); if (error) { kfree(bridge); diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index e9450ef..f8d62e3 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -138,12 +138,38 @@ extern struct list_head pci_mmcfg_list; #define PCI_MMCFG_BUS_OFFSET(bus) ((bus) << 20) #define PCI_MMCFG_OFFSET(bus, devfn) ((bus) << 20 | (devfn) << 12) - #else /* CONFIG_ACPI */ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } static inline void acpi_pci_remove_bus(struct pci_bus *bus) { } #endif /* CONFIG_ACPI */ +#if defined(CONFIG_ACPI) && defined(CONFIG_ACPI_PCI_HOST_GENERIC) +static inline void pci_acpi_set_companion(struct pci_host_bridge *bridge) +{ + struct pci_bus *b = bridge->bus; + struct acpi_pci_root_info *ci = (struct acpi_pci_root_info *)b->sysdata; + + ACPI_COMPANION_SET(&bridge->dev, ci->bridge); +} + +static inline u16 acpi_pci_get_segment(void *sysdata) +{ + struct acpi_pci_root_info *ci = (struct acpi_pci_root_info *)sysdata; + + return ci->root->segment; +} +#else +static inline void pci_acpi_set_companion(struct pci_host_bridge *bridge) +{ + /* leave it to the platform for now */ +} + +static inline u16 acpi_pci_get_segment(void *sysdata) +{ + return 0; +} +#endif + #ifdef CONFIG_ACPI_APEI extern bool aer_acpi_firmware_first(void); #else -- 1.9.1