The main benefit of using ACPI host bridge window information is that we can do better resource allocation in systems with multiple host bridges, e.g., http://bugzilla.kernel.org/show_bug.cgi?id=14183 Sometimes we need _CRS information even if we only have one host bridge, e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/341681 Most of these systems are relatively new, so this patch turns on "pci=use_crs" only on machines with a BIOS date of 2008 or newer. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx> --- Documentation/kernel-parameters.txt | 8 ++++- arch/ia64/include/asm/acpi.h | 1 + arch/x86/include/asm/pci_x86.h | 1 + arch/x86/pci/acpi.c | 53 +++++++++++++++++++++++++++++++---- arch/x86/pci/common.c | 3 ++ drivers/acpi/pci_root.c | 1 + include/acpi/acpi_drivers.h | 1 + 7 files changed, 60 insertions(+), 8 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 01e2a98..6913e9a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1939,8 +1939,12 @@ and is between 256 and 4096 characters. It is defined in the file IRQ routing is enabled. noacpi [X86] Do not use ACPI for IRQ routing or for PCI scanning. - use_crs [X86] Use _CRS for PCI resource - allocation. + use_crs [X86] Use PCI host bridge window information + from ACPI. On BIOSes from 2008 or later, this + is enabled by default. If you need to use this, + please report a bug. + nocrs [X86] Ignore PCI host bridge windows from ACPI. + If you need to use this, please report a bug. routeirq Do IRQ routing for all PCI devices. This is normally done in pci_enable_device(), so this option is a temporary workaround diff --git a/arch/ia64/include/asm/acpi.h b/arch/ia64/include/asm/acpi.h index 7ae5889..7f2d7f2 100644 --- a/arch/ia64/include/asm/acpi.h +++ b/arch/ia64/include/asm/acpi.h @@ -97,6 +97,7 @@ ia64_acpi_release_global_lock (unsigned int *lock) #endif #define acpi_processor_cstate_check(x) (x) /* no idle limits on IA64 :) */ static inline void disable_acpi(void) { } +static inline void pci_acpi_crs_quirks(void) { } const char *acpi_get_sysname (void); int acpi_request_vector (u32 int_type); diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h index b4bf9a9..05b58cc 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -29,6 +29,7 @@ #define PCI_CHECK_ENABLE_AMD_MMCONF 0x20000 #define PCI_HAS_IO_ECS 0x40000 #define PCI_NOASSIGN_ROMS 0x80000 +#define PCI_ROOT_NO_CRS 0x100000 extern unsigned int pci_probe; extern unsigned long pirq_table_addr; diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index a2f8cdb..5f11ff6 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -15,6 +15,51 @@ struct pci_root_info { int busnum; }; +static bool pci_use_crs = true; + +static int __init set_use_crs(const struct dmi_system_id *id) +{ + pci_use_crs = true; + return 0; +} + +static const struct dmi_system_id pci_use_crs_table[] __initconst = { + /* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */ + { + .callback = set_use_crs, + .ident = "IBM System x3800", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "IBM"), + DMI_MATCH(DMI_PRODUCT_NAME, "x3800"), + }, + }, + {} +}; + +void __init pci_acpi_crs_quirks(void) +{ + int year; + + if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year < 2008) + pci_use_crs = false; + + dmi_check_system(pci_use_crs_table); + + /* + * If the user specifies "pci=use_crs" or "pci=nocrs" explicitly, that + * takes precedence over anything we figured out above. + */ + if (pci_probe & PCI_ROOT_NO_CRS) + pci_use_crs = false; + else if (pci_probe & PCI_USE__CRS) + pci_use_crs = true; + + printk(KERN_INFO "PCI: %s host bridge windows from ACPI; " + "if necessary, use \"pci=%s\" and report a bug\n", + pci_use_crs ? "Using" : "Ignoring", + pci_use_crs ? "nocrs" : "use_crs"); +} + static acpi_status resource_to_addr(struct acpi_resource *resource, struct acpi_resource_address64 *addr) @@ -106,7 +151,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data) res->child = NULL; align_resource(info->bridge, res); - if (!(pci_probe & PCI_USE__CRS)) { + if (!pci_use_crs) { dev_printk(KERN_DEBUG, &info->bridge->dev, "host bridge window %pR (ignored)\n", res); return AE_OK; @@ -137,12 +182,8 @@ get_current_resources(struct acpi_device *device, int busnum, struct pci_root_info info; size_t size; - if (pci_probe & PCI_USE__CRS) + if (pci_use_crs) pci_bus_remove_resources(bus); - else - dev_info(&device->dev, - "ignoring host bridge windows from ACPI; " - "boot with \"pci=use_crs\" to use them\n"); info.bridge = device; info.bus = bus; diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index d2552c6..3736176 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -520,6 +520,9 @@ char * __devinit pcibios_setup(char *str) } else if (!strcmp(str, "use_crs")) { pci_probe |= PCI_USE__CRS; return NULL; + } else if (!strcmp(str, "nocrs")) { + pci_probe |= PCI_ROOT_NO_CRS; + return NULL; } else if (!strcmp(str, "earlydump")) { pci_early_dump_regs = 1; return NULL; diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 64ae2f2..4a46051 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -566,6 +566,7 @@ static int __init acpi_pci_root_init(void) if (acpi_pci_disabled) return 0; + pci_acpi_crs_quirks(); if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0) return -ENODEV; diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h index f4906f6..3a4767c 100644 --- a/include/acpi/acpi_drivers.h +++ b/include/acpi/acpi_drivers.h @@ -104,6 +104,7 @@ int acpi_pci_bind_root(struct acpi_device *device); struct pci_bus *pci_acpi_scan_root(struct acpi_device *device, int domain, int bus); +void pci_acpi_crs_quirks(void); /* -------------------------------------------------------------------------- Processor -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
