x86/PCI: use host bridge _CRS info by default on 2008 and newer machines

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@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 516225a864f942ffcc10e1672657812bda74f3b1..3e69c1c4f508139cf942a7c37edb09f6f9d082db 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1948,8 +1948,12 @@ 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 e97b255d97bcd8e74edbf0f501fa701bc588a51f..93997bd5edc3031bf724c6f54fcb53fc98c8feb3 100644 (file)
--- a/arch/ia64/include/asm/acpi.h
+++ b/arch/ia64/include/asm/acpi.h
@@ -98,6 +98,7 @@ 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 b4bf9a942ed0810418613f75b156e328fc0fd5d9..05b58ccb2e826521e627e439e466412e3e42027a 100644 (file)
--- 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 a2f8cdb8c1d5d10cceb424e70e6053716f4d3906..5f11ff6f5389bd45c6279b98c347c7754b164a8a 100644 (file)
--- 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 d2552c68e94d9670a7086c2eca1258a453c1a516..3736176acaab6a362f4e97a889af6d07591b6ce3 100644 (file)
--- 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 9cd8bedb1e5ac8ce42a688cb16357190c90ced99..d724736d56c8e0f25345d28c50f8b76295f4bfaa 100644 (file)
--- 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 f4906f6568d4142d1eb77c12f5997ba5da8ce5f7..3a4767c01c5fd6ecee67d409fdf4a906bbe5da5f 100644 (file)
--- 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