From 928bea964827d7824b548c1f8e06eccbbc4d0d7d Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 22 Jul 2013 14:37:17 -0700 Subject: PCI: Delay enabling bridges until they're needed We currently enable PCI bridges after scanning a bus and assigning resources. This is often done in arch code. This patch changes this so we don't enable a bridge until necessary, i.e., until we enable a PCI device behind the bridge. We do this in the generic pci_enable_device() path, so this also removes the arch-specific code to enable bridges. [bhelgaas: changelog] Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas --- drivers/acpi/pci_root.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 5917839321b8..faa1d29c0261 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -527,9 +527,6 @@ static int acpi_pci_root_add(struct acpi_device *device, if (system_state != SYSTEM_BOOTING) { pcibios_resource_survey_bus(root->bus); pci_assign_unassigned_bus_resources(root->bus); - - /* need to after hot-added ioapic is registered */ - pci_enable_bridges(root->bus); } pci_bus_add_devices(root->bus); -- cgit v1.2.3 From 39772038ea93e85ea4f1307ec9c1f48a063d89a0 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 22 Jul 2013 14:37:18 -0700 Subject: PCI: Assign resources for hot-added host bridge more aggressively When hot-adding an ACPI host bridge, use pci_assign_unassigned_root_bus_resources() instead of pci_assign_unassigned_bus_resources(). The former is more aggressive and will release and reassign existing resources if necessary. This is safe at hot-add time because no drivers are bound to devices below the new host bridge yet. [bhelgaas: changelog, split __init changes out for reviewability] Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas --- drivers/acpi/pci_root.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index faa1d29c0261..ce04eb28e029 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -526,7 +526,7 @@ static int acpi_pci_root_add(struct acpi_device *device, if (system_state != SYSTEM_BOOTING) { pcibios_resource_survey_bus(root->bus); - pci_assign_unassigned_bus_resources(root->bus); + pci_assign_unassigned_root_bus_resources(root->bus); } pci_bus_add_devices(root->bus); -- cgit v1.2.3 From 3dc48af310709b85d07c8b0d3aa8f1ead02829d3 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Thu, 29 Aug 2013 16:17:05 -0400 Subject: PCI/ACPI: Fix _OSC ordering to allow PCIe hotplug use when available This fixes the problem of acpiphp claiming slots that should be managed by pciehp, which may keep ExpressCard slots from working. The acpiphp driver claims PCIe slots unless the BIOS has granted us control of PCIe native hotplug via _OSC. Prior to v3.10, the acpiphp .add method (add_bridge()) was always called *after* we had requested native hotplug control with _OSC. But after 3b63aaa70e ("PCI: acpiphp: Do not use ACPI PCI subdriver mechanism"), which appeared in v3.10, acpiphp initialization is done during the bus scan via the pcibios_add_bus() hook, and this happens *before* we request native hotplug control. Therefore, acpiphp doesn't know yet whether the BIOS will grant control, and it claims slots that we should be handling with native hotplug. This patch requests native hotplug control earlier, so we know whether the BIOS granted it to us before we initialize acpiphp. To avoid reintroducing the ASPM issue fixed by b8178f130e ('Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus"'), we run _OSC earlier but defer the actual ASPM calls until after the bus scan is complete. Tested successfully by myself. [bhelgaas: changelog, mark for stable] Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60736 Signed-off-by: Neil Horman Signed-off-by: Bjorn Helgaas Acked-by: Yinghai Lu CC: stable@vger.kernel.org # v3.10+ CC: Len Brown CC: "Rafael J. Wysocki" --- drivers/acpi/pci_root.c | 62 ++++++++++++++++++++++++++++++------------------- 1 file changed, 38 insertions(+), 24 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 5917839321b8..a67853e3c419 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -378,6 +378,7 @@ static int acpi_pci_root_add(struct acpi_device *device, struct acpi_pci_root *root; u32 flags, base_flags; acpi_handle handle = device->handle; + bool no_aspm = false, clear_aspm = false; root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); if (!root) @@ -437,27 +438,6 @@ static int acpi_pci_root_add(struct acpi_device *device, flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT; acpi_pci_osc_support(root, flags); - /* - * TBD: Need PCI interface for enumeration/configuration of roots. - */ - - /* - * Scan the Root Bridge - * -------------------- - * Must do this prior to any attempt to bind the root device, as the - * PCI namespace does not get created until this call is made (and - * thus the root bridge's pci_dev does not exist). - */ - root->bus = pci_acpi_scan_root(root); - if (!root->bus) { - dev_err(&device->dev, - "Bus %04x:%02x not present in PCI namespace\n", - root->segment, (unsigned int)root->secondary.start); - result = -ENODEV; - goto end; - } - - /* Indicate support for various _OSC capabilities. */ if (pci_ext_cfg_avail()) flags |= OSC_EXT_PCI_CONFIG_SUPPORT; if (pcie_aspm_support_enabled()) { @@ -471,7 +451,7 @@ static int acpi_pci_root_add(struct acpi_device *device, if (ACPI_FAILURE(status)) { dev_info(&device->dev, "ACPI _OSC support " "notification failed, disabling PCIe ASPM\n"); - pcie_no_aspm(); + no_aspm = true; flags = base_flags; } } @@ -503,7 +483,7 @@ static int acpi_pci_root_add(struct acpi_device *device, * We have ASPM control, but the FADT indicates * that it's unsupported. Clear it. */ - pcie_clear_aspm(root->bus); + clear_aspm = true; } } else { dev_info(&device->dev, @@ -512,7 +492,14 @@ static int acpi_pci_root_add(struct acpi_device *device, acpi_format_exception(status), flags); dev_info(&device->dev, "ACPI _OSC control for PCIe not granted, disabling ASPM\n"); - pcie_no_aspm(); + /* + * We want to disable ASPM here, but aspm_disabled + * needs to remain in its state from boot so that we + * properly handle PCIe 1.1 devices. So we set this + * flag here, to defer the action until after the ACPI + * root scan. + */ + no_aspm = true; } } else { dev_info(&device->dev, @@ -520,6 +507,33 @@ static int acpi_pci_root_add(struct acpi_device *device, "(_OSC support mask: 0x%02x)\n", flags); } + /* + * TBD: Need PCI interface for enumeration/configuration of roots. + */ + + /* + * Scan the Root Bridge + * -------------------- + * Must do this prior to any attempt to bind the root device, as the + * PCI namespace does not get created until this call is made (and + * thus the root bridge's pci_dev does not exist). + */ + root->bus = pci_acpi_scan_root(root); + if (!root->bus) { + dev_err(&device->dev, + "Bus %04x:%02x not present in PCI namespace\n", + root->segment, (unsigned int)root->secondary.start); + result = -ENODEV; + goto end; + } + + if (clear_aspm) { + dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n"); + pcie_clear_aspm(root->bus); + } + if (no_aspm) + pcie_no_aspm(); + pci_acpi_add_bus_pm_notifier(device, root->bus); if (device->wakeup.flags.run_wake) device_set_run_wake(root->bus->bridge, true); -- cgit v1.2.3