diff options
Diffstat (limited to 'drivers/pci/hotplug/acpi_pcihp.c')
| -rw-r--r-- | drivers/pci/hotplug/acpi_pcihp.c | 85 |
1 files changed, 81 insertions, 4 deletions
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c index f8c187a..93e37f0 100644 --- a/drivers/pci/hotplug/acpi_pcihp.c +++ b/drivers/pci/hotplug/acpi_pcihp.c @@ -30,6 +30,7 @@ #include <linux/types.h> #include <linux/pci.h> #include <linux/pci_hotplug.h> +#include <linux/pci-acpi.h> #include <acpi/acpi.h> #include <acpi/acpi_bus.h> #include <acpi/actypes.h> @@ -299,7 +300,7 @@ free_and_return: * * @handle - the handle of the hotplug controller. */ -acpi_status acpi_run_oshp(acpi_handle handle) +static acpi_status acpi_run_oshp(acpi_handle handle) { acpi_status status; struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL }; @@ -322,9 +323,6 @@ acpi_status acpi_run_oshp(acpi_handle handle) kfree(string.pointer); return status; } -EXPORT_SYMBOL_GPL(acpi_run_oshp); - - /* acpi_get_hp_params_from_firmware * @@ -374,6 +372,85 @@ acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus, } EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware); +/** + * acpi_get_hp_hw_control_from_firmware + * @dev: the pci_dev of the bridge that has a hotplug controller + * @flags: requested control bits for _OSC + * + * Attempt to take hotplug control from firmware. + */ +int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags) +{ + acpi_status status; + acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev)); + struct pci_dev *pdev = dev; + struct pci_bus *parent; + struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL }; + + flags &= (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL | + OSC_SHPC_NATIVE_HP_CONTROL | + OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL); + if (!flags) { + err("Invalid flags %u specified!\n", flags); + return -EINVAL; + } + + /* + * Per PCI firmware specification, we should run the ACPI _OSC + * method to get control of hotplug hardware before using it. If + * an _OSC is missing, we look for an OSHP to do the same thing. + * To handle different BIOS behavior, we look for _OSC and OSHP + * within the scope of the hotplug controller and its parents, + * upto the host bridge under which this controller exists. + */ + while (!handle) { + /* + * This hotplug controller was not listed in the ACPI name + * space at all. Try to get acpi handle of parent pci bus. + */ + if (!pdev || !pdev->bus->parent) + break; + parent = pdev->bus->parent; + dbg("Could not find %s in acpi namespace, trying parent\n", + pci_name(pdev)); + if (!parent->self) + /* Parent must be a host bridge */ + handle = acpi_get_pci_rootbridge_handle( + pci_domain_nr(parent), + parent->number); + else + handle = DEVICE_ACPI_HANDLE(&(parent->self->dev)); + pdev = parent->self; + } + + while (handle) { + acpi_get_name(handle, ACPI_FULL_PATHNAME, &string); + dbg("Trying to get hotplug control for %s \n", + (char *)string.pointer); + status = pci_osc_control_set(handle, flags); + if (status == AE_NOT_FOUND) + status = acpi_run_oshp(handle); + if (ACPI_SUCCESS(status)) { + dbg("Gained control for hotplug HW for pci %s (%s)\n", + pci_name(dev), (char *)string.pointer); + kfree(string.pointer); + return 0; + } + if (acpi_root_bridge(handle)) + break; + chandle = handle; + status = acpi_get_parent(chandle, &handle); + if (ACPI_FAILURE(status)) + break; + } + + dbg("Cannot get control of hotplug hardware for pci %s\n", + pci_name(dev)); + + kfree(string.pointer); + return -ENODEV; +} +EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware); /* acpi_root_bridge - check to see if this acpi object is a root bridge * |