drivers/pci/pcie/portdrv_acpi.c

   1 /*
   2  * PCIe Port Native Services Support, ACPI-Related Part
   3  *
   4  * Copyright (C) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License V2.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/pci.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/acpi.h>
  15 #include <linux/pci-acpi.h>
  16 #include <linux/pcieport_if.h>
  17
  18 #include "aer/aerdrv.h"
  19 #include "../pci.h"
  20
  21 /**
  22  * pcie_port_acpi_setup - Request the BIOS to release control of PCIe services.
  23  * @port: PCIe Port service for a root port or event collector.
  24  * @srv_mask: Bit mask of services that can be enabled for @port.
  25  *
  26  * Invoked when @port is identified as a PCIe port device.  To avoid conflicts
  27  * with the BIOS PCIe port native services support requires the BIOS to yield
  28  * control of these services to the kernel.  The mask of services that the BIOS
  29  * allows to be enabled for @port is written to @srv_mask.
  30  *
  31  * NOTE: It turns out that we cannot do that for individual port services
  32  * separately, because that would make some systems work incorrectly.
  33  */
  34 int pcie_port_acpi_setup(struct pci_dev *port, int *srv_mask)
  35 {
  36         struct acpi_pci_root *root;
  37         acpi_handle handle;
  38         u32 flags;
  39
  40         if (acpi_pci_disabled)
  41                 return 0;
  42
  43         handle = acpi_find_root_bridge_handle(port);
  44         if (!handle)
  45                 return -EINVAL;
  46
  47         root = acpi_pci_find_root(handle);
  48         if (!root)
  49                 return -ENODEV;
  50
  51         flags = root->osc_control_set;
  52
  53         *srv_mask = PCIE_PORT_SERVICE_VC;
  54         if (flags & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)
  55                 *srv_mask |= PCIE_PORT_SERVICE_HP;
  56         if (flags & OSC_PCI_EXPRESS_PME_CONTROL)
  57                 *srv_mask |= PCIE_PORT_SERVICE_PME;
  58         if (flags & OSC_PCI_EXPRESS_AER_CONTROL)
  59                 *srv_mask |= PCIE_PORT_SERVICE_AER;
  60
  61         return 0;
  62 }