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 #include "portdrv.h"
  21
  22 /**
  23  * pcie_port_acpi_setup - Request the BIOS to release control of PCIe services.
  24  * @port: PCIe Port service for a root port or event collector.
  25  * @srv_mask: Bit mask of services that can be enabled for @port.
  26  *
  27  * Invoked when @port is identified as a PCIe port device.  To avoid conflicts
  28  * with the BIOS PCIe port native services support requires the BIOS to yield
  29  * control of these services to the kernel.  The mask of services that the BIOS
  30  * allows to be enabled for @port is written to @srv_mask.
  31  *
  32  * NOTE: It turns out that we cannot do that for individual port services
  33  * separately, because that would make some systems work incorrectly.
  34  */
  35 int pcie_port_acpi_setup(struct pci_dev *port, int *srv_mask)
  36 {
  37         struct acpi_pci_root *root;
  38         acpi_handle handle;
  39         u32 flags;
  40
  41         if (acpi_pci_disabled)
  42                 return 0;
  43
  44         handle = acpi_find_root_bridge_handle(port);
  45         if (!handle)
  46                 return -EINVAL;
  47
  48         root = acpi_pci_find_root(handle);
  49         if (!root)
  50                 return -ENODEV;
  51
  52         flags = root->osc_control_set;
  53
  54         *srv_mask = PCIE_PORT_SERVICE_VC;
  55         if (flags & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)
  56                 *srv_mask |= PCIE_PORT_SERVICE_HP;
  57         if (flags & OSC_PCI_EXPRESS_PME_CONTROL)
  58                 *srv_mask |= PCIE_PORT_SERVICE_PME;
  59         if (flags & OSC_PCI_EXPRESS_AER_CONTROL)
  60                 *srv_mask |= PCIE_PORT_SERVICE_AER;
  61
  62         return 0;
  63 }