drivers/pci/pcie/portdrv_acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PCIe Port Native Services Support, ACPI-Related Part
   4  *
   5  * Copyright (C) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   6  */
   7
   8 #include <linux/pci.h>
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/acpi.h>
  12 #include <linux/pci-acpi.h>
  13 #include <linux/pcieport_if.h>
  14
  15 #include "aer/aerdrv.h"
  16 #include "../pci.h"
  17 #include "portdrv.h"
  18
  19 /**
  20  * pcie_port_acpi_setup - Request the BIOS to release control of PCIe services.
  21  * @port: PCIe Port service for a root port or event collector.
  22  * @srv_mask: Bit mask of services that can be enabled for @port.
  23  *
  24  * Invoked when @port is identified as a PCIe port device.  To avoid conflicts
  25  * with the BIOS PCIe port native services support requires the BIOS to yield
  26  * control of these services to the kernel.  The mask of services that the BIOS
  27  * allows to be enabled for @port is written to @srv_mask.
  28  *
  29  * NOTE: It turns out that we cannot do that for individual port services
  30  * separately, because that would make some systems work incorrectly.
  31  */
  32 void pcie_port_acpi_setup(struct pci_dev *port, int *srv_mask)
  33 {
  34         struct acpi_pci_root *root;
  35         acpi_handle handle;
  36         u32 flags;
  37
  38         if (acpi_pci_disabled)
  39                 return;
  40
  41         handle = acpi_find_root_bridge_handle(port);
  42         if (!handle)
  43                 return;
  44
  45         root = acpi_pci_find_root(handle);
  46         if (!root)
  47                 return;
  48
  49         flags = root->osc_control_set;
  50
  51         *srv_mask = PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
  52         if (flags & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)
  53                 *srv_mask |= PCIE_PORT_SERVICE_HP;
  54         if (flags & OSC_PCI_EXPRESS_PME_CONTROL)
  55                 *srv_mask |= PCIE_PORT_SERVICE_PME;
  56         if (flags & OSC_PCI_EXPRESS_AER_CONTROL)
  57                 *srv_mask |= PCIE_PORT_SERVICE_AER;
  58 }