File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
new file mode 100644
index 0000000..876ccc6
--- /dev/null
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -0,0 +1,227 @@
+/*
+ * Common ACPI functions for hot plug platforms
+ *
+ * Copyright (C) 2006 Intel Corporation
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to <kristen.c.accardi@intel.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/acpi.h>
+#include <linux/pci-acpi.h>
+#include <linux/slab.h>
+
+#define MY_NAME "acpi_pcihp"
+
+#define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
+#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
+#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
+#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
+
+#define METHOD_NAME__SUN "_SUN"
+#define METHOD_NAME_OSHP "OSHP"
+
+static bool debug_acpi;
+
+/* acpi_run_oshp - get control of hotplug from the firmware
+ *
+ * @handle - the handle of the hotplug controller.
+ */
+static acpi_status acpi_run_oshp(acpi_handle handle)
+{
+ acpi_status status;
+ struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
+
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+
+ /* run OSHP */
+ status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
+ if (ACPI_FAILURE(status))
+ if (status != AE_NOT_FOUND)
+ printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
+ __func__, (char *)string.pointer, status);
+ else
+ dbg("%s:%s OSHP not found\n",
+ __func__, (char *)string.pointer);
+ else
+ pr_debug("%s:%s OSHP passes\n", __func__,
+ (char *)string.pointer);
+
+ kfree(string.pointer);
+ return status;
+}
+
+/**
+ * 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 *pdev, u32 flags)
+{
+ acpi_status status;
+ acpi_handle chandle, handle;
+ struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
+
+ flags &= OSC_PCI_SHPC_NATIVE_HP_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 on a root
+ * bridge preferentially (according to PCI fw spec). Later for
+ * OSHP within the scope of the hotplug controller and its parents,
+ * up to the host bridge under which this controller exists.
+ */
+ handle = acpi_find_root_bridge_handle(pdev);
+ if (handle) {
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+ dbg("Trying to get hotplug control for %s\n",
+ (char *)string.pointer);
+ status = acpi_pci_osc_control_set(handle, &flags, flags);
+ if (ACPI_SUCCESS(status))
+ goto got_one;
+ if (status == AE_SUPPORT)
+ goto no_control;
+ kfree(string.pointer);
+ string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
+ }
+
+ handle = ACPI_HANDLE(&pdev->dev);
+ if (!handle) {
+ /*
+ * This hotplug controller was not listed in the ACPI name
+ * space at all. Try to get acpi handle of parent pci bus.
+ */
+ struct pci_bus *pbus;
+ for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
+ handle = acpi_pci_get_bridge_handle(pbus);
+ if (handle)
+ break;
+ }
+ }
+
+ while (handle) {
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+ dbg("Trying to get hotplug control for %s \n",
+ (char *)string.pointer);
+ status = acpi_run_oshp(handle);
+ if (ACPI_SUCCESS(status))
+ goto got_one;
+ if (acpi_is_root_bridge(handle))
+ break;
+ chandle = handle;
+ status = acpi_get_parent(chandle, &handle);
+ if (ACPI_FAILURE(status))
+ break;
+ }
+no_control:
+ dbg("Cannot get control of hotplug hardware for pci %s\n",
+ pci_name(pdev));
+ kfree(string.pointer);
+ return -ENODEV;
+got_one:
+ dbg("Gained control for hotplug HW for pci %s (%s)\n",
+ pci_name(pdev), (char *)string.pointer);
+ kfree(string.pointer);
+ return 0;
+}
+EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
+
+static int pcihp_is_ejectable(acpi_handle handle)
+{
+ acpi_status status;
+ unsigned long long removable;
+ if (!acpi_has_method(handle, "_ADR"))
+ return 0;
+ if (acpi_has_method(handle, "_EJ0"))
+ return 1;
+ status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
+ if (ACPI_SUCCESS(status) && removable)
+ return 1;
+ return 0;
+}
+
+/**
+ * acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
+ * @pbus: the PCI bus of the PCI slot corresponding to 'handle'
+ * @handle: ACPI handle to check
+ *
+ * Return 1 if handle is ejectable PCI slot, 0 otherwise.
+ */
+int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
+{
+ acpi_handle bridge_handle, parent_handle;
+
+ bridge_handle = acpi_pci_get_bridge_handle(pbus);
+ if (!bridge_handle)
+ return 0;
+ if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
+ return 0;
+ if (bridge_handle != parent_handle)
+ return 0;
+ return pcihp_is_ejectable(handle);
+}
+EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);
+
+static acpi_status
+check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+ int *found = (int *)context;
+ if (pcihp_is_ejectable(handle)) {
+ *found = 1;
+ return AE_CTRL_TERMINATE;
+ }
+ return AE_OK;
+}
+
+/**
+ * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
+ * @handle - handle of the PCI bus to scan
+ *
+ * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
+ */
+int acpi_pci_detect_ejectable(acpi_handle handle)
+{
+ int found = 0;
+
+ if (!handle)
+ return found;
+
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ check_hotplug, NULL, (void *)&found, NULL);
+ return found;
+}
+EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);
+
+module_param(debug_acpi, bool, 0644);
+MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");