/* * 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");