4 files changed, 583 insertions, 0 deletions

diff --git a/drivers/pci/pcie/pme/Makefile b/drivers/pci/pcie/pme/Makefile
new file mode 100644
index 000000000000..8b9238053080
--- /dev/null
+++ b/drivers/pci/pcie/pme/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for PCI-Express Root Port PME signaling driver
+#
+
+obj-$(CONFIG_PCIE_PME) += pmedriver.o
+
+pmedriver-objs := pcie_pme.o
+pmedriver-$(CONFIG_ACPI) += pcie_pme_acpi.o
diff --git a/drivers/pci/pcie/pme/pcie_pme.c b/drivers/pci/pcie/pme/pcie_pme.c
new file mode 100644
index 000000000000..b5f96fb3cd83
--- /dev/null
+++ b/drivers/pci/pcie/pme/pcie_pme.c
@@ -0,0 +1,493 @@
+/*
+ * PCIe Native PME support
+ *
+ * Copyright (C) 2007 - 2009 Intel Corp
+ * Copyright (C) 2007 - 2009 Shaohua Li <shaohua.li@intel.com>
+ * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License V2.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/pcieport_if.h>
+#include <linux/acpi.h>
+#include <linux/pci-acpi.h>
+#include <linux/pm_runtime.h>
+
+#include "../../pci.h"
+#include "pcie_pme.h"
+
+#define PCI_EXP_RTSTA_PME       0x10000 /* PME status */
+#define PCI_EXP_RTSTA_PENDING   0x20000 /* PME pending */
+
+/*
+ * If set, this switch will prevent the PCIe root port PME service driver from
+ * being registered.  Consequently, the interrupt-based PCIe PME signaling will
+ * not be used by any PCIe root ports in that case.
+ */
+static bool pcie_pme_disabled;
+
+/*
+ * The PCI Express Base Specification 2.0, Section 6.1.8, states the following:
+ * "In order to maintain compatibility with non-PCI Express-aware system
+ * software, system power management logic must be configured by firmware to use
+ * the legacy mechanism of signaling PME by default.  PCI Express-aware system
+ * software must notify the firmware prior to enabling native, interrupt-based
+ * PME signaling."  However, if the platform doesn't provide us with a suitable
+ * notification mechanism or the notification fails, it is not clear whether or
+ * not we are supposed to use the interrupt-based PCIe PME signaling.  The
+ * switch below can be used to indicate the desired behaviour.  When set, it
+ * will make the kernel use the interrupt-based PCIe PME signaling regardless of
+ * the platform notification status, although the kernel will attempt to notify
+ * the platform anyway.  When unset, it will prevent the kernel from using the
+ * the interrupt-based PCIe PME signaling if the platform notification fails,
+ * which is the default.
+ */
+static bool pcie_pme_force_enable;
+
+static int __init pcie_pme_setup(char *str)
+{
+        if (!strcmp(str, "off"))
+                pcie_pme_disabled = true;
+        else if (!strcmp(str, "force"))
+                pcie_pme_force_enable = true;
+        return 1;
+}
+__setup("pcie_pme=", pcie_pme_setup);
+
+/**
+ * pcie_pme_platform_setup - Ensure that the kernel controls the PCIe PME.
+ * @srv: PCIe PME root port service to use for carrying out the check.
+ *
+ * Notify the platform that the native PCIe PME is going to be used and return
+ * 'true' if the control of the PCIe PME registers has been acquired from the
+ * platform.
+ */
+static bool pcie_pme_platform_setup(struct pcie_device *srv)
+{
+        return !pcie_pme_platform_notify(srv) || pcie_pme_force_enable;
+}
+
+struct pcie_pme_service_data {
+        spinlock_t lock;
+        struct pcie_device *srv;
+        struct work_struct work;
+        bool noirq; /* Don't enable the PME interrupt used by this service. */
+};
+
+/**
+ * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
+ * @dev: PCIe root port or event collector.
+ * @enable: Enable or disable the interrupt.
+ */
+static void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
+{
+        int rtctl_pos;
+        u16 rtctl;
+
+        rtctl_pos = pci_find_capability(dev, PCI_CAP_ID_EXP) + PCI_EXP_RTCTL;
+
+        pci_read_config_word(dev, rtctl_pos, &rtctl);
+        if (enable)
+                rtctl |= PCI_EXP_RTCTL_PMEIE;
+        else
+                rtctl &= ~PCI_EXP_RTCTL_PMEIE;
+        pci_write_config_word(dev, rtctl_pos, rtctl);
+}
+
+/**
+ * pcie_pme_clear_status - Clear root port PME interrupt status.
+ * @dev: PCIe root port or event collector.
+ */
+static void pcie_pme_clear_status(struct pci_dev *dev)
+{
+        int rtsta_pos;
+        u32 rtsta;
+
+        rtsta_pos = pci_find_capability(dev, PCI_CAP_ID_EXP) + PCI_EXP_RTSTA;
+
+        pci_read_config_dword(dev, rtsta_pos, &rtsta);
+        rtsta |= PCI_EXP_RTSTA_PME;
+        pci_write_config_dword(dev, rtsta_pos, rtsta);
+}
+
+/**
+ * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
+ * @bus: PCI bus to scan.
+ *
+ * Scan given PCI bus and all buses under it for devices asserting PME#.
+ */
+static bool pcie_pme_walk_bus(struct pci_bus *bus)
+{
+        struct pci_dev *dev;
+        bool ret = false;
+
+        list_for_each_entry(dev, &bus->devices, bus_list) {
+                /* Skip PCIe devices in case we started from a root port. */
+                if (!dev->is_pcie && pci_check_pme_status(dev)) {
+                        pm_request_resume(&dev->dev);
+                        ret = true;
+                }
+
+                if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
+                        ret = true;
+        }
+
+        return ret;
+}
+
+/**
+ * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
+ * @bus: Secondary bus of the bridge.
+ * @devfn: Device/function number to check.
+ *
+ * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
+ * PCIe PME message.  In such that case the bridge should use the Requester ID
+ * of device/function number 0 on its secondary bus.
+ */
+static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
+{
+        struct pci_dev *dev;
+        bool found = false;
+
+        if (devfn)
+                return false;
+
+        dev = pci_dev_get(bus->self);
+        if (!dev)
+                return false;
+
+        if (dev->is_pcie && dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
+                down_read(&pci_bus_sem);
+                if (pcie_pme_walk_bus(bus))
+                        found = true;
+                up_read(&pci_bus_sem);
+        }
+
+        pci_dev_put(dev);
+        return found;
+}
+
+/**
+ * pcie_pme_handle_request - Find device that generated PME and handle it.
+ * @port: Root port or event collector that generated the PME interrupt.
+ * @req_id: PCIe Requester ID of the device that generated the PME.
+ */
+static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
+{
+        u8 busnr = req_id >> 8, devfn = req_id & 0xff;
+        struct pci_bus *bus;
+        struct pci_dev *dev;
+        bool found = false;
+
+        /* First, check if the PME is from the root port itself. */
+        if (port->devfn == devfn && port->bus->number == busnr) {
+                if (pci_check_pme_status(port)) {
+                        pm_request_resume(&port->dev);
+                        found = true;
+                } else {
+                        /*
+                         * Apparently, the root port generated the PME on behalf
+                         * of a non-PCIe device downstream.  If this is done by
+                         * a root port, the Requester ID field in its status
+                         * register may contain either the root port's, or the
+                         * source device's information (PCI Express Base
+                         * Specification, Rev. 2.0, Section 6.1.9).
+                         */
+                        down_read(&pci_bus_sem);
+                        found = pcie_pme_walk_bus(port->subordinate);
+                        up_read(&pci_bus_sem);
+                }
+                goto out;
+        }
+
+        /* Second, find the bus the source device is on. */
+        bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
+        if (!bus)
+                goto out;
+
+        /* Next, check if the PME is from a PCIe-PCI bridge. */
+        found = pcie_pme_from_pci_bridge(bus, devfn);
+        if (found)
+                goto out;
+
+        /* Finally, try to find the PME source on the bus. */
+        down_read(&pci_bus_sem);
+        list_for_each_entry(dev, &bus->devices, bus_list) {
+                pci_dev_get(dev);
+                if (dev->devfn == devfn) {
+                        found = true;
+                        break;
+                }
+                pci_dev_put(dev);
+        }
+        up_read(&pci_bus_sem);
+
+        if (found) {
+                /* The device is there, but we have to check its PME status. */
+                found = pci_check_pme_status(dev);
+                if (found)
+                        pm_request_resume(&dev->dev);
+                pci_dev_put(dev);
+        } else if (devfn) {
+                /*
+                 * The device is not there, but we can still try to recover by
+                 * assuming that the PME was reported by a PCIe-PCI bridge that
+                 * used devfn different from zero.
+                 */
+                dev_dbg(&port->dev, "PME interrupt generated for "
+                        "non-existent device %02x:%02x.%d\n",
+                        busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
+                found = pcie_pme_from_pci_bridge(bus, 0);
+        }
+
+ out:
+        if (!found)
+                dev_dbg(&port->dev, "Spurious native PME interrupt!\n");
+}
+
+/**
+ * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
+ * @work: Work structure giving access to service data.
+ */
+static void pcie_pme_work_fn(struct work_struct *work)
+{
+        struct pcie_pme_service_data *data =
+                        container_of(work, struct pcie_pme_service_data, work);
+        struct pci_dev *port = data->srv->port;
+        int rtsta_pos;
+        u32 rtsta;
+
+        rtsta_pos = pci_find_capability(port, PCI_CAP_ID_EXP) + PCI_EXP_RTSTA;
+
+        spin_lock_irq(&data->lock);
+
+        for (;;) {
+                if (data->noirq)
+                        break;
+
+                pci_read_config_dword(port, rtsta_pos, &rtsta);
+                if (rtsta & PCI_EXP_RTSTA_PME) {
+                        /*
+                         * Clear PME status of the port.  If there are other
+                         * pending PMEs, the status will be set again.
+                         */
+                        pcie_pme_clear_status(port);
+
+                        spin_unlock_irq(&data->lock);
+                        pcie_pme_handle_request(port, rtsta & 0xffff);
+                        spin_lock_irq(&data->lock);
+
+                        continue;
+                }
+
+                /* No need to loop if there are no more PMEs pending. */
+                if (!(rtsta & PCI_EXP_RTSTA_PENDING))
+                        break;
+
+                spin_unlock_irq(&data->lock);
+                cpu_relax();
+                spin_lock_irq(&data->lock);
+        }
+
+        if (!data->noirq)
+                pcie_pme_interrupt_enable(port, true);
+
+        spin_unlock_irq(&data->lock);
+}
+
+/**
+ * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
+ * @irq: Interrupt vector.
+ * @context: Interrupt context pointer.
+ */
+static irqreturn_t pcie_pme_irq(int irq, void *context)
+{
+        struct pci_dev *port;
+        struct pcie_pme_service_data *data;
+        int rtsta_pos;
+        u32 rtsta;
+        unsigned long flags;
+
+        port = ((struct pcie_device *)context)->port;
+        data = get_service_data((struct pcie_device *)context);
+
+        rtsta_pos = pci_find_capability(port, PCI_CAP_ID_EXP) + PCI_EXP_RTSTA;
+
+        spin_lock_irqsave(&data->lock, flags);
+        pci_read_config_dword(port, rtsta_pos, &rtsta);
+
+        if (!(rtsta & PCI_EXP_RTSTA_PME)) {
+                spin_unlock_irqrestore(&data->lock, flags);
+                return IRQ_NONE;
+        }
+
+        pcie_pme_interrupt_enable(port, false);
+        spin_unlock_irqrestore(&data->lock, flags);
+
+        /* We don't use pm_wq, because it's freezable. */
+        schedule_work(&data->work);
+
+        return IRQ_HANDLED;
+}
+
+/**
+ * pcie_pme_set_native - Set the PME interrupt flag for given device.
+ * @dev: PCI device to handle.
+ * @ign: Ignored.
+ */
+static int pcie_pme_set_native(struct pci_dev *dev, void *ign)
+{
+        dev_info(&dev->dev, "Signaling PME through PCIe PME interrupt\n");
+
+        device_set_run_wake(&dev->dev, true);
+        dev->pme_interrupt = true;
+        return 0;
+}
+
+/**
+ * pcie_pme_mark_devices - Set the PME interrupt flag for devices below a port.
+ * @port: PCIe root port or event collector to handle.
+ *
+ * For each device below given root port, including the port itself (or for each
+ * root complex integrated endpoint if @port is a root complex event collector)
+ * set the flag indicating that it can signal run-time wake-up events via PCIe
+ * PME interrupts.
+ */
+static void pcie_pme_mark_devices(struct pci_dev *port)
+{
+        pcie_pme_set_native(port, NULL);
+        if (port->subordinate) {
+                pci_walk_bus(port->subordinate, pcie_pme_set_native, NULL);
+        } else {
+                struct pci_bus *bus = port->bus;
+                struct pci_dev *dev;
+
+                /* Check if this is a root port event collector. */
+                if (port->pcie_type != PCI_EXP_TYPE_RC_EC || !bus)
+                        return;
+
+                down_read(&pci_bus_sem);
+                list_for_each_entry(dev, &bus->devices, bus_list)
+                        if (dev->is_pcie
+                            && dev->pcie_type == PCI_EXP_TYPE_RC_END)
+                                pcie_pme_set_native(dev, NULL);
+                up_read(&pci_bus_sem);
+        }
+}
+
+/**
+ * pcie_pme_probe - Initialize PCIe PME service for given root port.
+ * @srv: PCIe service to initialize.
+ */
+static int pcie_pme_probe(struct pcie_device *srv)
+{
+        struct pci_dev *port;
+        struct pcie_pme_service_data *data;
+        int ret;
+
+        if (!pcie_pme_platform_setup(srv))
+                return -EACCES;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        spin_lock_init(&data->lock);
+        INIT_WORK(&data->work, pcie_pme_work_fn);
+        data->srv = srv;
+        set_service_data(srv, data);
+
+        port = srv->port;
+        pcie_pme_interrupt_enable(port, false);
+        pcie_pme_clear_status(port);
+
+        ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
+        if (ret) {
+                kfree(data);
+        } else {
+                pcie_pme_mark_devices(port);
+                pcie_pme_interrupt_enable(port, true);
+        }
+
+        return ret;
+}
+
+/**
+ * pcie_pme_suspend - Suspend PCIe PME service device.
+ * @srv: PCIe service device to suspend.
+ */
+static int pcie_pme_suspend(struct pcie_device *srv)
+{
+        struct pcie_pme_service_data *data = get_service_data(srv);
+        struct pci_dev *port = srv->port;
+
+        spin_lock_irq(&data->lock);
+        pcie_pme_interrupt_enable(port, false);
+        pcie_pme_clear_status(port);
+        data->noirq = true;
+        spin_unlock_irq(&data->lock);
+
+        synchronize_irq(srv->irq);
+
+        return 0;
+}
+
+/**
+ * pcie_pme_resume - Resume PCIe PME service device.
+ * @srv - PCIe service device to resume.
+ */
+static int pcie_pme_resume(struct pcie_device *srv)
+{
+        struct pcie_pme_service_data *data = get_service_data(srv);
+        struct pci_dev *port = srv->port;
+
+        spin_lock_irq(&data->lock);
+        data->noirq = false;
+        pcie_pme_clear_status(port);
+        pcie_pme_interrupt_enable(port, true);
+        spin_unlock_irq(&data->lock);
+
+        return 0;
+}
+
+/**
+ * pcie_pme_remove - Prepare PCIe PME service device for removal.
+ * @srv - PCIe service device to resume.
+ */
+static void pcie_pme_remove(struct pcie_device *srv)
+{
+        pcie_pme_suspend(srv);
+        free_irq(srv->irq, srv);
+        kfree(get_service_data(srv));
+}
+
+static struct pcie_port_service_driver pcie_pme_driver = {
+        .name           = "pcie_pme",
+        .port_type      = PCI_EXP_TYPE_ROOT_PORT,
+        .service        = PCIE_PORT_SERVICE_PME,
+
+        .probe          = pcie_pme_probe,
+        .suspend        = pcie_pme_suspend,
+        .resume         = pcie_pme_resume,
+        .remove         = pcie_pme_remove,
+};
+
+/**
+ * pcie_pme_service_init - Register the PCIe PME service driver.
+ */
+static int __init pcie_pme_service_init(void)
+{
+        return pcie_pme_disabled ?
+                -ENODEV : pcie_port_service_register(&pcie_pme_driver);
+}
+
+module_init(pcie_pme_service_init);
diff --git a/drivers/pci/pcie/pme/pcie_pme.h b/drivers/pci/pcie/pme/pcie_pme.h
new file mode 100644
index 000000000000..b30d2b7c9775
--- /dev/null
+++ b/drivers/pci/pcie/pme/pcie_pme.h
@@ -0,0 +1,28 @@
+/*
+ * drivers/pci/pcie/pme/pcie_pme.h
+ *
+ * PCI Express Root Port PME signaling support
+ *
+ * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ */
+
+#ifndef _PCIE_PME_H_
+#define _PCIE_PME_H_
+
+struct pcie_device;
+
+#ifdef CONFIG_ACPI
+extern int pcie_pme_acpi_setup(struct pcie_device *srv);
+
+static inline int pcie_pme_platform_notify(struct pcie_device *srv)
+{
+        return pcie_pme_acpi_setup(srv);
+}
+#else /* !CONFIG_ACPI */
+static inline int pcie_pme_platform_notify(struct pcie_device *srv)
+{
+        return 0;
+}
+#endif /* !CONFIG_ACPI */
+
+#endif
diff --git a/drivers/pci/pcie/pme/pcie_pme_acpi.c b/drivers/pci/pcie/pme/pcie_pme_acpi.c
new file mode 100644
index 000000000000..83ab2287ae3f
--- /dev/null
+++ b/drivers/pci/pcie/pme/pcie_pme_acpi.c
@@ -0,0 +1,54 @@
+/*
+ * PCIe Native PME support, ACPI-related part
+ *
+ * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License V2.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/acpi.h>
+#include <linux/pci-acpi.h>
+#include <linux/pcieport_if.h>
+
+/**
+ * pcie_pme_acpi_setup - Request the ACPI BIOS to release control over PCIe PME.
+ * @srv - PCIe PME service for a root port or event collector.
+ *
+ * Invoked when the PCIe bus type loads PCIe PME service driver.  To avoid
+ * conflict with the BIOS PCIe support requires the BIOS to yield PCIe PME
+ * control to the kernel.
+ */
+int pcie_pme_acpi_setup(struct pcie_device *srv)
+{
+        acpi_status status = AE_NOT_FOUND;
+        struct pci_dev *port = srv->port;
+        acpi_handle handle;
+        int error = 0;
+
+        if (acpi_pci_disabled)
+                return -ENOSYS;
+
+        dev_info(&port->dev, "Requesting control of PCIe PME from ACPI BIOS\n");
+
+        handle = acpi_find_root_bridge_handle(port);
+        if (!handle)
+                return -EINVAL;
+
+        status = acpi_pci_osc_control_set(handle,
+                        OSC_PCI_EXPRESS_PME_CONTROL |
+                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+        if (ACPI_FAILURE(status)) {
+                dev_info(&port->dev,
+                        "Failed to receive control of PCIe PME service: %s\n",
+                        (status == AE_SUPPORT || status == AE_NOT_FOUND) ?
+                        "no _OSC support" : "ACPI _OSC failed");
+                error = -ENODEV;
+        }
+
+        return error;
+}