pme.rar_V2

/* * 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/slab.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/device.h> #include <linux/pcieport_if.h> #include <linux/pm_runtime.h> #include "../pci.h" #include "portdrv.h" /* * If this switch is set, MSI will not be used for PCIe PME signaling. This * causes the PCIe port driver to use INTx interrupts only, but it turns out * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based * wake-up from system sleep states. */ bool pcie_pme_msi_disabled; static int __init pcie_pme_setup(char *str) { if (!strncmp(str, "nomsi", 5)) pcie_pme_msi_disabled = true; return 1; } __setup("pcie_pme=", pcie_pme_setup); enum pme_suspend_level { PME_SUSPEND_NONE = 0, PME_SUSPEND_WAKEUP, PME_SUSPEND_NOIRQ, }; struct pcie_pme_service_data { spinlock_t lock; struct pcie_device *srv; struct work_struct work; enum pme_suspend_level suspend_level; }; /** * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation. * @dev: PCIe root port or event collector. * @enable: Enable or disable the interrupt. */ void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable) { if (enable) pcie_capability_set_word(dev, PCI_EXP_RTCTL, PCI_EXP_RTCTL_PMEIE); else pcie_capability_clear_word(dev, PCI_EXP_RTCTL, PCI_EXP_RTCTL_PMEIE); } /** * 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 (!pci_is_pcie(dev) && pci_check_pme_status(dev)) { if (dev->pme_poll) dev->pme_poll = false; pci_wakeup_event(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 (pci_is_pcie(dev) && pci_pcie_type(dev) == 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 (port->pme_poll) port->pme_poll = false; 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) { if (dev->pme_poll) dev->pme_poll = false; pci_wakeup_event(dev); 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; u32 rtsta; spin_lock_irq(&data->lock); for (;;) { if (data->suspend_level != PME_SUSPEND_NONE) break; pcie_capability_read_dword(port, PCI_EXP_RTSTA, &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_clear_root_pme_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->suspend_level == PME_SUSPEND_NONE) 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; u32 rtsta; unsigned long flags; port = ((struct pcie_device *)context)->port; data = get_service_data((struct pcie_device *)context); spin_lock_irqsave(&data->lock, flags); pcie_capability_read_dword(port, PCI_EXP_RTSTA, &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