PCIe defines a native PME detection mechanism. When a PCIe endpoint invokes PME, PCIe root port has a set of regisets to detect the endpoint's bus/device/function number and root port will send out interrupt when PME is received. See PCIe spec for detail. This patch implements this feature.
---
drivers/pci/pcie/Kconfig | 7 +
drivers/pci/pcie/Makefile | 2
drivers/pci/pcie/npme.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci_regs.h | 1
4 files changed, 322 insertions(+)
Index: linux/drivers/pci/pcie/Kconfig
===================================================================
--- linux.orig/drivers/pci/pcie/Kconfig 2008-09-11 11:27:44.000000000 +0800
+++ linux/drivers/pci/pcie/Kconfig 2008-09-11 11:28:39.000000000 +0800
@@ -46,3 +46,10 @@ config PCIEASPM_DEBUG
help
This enables PCI Express ASPM debug support. It will add per-device
interface to control ASPM.
+
+config PCIENPME
+ bool "PCIE Native PME support(Experimental)"
+ depends on PCIEPORTBUS && EXPERIMENTAL
+ help
+ This enables PCI Express Native PME Reporting.
+
Index: linux/drivers/pci/pcie/Makefile
===================================================================
--- linux.orig/drivers/pci/pcie/Makefile 2008-09-11 11:27:44.000000000 +0800
+++ linux/drivers/pci/pcie/Makefile 2008-09-11 11:28:39.000000000 +0800
@@ -11,3 +11,5 @@ obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv
# Build PCI Express AER if needed
obj-$(CONFIG_PCIEAER) += aer/
+
+obj-$(CONFIG_PCIENPME) += npme.o
Index: linux/drivers/pci/pcie/npme.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/pci/pcie/npme.c 2008-09-11 11:30:26.000000000 +0800
@@ -0,0 +1,312 @@
+/*
+ * PCIE Native PME support
+ *
+ * Copyright (C) 2007 - 2008 Intel Corp
+ * Shaohua Li <shaohua.li@xxxxxxxxx>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. 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>
+
+static int disabled;
+module_param(disabled, bool, 0);
+static int force = 1;
+module_param(force, bool, 0);
+
+static struct pcie_port_service_id npme_id[] = {
+ {
+ .vendor = PCI_ANY_ID,
+ .device = PCI_ANY_ID,
+ .port_type = PCIE_RC_PORT,
+ .service_type = PCIE_PORT_SERVICE_PME,
+ },
+ { /* end: all zeroes */ }
+};
+
+struct npme_data {
+ spinlock_t lock;
+ struct pcie_device *dev;
+ struct work_struct work;
+ u16 bdf; /* device which invokes PME */
+ int exit;
+};
+
+static inline void npme_enable_pme(struct pci_dev *pdev, bool enable)
+{
+ int pos;
+ u16 rtctl;
+
+ pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
+
+ pci_read_config_word(pdev, pos + PCI_EXP_RTCTL, &rtctl);
+ if (!enable)
+ rtctl &= ~PCI_EXP_RTCTL_PMEIE;
+ else
+ rtctl |= PCI_EXP_RTCTL_PMEIE;
+ pci_write_config_word(pdev, pos + PCI_EXP_RTCTL, rtctl);
+}
+
+static inline void npme_clear_pme(struct pci_dev *pdev)
+{
+ int pos;
+ u32 rtsta;
+
+ pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
+
+ pci_read_config_dword(pdev, pos + PCI_EXP_RTSTA, &rtsta);
+ rtsta |= PCI_EXP_RTSTA_PME;
+ pci_write_config_dword(pdev, pos + PCI_EXP_RTSTA, rtsta);
+}
+
+static bool npme_pme_target(struct pci_dev *target)
+{
+ bool ret = false;
+ if (target->dev.bus->pm && target->dev.bus->pm->base.wakeup_event)
+ ret = target->dev.bus->pm->base.wakeup_event(&target->dev);
+ return ret;
+}
+
+static void npme_work_handle(struct work_struct *work)
+{
+ struct npme_data *data = container_of(work, struct npme_data, work);
+ struct pcie_device *dev = data->dev;
+ unsigned long flags;
+ struct pci_dev *target;
+ bool has_dev = false;
+
+ target = pci_get_bus_and_slot(data->bdf >> 8, data->bdf & 0xff);
+ /* PCIe-PCI bridge might change bdf to (secondary bus numer, 0, 0) */
+ if (!target && (data->bdf & 0xff) == 0) {
+ struct pci_bus *bus;
+
+ bus = pci_find_bus(pci_domain_nr(dev->port->bus),
+ data->bdf >> 8);
+ if (bus) {
+ target = bus->self;
+ if (!target->is_pcie || target->pcie_type !=
+ PCI_EXP_TYPE_PCI_BRIDGE)
+ target = NULL;
+ }
+ if (target)
+ pci_dev_get(target);
+ }
+
+ if (target)
+ has_dev = npme_pme_target(target);
+ else
+ printk(KERN_ERR"Can't find device %02d:%d.%d which invokes PME\n",
+ data->bdf >> 8, PCI_SLOT(data->bdf),
+ PCI_FUNC(data->bdf));
+
+ spin_lock_irqsave(&data->lock, flags);
+ /* clear pending PME */
+ npme_clear_pme(dev->port);
+ /* reenable native PME */
+ if (!data->exit)
+ npme_enable_pme(dev->port, true);
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ if (!has_dev)
+ printk(KERN_ERR"Spurious Native PME interrupt %d received\n",
+ dev->irq);
+
+ if (target)
+ pci_dev_put(target);
+}
+
+static irqreturn_t npme_irq(int irq, void *context)
+{
+ int pos;
+ struct pci_dev *pdev;
+ u32 rtsta;
+ struct npme_data *data;
+ unsigned long flags;
+
+ pdev = ((struct pcie_device *)context)->port;
+ data = get_service_data((struct pcie_device *)context);
+
+ pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
+
+ spin_lock_irqsave(&data->lock, flags);
+ pci_read_config_dword(pdev, pos + PCI_EXP_RTSTA, &rtsta);
+ if (!(rtsta & PCI_EXP_RTSTA_PME)) {
+ spin_unlock_irqrestore(&data->lock, flags);
+ return IRQ_NONE;
+ }
+
+ data->bdf = (u16)rtsta;
+
+ /* disable PME to avoid interrupt flood */
+ npme_enable_pme(pdev, false);
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ schedule_work(&data->work);
+
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_ACPI
+static int npme_osc_setup(struct pcie_device *pciedev)
+{
+ acpi_status status = AE_NOT_FOUND;
+ struct pci_dev *pdev = pciedev->port;
+ acpi_handle handle = DEVICE_ACPI_HANDLE(&pdev->dev);
+
+ if (!handle)
+ return -EINVAL;
+ pcie_osc_support_set(OSC_EXT_PCI_CONFIG_SUPPORT);
+ status = pci_osc_control_set(handle,
+ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |
+ OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_DEBUG "Native PME service couldn't init device "
+ "%s - %s\n", pciedev->device.bus_id,
+ (status == AE_SUPPORT || status == AE_NOT_FOUND) ?
+ "no _OSC support" : "Run ACPI _OSC fails");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+#else
+static inline int npme_osc_setup(struct pcie_device *pciedev)
+{
+ return 0;
+}
+#endif
+
+static int __devinit npme_probe(struct pcie_device *dev,
+ const struct pcie_port_service_id *id)
+{
+ struct pci_dev *pdev;
+ int status;
+ struct npme_data *data;
+
+ if (npme_osc_setup(dev) && !force)
+ return -EINVAL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ spin_lock_init(&data->lock);
+ INIT_WORK(&data->work, npme_work_handle);
+ data->dev = dev;
+ set_service_data(dev, data);
+
+ pdev = dev->port;
+
+ /* clear pending PME */
+ npme_clear_pme(pdev);
+
+ status = request_irq(dev->irq, npme_irq, IRQF_SHARED, "npme", dev);
+ if (status) {
+ kfree(data);
+ return status;
+ }
+
+ /* enable PME interrupt */
+ npme_enable_pme(pdev, true);
+
+ return 0;
+}
+
+static void npme_remove(struct pcie_device *dev)
+{
+ struct pci_dev *pdev;
+ unsigned long flags;
+ struct npme_data *data = get_service_data(dev);
+
+ pdev = dev->port;
+
+ /* disable PME interrupt */
+ spin_lock_irqsave(&data->lock, flags);
+ data->exit = 1;
+ npme_enable_pme(pdev, false);
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ flush_scheduled_work();
+ free_irq(dev->irq, dev);
+
+ /* clear pending PME */
+ npme_clear_pme(pdev);
+
+ set_service_data(dev, NULL);
+ kfree(data);
+}
+
+static int npme_suspend(struct pcie_device *dev, pm_message_t state)
+{
+ struct pci_dev *pdev;
+ struct npme_data *data;
+ unsigned long flags;
+
+ pdev = dev->port;
+ data = get_service_data(dev);
+
+ spin_lock_irqsave(&data->lock, flags);
+ /* disable PME to avoid further interrupt */
+ npme_enable_pme(pdev, false);
+
+ /* clear pending PME */
+ npme_clear_pme(pdev);
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static int npme_resume(struct pcie_device *dev)
+{
+ struct pci_dev *pdev = dev->port;
+ unsigned long flags;
+ struct npme_data *data = get_service_data(dev);
+
+ spin_lock_irqsave(&data->lock, flags);
+ npme_clear_pme(pdev);
+ npme_enable_pme(pdev, true);
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static struct pcie_port_service_driver npme_driver = {
+ .name = "npme",
+ .id_table = &npme_id[0],
+
+ .probe = npme_probe,
+ .remove = npme_remove,
+ .suspend = npme_suspend,
+ .resume = npme_resume,
+};
+
+
+static int __init npme_service_init(void)
+{
+ if (disabled)
+ return -EINVAL;
+ return pcie_port_service_register(&npme_driver);
+}
+
+static void __exit npme_service_exit(void)
+{
+ pcie_port_service_unregister(&npme_driver);
+}
+
+module_init(npme_service_init);
+module_exit(npme_service_exit);
+
+MODULE_AUTHOR("Shaohua Li<shaohua.li@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
Index: linux/include/linux/pci_regs.h
===================================================================
--- linux.orig/include/linux/pci_regs.h 2008-09-11 11:27:44.000000000 +0800
+++ linux/include/linux/pci_regs.h 2008-09-11 11:28:39.000000000 +0800
@@ -419,6 +419,7 @@
#define PCI_EXP_RTCTL_CRSSVE 0x10 /* CRS Software Visibility Enable */
#define PCI_EXP_RTCAP 30 /* Root Capabilities */
#define PCI_EXP_RTSTA 32 /* Root Status */
+#define PCI_EXP_RTSTA_PME 0x10000 /* PME status */
/* Extended Capabilities (PCI-X 2.0 and Express) */
#define PCI_EXT_CAP_ID(header) (header & 0x0000ffff)
--
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