--- /dev/null
+/*
+ * PCI Express Downstream Port Containment services driver
+ * Copyright (C) 2016 Intel Corp.
+ *
+ * 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/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pcieport_if.h>
+
+struct dpc_dev {
+ struct pcie_device *dev;
+ struct work_struct work;
+ int cap_pos;
+};
+
+static void dpc_wait_link_inactive(struct pci_dev *pdev)
+{
+ unsigned long timeout = jiffies + HZ;
+ u16 lnk_status;
+
+ pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+ while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
+ !time_after(jiffies, timeout)) {
+ msleep(10);
+ pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+ }
+ if (lnk_status & PCI_EXP_LNKSTA_DLLLA)
+ dev_warn(&pdev->dev, "Link state not disabled for DPC event");
+}
+
+static void interrupt_event_handler(struct work_struct *work)
+{
+ struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
+ struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
+ struct pci_bus *parent = pdev->subordinate;
+
+ pci_lock_rescan_remove();
+ list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
+ bus_list) {
+ pci_dev_get(dev);
+ pci_stop_and_remove_bus_device(dev);
+ pci_dev_put(dev);
+ }
+ pci_unlock_rescan_remove();
+
+ dpc_wait_link_inactive(pdev);
+ pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
+ PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
+}
+
+static irqreturn_t dpc_irq(int irq, void *context)
+{
+ struct dpc_dev *dpc = (struct dpc_dev *)context;
+ struct pci_dev *pdev = dpc->dev->port;
+ u16 status, source;
+
+ pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
+ pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_SOURCE_ID,
+ &source);
+ if (!status)
+ return IRQ_NONE;
+
+ dev_info(&dpc->dev->device, "DPC containment event, status:%#06x source:%#06x\n",
+ status, source);
+
+ if (status & PCI_EXP_DPC_STATUS_TRIGGER) {
+ u16 reason = (status >> 1) & 0x3;
+
+ dev_warn(&dpc->dev->device, "DPC %s triggered, remove downstream devices\n",
+ (reason == 0) ? "unmasked uncorrectable error" :
+ (reason == 1) ? "ERR_NONFATAL" :
+ (reason == 2) ? "ERR_FATAL" : "extended error");
+ schedule_work(&dpc->work);
+ }
+ return IRQ_HANDLED;
+}
+
+#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
+static int dpc_probe(struct pcie_device *dev)
+{
+ struct dpc_dev *dpc;
+ struct pci_dev *pdev = dev->port;
+ int status;
+ u16 ctl, cap;
+
+ dpc = kzalloc(sizeof(*dpc), GFP_KERNEL);
+ if (!dpc)
+ return -ENOMEM;
+
+ dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
+ dpc->dev = dev;
+ INIT_WORK(&dpc->work, interrupt_event_handler);
+ set_service_data(dev, dpc);
+
+ status = request_irq(dev->irq, dpc_irq, IRQF_SHARED, "pcie-dpc", dpc);
+ if (status) {
+ dev_warn(&dev->device, "request IRQ%d failed: %d\n", dev->irq,
+ status);
+ goto out;
+ }
+
+ pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
+ pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
+
+ ctl |= PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN;
+ pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+
+ dev_info(&dev->device, "DPC error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n",
+ cap & 0xf, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT),
+ FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP),
+ FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), (cap >> 8) & 0xf,
+ FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
+ return status;
+ out:
+ kfree(dpc);
+ return status;
+}
+
+static void dpc_remove(struct pcie_device *dev)
+{
+ struct dpc_dev *dpc = get_service_data(dev);
+ struct pci_dev *pdev = dev->port;
+ u16 ctl;
+
+ pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
+ ctl &= ~(PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN);
+ pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+
+ free_irq(dev->irq, dpc);
+ kfree(dpc);
+}
+
+static struct pcie_port_service_driver dpcdriver = {
+ .name = "dpc",
+ .port_type = PCI_EXP_TYPE_ROOT_PORT | PCI_EXP_TYPE_DOWNSTREAM,
+ .service = PCIE_PORT_SERVICE_DPC,
+ .probe = dpc_probe,
+ .remove = dpc_remove,
+};
+
+static int __init dpc_service_init(void)
+{
+ return pcie_port_service_register(&dpcdriver);
+}
+
+static void __exit dpc_service_exit(void)
+{
+ pcie_port_service_unregister(&dpcdriver);
+}
+
+MODULE_DESCRIPTION("PCI Express Downstream Port Containment driver");
+MODULE_AUTHOR("Keith Busch <keith.busch@intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
+
+module_init(dpc_service_init);
+module_exit(dpc_service_exit);
git.samba.org / sfrench / cifs-2.6.git / commitdiff