Linux-libre 4.7.1-gnupck-4.7.1-gnu

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
new file mode 100644
index 000000000..ab552f1bc
--- /dev/null
+++ b/drivers/pci/pcie/pcie-dpc.c
@@ -0,0 +1,163 @@
+/*
+ * 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);