149 lines
4.2 KiB
C
149 lines
4.2 KiB
C
/*
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* PCI Express Downstream Port Containment services driver
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* Author: Keith Busch <keith.busch@intel.com>
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*
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* Copyright (C) 2016 Intel Corp.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/pci.h>
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#include <linux/pcieport_if.h>
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struct dpc_dev {
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struct pcie_device *dev;
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struct work_struct work;
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int cap_pos;
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};
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static void dpc_wait_link_inactive(struct pci_dev *pdev)
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{
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unsigned long timeout = jiffies + HZ;
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u16 lnk_status;
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pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
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while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
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!time_after(jiffies, timeout)) {
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msleep(10);
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pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
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}
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if (lnk_status & PCI_EXP_LNKSTA_DLLLA)
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dev_warn(&pdev->dev, "Link state not disabled for DPC event");
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}
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static void interrupt_event_handler(struct work_struct *work)
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{
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struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
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struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
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struct pci_bus *parent = pdev->subordinate;
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pci_lock_rescan_remove();
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list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
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bus_list) {
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pci_dev_get(dev);
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pci_stop_and_remove_bus_device(dev);
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pci_dev_put(dev);
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}
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pci_unlock_rescan_remove();
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dpc_wait_link_inactive(pdev);
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pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
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PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
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}
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static irqreturn_t dpc_irq(int irq, void *context)
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{
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struct dpc_dev *dpc = (struct dpc_dev *)context;
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struct pci_dev *pdev = dpc->dev->port;
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u16 status, source;
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pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
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pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_SOURCE_ID,
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&source);
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if (!status)
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return IRQ_NONE;
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dev_info(&dpc->dev->device, "DPC containment event, status:%#06x source:%#06x\n",
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status, source);
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if (status & PCI_EXP_DPC_STATUS_TRIGGER) {
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u16 reason = (status >> 1) & 0x3;
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dev_warn(&dpc->dev->device, "DPC %s triggered, remove downstream devices\n",
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(reason == 0) ? "unmasked uncorrectable error" :
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(reason == 1) ? "ERR_NONFATAL" :
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(reason == 2) ? "ERR_FATAL" : "extended error");
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schedule_work(&dpc->work);
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}
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return IRQ_HANDLED;
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}
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#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
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static int dpc_probe(struct pcie_device *dev)
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{
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struct dpc_dev *dpc;
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struct pci_dev *pdev = dev->port;
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int status;
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u16 ctl, cap;
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dpc = devm_kzalloc(&dev->device, sizeof(*dpc), GFP_KERNEL);
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if (!dpc)
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return -ENOMEM;
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dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
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dpc->dev = dev;
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INIT_WORK(&dpc->work, interrupt_event_handler);
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set_service_data(dev, dpc);
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status = devm_request_irq(&dev->device, dev->irq, dpc_irq, IRQF_SHARED,
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"pcie-dpc", dpc);
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if (status) {
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dev_warn(&dev->device, "request IRQ%d failed: %d\n", dev->irq,
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status);
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return status;
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}
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pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
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pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
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ctl |= PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN;
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pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
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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",
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cap & 0xf, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT),
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FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP),
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FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), (cap >> 8) & 0xf,
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FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
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return status;
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}
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static void dpc_remove(struct pcie_device *dev)
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{
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struct dpc_dev *dpc = get_service_data(dev);
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struct pci_dev *pdev = dev->port;
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u16 ctl;
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pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
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ctl &= ~(PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN);
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pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
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}
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static struct pcie_port_service_driver dpcdriver = {
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.name = "dpc",
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.port_type = PCIE_ANY_PORT,
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.service = PCIE_PORT_SERVICE_DPC,
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.probe = dpc_probe,
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.remove = dpc_remove,
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};
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static int __init dpc_service_init(void)
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{
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return pcie_port_service_register(&dpcdriver);
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}
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device_initcall(dpc_service_init);
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