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bdc5c1812c
While shuting down a HVM guest with pci devices passed through we get this: pciback 0000:04:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100002) ------------[ cut here ]------------ WARNING: at drivers/pci/pci.c:1397 pci_disable_device+0x88/0xa0() Hardware name: MS-7640 Device pciback disabling already-disabled device Modules linked in: Pid: 53, comm: xenwatch Not tainted 3.9.0-rc1-20130304a+ #1 Call Trace: [<ffffffff8106994a>] warn_slowpath_common+0x7a/0xc0 [<ffffffff81069a31>] warn_slowpath_fmt+0x41/0x50 [<ffffffff813cf288>] pci_disable_device+0x88/0xa0 [<ffffffff814554a7>] xen_pcibk_reset_device+0x37/0xd0 [<ffffffff81454b6f>] ? pcistub_put_pci_dev+0x6f/0x120 [<ffffffff81454b8d>] pcistub_put_pci_dev+0x8d/0x120 [<ffffffff814582a9>] __xen_pcibk_release_devices+0x59/0xa0 This fixes the bug. CC: stable@vger.kernel.org Reported-and-Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
385 lines
10 KiB
C
385 lines
10 KiB
C
/*
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* PCI Backend Operations - respond to PCI requests from Frontend
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*
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* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
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*/
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#include <linux/module.h>
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#include <linux/wait.h>
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#include <linux/bitops.h>
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#include <xen/events.h>
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#include <linux/sched.h>
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#include "pciback.h"
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int verbose_request;
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module_param(verbose_request, int, 0644);
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static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
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/* Ensure a device is has the fake IRQ handler "turned on/off" and is
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* ready to be exported. This MUST be run after xen_pcibk_reset_device
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* which does the actual PCI device enable/disable.
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*/
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static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
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{
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struct xen_pcibk_dev_data *dev_data;
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int rc;
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int enable = 0;
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dev_data = pci_get_drvdata(dev);
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if (!dev_data)
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return;
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/* We don't deal with bridges */
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if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
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return;
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if (reset) {
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dev_data->enable_intx = 0;
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dev_data->ack_intr = 0;
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}
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enable = dev_data->enable_intx;
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/* Asked to disable, but ISR isn't runnig */
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if (!enable && !dev_data->isr_on)
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return;
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/* Squirrel away the IRQs in the dev_data. We need this
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* b/c when device transitions to MSI, the dev->irq is
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* overwritten with the MSI vector.
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*/
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if (enable)
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dev_data->irq = dev->irq;
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/*
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* SR-IOV devices in all use MSI-X and have no legacy
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* interrupts, so inhibit creating a fake IRQ handler for them.
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*/
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if (dev_data->irq == 0)
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goto out;
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dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
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dev_data->irq_name,
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dev_data->irq,
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pci_is_enabled(dev) ? "on" : "off",
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dev->msi_enabled ? "MSI" : "",
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dev->msix_enabled ? "MSI/X" : "",
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dev_data->isr_on ? "enable" : "disable",
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enable ? "enable" : "disable");
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if (enable) {
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rc = request_irq(dev_data->irq,
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xen_pcibk_guest_interrupt, IRQF_SHARED,
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dev_data->irq_name, dev);
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if (rc) {
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dev_err(&dev->dev, "%s: failed to install fake IRQ " \
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"handler for IRQ %d! (rc:%d)\n",
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dev_data->irq_name, dev_data->irq, rc);
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goto out;
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}
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} else {
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free_irq(dev_data->irq, dev);
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dev_data->irq = 0;
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}
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dev_data->isr_on = enable;
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dev_data->ack_intr = enable;
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out:
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dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
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dev_data->irq_name,
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dev_data->irq,
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pci_is_enabled(dev) ? "on" : "off",
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dev->msi_enabled ? "MSI" : "",
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dev->msix_enabled ? "MSI/X" : "",
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enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
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(dev_data->isr_on ? "failed to disable" : "disabled"));
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}
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/* Ensure a device is "turned off" and ready to be exported.
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* (Also see xen_pcibk_config_reset to ensure virtual configuration space is
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* ready to be re-exported)
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*/
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void xen_pcibk_reset_device(struct pci_dev *dev)
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{
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u16 cmd;
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xen_pcibk_control_isr(dev, 1 /* reset device */);
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/* Disable devices (but not bridges) */
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if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
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#ifdef CONFIG_PCI_MSI
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/* The guest could have been abruptly killed without
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* disabling MSI/MSI-X interrupts.*/
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if (dev->msix_enabled)
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pci_disable_msix(dev);
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if (dev->msi_enabled)
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pci_disable_msi(dev);
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#endif
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if (pci_is_enabled(dev))
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pci_disable_device(dev);
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pci_write_config_word(dev, PCI_COMMAND, 0);
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dev->is_busmaster = 0;
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} else {
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pci_read_config_word(dev, PCI_COMMAND, &cmd);
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if (cmd & (PCI_COMMAND_INVALIDATE)) {
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cmd &= ~(PCI_COMMAND_INVALIDATE);
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pci_write_config_word(dev, PCI_COMMAND, cmd);
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dev->is_busmaster = 0;
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}
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}
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}
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#ifdef CONFIG_PCI_MSI
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static
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int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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struct xen_pcibk_dev_data *dev_data;
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int status;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
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status = pci_enable_msi(dev);
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if (status) {
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pr_warn_ratelimited(DRV_NAME ": %s: error enabling MSI for guest %u: err %d\n",
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pci_name(dev), pdev->xdev->otherend_id,
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status);
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op->value = 0;
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return XEN_PCI_ERR_op_failed;
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}
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/* The value the guest needs is actually the IDT vector, not the
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* the local domain's IRQ number. */
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op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
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op->value);
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dev_data = pci_get_drvdata(dev);
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if (dev_data)
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dev_data->ack_intr = 0;
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return 0;
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}
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static
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int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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struct xen_pcibk_dev_data *dev_data;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
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pci_name(dev));
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pci_disable_msi(dev);
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op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
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op->value);
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dev_data = pci_get_drvdata(dev);
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if (dev_data)
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dev_data->ack_intr = 1;
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return 0;
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}
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static
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int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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struct xen_pcibk_dev_data *dev_data;
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int i, result;
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struct msix_entry *entries;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
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pci_name(dev));
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if (op->value > SH_INFO_MAX_VEC)
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return -EINVAL;
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entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
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if (entries == NULL)
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return -ENOMEM;
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for (i = 0; i < op->value; i++) {
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entries[i].entry = op->msix_entries[i].entry;
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entries[i].vector = op->msix_entries[i].vector;
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}
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result = pci_enable_msix(dev, entries, op->value);
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if (result == 0) {
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for (i = 0; i < op->value; i++) {
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op->msix_entries[i].entry = entries[i].entry;
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if (entries[i].vector)
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op->msix_entries[i].vector =
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xen_pirq_from_irq(entries[i].vector);
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: " \
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"MSI-X[%d]: %d\n",
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pci_name(dev), i,
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op->msix_entries[i].vector);
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}
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} else
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pr_warn_ratelimited(DRV_NAME ": %s: error enabling MSI-X for guest %u: err %d!\n",
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pci_name(dev), pdev->xdev->otherend_id,
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result);
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kfree(entries);
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op->value = result;
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dev_data = pci_get_drvdata(dev);
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if (dev_data)
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dev_data->ack_intr = 0;
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return result > 0 ? 0 : result;
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}
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static
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int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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struct xen_pcibk_dev_data *dev_data;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
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pci_name(dev));
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pci_disable_msix(dev);
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/*
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* SR-IOV devices (which don't have any legacy IRQ) have
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* an undefined IRQ value of zero.
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*/
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op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
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op->value);
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dev_data = pci_get_drvdata(dev);
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if (dev_data)
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dev_data->ack_intr = 1;
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return 0;
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}
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#endif
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/*
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* Now the same evtchn is used for both pcifront conf_read_write request
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* as well as pcie aer front end ack. We use a new work_queue to schedule
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* xen_pcibk conf_read_write service for avoiding confict with aer_core
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* do_recovery job which also use the system default work_queue
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*/
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void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
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{
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/* Check that frontend is requesting an operation and that we are not
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* already processing a request */
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if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
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&& !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
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queue_work(xen_pcibk_wq, &pdev->op_work);
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}
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/*_XEN_PCIB_active should have been cleared by pcifront. And also make
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sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
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if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
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&& test_bit(_PCIB_op_pending, &pdev->flags)) {
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wake_up(&xen_pcibk_aer_wait_queue);
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}
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}
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/* Performing the configuration space reads/writes must not be done in atomic
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* context because some of the pci_* functions can sleep (mostly due to ACPI
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* use of semaphores). This function is intended to be called from a work
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* queue in process context taking a struct xen_pcibk_device as a parameter */
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void xen_pcibk_do_op(struct work_struct *data)
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{
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struct xen_pcibk_device *pdev =
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container_of(data, struct xen_pcibk_device, op_work);
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struct pci_dev *dev;
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struct xen_pcibk_dev_data *dev_data = NULL;
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struct xen_pci_op *op = &pdev->sh_info->op;
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int test_intx = 0;
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dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
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if (dev == NULL)
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op->err = XEN_PCI_ERR_dev_not_found;
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else {
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dev_data = pci_get_drvdata(dev);
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if (dev_data)
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test_intx = dev_data->enable_intx;
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switch (op->cmd) {
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case XEN_PCI_OP_conf_read:
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op->err = xen_pcibk_config_read(dev,
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op->offset, op->size, &op->value);
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break;
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case XEN_PCI_OP_conf_write:
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op->err = xen_pcibk_config_write(dev,
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op->offset, op->size, op->value);
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break;
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#ifdef CONFIG_PCI_MSI
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case XEN_PCI_OP_enable_msi:
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op->err = xen_pcibk_enable_msi(pdev, dev, op);
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break;
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case XEN_PCI_OP_disable_msi:
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op->err = xen_pcibk_disable_msi(pdev, dev, op);
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break;
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case XEN_PCI_OP_enable_msix:
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op->err = xen_pcibk_enable_msix(pdev, dev, op);
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break;
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case XEN_PCI_OP_disable_msix:
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op->err = xen_pcibk_disable_msix(pdev, dev, op);
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break;
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#endif
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default:
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op->err = XEN_PCI_ERR_not_implemented;
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break;
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}
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}
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if (!op->err && dev && dev_data) {
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/* Transition detected */
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if ((dev_data->enable_intx != test_intx))
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xen_pcibk_control_isr(dev, 0 /* no reset */);
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}
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/* Tell the driver domain that we're done. */
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wmb();
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clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
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notify_remote_via_irq(pdev->evtchn_irq);
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/* Mark that we're done. */
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smp_mb__before_clear_bit(); /* /after/ clearing PCIF_active */
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clear_bit(_PDEVF_op_active, &pdev->flags);
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smp_mb__after_clear_bit(); /* /before/ final check for work */
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/* Check to see if the driver domain tried to start another request in
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* between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
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*/
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xen_pcibk_test_and_schedule_op(pdev);
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}
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irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
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{
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struct xen_pcibk_device *pdev = dev_id;
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xen_pcibk_test_and_schedule_op(pdev);
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return IRQ_HANDLED;
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}
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static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
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{
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struct pci_dev *dev = (struct pci_dev *)dev_id;
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struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
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if (dev_data->isr_on && dev_data->ack_intr) {
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dev_data->handled++;
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if ((dev_data->handled % 1000) == 0) {
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if (xen_test_irq_shared(irq)) {
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printk(KERN_INFO "%s IRQ line is not shared "
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"with other domains. Turning ISR off\n",
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dev_data->irq_name);
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dev_data->ack_intr = 0;
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}
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}
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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}
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