drivers/xen/xen-pciback/conf_space_capability_msi.c

   1 /*
   2  * PCI Backend -- Configuration overlay for MSI capability
   3  */
   4 #include <linux/pci.h>
   5 #include <linux/slab.h>
   6 #include "conf_space.h"
   7 #include "conf_space_capability.h"
   8 #include <xen/interface/io/pciif.h>
   9 #include <xen/events.h>
  10 #include "pciback.h"
  11
  12 int pciback_enable_msi(struct pciback_device *pdev,
  13                 struct pci_dev *dev, struct xen_pci_op *op)
  14 {
  15         int otherend = pdev->xdev->otherend_id;
  16         int status;
  17
  18         status = pci_enable_msi(dev);
  19
  20         if (status) {
  21                 printk(KERN_ERR "error enable msi for guest %x status %x\n",
  22                         otherend, status);
  23                 op->value = 0;
  24                 return XEN_PCI_ERR_op_failed;
  25         }
  26
  27         /* The value the guest needs is actually the IDT vector, not the
  28          * the local domain's IRQ number. */
  29
  30         op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
  31         return 0;
  32 }
  33
  34 int pciback_disable_msi(struct pciback_device *pdev,
  35                 struct pci_dev *dev, struct xen_pci_op *op)
  36 {
  37         pci_disable_msi(dev);
  38
  39         op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
  40         return 0;
  41 }
  42
  43 int pciback_enable_msix(struct pciback_device *pdev,
  44                 struct pci_dev *dev, struct xen_pci_op *op)
  45 {
  46         int i, result;
  47         struct msix_entry *entries;
  48
  49         if (op->value > SH_INFO_MAX_VEC)
  50                 return -EINVAL;
  51
  52         entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
  53         if (entries == NULL)
  54                 return -ENOMEM;
  55
  56         for (i = 0; i < op->value; i++) {
  57                 entries[i].entry = op->msix_entries[i].entry;
  58                 entries[i].vector = op->msix_entries[i].vector;
  59         }
  60
  61         result = pci_enable_msix(dev, entries, op->value);
  62
  63         if (result == 0) {
  64                 for (i = 0; i < op->value; i++) {
  65                         op->msix_entries[i].entry = entries[i].entry;
  66                         if (entries[i].vector)
  67                                 op->msix_entries[i].vector =
  68                                         xen_pirq_from_irq(entries[i].vector);
  69                 }
  70         } else {
  71                 printk(KERN_WARNING "pciback: %s: failed to enable MSI-X: err %d!\n",
  72                         pci_name(dev), result);
  73         }
  74         kfree(entries);
  75
  76         op->value = result;
  77
  78         return result;
  79 }
  80
  81 int pciback_disable_msix(struct pciback_device *pdev,
  82                 struct pci_dev *dev, struct xen_pci_op *op)
  83 {
  84
  85         pci_disable_msix(dev);
  86
  87         /*
  88          * SR-IOV devices (which don't have any legacy IRQ) have
  89          * an undefined IRQ value of zero.
  90          */
  91         op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
  92         return 0;
  93 }
  94