Merge tag 'hwmon-for-linus-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / drivers / xen / platform-pci.c

diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index 112ce422dc2268f25d7266e42797d6ddfa1a8fe4..2a165cc8a43cd6768529ffe48126c172e5b9f7df 100644 (file)
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -42,6 +42,7 @@
 static unsigned long platform_mmio;
 static unsigned long platform_mmio_alloc;
 static unsigned long platform_mmiolen;
+static uint64_t callback_via;
 
 static unsigned long alloc_xen_mmio(unsigned long len)
 {
@@ -54,6 +55,51 @@ static unsigned long alloc_xen_mmio(unsigned long len)
        return addr;
 }
 
+static uint64_t get_callback_via(struct pci_dev *pdev)
+{
+       u8 pin;
+       int irq;
+
+       irq = pdev->irq;
+       if (irq < 16)
+               return irq; /* ISA IRQ */
+
+       pin = pdev->pin;
+
+       /* We don't know the GSI. Specify the PCI INTx line instead. */
+       return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
+               ((uint64_t)pci_domain_nr(pdev->bus) << 32) |
+               ((uint64_t)pdev->bus->number << 16) |
+               ((uint64_t)(pdev->devfn & 0xff) << 8) |
+               ((uint64_t)(pin - 1) & 3);
+}
+
+static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
+{
+       xen_hvm_evtchn_do_upcall();
+       return IRQ_HANDLED;
+}
+
+static int xen_allocate_irq(struct pci_dev *pdev)
+{
+       return request_irq(pdev->irq, do_hvm_evtchn_intr,
+                       IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
+                       "xen-platform-pci", pdev);
+}
+
+static int platform_pci_resume(struct pci_dev *pdev)
+{
+       int err;
+       if (!xen_pv_domain())
+               return 0;
+       err = xen_set_callback_via(callback_via);
+       if (err) {
+               dev_err(&pdev->dev, "platform_pci_resume failure!\n");
+               return err;
+       }
+       return 0;
+}
+
 static int platform_pci_probe(struct pci_dev *pdev,
                              const struct pci_device_id *ent)
 {
@@ -92,6 +138,28 @@ static int platform_pci_probe(struct pci_dev *pdev,
        platform_mmio = mmio_addr;
        platform_mmiolen = mmio_len;
 
+       /* 
+        * Xen HVM guests always use the vector callback mechanism.
+        * L1 Dom0 in a nested Xen environment is a PV guest inside in an
+        * HVM environment. It needs the platform-pci driver to get
+        * notifications from L0 Xen, but it cannot use the vector callback
+        * as it is not exported by L1 Xen.
+        */
+       if (xen_pv_domain()) {
+               ret = xen_allocate_irq(pdev);
+               if (ret) {
+                       dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
+                       goto out;
+               }
+               callback_via = get_callback_via(pdev);
+               ret = xen_set_callback_via(callback_via);
+               if (ret) {
+                       dev_warn(&pdev->dev, "Unable to set the evtchn callback "
+                                        "err=%d\n", ret);
+                       goto out;
+               }
+       }
+
        max_nr_gframes = gnttab_max_grant_frames();
        grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
        ret = gnttab_setup_auto_xlat_frames(grant_frames);
@@ -123,6 +191,9 @@ static struct pci_driver platform_driver = {
        .name =           DRV_NAME,
        .probe =          platform_pci_probe,
        .id_table =       platform_pci_tbl,
+#ifdef CONFIG_PM
+       .resume_early =   platform_pci_resume,
+#endif
 };
 
 builtin_pci_driver(platform_driver);