From db0cb5681d34f0d78ae417a786ebdc0c4785fa03 Mon Sep 17 00:00:00 2001
From: Marcel Apfelbaum <marcel@redhat.com>
Date: Wed, 24 Jun 2015 13:53:32 +0200
Subject: [PATCH 209/217] hw/pxb: add map_irq func

Message-id: <1435154016-26233-40-git-send-email-marcel@redhat.com>
Patchwork-id: 66467
O-Subject: [RHEL-7.2 qemu-kvm-rhev PATCH 39/43] hw/pxb: add map_irq func
Bugzilla: 1103313
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>

The bios does not index the pxb slot number when
it computes the IRQ because it resides on bus 0
and not on the current bus.
However Qemu routes the irq through bus 0 and adds
the pxb slot to the IRQ computation of the PXB device.

Synchronize between bios and Qemu by canceling
pxb's effect.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
(cherry picked from commit 0639b00d055b313930c23c4d6c9ebfb4af61c00c)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/pci-bridge/pci_expander_bridge.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index 88e85c1..8660a00 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -120,6 +120,24 @@ static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
     return 0;
 }
 
+static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
+{
+    PCIDevice *pxb = pci_dev->bus->parent_dev;
+
+    /*
+     * The bios does not index the pxb slot number when
+     * it computes the IRQ because it resides on bus 0
+     * and not on the current bus.
+     * However QEMU routes the irq through bus 0 and adds
+     * the pxb slot to the IRQ computation of the PXB
+     * device.
+     *
+     * Synchronize between bios and QEMU by canceling
+     * pxb's effect.
+     */
+    return pin - PCI_SLOT(pxb->devfn);
+}
+
 static int pxb_dev_initfn(PCIDevice *dev)
 {
     PXBDev *pxb = PXB_DEV(dev);
@@ -137,7 +155,7 @@ static int pxb_dev_initfn(PCIDevice *dev)
     bus->parent_dev = dev;
     bus->address_space_mem = dev->bus->address_space_mem;
     bus->address_space_io = dev->bus->address_space_io;
-    bus->map_irq = pci_swizzle_map_irq_fn;
+    bus->map_irq = pxb_map_irq_fn;
 
     bds = qdev_create(BUS(bus), "pci-bridge");
     bds->id = dev_name;
-- 
1.8.3.1