passthrough: move pci_read_intx() and pci_intx()

Move pci_read_intx() and pci_intx() to above pt_irqpin_reg_init().
This is requred for a subsequent patch where pt_irqpin_reg_init()
calls pci_read_intx().

Cc: Tom Rotenberg <tom.rotenberg@gmail.com>
Cc: Edwin Zhai <edwin.zhai@intel.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
[patch 1/2] qemu-xen: pass-through: move pci_read_intx() and pci_intx()

From:

[patch 0/2] qemu-xen: pass-through: always use hw intx
pass-through: always use hw intx and always get it from the same place

The assumption that function zero always uses INTA tuns out not
to be true in the wild. This leaves us with three options.

1) Always use INTA

   This was the case before multi-function pass-through was possible.
   But with the advent of multi-function pass-through this may lead
   to excessive virtual GSI sharing.

2) Fix emulation to use INTA for function zero

3) Always use the hardware value for INTx

There doesn't seem to be much between 2) and 3) but the latter seems
slightly cleaner so I advocate that approach.

diff --git a/hw/pass-through.c b/hw/pass-through.c
index e7bd38602a4ad1bf084e3655e535ef4288f1cbe5..bda908ab4557bb2951cc44242268d19a50b26845 100644 (file)
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -1021,6 +1021,64 @@ int bdf_to_devfn(char *bdf_str)
     return -1;
 }
 
+/* The PCI Local Bus Specification, Rev. 3.0,
+ * Section 6.2.4 Miscellaneous Registers, pp 223
+ * outlines 5 valid values for the intertupt pin (intx).
+ *  0: For devices (or device functions) that don't use an interrupt in
+ *  1: INTA#
+ *  2: INTB#
+ *  3: INTC#
+ *  4: INTD#
+ *
+ * Xen uses the following 4 values for intx
+ *  0: INTA#
+ *  1: INTB#
+ *  2: INTC#
+ *  3: INTD#
+ *
+ * Observing that these list of values are not the same, pci_read_intx()
+ * uses the following mapping from hw to xen values.
+ * This seems to reflect the current usage within Xen.
+ *
+ * PCI hardware    | Xen | Notes
+ * ----------------+-----+----------------------------------------------------
+ * 0               | 0   | No interrupt
+ * 1               | 0   | INTA#
+ * 2               | 1   | INTB#
+ * 3               | 2   | INTC#
+ * 4               | 3   | INTD#
+ * any other value | 0   | This should never happen, log error message
+ */
+static uint8_t pci_read_intx(struct pt_dev *ptdev)
+{
+    uint8_t r_val = pci_read_byte(ptdev->pci_dev, PCI_INTERRUPT_PIN);
+
+    PT_LOG("intx=%i\n", r_val);
+    if (r_val < 1 || r_val > 4)
+    {
+        PT_LOG("Interrupt pin read from hardware is out of range: "
+               "value=%i, acceptable range is 1 - 4\n", r_val);
+        r_val = 0;
+    }
+    else
+    {
+        r_val -= 1;
+    }
+
+    return r_val;
+}
+
+/*
+ * For virtual function 0, always use INTA#,
+ * otherwise use the hardware value
+ */
+uint8_t pci_intx(struct pt_dev *ptdev)
+{
+    if (!PCI_FUNC(ptdev->dev.devfn))
+        return 0;
+    return pci_read_intx(ptdev);
+}
+
 /* Being called each time a mmio region has been updated */
 static void pt_iomem_map(PCIDevice *d, int i, uint32_t e_phys, uint32_t e_size,
                          int type)
@@ -4470,61 +4528,3 @@ int pt_init(PCIBus *e_bus)
 
     return 0;
 }
-
-/* The PCI Local Bus Specification, Rev. 3.0,
- * Section 6.2.4 Miscellaneous Registers, pp 223
- * outlines 5 valid values for the intertupt pin (intx).
- *  0: For devices (or device functions) that don't use an interrupt in
- *  1: INTA#
- *  2: INTB#
- *  3: INTC#
- *  4: INTD#
- *
- * Xen uses the following 4 values for intx
- *  0: INTA#
- *  1: INTB#
- *  2: INTC#
- *  3: INTD#
- *
- * Observing that these list of values are not the same, pci_read_intx()
- * uses the following mapping from hw to xen values.
- * This seems to reflect the current usage within Xen.
- *
- * PCI hardware    | Xen | Notes
- * ----------------+-----+----------------------------------------------------
- * 0               | 0   | No interrupt
- * 1               | 0   | INTA#
- * 2               | 1   | INTB#
- * 3               | 2   | INTC#
- * 4               | 3   | INTD#
- * any other value | 0   | This should never happen, log error message
- */
-static uint8_t pci_read_intx(struct pt_dev *ptdev)
-{
-    uint8_t r_val = pci_read_byte(ptdev->pci_dev, PCI_INTERRUPT_PIN);
-
-    PT_LOG("intx=%i\n", r_val);
-    if (r_val < 1 || r_val > 4)
-    {
-        PT_LOG("Interrupt pin read from hardware is out of range: "
-               "value=%i, acceptable range is 1 - 4\n", r_val);
-        r_val = 0;
-    }
-    else
-    {
-        r_val -= 1;
-    }
-
-    return r_val;
-}
-
-/*
- * For virtual function 0, always use INTA#,
- * otherwise use the hardware value
- */
-uint8_t pci_intx(struct pt_dev *ptdev)
-{
-    if (!PCI_FUNC(ptdev->dev.devfn))
-        return 0;
-    return pci_read_intx(ptdev);
-}