[Qemu-devel] [PATCH v3 2/8] hw/pci: add pci wrappers for allocating and asserting irqs

[Marcel Apfelbaum <marcel.a@redhat.com>]

Interrupt pin is selected and saved into PCI_INTERRUPT_PIN
register during device initialization. Devices should not call
directly qemu_set_irq and specify the INTx pin on each call.

Added pci_* wrappers to replace qemu_set_irq, qemu_irq_raise,
qemu_irq_lower and qemu_irq_pulse, setting the irq
based on PCI_INTERRUPT_PIN.

Added pci_allocate_irq wrapper to be used by devices that
still need PCIDevice infrastructure to assert irqs.

Renamed a static method which was named already pci_set_irq.

Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
---
Changes from v2:
 - Addressed Michael S. Tsirkin's comments:
   - Add "fixme" comment to pci_irq_pulse
 - Addressed Alex Williamson's comments
   - replaced pci_irq_raise/lower with
     pci_irq_assert/deassert
 - Addressed Paolo Bonzini's comment:
   - fixed implementation of pci_irq_pulse
 
 hw/pci/pci.c         | 26 ++++++++++++++++++++++----
 include/hw/pci/pci.h | 23 +++++++++++++++++++++++
 2 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 00554a0..fbfd8f7 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -83,7 +83,7 @@ static const TypeInfo pcie_bus_info = {
 
 static PCIBus *pci_find_bus_nr(PCIBus *bus, int bus_num);
 static void pci_update_mappings(PCIDevice *d);
-static void pci_set_irq(void *opaque, int irq_num, int level);
+static void pci_irq_handler(void *opaque, int irq_num, int level);
 static int pci_add_option_rom(PCIDevice *pdev, bool is_default_rom);
 static void pci_del_option_rom(PCIDevice *pdev);
 
@@ -161,7 +161,7 @@ void pci_device_deassert_intx(PCIDevice *dev)
 {
     int i;
     for (i = 0; i < PCI_NUM_PINS; ++i) {
-        qemu_set_irq(dev->irq[i], 0);
+        pci_irq_handler(dev, i, 0);
     }
 }
 
@@ -863,7 +863,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
     pci_dev->config_read = config_read;
     pci_dev->config_write = config_write;
     bus->devices[devfn] = pci_dev;
-    pci_dev->irq = qemu_allocate_irqs(pci_set_irq, pci_dev, PCI_NUM_PINS);
+    pci_dev->irq = qemu_allocate_irqs(pci_irq_handler, pci_dev, PCI_NUM_PINS);
     pci_dev->version_id = 2; /* Current pci device vmstate version */
     return pci_dev;
 }
@@ -1175,7 +1175,7 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
 /* generic PCI irq support */
 
 /* 0 <= irq_num <= 3. level must be 0 or 1 */
-static void pci_set_irq(void *opaque, int irq_num, int level)
+static void pci_irq_handler(void *opaque, int irq_num, int level)
 {
     PCIDevice *pci_dev = opaque;
     int change;
@@ -1191,6 +1191,24 @@ static void pci_set_irq(void *opaque, int irq_num, int level)
     pci_change_irq_level(pci_dev, irq_num, change);
 }
 
+static inline int pci_intx(PCIDevice *pci_dev)
+{
+    return pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
+}
+
+qemu_irq pci_allocate_irq(PCIDevice *pci_dev)
+{
+    int intx = pci_intx(pci_dev);
+
+    return qemu_allocate_irq(pci_irq_handler, pci_dev, intx);
+}
+
+void pci_set_irq(PCIDevice *pci_dev, int level)
+{
+    int intx = pci_intx(pci_dev);
+    pci_irq_handler(pci_dev, intx, level);
+}
+
 /* Special hooks used by device assignment */
 void pci_bus_set_route_irq_fn(PCIBus *bus, pci_route_irq_fn route_intx_to_irq)
 {
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 4b90e5d..990342c 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -632,6 +632,29 @@ PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn,
 PCIDevice *pci_create(PCIBus *bus, int devfn, const char *name);
 PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name);
 
+qemu_irq pci_allocate_irq(PCIDevice *pci_dev);
+void pci_set_irq(PCIDevice *pci_dev, int level);
+
+static inline void pci_irq_assert(PCIDevice *pci_dev)
+{
+    pci_set_irq(pci_dev, 1);
+}
+
+static inline void pci_irq_deassert(PCIDevice *pci_dev)
+{
+    pci_set_irq(pci_dev, 0);
+}
+
+/*
+ * FIXME: PCI does not work this way.
+ * All the callers to this method should be fixed.
+ */
+static inline void pci_irq_pulse(PCIDevice *pci_dev)
+{
+    pci_irq_assert(pci_dev);
+    pci_irq_deassert(pci_dev);
+}
+
 static inline int pci_is_express(const PCIDevice *d)
 {
     return d->cap_present & QEMU_PCI_CAP_EXPRESS;
-- 
1.8.3.1