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authorMichael S. Tsirkin <mst@redhat.com>2014-01-26 12:31:27 +0200
committerMichael S. Tsirkin <mst@redhat.com>2014-02-05 16:55:49 +0200
commit5a2223ca26b1a34e131b5b9a63599d9426d2c25c (patch)
tree7d5c543c94afdaab0cc4e3abef828bb4ac51fe99 /hw/acpi/pcihp.c
parent2b2449f7e467957778ca006904471b231dc0ac8e (diff)
pcihp: reduce number of device check events
PIIX created a made-up value for the UP register since it was read by guest 32 times for each interrupt. There's no reason to do this for the new PCIHP: register is only read once for each interrupt, so clean up code by making read act as an interrupt acknowledgement: the new UP register clear on read. In this way we cut down the number of bus rescans by a factor of 32, and drop a bunch of code that's now unused. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/acpi/pcihp.c')
-rw-r--r--hw/acpi/pcihp.c21
1 files changed, 5 insertions, 16 deletions
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 3fa3d7c290..4345f5d70d 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -116,7 +116,6 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo
{
BusChild *kid, *next;
int slot = ffs(slots) - 1;
- bool slot_free = true;
PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
if (!bus) {
@@ -125,21 +124,17 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo
/* Mark request as complete */
s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
+ s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
DeviceState *qdev = kid->child;
PCIDevice *dev = PCI_DEVICE(qdev);
if (PCI_SLOT(dev->devfn) == slot) {
- if (acpi_pcihp_pc_no_hotplug(s, dev)) {
- slot_free = false;
- } else {
+ if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
object_unparent(OBJECT(qdev));
}
}
}
- if (slot_free) {
- s->acpi_pcihp_pci_status[bsel].device_present &= ~(1U << slot);
- }
}
static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
@@ -153,7 +148,6 @@ static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
}
s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
- s->acpi_pcihp_pci_status[bsel].device_present = 0;
if (!bus) {
return;
@@ -166,8 +160,6 @@ static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
}
-
- s->acpi_pcihp_pci_status[bsel].device_present |= (1U << slot);
}
}
@@ -187,7 +179,7 @@ void acpi_pcihp_reset(AcpiPciHpState *s)
static void enable_device(AcpiPciHpState *s, unsigned bsel, int slot)
{
- s->acpi_pcihp_pci_status[bsel].device_present |= (1U << slot);
+ s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
}
static void disable_device(AcpiPciHpState *s, unsigned bsel, int slot)
@@ -208,7 +200,6 @@ int acpi_pcihp_device_hotplug(AcpiPciHpState *s, PCIDevice *dev,
* it is present on boot, no hotplug event is necessary. We do send an
* event when the device is disabled later. */
if (state == PCI_COLDPLUG_ENABLED) {
- s->acpi_pcihp_pci_status[bsel].device_present |= (1U << slot);
return 0;
}
@@ -233,10 +224,8 @@ static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
switch (addr) {
case PCI_UP_BASE - PCI_HOTPLUG_ADDR:
- /* Manufacture an "up" value to cause a device check on any hotplug
- * slot with a device. Extra device checks are harmless. */
- val = s->acpi_pcihp_pci_status[bsel].device_present &
- s->acpi_pcihp_pci_status[bsel].hotplug_enable;
+ val = s->acpi_pcihp_pci_status[bsel].up;
+ s->acpi_pcihp_pci_status[bsel].up = 0;
ACPI_PCIHP_DPRINTF("pci_up_read %" PRIu32 "\n", val);
break;
case PCI_DOWN_BASE - PCI_HOTPLUG_ADDR: