From 5a2223ca26b1a34e131b5b9a63599d9426d2c25c Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 26 Jan 2014 12:31:27 +0200 Subject: 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 --- hw/acpi/pcihp.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'hw/acpi') 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: -- cgit v1.2.1