On 3/12/24 07:46, Bernhard Beschow wrote:
Am 21. November 2024 10:01:52 UTC schrieb "Philippe Mathieu-Daudé"
<phi...@linaro.org>:
object_dynamic_cast() is expensive; IRQ helpers are certainly
a bad place to call it. Since the device type won't change at
runtime, resolve it once when the AHCI context is initialized
in ahci_init().
Reported-by: Peter Xu <pet...@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
include/hw/ide/ahci.h | 2 +-
hw/ide/ahci.c | 17 +++++------------
2 files changed, 6 insertions(+), 13 deletions(-)
@@ -196,13 +192,9 @@ static void ahci_irq_raise(AHCIState *s)
static void ahci_irq_lower(AHCIState *s)
{
- DeviceState *dev_state = s->container;
- PCIDevice *pci_dev = (PCIDevice *) object_dynamic_cast(OBJECT(dev_state),
- TYPE_PCI_DEVICE);
-
trace_ahci_irq_lower(s);
- if (!pci_dev || !msi_enabled(pci_dev)) {
+ if (!s->pci_dev || !msi_enabled(s->pci_dev)) {
qemu_irq_lower(s->irq);
}
}
By always triggering the "irq" property, it might be possible to push out the above two
methods to the caller, i.e. the parent PCI device. This would make this device model independent
from PCI, essentially turning it into an "IP block". At the same time this eliminates the
need for the dynamic casts and AFAICS would also fix the missing PCI dependency in the Kconfig
file. I could send a patch.
Oh. Please go ahead, that is appreciated!
Best regards,
Bernhard
