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Re: [PATCH 3/3] sam460ex: Use type cast macro instead of simple cast
From: |
Greg Kurz |
Subject: |
Re: [PATCH 3/3] sam460ex: Use type cast macro instead of simple cast |
Date: |
Thu, 7 Jan 2021 09:08:15 +0100 |
On Wed, 6 Jan 2021 16:24:01 +0100
BALATON Zoltan via <qemu-ppc@nongnu.org> wrote:
> Use the PCI_BUS type cast macro to convert result of
> qdev_get_child_bus(). Also remove the check for NULL afterwards which
> should not be needed because sysbus_create_simple() uses error_abort
It seems to me that sysbus_create_simple() doesn't return NULL because
it ends up calling object_new_with_type(). This allocates the object
with either g_malloc() or qemu_memalign(), both of which abort on
failure.
> and PCI_BUS macro also checks its argument by default so this
AFAICT, PCI_BUS() and all other instance type checking macros are
happy with a NULL argument. They simply return NULL in this case.
> shouldn't fail here.
>
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
> hw/ppc/sam460ex.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/hw/ppc/sam460ex.c b/hw/ppc/sam460ex.c
> index 14e6583eb0..cc67e9c39b 100644
> --- a/hw/ppc/sam460ex.c
> +++ b/hw/ppc/sam460ex.c
> @@ -384,11 +384,8 @@ static void sam460ex_init(MachineState *machine)
> ppc460ex_pcie_init(env);
> /* All PCI irqs are connected to the same UIC pin (cf. UBoot source) */
> dev = sysbus_create_simple("ppc440-pcix-host", 0xc0ec00000, uic[1][0]);
> - pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci.0");
> - if (!pci_bus) {
> - error_report("couldn't create PCI controller!");
> - exit(1);
> - }
> + pci_bus = PCI_BUS(qdev_get_child_bus(dev, "pci.0"));
> +
But PCI_BUS() is being passed qdev_get_child_bus(dev, "pci.0"), not
dev... so the real question here is whether this can return NULL
or not. And if this happens, is this a (1) user or (2) programming
error ?
If (1) then the "if (!pci_bus) { }" should be kept. If (2) then
it should be converted to an assert().
> memory_region_init_alias(isa, NULL, "isa_mmio", get_system_io(),
> 0, 0x10000);
> memory_region_add_subregion(get_system_memory(), 0xc08000000, isa);
[PATCH 1/3] Revert "sam460ex: Remove FDT_PPC dependency from KConfig", BALATON Zoltan, 2021/01/06