Re: [PATCH v2 4/8] hw/pci-host/bonito: Fixup pci.lomem mapping

[Jiaxun Yang]

在 2020/12/22 上午4:45, Philippe Mathieu-Daudé 写道:
> On 12/19/20 8:18 AM, Jiaxun Yang wrote:
> > The original mapping had wrong base address.
> > Fix by correct the base adress and merge three alias into
> > a single.
> Why merge? Beside, typo "address".


Hi Philippe,

Thanks for your reviewing!

Because I can't understand why it was in three pieces.
I was just trying to do what kernel as I don't have much knowledge with
Fuloong2E.

The kernel treated PCI region as a whole part[1] at 0x10000000 with size
0x0c000000.

It fixed long lasting radeonfb starting failure.

> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> > ---
> >   hw/pci-host/bonito.c | 17 ++++++-----------
> >   1 file changed, 6 insertions(+), 11 deletions(-)
> >
> > diff --git a/hw/pci-host/bonito.c b/hw/pci-host/bonito.c
> > index 43b79448a9..3a31ba42f2 100644
> > --- a/hw/pci-host/bonito.c
> > +++ b/hw/pci-host/bonito.c
> > @@ -608,7 +608,7 @@ static void bonito_pcihost_realize(DeviceState *dev, Error 
> > **errp)
> >   {
> >       PCIHostState *phb = PCI_HOST_BRIDGE(dev);
> >       BonitoState *bs = BONITO_PCI_HOST_BRIDGE(dev);
> > -    MemoryRegion *pcimem_lo_alias = g_new(MemoryRegion, 3);
> > +    MemoryRegion *pcimem_lo_alias = g_new(MemoryRegion, 1);
> >   
> >       memory_region_init(&bs->pci_mem, OBJECT(dev), "pci.mem", BONITO_PCIHI_SIZE);
> >       phb->bus = pci_register_root_bus(dev, "pci",
> > @@ -616,16 +616,11 @@ static void bonito_pcihost_realize(DeviceState *dev, 
> > Error **errp)
> >                                        dev, &bs->pci_mem, get_system_io(),
> >                                        0x28, 32, TYPE_PCI_BUS);
> >   
> > -    for (size_t i = 0; i < 3; i++) {
> > -        char *name = g_strdup_printf("pci.lomem%zu", i);
> > -
> > -        memory_region_init_alias(&pcimem_lo_alias[i], NULL, name,
> > -                                 &bs->pci_mem, i * 64 * MiB, 64 * MiB);
> > -        memory_region_add_subregion(get_system_memory(),
> > -                                    BONITO_PCILO_BASE + i * 64 * MiB,
> > -                                    &pcimem_lo_alias[i]);
> > -        g_free(name);
> > -    }
> > +    memory_region_init_alias(pcimem_lo_alias, OBJECT(dev), "pci.lomem",
> > +                             &bs->pci_mem, BONITO_PCILO_BASE,
> > +                             BONITO_PCILO_SIZE);
> Why is your pci_mem mapped at 0?

It is actually started at 0x10000000.

As: #define BONITO_PCILO_BASE       0x10000000


Thanks.

[1]: 
https://elixir.bootlin.com/linux/latest/source/arch/mips/loongson2ef/common/pci.c

- Jiaxun
> > +    memory_region_add_subregion(get_system_memory(), BONITO_PCILO_BASE,
> > +                                pcimem_lo_alias);
> >   
> >       create_unimplemented_device("pci.io", BONITO_PCIIO_BASE, 1 * MiB);
> >   }