tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: 4byte aligned com(4) and PCI_MAPREG_TYPE_MEM

In article <>,
SAITOH Masanobu  <> wrote:
>Hello, all.
> I'm now working to support Intel Quark X1000.
>This chip's internal com is MMIO(PCI_MAPREG_TYPE_MEM).
>Our com and puc don't support such type of device, yet.
>To solve the problem, I wrote a patch.
> Registers of Quark X1000's com are 4byte aligned.
>Some other machines have such type of device, so
>I modified COM_INIT_REGS() macro to support both
>byte aligned and 4byte aligned. This change reduce
>special modifications done in atheros, rmi and
>marvell drivers.
> One of problem is serial console on i386 and amd64.
>These archs calls consinit() three times. The function
>is called in the following order:
>       1) machdep.c::init386() or init_x86_64()
>       2) init_main.c::main()
>       *) (call uvm_init())
>       *) (call extent_init())
>       3) machdep.c::cpu_startup()
>When consinit() called in init386(), it calls
>  comcnattach()
>    ->comcnattach1()
>      ->comcninit()
>        -> bus_space_map() with x86_bus_space_mem tag.
>          ->bus_space_reservation_map()
>            ->x86_mem_add_mapping()
>              ->uvm_km_alloc()
>                panic in KASSERT(vm_map_pmap(map) == pmap_kernel());
>What should I do?
>One of the solution is to check whether extent_init() was called
>or not. There is no easy way to know it, so I added a global
>variable "extent_initted". Is it acceptable?

Looks great, can't you use "cold" instead, or is that too late?


Home | Main Index | Thread Index | Old Index