[Qemu-devel] Re: [PATCH v2 1/2] pci: introduce pci_region to manage pci io/memory/prefmemory regions.

[Isaku Yamahata <yamahata@valinux.co.jp>]

On Thu, Oct 28, 2010 at 07:56:41AM +0200, Michael S. Tsirkin wrote:
> > diff --git a/src/util.h b/src/util.h
> > index 5cc9f17..17eedd0 100644
> > --- a/src/util.h
> > +++ b/src/util.h
> > @@ -344,6 +344,34 @@ void qemu_prep_reset(void);
> >  void smm_save_and_copy(void);
> >  void smm_relocate_and_restore(void);
> >  
> > +// pci_region.c
> > +// region allocator. pci region allocates the requested region
> > +// sequentially with overflow check.
> > +struct pci_region {
> > +    // The region is [start, region).
> 
> [start end)?

Yes. Will fix.

> > +    u32 start;
> > +    u32 end;
> > +
> > +    // The next allocation is start from this.
> > +    // i.e. [start, cur_end) is allocated.
> > +    // Right after initialization cur_end == start.
> > +    u32 cur_end;
> 
> What is the value for a region at 0xfffff000 and size 0x1000?
>
> 
> Maybe first, last is better to detect this?

You mean [first, last] instead of [start, end).
Maybe Makes sense.
Anyway the area right below 4G can't be used for PCI
because it's used for LAPIC and so on.


> 
> > +};
> > +// initialize the pci_region of [start, end)
> > +void pci_region_init(struct pci_region *r, u32 start, u32 end);
> > +// allocate the region of size
> > +u32 pci_region_alloc(struct pci_region *r, u32 size);
> > +// make the next allocation aligned to align
> > +u32 pci_region_align(struct pci_region *r, u32 align);
> > +// revert the allocation to addr.
> > +void pci_region_revert(struct pci_region *r, u32 addr);
> > +// make the allocation fail.
> > +u32 pci_region_disable(struct pci_region *r);
> > +// returns the current allocation point.
> > +u32 pci_region_addr(const struct pci_region *r);
> > +// returns the region size.
> > +u32 pci_region_size(const struct pci_region *r);
> > +
> >  // pciinit.c
> >  extern const u8 pci_irqs[4];
> >  void pci_bios_allocate_regions(u16 bdf, void *arg);
> > -- 
> > 1.7.1.1
> 

-- 
yamahata