Re: bus_space_physload(9)

[David Young <dyoung%pobox.com@localhost>]

On Wed, Mar 24, 2010 at 05:09:23PM +0900, Masao Uebayashi wrote:
> On Wed, Mar 24, 2010 at 03:06:08PM +0900, Masao Uebayashi wrote:
> >     void *bus_space_physload(bus_space_tag_t space, bus_addr_t addr,
> >         bus_size_t size);
> 
> This function should take the same arguments as bus_space_mmap(9).  I've
> added "int prot" and "int flags":
> 
>       void *bus_space_physload(bus_space_tag_t space, bus_addr_t addr,
>           bus_size_t size, int prot, int flags);
> 
> "int prot" is the device's characteristic.  Audio mic devices would use
> VM_PROT_READ.  Framebuffers would use VM_PROT_WRITE.  We need to introduce
> BUS_SPACE_PROT_* symbols too.

Can it be implemented like this?

void *
bus_space_physload(bus_space_tag_t bst, bus_addr_t addr, bus_size_t size,
    vm_prot_t prot, int flags)
{
        bus_space_handle_t bsh;
        void *p;
        int rc;

        rc = bus_space_map(bst, addr, size, flags | BUS_SPACE_MAP_LINEAR, &bsh);
        if (rc != 0)
                return NULL;

        p = bus_space_vaddr(bst, bsh);

        if (p == NULL) {
                bus_space_unmap(bst, bsh, size);
                return NULL;
        }

        rc = vm_map_protect(kernel_map, (vaddr_t)p, (vaddr_t)p + size, prot,
            true);

        if (rc != 0) {
                bus_space_unmap(bst, bsh, size);
                return NULL;
        }

        return p;
}

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933