Re: [Qemu-ppc] [PATCH v3 4/6] PPC: 85xx: Generalize DDR TLB mapping function

[Scott Wood]

On Thu, 2014-02-20 at 11:25 +0100, Alexander Graf wrote:
> On 19.02.2014, at 00:21, Scott Wood <address@hidden> wrote:
> 
> > On Tue, 2014-02-11 at 01:10 +0100, Alexander Graf wrote:
> >> -  if (memsize)
> >> -          print_size(memsize, " left unmapped\n");
> >> +  if (size)
> >> +          print_size(size, " left unmapped\n");
> >> +}
> > 
> > The print_size should move to the caller, with some way to pass back the
> > amout left unmapped.  Non-RAM callers would treat a non-zero unmapped
> > value as an error.
> > 
> >> +unsigned int
> >> +setup_ddr_tlbs_phys(phys_addr_t p_addr, unsigned int memsize_in_meg)
> >> +{
> >> +  unsigned int ram_tlb_address = (unsigned int)CONFIG_SYS_DDR_SDRAM_BASE;
> >> +  u64 memsize = (u64)memsize_in_meg << 20;
> >> +
> >> +  memsize = min(memsize, CONFIG_MAX_MEM_MAPPED);
> >> +  tlb_map_range(ram_tlb_address, p_addr, memsize, true);
> >>    return memsize_in_meg;
> >> }
> > 
> > Here you seem to be hiding the message for RAM.
> 
> It could still fail if we're running out of TLB entries, no?

That's not the usual reason for that message to be printed.

> > York, are you OK with just removing the message altogether, and having
> > tlb_map_range return a normal error code if it can't map everything
> > (with DDR size reduced in advance as above)?
> 
> How about we just change the return value of tlb_map_range to uint64_t
> and return size? That way we can 1:1 move the print code out of the
> function into the RAM map code and IO callers can just call assert(r !=
> 0).

That's fine.  I was just wondering if the message had value at all,
given that it's expected if you have more than 2 GiB of RAM.
 
-Scott