There's a few places where we need to fix things up for the kernel to work
if it's linked at 32MB:
- platforms/powermac/smp.c
To start secondary cpus on pmac we patch the reset vector, which is fine.
Except if we're above 32MB we don't have enough bits for an absolute branch,
it needs to relative.
- kernel/head_64.s
- A few branches in the cpu hold code need to load the full target address
and do a bctr.
- after_prom_start needs to load PHYSICAL_START as the dest address, not 0.
- The exception prolog needs to load the low word of the target adddress,
not just the low halfword.
- Fixup handling of the initial stab address.
- kernel/setup_64.c
smp_release_cpus() needs to write 1 to the spinloop flag near 0, not 32 MB.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Parsing addresses extracted from Open Firmware isn't a simple matter. We
have various bits of code that try to do it in various place, including
some heuristics in prom.c that pre-parse addresses at boot and fill
device-nodes "addrs", but those are dodgy at best and I want to
deprecate them. So this patch introduces a new set of routines that
should be capable of parsing most types of addresses and translating
them into CPU physical addresses. It currently works for things on PCI
busses and ISA busses and should work on "standard" busses like the root
bus or the MacIO bus that don't put funky flags in addresses. If you
have other bus types that do use funky flags, you'll have to add new bus
type translators, which is fairly easy.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On most powerpc CPUs, the dcache and icache are not coherent so
between writing and executing a page, the caches must be flushed.
Userspace programs assume pages given to them by the kernel are icache
clean, so we must do this flush between the kernel clearing a page and
it being mapped into userspace for execute. We were not doing this
for hugepages, this patch corrects the situation.
We use the same lazy mechanism as we use for normal pages, delaying
the flush until userspace actually attempts to execute from the page
in question.
Tested on G5.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For these, I have just done the lame-o merge where the file ends up
looking like:
#ifndef CONFIG_PPC64
#include <asm-ppc/foo.h>
#else
... contents from asm-ppc64/foo.h
#endif
so nothing has changed, really, except that we reduce include/asm-ppc64
a bit more.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Michael Ellerman