The trick is that we do the kernel linear mapping TLB miss starting
with an instruction sequence like this:

	ba,pt		%xcc, kvmap_load
	 xor		%g2, %g4, %g5

succeeded by an instruction sequence which performs a full page table
walk starting at swapper_pg_dir.

We first take over the trap table from the firmware.  Then, using this
constant PTE generation for the linear mapping area above, we build
the kernel page tables for the linear mapping.

After this is setup, we patch that branch above into a "nop", which
will cause TLB misses to fall through to the full page table walk.

With this, the page unmapping for CONFIG_DEBUG_PAGEALLOC is trivial.
Signed-off-by: David S. Miller <davem@davemloft.net>

"1" needs to be "1UL", this is a 64-bit mask we're creating.
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

'highest_paddr' is set, but never actually used.
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of all of this cpu-specific code to remap the kernel
to the correct location, use portable firmware calls to do
this instead.

What we do now is the following in position independant
assembler:

	chosen_node = prom_finddevice("/chosen");
	prom_mmu_ihandle_cache = prom_getint(chosen_node, "mmu");
	vaddr = 4MB_ALIGN(current_text_addr());
	prom_translate(vaddr, &paddr_high, &paddr_low, &mode);
	prom_boot_mapping_mode = mode;
	prom_boot_mapping_phys_high = paddr_high;
	prom_boot_mapping_phys_low = paddr_low;
	prom_map(-1, 8 * 1024 * 1024, KERNBASE, paddr_low);

and that replaces the massive amount of by-hand TLB probing and
programming we used to do here.

The new code should also handle properly the case where the kernel
is mapped at the correct address already (think: future kexec
support).

Consequently, the bulk of remap_kernel() dies as does the entirety
of arch/sparc64/prom/map.S

We try to share some strings in the PROM library with the ones used
at bootup, and while we're here mark input strings to oplib.h routines
with "const" when appropriate.

There are many more simplifications now possible.  For one thing, we
can consolidate the two copies we now have of a lot of cpu setup code
sitting in head.S and trampoline.S.

This is a significant step towards CONFIG_DEBUG_PAGEALLOC support.
Signed-off-by: David S. Miller <davem@davemloft.net>

Testing shows that the prom_unmap() calls do absolutely
nothing.
Signed-off-by: David S. Miller <davem@davemloft.net>

Because we don't access the PAGE_OFFSET linear mappings
any longer before we take over the trap table from the
firmware, we don't need to load dummy mappings there
into the TLB and we don't need the bootmap_base hack
any longer either.

While we are here, check for a larger than 8MB kernel
and halt the boot with an error message.  We know that
doesn't work, so instead of failing mysteriously we
should let the user know exactly what's wrong.
Signed-off-by: David S. Miller <davem@davemloft.net>

Just allocate them physically starting from the end of
the kernel image.  This incredibly simplifies our MM
bootstrap in that we don't need any mappings in the linear
PAGE_OFFSET area working in order to bootstrap ourselves and
take over the trap table from the firmware.

Many further simplifications are possible now, and this also
sets the stage for CONFIG_DEBUG_PAGEALLOC support.
Signed-off-by: David S. Miller <davem@davemloft.net>

This thing was just a huge monolithic mess, so chop it up.
Signed-off-by: David S. Miller <davem@davemloft.net>

Use __initdata instead.
Signed-off-by: David S. Miller <davem@davemloft.net>

This was kind of ugly, and actually buggy.  The bug was that
we didn't handle a machine with memory starting > 4GB.  If
the 'prompmd' was allocated in physical memory > 4GB we'd
croak because the obp_iaddr_patch and obp_daddr_patch things
only supported a 32-bit physical address.

So fix this by just loading the appropriate values from two
variables in the kernel image, which is locked into the TLB
and thus accesses to them can't cause a recursive TLB miss.
Signed-off-by: David S. Miller <davem@davemloft.net>

This is just a replica of the existing _PAGE_SZBITS,
and thus unnecessary.
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

The header declaring this function wasn't included, so the function declaration
was totally bogus wrt. the proto - even if this wasn't going to fail at all.

It was so bad that the compile warning I got was "control reaches end of
non-void function", i.e. missing return. Actually, this has been there for ages,
the consolidation patch just added the warning which was needed to clean it up.
Nice. Really.

Cc: Allan Graves <allan.graves@gmail.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Explain why the casting we do to silence this warning is indeed safe.

It is because the field we're casting from, though being 64-bit wide, was filled
with a pointer in first place by ourselves.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Readd this header (deleted in 60d339f6). A
warning is spit out here about undeclared getpgrp().
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Even if with a bit of misunderstanding, Al fixed this in commit
95608261.

Well, the symbol was intended to come from userspace (it exists there on normal
host), but since some hosts may miss that, using the kernel one is just as fine.
However, rename it to be named consistently with the rest.

Actually, he missed converting ELFCLASS32 to coming from kernel headers. For
consistence, add ELFCLASS64 too.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

gcc is now complaining during link on some hosts - fix it as for other things.
Reported by Antoine Martin <antoine@nagafix.co.uk>.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Translate uname output taken from the host if needed.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

I am a lamer :-(. Luckily, Luo Xin performed LTP testing and found this failure.
Btw, the fact that the patch in which I introduced this was merged shows that:

a) I'm really trusted by people
b) sometimes they're wrong about point a).
c) lack of time for reviewers.

CC: Luo Xin <luothing@sina.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

When removing verify_area, verify_area_{tt,skas} were forgotten.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

As recently done by Russell King for ARM, commit
4732efbe introduces a generic asm/futex.h copied
along most arches, which includes a "-ENOSYS support" to be changed if needed.
However, it includes an unused var (taken from the "real" version) which GCC
warns about.

Remove it from all arches having that file version (i.e. same GIT id).
$ git-diff-tree -r HEAD
and
$ git-ls-tree  -r HEAD include/|grep 9feff4ce1424bc390608326240be369eb13aa648

may be more interesting than looking at the patch itself, to make sure I've
just copied the arm header to all other archs having the original dummy version
of this file.

Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Follow up to 4732efbe - uml must just reuse
as-is the backing architecture support. There is a micro-fixup is needed for the
included file, which won't affect i386 behaviour at all.

I've not tested compilation on x86_64, only on x86, but the code is almost the
same except the culprit test, so everything should be ok on x86_64 too.

Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Patch from Catalin Marinas

This patch prevents the "noreturn function does return" warning in the
__bug() function in arch/arm/kernel/traps.c
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Based on simplification idea from Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

Clean up code by using enums instead of hard-coded magic numbers.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

During a forensic analysis on the fat file system, I found than the result for
the last access date on this file system was different between the stat
command and the istat command (package tct-utils).

The istat command display a true date (the right windows date) but the stat
primitive (so stat, find, ls command) displays a wrong date.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Correct URL for HPET spec.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add MAINTAINER record for Andrew ;-)
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

__FUNCTION__ is the prefered kernel idiom, __func__ is not supported by gcc
2.95 (we actually map __FUNCTION__ to __func__ for more recent compilers,
but it should never be used directly)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Hugh made me note this line for permission checking in mprotect():

		if ((newflags & ~(newflags >> 4)) & 0xf) {

after figuring out what's that about, I decided it's nasty enough.  Btw
Hugh itself didn't like the 0xf.

We can safely change it to VM_READ|VM_WRITE|VM_EXEC because we never change
VM_SHARED, so no need to check that.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Update comment for the 2.6.6-rc1 conversion from page->list and
address_space->{clean,dirty,locked}_pages to radix tree tagging and ->lru.

I've mostly avoided to mention page lists (at least I've shortened the
comment).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

We have no options which the user can set in the Makefile.  Only the
EXTRAVERSION, which is also useful in place of the "backup modules"
suggestion.

We don't have configuration options in the top Makefile.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

That comment is plain wrong (we even take the pagetable lock inside
unmap_region()).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

We currently unregister the config-osm driver if initialization of the
legacy ioctl() handlers failed but still return success.  We should be
returning -EBUSY in this case.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

zImage.vmode was recently added.  It's a version of zImage in which the ELF
note section used by open firmware indicates that it requires a virtual
mode instance of OF instead of real mode.  This allows it to work with
Apple OF, and thus is directly bootable (or netbootable) from OF command
line.  (Unfortunately, pSeries OF sort-of requires real mode and Apple OF
sort-of requires virtual mode, and both tend to be unhappy if no notes
section specifies the mode at all).

However, we forgot to add zImage.vmode to the default G5 build. This
fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>