The Kconfig text for CONFIG_DEBUG_SLAB and CONFIG_DEBUG_PAGEALLOC have always
seemed a bit confusing.  Change them to:

CONFIG_DEBUG_SLAB: "Debug slab memory allocations"
CONFIG_DEBUG_PAGEALLOC: "Debug page memory allocations"

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: NKyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Merge clash will have broken sparc64. Synch up its online_page
implementation with powerpc, which was identical until the
set_page_count removal.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Quite a long time back, prepare_hugepage_range() replaced
is_aligned_hugepage_range() as the callback from mm/mmap.c to arch code to
verify if an address range is suitable for a hugepage mapping.
is_aligned_hugepage_range() stuck around, but only to implement
prepare_hugepage_range() on archs which didn't implement their own.

Most archs (everything except ia64 and powerpc) used the same
implementation of is_aligned_hugepage_range().  On powerpc, which
implements its own prepare_hugepage_range(), the custom version was never
used.

In addition, "is_aligned_hugepage_range()" was a bad name, because it
suggests it returns true iff the given range is a good hugepage range,
whereas in fact it returns 0-or-error (so the sense is reversed).

This patch cleans up by abolishing is_aligned_hugepage_range().  Instead
prepare_hugepage_range() is defined directly.  Most archs use the default
version, which simply checks the given region is aligned to the size of a
hugepage.  ia64 and powerpc define custom versions.  The ia64 one simply
checks that the range is in the correct address space region in addition to
being suitably aligned.  The powerpc version (just as previously) checks
for suitable addresses, and if necessary performs low-level MMU frobbing to
set up new areas for use by hugepages.

No libhugetlbfs testsuite regressions on ppc64 (POWER5 LPAR).
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NZhang Yanmin <yanmin.zhang@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

set_page_count usage outside mm/ is limited to setting the refcount to 1.
Remove set_page_count from outside mm/, and replace those users with
init_page_count() and set_page_refcounted().

This allows more debug checking, and tighter control on how code is allowed
to play around with page->_count.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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

Make sure the callers do a pgprot_noncached() on
vma->vm_page_prot.

Pointed out by Hugh Dickens.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

1) huge_pte_offset() did not check the page table hierarchy
   elements as being empty correctly, resulting in an OOPS

2) Need platform specific hugetlb_get_unmapped_area() to handle
   the top-down vs. bottom-up address space allocation strategies.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

init/do_mounts_rd.c depends upon CONFIG_BLK_DEV_RAM, not CONFIG_BLK_DEV_INITRD.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We only need to write an invalid tag every 16 bytes,
so taking advantage of this can save many instructions
compared to the simple memset() call we make now.

A prefetching implementation is implemented for sun4u
and a block-init store version if implemented for Niagara.

The next trick is to be able to perform an init and
a copy_tsb() in parallel when growing a TSB table.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

online_page() is straightforward, and then add a dummy
remove_memory() that returns -EINVAL just like i386.

There is no point in implementing remove_memory() since
__remove_pages() has no implementation either.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Try only lightly on > 1 order allocations.

If a grow fails, we are under memory pressure, so do not try
to grow the TSB for this address space any more.

If a > 0 order TSB allocation fails on a new fork, retry using
a 0 order allocation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Put it one page below the top of the 32-bit address space.
This gives us ~16MB more address space to work with.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently allocations are very constrained for 32-bit processes.
It grows down-up from 0x70000000 to 0xf0000000 which gives about
2GB of stack + dynamic mmap() space.

So support the top-down method, and we need to override the
generic helper function in order to deal with D-cache coloring.

With these changes I was able to squeeze out a mmap() just over
3.6GB in size in a 32-bit process.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is good for up to %50 performance improvement of some test cases.
The problem has been the race conditions, and hopefully I've plugged
them all up here.

1) There was a serious race in switch_mm() wrt. lazy TLB
   switching to and from kernel threads.

   We could erroneously skip a tsb_context_switch() and thus
   use a stale TSB across a TSB grow event.

   There is a big comment now in that function describing
   exactly how it can happen.

2) All code paths that do something with the TSB need to be
   guarded with the mm->context.lock spinlock.  This makes
   page table flushing paths properly synchronize with both
   TSB growing and TLB context changes.

3) TSB growing events are moved to the end of successful fault
   processing.  Previously it was in update_mmu_cache() but
   that is deadlock prone.  At the end of do_sparc64_fault()
   we hold no spinlocks that could deadlock the TSB grow
   sequence.  We also have dropped the address space semaphore.

While we're here, add prefetching to the copy_tsb() routine
and put it in assembler into the tsb.S file.  This piece of
code is quite time critical.

There are some small negative side effects to this code which
can be improved upon.  In particular we grab the mm->context.lock
even for the tsb insert done by update_mmu_cache() now and that's
a bit excessive.  We can get rid of that locking, and the same
lock taking in flush_tsb_user(), by disabling PSTATE_IE around
the whole operation including the capturing of the tsb pointer
and tsb_nentries value.  That would work because anyone growing
the TSB won't free up the old TSB until all cpus respond to the
TSB change cross call.

I'm not quite so confident in that optimization to put it in
right now, but eventually we might be able to and the description
is here for reference.

This code seems very solid now.  It passes several parallel GCC
bootstrap builds, and our favorite "nut cruncher" stress test which is
a full "make -j8192" build of a "make allmodconfig" kernel.  That puts
about 256 processes on each cpu's run queue, makes lots of process cpu
migrations occur, causes lots of page table and TLB flushing activity,
incurs many context version number changes, and it swaps the machine
real far out to disk even though there is 16GB of ram on this test
system. :-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Niagara does not implement some of the VIS instructions in
hardware, so we have to emulate them.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report 'sun4v' when appropriate in /proc/cpuinfo

Remove all the verifications of the OBP version string.  Just
make sure it's there, and report it raw in the bootup logs and
via /proc/cpuinfo.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mapping is a simple "(cpuid >> 2) == core" for now.
Later we'll add more sophisticated code that will walk
the sun4v machine description and figure this out from
there.

We should also add core mappings for jaguar and panther
processors.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The page->flags manipulations done by the D-cache dirty
state tracking was broken because the constants were not
marked with "UL" to make them 64-bit, which means we were
clobbering the upper 32-bits of page->flags all the time.

This doesn't jive well with sparsemem which stores the
section and indexing information in the top 32-bits of
page->flags.

This is yet another sparc64 bug which has been with us
forever.

While we're here, tidy up some things in bootmem_init()
and paginig_init():

1) Pass min_low_pfn to init_bootmem_node(), it's identical
   to (phys_base >> PAGE_SHIFT) but we should use consistent
   with the variable names we print in CONFIG_BOOTMEM_DEBUG

2) max_mapnr, although no longer used, was being set
   inaccurately, we shouldn't subtract pfn_base any more.

3) All the games with phys_base in the zones_*[] arrays
   we pass to free_area_init_node() are no longer necessary.

Thanks to Josh Grebe and Fabbione for the bug reports
and testing.  Fix also verified locally on an SB2500
which had a memory layout that triggered the same problem.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This has been pending for a long time, and the fact
that we waste a ton of ram on some configurations
kind of pushed things over the edge.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't piggy back the SMP receive signal code to do the
context version change handling.

Instead allocate another fixed PIL number for this
asynchronous cross-call.  We can't use smp_call_function()
because this thing is invoked with interrupts disabled
and a few spinlocks held.

Also, fix smp_call_function_mask() to count "cpus" correctly.
There is no guarentee that the local cpu is in the mask
yet that is exactly what this code was assuming.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) Always spin_lock_init() in init_context().  The caller essentially
   clears it out, or copies the mm info from the parent.  In both
   cases we need to explicitly initialize the spinlock.

2) Always do explicit IRQ disabling while taking mm->context.lock
   and ctx_alloc_lock.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

this patch converts arch/sparc64 to kzalloc usage.
Crosscompile tested with allyesconfig.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we were aligned, but didn't have at least 256MB left
to process, we would loop forever.

Thanks to fabbione for the report and testing the fix.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't try to avoid putting non-base page sized entries
into the user TSB.  It actually costs us more to check
this than it helps.

Eventually we'll have a multiple TSB scheme for user
processes.  Once a process starts using larger pages,
we'll allocate and use such a TSB.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This cpu mondo sending interface isn't all that easy to
use correctly...

We were clearing out the wrong bits from the "mask" after getting
something other than EOK from the hypervisor.

It turns out the hypervisor can just be resent the same cpu_list[]
array, with the 0xffff "done" entries still in there, and it will do
the right thing.

So don't update or try to rebuild the cpu_list[] array to condense it.

This requires the "forward_progress" check to be done slightly
differently, but this new scheme is less bug prone than what we were
doing before.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We were clobbering a base register before we were done
using it.  Fix a comment typo while we're here.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to subtract 1900 from year and 1 from month before
giving it back to userspace.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The UltraSPARC T1 manual recommends this because the chip
could instruction prefetch into the VA hole, and this would
also make decoding  certain kinds of memory access traps
more difficult (because the chip sign extends certain pieces
of trap state).
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

First of all, use the known _PAGE_EXEC_{4U,4V} value instead
of loading _PAGE_EXEC from memory.  We either know which one
to use by context, or we can code patch the test.

Next, we need to check executability of a PTE in the generic
TSB miss handler.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Should put FAULT_CODE_DTLB into %g3 not FAULT_CODE_ITLB.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

There were several bugs in the SUN4V cpu mondo dispatch code.

In fact, if we ever got a EWOULDBLOCK or other error from
the hypervisor call, we'd potentially send a cpu mondo multiple
times to the same cpu and even worse we could loop until the
timeout resending the same mondo over and over to such cpus.

So let's bulletproof this thing as follows:

1) Implement cpu_mondo_send() and cpu_state() hypervisor calls
   in arch/sparc64/kernel/entry.S, add prototypes to asm/hypervisor.h

2) Don't build and update the cpulist using inline functions, this
   was causing the cpu mask to not get updated in the caller.

3) Disable interrupts during the entire mondo send, otherwise our
   cpu list and/or mondo block could get overwritten if we take
   an interrupt and do a cpu mondo send on the current cpu.

4) Check for all possible error return types from the cpu_mondo_send()
   hypervisor call.  In particular:

   HV_EOK) Our work is done, all cpus have received the mondo.
   HV_CPUERROR) One or more of the cpus in the cpu list we passed
                to the hypervisor are in error state.  Use cpu_state()
                calls over the entries in the cpu list to see which
		ones.  Record them in "error_mask" and report this
		after we are done sending the mondo to cpus which are
		not in error state.
   HV_EWOULDBLOCK) We need to keep trying.

   Any other error we consider fatal, we report the event and exit
   immediately.

5) We only timeout if forward progress is not made.  Forward progress
   is defined as having at least one cpu get the mondo successfully
   in a given cpu_mondo_send() call.  Otherwise we bump a counter
   and delay a little.  If the counter hits a limit, we signal an
   error and report the event.

Also, smp_call_function_mask() error handling reports the number
of cpus incorrectly.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) We must flush the TLB, duh.

2) Even if the sw context was seen to be valid, the local cpu's
   hw context can be out of date, so reload it unconditionally.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to shift back up by 3 bits to get 8-byte entry
index.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is totally wasted work, since we have no D-cache aliasing
issues on sun4v.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>