x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic.  It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.

This patch exposes it to the other architectures.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: build fix

Move kmap_atomic_prot_pfn() to iomap_32.c. It is used on all 32-bit
kernels, while highmem_32.c is only built on highmem kernels.

( Note: the debug_kmap_atomic_prot() check is removed for now, that
  problem is handled via another patch. )
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090311143317.GA22244@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It may be useful for kmap_atomic_pfn() and iomap_atomic_prot_pfn()
to check invalid kmap usage as well as kmap_atomic.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090311143449.GB22244@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kmap_atomic_pfn() and iomap_atomic_prot_pfn() are almost same
except pgprot. This patch removes the code duplication for these
two functions.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090311143317.GA22244@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

The zones are set up at this stage so there's a highmem zone
available even for the UMA case.

The only difference there is that for machines that have
CONFIG_HIGHMEM enabled but don't have any highmem available,
->zone_start_pfn is zero whereas highstart_pfn is non-zero).

The field is left zeroed because of the !size test in
free_area_init_core() but shouldn't be a problem because
add_highpages_with_active_regions() handles empty ranges just
fine.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Mel Gorman <mel@csn.ul.ie>
LKML-Reference: <1236154567.29024.23.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: build fix

 arch/x86/mm/highmem_32.c:187: error: static declaration of 'set_highmem_pages_init' follows non-static declaration
 arch/x86/include/asm/numa_32.h:8: error: previous declaration of 'set_highmem_pages_init' was here
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236082212.2675.24.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

This patch moves set_highmem_pages_init() to arch/x86/mm/highmem_32.c.

The declaration of the function is kept in asm/numa_32.h because
asm/highmem.h is included only if CONFIG_HIGHMEM is enabled so we
can't put the empty static inline function there.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236082212.2675.24.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The driver would like to map IO space directly for copying data in when
appropriate, to avoid CPU cache flushing for streaming writes.
kmap_atomic_pfn lets us avoid IPIs associated with ioremap for this process.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This patch removes the no longer used export of kmap_atomic_to_page.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

I believe http://bugzilla.kernel.org/show_bug.cgi?id=10318 is a false
positive.  There's no way in which networking will be using highmem pages
here, so it won't be taking the KM_USER0 kmap slot, so there's no point in
performing these checks.

Cc: Pawel Staszewski <pstaszewski@artcom.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NChristoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
 [ Really sad.  We lose almost all real-life coverage of the debug tests
   with this patch. Now it will only report problems for the cases where
   people actually end up using a HIGHMEM page, not when they just _might_
   use one.    - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[ mingo@elte.hu: cleanups and made dependent on CONFIG_DEBUG_HIGHMEM.

  this caught a handful of bugs already, so lets apply it. If it gets
  things wrong we'll disable it. ]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Revert

	commit 656dad31
	Author: Ingo Molnar <mingo@elte.hu>
	Date:   Sat Feb 10 01:46:36 2007 -0800

	[PATCH] highmem: catch illegal nesting

	Catch illegally nested kmap_atomic()s even if the page that is mapped by
	the 'inner' instance is from lowmem.

	This avoids spuriously zapped kmap-atomic ptes and turns hard to find
	crashes into clear asserts at the bug site.

Problem is, a get_zeroed_page(GFP_KERNEL) from interrupt context will trigger
this check if non-irq code on this CPU holds a KM_USER0 mapping.  But that
get_zeroed_page() will never be altering the kmap slot anyway due to the
GFP_KERNEL.

Cc: Christoph Lameter <clameter@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kunmap_atomic should flush any pending lazy mmu updates, mainly to be
consistent with kmap_atomic, and to preserve its normal behaviour.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Xen and VMI both have special requirements when mapping a highmem pte
page into the kernel address space.  These can be dealt with by adding
a new kmap_atomic_pte() function for mapping highptes, and hooking it
into the paravirt_ops infrastructure.

Xen specifically wants to map the pte page RO, so this patch exposes a
helper function, kmap_atomic_prot, which maps the page with the
specified page protections.

This also adds a kmap_flush_unused() function to clear out the cached
kmap mappings.  Xen needs this to clear out any potential stray RW
mappings of pages which will become part of a pagetable.

[ Zach - vmi.c will need some attention after this patch.  It wasn't
  immediately obvious to me what needs to be done. ]
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>

Since lazy MMU batching mode still allows interrupts to enter, it is
possible for interrupt handlers to try to use kmap_atomic, which fails when
lazy mode is active, since the PTE update to highmem will be delayed.  The
best workaround is to issue an explicit flush in kmap_atomic_functions
case; this is the only way nested PTE updates can happen in the interrupt
handler.

Thanks to Jeremy Fitzhardinge for noting the bug and suggestions on a fix.

This patch gets reverted again when we start 2.6.22 and the bug gets fixed
differently.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Catch illegally nested kmap_atomic()s even if the page that is mapped by
the 'inner' instance is from lowmem.

This avoids spuriously zapped kmap-atomic ptes and turns hard to find
crashes into clear asserts at the bug site.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments which
don't correspond if the vaddr is just a normal lowmem address (ie, not in
the KMAP area).  This patch makes sure that the pte is only cleared if kmap
area was actually used for the mapping.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce pagefault_{disable,enable}() and use these where previously we did
manual preempt increments/decrements to make the pagefault handler do the
atomic thing.

Currently they still rely on the increased preempt count, but do not rely on
the disabled preemption, this might go away in the future.

(NOTE: the extra barrier() in pagefault_disable might fix some holes on
       machines which have too many registers for their own good)

[heiko.carstens@de.ibm.com: s390 fix]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NNick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create a new PTE function which combines clearing a kernel PTE with the
subsequent flush.  This allows the two to be easily combined into a single
hypercall or paravirt-op.  More subtly, reverse the order of the flush for
kmap_atomic.  Instead of flushing on establishing a mapping, flush on clearing
a mapping.  This eliminates the possibility of leaving stale kmap entries
which may still have valid TLB mappings.  This is required for direct mode
hypervisors, which need to reprotect all mappings of a given page when
changing the page type from a normal page to a protected page (such as a page
table or descriptor table page).  But it also provides some nicer semantics
for real hardware, by providing extra debug-proofing against using stale
mappings, as well as ensuring that no stale mappings exist when changing the
cacheability attributes of a page, which could lead to cache conflicts when
two different types of mappings exist for the same page.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move initialization of all memory end variables to as early as
possible, so that dependent code doesn't need to check whether these
variables have already been set.

Change the range check in kunmap_atomic to actually make use of this
so that the no-mapping-estabished path (under CONFIG_DEBUG_HIGHMEM)
gets used only when the address is inside the lowmem area (and BUG()
otherwise).
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch provides the interfaces necessary to read the dump contents,
treating it as a high memory device.

Signed off by Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* EXPORT_SYMBOL's moved to other files
* #include <linux/config.h>, <linux/module.h> where needed
* #include's in i386_ksyms.c cleaned up
* After copy-paste, redundant due to Makefiles rules preprocessor directives
  removed:

	#ifdef CONFIG_FOO
	EXPORT_SYMBOL(foo);
	#endif

	obj-$(CONFIG_FOO) += foo.o

* Tiny reformat to fit in 80 columns
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!