Impact: remove spurious WARN on legacy SMP percpu allocator

Commit f2a8205c incorrectly added too
tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu
allocator.  Commit e3176036 fixed it
for UP but legacy SMP allocator was forgotten.  Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sachin P. Sant <sachinp@in.ibm.com>

Impact: code reorganization

Separate out embedding first chunk setup helper from x86 embedding
first chunk allocator and put it in mm/percpu.c.  This will be used by
the default percpu first chunk allocator and possibly by other archs.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: cleanup, more flexibility for first chunk init

Non-negative @dyn_size used to be allowed iff @unit_size wasn't auto.
This restriction stemmed from implementation detail and made things a
bit less intuitive.  This patch allows @dyn_size to be specified
regardless of @unit_size and swaps the positions of @dyn_size and
@unit_size so that the parameter order makes more sense (static,
reserved and dyn sizes followed by enclosing unit_size).

While at it, add @unit_size >= PCPU_MIN_UNIT_SIZE sanity check.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: generic addr <-> pcpu ptr conversion macros

There's nothing arch specific about x86 __addr_to_pcpu_ptr() and
__pcpu_ptr_to_addr().  With proper __per_cpu_load and __per_cpu_start
defined, they'll do the right thing regardless of actual layout.

Move these macros from arch/x86/include/asm/percpu.h to mm/percpu.c
and allow archs to override it as necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: __per_cpu_load available on all SMP capable archs

Percpu now requires three symbols to be defined - __per_cpu_load,
__per_cpu_start and __per_cpu_end.  There were three archs which
didn't have it.  Update them as follows.

* powerpc: can use generic PERCPU() macro.  Compile tested for
  powerpc32, compile/boot tested for powerpc64.

* ia64: can use generic PERCPU_VADDR() macro.  __phys_per_cpu_start is
  identical to __per_cpu_load.  Compile tested and symbol table looks
  identical after the change except for the additional __per_cpu_load.

* arm: added explicit __per_cpu_load definition.  Currently uses
  unified .init output section so can't use the generic macro.  Dunno
  whether the unified .init ouput section is required by arch
  peculiarity so I left it alone.  Please break it up and use PERCPU()
  if possible.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Pat Gefre <pfg@sgi.com>
Cc: Russell King <rmk@arm.linux.org.uk>

In uv_flush_tlb_others() (arch/x86/kernel/tlb_uv.c),
the "WARN_ON(!in_atomic())" fails if CONFIG_PREEMPT is not enabled.

And CONFIG_PREEMPT is not enabled by default in the distribution that
most UV owners will use.

We could #ifdef CONFIG_PREEMPT the warning, but that is not good form.
And there seems to be no suitable fix to in_atomic() when CONFIG_PREMPT
is not on.

As Ingo commented:

  > and we have no proper primitive to test for atomicity. (mainly
  > because we dont know about atomicity on a non-preempt kernel)

So we drop the WARN_ON.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix deadlock and allow atomic free

Percpu allocation always uses GFP_KERNEL and whole alloc/free paths
were protected by single mutex.  All percpu allocations have been from
GFP_KERNEL-safe context and the original allocator had this assumption
too.  However, by protecting both alloc and free paths with the same
mutex, the new allocator creates free -> alloc -> GFP_KERNEL
dependency which the original allocator didn't have.  This can lead to
deadlock if free is called from FS or IO paths.  Also, in general,
allocators are expected to allow free to be called from atomic
context.

This patch implements finer grained locking to break the deadlock and
allow atomic free.  For details, please read the "Synchronization
rules" comment.

While at it, also add CONTEXT: to function comments to describe which
context they expect to be called from and what they do to it.

This problem was reported by Thomas Gleixner and Peter Zijlstra.

  http://thread.gmane.org/gmane.linux.kernel/802384Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Peter Zijlstra <peterz@infradead.org>

Impact: code reorganization for later changes

Do fully free chunk reclamation using a work.  This change is to
prepare for locking changes.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: code reorganization for later changes

Separate out chunk area map extension into a separate function -
pcpu_extend_area_map() - and call it directly from pcpu_alloc() such
that pcpu_alloc_area() is guaranteed to have enough area map slots on
invocation.

With this change, pcpu_alloc_area() does only area allocation and the
only failure mode is when the chunk doens't have enough room, so
there's no need to distinguish it from memory allocation failures.
Make it return -1 on such cases instead of hacky -ENOSPC.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: code reorganization for later changes

With static map handling moved to pcpu_split_block(), pcpu_realloc()
only clutters the code and it's also unsuitable for scheduled locking
changes.  Implement and use pcpu_mem_alloc/free() instead.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: fix relocation overflow during module load

x86_64 uses 32bit relocations for symbol access and static percpu
symbols whether in core or modules must be inside 2GB of the percpu
segement base which the dynamic percpu allocator doesn't guarantee.
This patch makes x86_64 reserve PERCPU_MODULE_RESERVE bytes in the
first chunk so that module percpu areas are always allocated from the
first chunk which is always inside the relocatable range.

This problem exists for any percpu allocator but is easily triggered
when using the embedding allocator because the second chunk is located
beyond 2GB on it.

This patch also changes the meaning of PERCPU_DYNAMIC_RESERVE such
that it only indicates the size of the area to reserve for dynamic
allocation as static and dynamic areas can be separate.  New
PERCPU_DYNAMIC_RESERVED is increased by 4k for both 32 and 64bits as
the reserved area separation eats away some allocatable space and
having slightly more headroom (currently between 4 and 8k after
minimal boot sans module area) makes sense for common case
performance.

x86_32 can address anywhere from anywhere and doesn't need reserving.

Mike Galbraith first reported the problem first and bisected it to the
embedding percpu allocator commit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>

Impact: add reserved allocation functionality and use it for module
	percpu variables

This patch implements reserved allocation from the first chunk.  When
setting up the first chunk, arch can ask to set aside certain number
of bytes right after the core static area which is available only
through a separate reserved allocator.  This will be used primarily
for module static percpu variables on architectures with limited
relocation range to ensure that the module perpcu symbols are inside
the relocatable range.

If reserved area is requested, the first chunk becomes reserved and
isn't available for regular allocation.  If the first chunk also
includes piggy-back dynamic allocation area, a separate chunk mapping
the same region is created to serve dynamic allocation.  The first one
is called static first chunk and the second dynamic first chunk.
Although they share the page map, their different area map
initializations guarantee they serve disjoint areas according to their
purposes.

If arch doesn't setup reserved area, reserved allocation is handled
like any other allocation.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: allow sharing page map, no functional difference yet

Make chunk->page access indirect by adding a pointer and renaming the
actual array to page_ar.  This will be used by future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: reduce unnecessary memory usage on certain configurations

Embedding percpu allocator allocates unit_size *
smp_num_possible_cpus() bytes consecutively and use it for the first
chunk.  However, if the static area is small, this can result in
excessive prellocated free space in the first chunk due to
PCPU_MIN_UNIT_SIZE restriction.

This patch makes embedding percpu allocator preallocate only what's
necessary as described by PERPCU_DYNAMIC_RESERVE and return the
leftover to the bootmem allocator.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: argument semantic cleanup

In pcpu_setup_first_chunk(), zero @unit_size and @dyn_size meant
auto-sizing.  It's okay for @unit_size as 0 doesn't make sense but 0
dynamic reserve size is valid.  Alos, if arch @dyn_size is calculated
from other parameters, it might end up passing in 0 @dyn_size and
malfunction when the size is automatically adjusted.

This patch makes both @unit_size and @dyn_size ssize_t and use -1 for
auto sizing.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: no functional change

When the first chunk is created, its initial area map is not allocated
because kmalloc isn't online yet.  The map is allocated and
initialized on the first allocation request on the chunk.  This works
fine but the scattering of initialization logic between the init
function and allocation path is a bit confusing.

This patch makes the first chunk initialize and use minimal statically
allocated map from pcpu_setpu_first_chunk().  The map resizing path
still needs to handle this specially but it's more straight-forward
and gives more latitude to the init path.  This will ease future
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: cosmetic, preparation for future changes

Make the following renames in pcpur_setup_first_chunk() in preparation
for future changes.

* s/free_size/dyn_size/
* s/static_vm/first_vm/
* s/static_chunk/schunk/
Signed-off-by: Tejun Heo <tj@kernel.org>

Impact: cleaup

Make the following cleanups.

* There isn't much arch-specific about PERCPU_MODULE_RESERVE.  Always
  define it whether arch overrides PERCPU_ENOUGH_ROOM or not.

* blackfin overrides PERCPU_ENOUGH_ROOM to align static area size.  Do
  it by default.

* percpu allocation sizes doesn't have much to do with the page size.
  Don't use PAGE_SHIFT in their definition.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>

They are used by __set_fixmap->set_pte_vaddr_pud, which can
be used by arch_setup_additional_pages(), and so is used
after init.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The function seems to have disappeared at some point, leaving
some vestigial prototypes behind...
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branches 'x86/apic', 'x86/cpu', 'x86/fixmap', 'x86/mm', 'x86/sched', 'x86/setup-lzma', 'x86/signal' and 'x86/urgent' into x86/core

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: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236082212.2675.24.camel@penberg-laptop>
Signed-off-by: Ingo 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: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236082212.2675.24.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: unification

This patch introduces a common arch/x86/mm/init.c and moves the identical
free_init_pages() and free_initmem() functions to the file.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236078906.2675.18.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: unification

This patch ports commit 3c1df68b ("x86: make
sure initmem is writable") to the 64-bit version to unify implementations of
free_init_pages().
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <1236078904.2675.17.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: unification

This patch adds sanity checks that are already in init_64.c to init_32.c.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236078902.2675.16.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

This patch changes find_early_table_space() to use roundup() for rounding up
tables to page size to unify the common parts of the 32-bit and 64-bit
implementations.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236077705.2675.6.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

The __VMALLOC_RESERVE global variable is not used in init_32.c. Move that to
pgtable_32.c to reduce the diff between init_32.c and init_64.c.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236077704.2675.4.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix stuck NMIs and non-working oprofile on certain CPUs

Resetting the counter width of the performance counters on Intel's
Core2 CPUs, breaks the delivery of NMIs, when running in x86_64 mode.

This should fix bug #12395:

  http://bugzilla.kernel.org/show_bug.cgi?id=12395Signed-off-by: Tim Blechmann <tim@klingt.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <20090303100412.GC10085@erda.amd.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix bad frame in rt_sigreturn on 64-bit

After commit 97286a2b some applications
fail to return from signal handler:

[  145.150133] firefox[3250] bad frame in rt_sigreturn frame:00007f902b44eb28 ip:352e80b307 sp:7f902b44ef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]
[  665.519017] firefox[5420] bad frame in rt_sigreturn frame:00007faa8deaeb28 ip:352e80b307 sp:7faa8deaef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]

The root cause is forgetting to keep 64 byte aligned value of
fpstate for next stack pointer calculation.
Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
LKML-Reference: <49AC85C1.7060600@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix failed EFI bootup in certain circumstances

Ying Huang found init_memory_mapping() has problem with small ranges
less than 2M when he tried to direct map the EFI runtime code out of
max_low_pfn_mapped.

It turns out we never considered that case and didn't check the range...
Reported-by: Ying Huang <ying.huang@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Brian Maly <bmaly@redhat.com>
LKML-Reference: <49ACDDED.1060508@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

This reverts commit 155b25bc, which was
totally wrong - the "embedded" options still exists (very much so) even
on non-embedded platforms.

It's just that we don't bother with actually asking about them when
we're not embedded, we just take their default values (which is usually
'y' - the options add features that may not be worth it in a constrained
environment).
Noticed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/i915: Fix use-before-null-check in i915_irq_emit().
  drm: Avoid client deadlocks when the master disappears.
  drm: Wake up all lock waiters when the master disappears.
  drm: Don't return ERESTARTSYS to user-space.

This could be triggered by a client asking to emit an irq when the device
wasn't initialized.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

This is done by
1) Wake up lock waiters when we close the master file descriptor.
   Not when the master structure is removed, since the latter
   requires the waiters themselves to release the refcount on the
   master structure -> Deadlock.
2) Send a SIGTERM to all clients waiting for the lock.
   Normally these clients will get a SIGPIPE when the X server dies,
   but clients may also spin trying to grab the DRM lock, without
   getting any sort of notification.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>

Currently only one waiter is woken up, leaving other waiters
hanging waiting for the DRM lock.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>

That return code is for in-kernel use only.
Use EINTR instead.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>

The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in
the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED
menu.  Fix by moving it to just after all of the EMBEDDED menu symbols.

Also, surround all of the EMBEDDED symbols with "if EMBEDDED"/"endif" so
that this EMBEDDED block is clearer.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
  sdhci: Add NO_BUSY_IRQ quirk for Marvell CAFE host chip
  sdhci: Add quirk for controllers with no end-of-busy IRQ