Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This is just an aesthetic change but it was silly to say TILEPro
when booting up on the tilegx architecture.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The return path as we reload registers and core state requires that r30
hold a boolean indicating whether we are returning from an NMI, but in a
couple of cases we weren't setting this properly, with the result that we
could accidentally unmask the NMI interrupt(s), which could cause confusion.
Now we set r30 in every place where we jump into the interrupt return path.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We were re-homing the initial task's kernel stack on the boot cpu,
but in fact it's better to let it stay globally homed, since that
task isn't bound to the boot cpu anyway.  This is more of a general
cleanup than an actual performance optimization, but it removes
code, which is a good thing. :-)
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Previously we were returning SIGSEGV in this case.  It seems cleaner
to return SIGBUS since the hardware figures out alignment traps
before TLB violations, so SIGBUS is the "more correct" signal.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

There were some correctness issues with this code that are now fixed
with this change.  The change is likely less performant than it could
be, but it should no longer be vulnerable to any races with memory
operations on the memory network while invalidating a range of memory.
This code is run infrequently so performance isn't critical, but
correctness definitely is.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This idiom is used elsewhere when we do an unlock by writing a zero,
but I missed it here.  Using an atomic operation avoids waiting
on the write buffer for the unlocking write to be sent to the home cache.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

It causes "make clean" to fail, for example.  Once we have KVM support
complete, we'll reinstate the subdir reference.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This avois a bug in modules trying to use the function.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Pragmatically it couldn't be wrong to cast pointers to long to compare
them (since all kernel addresses are in the top half of VA space),
but it's more correct to cast to unsigned long.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

If we are single-stepping and make a syscall, we call ptrace_notify()
explicitly on the return path back to user space, since we are returning
to a pc value set artificially to the next instruction, and otherwise
we won't register that we stepped over the syscall instruction (swint1).
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This allows the later-panicking tiles to wait in a lower power state
until they get interrupted with an smp_send_stop().
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This avoids the hardware istream prefetcher doing unnecessary work.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This is more standard and avoids having to remember what units
the options actually take.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We should be holding the init_mm.page_table_lock in shatter_huge_page()
since we are modifying the kernel page tables.  Then, only if we are
walking the other root page tables to update them, do we want to take
the pgd_lock.

Add a comment about taking the pgd_lock that we always do it with
interrupts disabled and therefore are not at risk from the tlbflush
IPI deadlock as is seen on x86.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We were failing to track the memory when we allocated it.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We were carefully computing a value to use for the number of loops
to spin for, and then ignoring it.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Previously we only handled kernels up to a single huge page in size.
Now we create additional PTEs appropriately.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

If we took a page fault while we had interrupts disabled, we
shouldn't enable them in the page fault handler.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We make sure not to try to set the home for an MMIO PTE (on tilegx)
or a PTE that isn't referencing memory managed by Linux.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Doing so raises the possibility of self-deadlock if we are waiting
for a backtrace for an oprofile or perf interrupt while we are
in the middle of migrating our own stack page.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Not associated with any code changes, so I'm just lumping these
comment changes into a commit by themselves.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We now respond to MEM_ERROR traps (e.g. an atomic instruction to
non-cacheable memory) with a SIGBUS.

We also no longer generate a console crash message if a user
process die due to a SIGTRAP.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

In certain circumstances we need to do a bunch of jump-and-link
instructions to fill the hardware return-address stack with nonzero values.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Fix a long-standing bug in the stack backtracer where we would print
garbage to the console instead of kernel function names, if the kernel
wasn't built with symbol support (e.g. mboot).

Make sure to tag every line of userspace backtrace output if we actually
have the mmap_sem, since that way if there's no tag, we know that it's
because we couldn't trylock the semaphore.

Stop doing a TLB flush and examining page tables during backtrace.
Instead, just trust that __copy_from_user_inatomic() will properly fault
and return a failure, which it should do in all cases.

Fix a latent bug where the backtracer would directly examine a signal
context in user space, rather than copying it safely to kernel memory
first.  This meant that a race with another thread could potentially
have caused a kernel panic.

Guard against unaligned sp when trying to restart backtrace at an
interrupt or signal handler point in the kernel backtracer.

Report kernel symbolic information for the call instruction rather
than for the following instruction.  We still report the actual numeric
address corresponding to the instruction after the call, for the sake
of consistency with the normal expectations for stack backtracers.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Add a comment explaining why this is important, and add a CFLAGS_REMOVE
clause to the Makefile to make sure it happens.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

With lockstat we can end up trying to get a backtrace before
"high_memory" is initialized, so don't worry about range testing
if it is zero.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This avoids assigning IRQ 0 to PCI devices, because we've seen that
doesn't always work well.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Fix some signedness and variable usage warnings in change_bit()
and test_and_change_bit().
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

It still returns whether @v was not @u, not the old value,
unlike __atomic_add_unless().
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArun Sharma <asharma@fb.com>

We aren't yet using this definition in the kernel, but fix it up
before someone goes looking for it.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

It's fixed at half the VA space and there's no point in configuring it.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We switched to using "tilepro" for the 32-bit stuff a while ago,
but missed this one usage.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Looks like a cut and paste bug from the x86 version.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Commit bd119c69

    "Disintegrate asm/system.h for Tile"

created the asm/switch_to.h file, but did not add an include
of it to all its users.

Also, commit b4816afa

        "Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h"

introduced the concept of asm/cmpxchg.h but the tile arch
never got one.  Fork the cmpxchg content out of the asm/atomic.h
file to create one.
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Pull virtio S3 support patches from Amit Shah:
 "Turns out S3 is not different from S4 for virtio devices: the device
  is assumed to be reset, so the host and guest state are to be assumed
  to be out of sync upon resume.  We handle the S4 case with exactly the
  same scenario, so just point the suspend/resume routines to the
  freeze/restore ones.

  Once that is done, we also use the PM API's macro to initialise the
  sleep functions.

  A couple of cleanups are included: there's no need for special thaw
  processing in the balloon driver, so that's addressed in patches 1 and
  2.

  Testing: both S3 and S4 support have been tested using these patches
  using a similar method used earlier during S4 patch development: a
  guest is started with virtio-blk as the only disk, a virtio network
  card, a virtio-serial port and a virtio balloon device.  Ping from
  guest to host, dd /dev/zero to a file on the disk, and IO from the
  host on the virtio-serial port, all at once, while exercising S4 and
  S3 (separately) were tested.  They all continue to work fine after
  resume.  virtio balloon values too were tested by inflating and
  deflating the balloon."

Pulling from Amit, since Rusty is off getting married (and presumably
shaving people).

* 's3-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/amit/virtio-console:
  virtio-pci: switch to PM ops macro to initialise PM functions
  virtio-pci: S3 support
  virtio-pci: drop restore_common()
  virtio: drop thaw PM operation
  virtio: balloon: Allow stats update after restore from S4

Pull second try at vfs part d#2 from Al Viro:
 "Miklos' first series (with do_lookup() rewrite split into edible
  chunks) + assorted bits and pieces.

  The 'untangling of do_lookup()' series is is a splitup of what used to
  be a monolithic patch from Miklos, so this series is basically "how do
  I convince myself that his patch is correct (or find a hole in it)".
  No holes found and I like the resulting cleanup, so in it went..."

Changes from try 1: Fix a boot problem with selinux, and commit messages
prettied up a bit.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits)
  vfs: fix out-of-date dentry_unhash() comment
  vfs: split __lookup_hash
  untangling do_lookup() - take __lookup_hash()-calling case out of line.
  untangling do_lookup() - switch to calling __lookup_hash()
  untangling do_lookup() - merge d_alloc_and_lookup() callers
  untangling do_lookup() - merge failure exits in !dentry case
  untangling do_lookup() - massage !dentry case towards __lookup_hash()
  untangling do_lookup() - get rid of need_reval in !dentry case
  untangling do_lookup() - eliminate a loop.
  untangling do_lookup() - expand the area under ->i_mutex
  untangling do_lookup() - isolate !dentry stuff from the rest of it.
  vfs: move MAY_EXEC check from __lookup_hash()
  vfs: don't revalidate just looked up dentry
  vfs: fix d_need_lookup/d_revalidate order in do_lookup
  ext3: move headers to fs/ext3/
  migrate ext2_fs.h guts to fs/ext2/ext2.h
  new helper: ext2_image_size()
  get rid of pointless includes of ext2_fs.h
  ext2: No longer export ext2_fs.h to user space
  mtdchar: kill persistently held vfsmount
  ...

Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix incorrect usage of for_each_cpu_mask() in select_fallback_rq()
  sched: Fix __schedule_bug() output when called from an interrupt
  sched/arch: Introduce the finish_arch_post_lock_switch() scheduler callback