Currently each available hugepage size uses a slightly different
pagetable layout: that is, the bottem level table of pointers to
hugepages is a different size, and may branch off from the normal page
tables at a different level.  Every hugepage aware path that needs to
walk the pagetables must therefore look up the hugepage size from the
slice info first, and work out the correct way to walk the pagetables
accordingly.  Future hardware is likely to add more possible hugepage
sizes, more layout options and more mess.

This patch, therefore reworks the handling of hugepage pagetables to
reduce this complexity.  In the new scheme, instead of having to
consult the slice mask, pagetable walking code can check a flag in the
PGD/PUD/PMD entries to see where to branch off to hugepage pagetables,
and the entry also contains the information (eseentially hugepage
shift) necessary to then interpret that table without recourse to the
slice mask.  This scheme can be extended neatly to handle multiple
levels of self-describing "special" hugepage pagetables, although for
now we assume only one level exists.

This approach means that only the pagetable allocation path needs to
know how the pagetables should be set out.  All other (hugepage)
pagetable walking paths can just interpret the structure as they go.

There already was a flag bit in PGD/PUD/PMD entries for hugepage
directory pointers, but it was only used for debug.  We alter that
flag bit to instead be a 0 in the MSB to indicate a hugepage pagetable
pointer (normally it would be 1 since the pointer lies in the linear
mapping).  This means that asm pagetable walking can test for (and
punt on) hugepage pointers with the same test that checks for
unpopulated page directory entries (beq becomes bge), since hugepage
pointers will always be positive, and normal pointers always negative.

While we're at it, we get rid of the confusing (and grep defeating)
#defining of hugepte_shift to be the same thing as mmu_huge_psizes.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we have a fair bit of rather fiddly code to manage the
various kmem_caches used to store page tables of various levels.  We
generally have two caches holding some combination of PGD, PUD and PMD
tables, plus several more for the special hugepage pagetables.

This patch cleans this all up by taking a different approach.  Rather
than the caches being designated as for PUDs or for hugeptes for 16M
pages, the caches are simply allocated to be a specific size.  Thus
sharing of caches between different types/levels of pagetables happens
naturally.  The pagetable size, where needed, is passed around encoded
in the same way as {PGD,PUD,PMD}_INDEX_SIZE; that is n where the
pagetable contains 2^n pointers.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently, hpte_need_flush() only correctly flushes the given address
for normal pages.  Callers for hugepages are required to mask the
address themselves.

But hpte_need_flush() already looks up the page sizes for its own
reasons, so this is a rather silly imposition on the callers.  This
patch alters it to mask based on the pagesize it has looked up itself,
and removes the awkward masking code in the hugepage caller.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When running Active Memory Sharing, the Collaborative Memory Manager (CMM)
may mark some pages as "loaned" with the hypervisor. Periodically, the
CMM will query the hypervisor for a loan request, which is a single signed
value. When kexec'ing into a kdump kernel, the CMM driver in the kdump
kernel is not aware of the pages the previous kernel had marked as "loaned",
so the hypervisor and the CMM driver are out of sync. Fix the CMM driver
to handle this scenario by ignoring requests to decrease the number of loaned
pages if we don't think we have any pages loaned. Pages that are marked as
"loaned" which are not in the balloon will automatically get switched to "active"
the next time we touch the page. This also fixes the case where totalram_pages
is smaller than min_mem_mb, which can occur during kdump.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

get_irq_desc() is a powerpc-specific version of irq_to_desc(). That
is reason enough to remove it, but it also doesn't know about sparse
irq_desc support which irq_to_desc() does (when we enable it).
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Rather than open-coding our own check, use irq_has_action()
to check if an irq has an action - ie. is "in use".

irq_has_action() doesn't take the descriptor lock, but it
shouldn't matter - we're just using it as an indicator
that the irq is in use. disable_irq_nosync() will take
the descriptor lock before doing anything also.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The irq_desc array consumes quite a lot of space, and for systems
that don't need or can't have 512 irqs it's just wasted space.

The first 16 are reserved for ISA, so the minimum of 32 is really
16 - and no one has asked for more than 512 so leave that as the
maximum.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Linux power management subsystem supports vast amount of new PM
callbacks that are crucial for proper suspend and hibernation support
in drivers.

This patch implements support for dev_pm_ops, preserving support
for legacy callbacks.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The CHRP code has some fishy timer based code to scan the RTAS event
log, which uses a 1KB stack buffer and doesn't even use the results.

The pSeries code as a nicer daemon that allows userspace to read the
event log and basically uses the same RTAS interface

This patch moves rtasd.c out of platform/pseries and makes it usable
by CHRP, after removing the old crufty event log mechanism in there.

The nvram logging part of the daemon is still only available on 64-bit
since the underlying nvram management routines aren't currently shared.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some of the stuff in /proc/ppc64 such as the RTAS bits are actually
useful to some 32-bit platforms. Rename the file, and create a
symlink on 64-bit for backward compatibility
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Just as with kexec, hibernation may fail even on well-tested platforms:
some PCI device, a driver of which doesn't play well with hibernation,
is enough to break resuming.

Hibernation code is not much platform dependent, and hiding features only
because these were not verified on a particular hardware is
counterproductive: we just prevent the features from being widely tested.

For example, with this patch I just tested hibernation on a MPC83xx
board, and it works quite well, modulo a few drivers that need some
fixing.

So, let's make it possible to select hibernation support for all
PowerPCs, then let's wait for any possible bug reports, and actually fix
(or just collect ;-) the bugs instead of hiding them. If some platforms
really can't stand hibernation, we can make a blacklist, with proper
comments why exactly hibernation doesn't work, whether it is possible to
fix, and what needs to be done to fix it.

CONFIG_HIBERNATION is still =n by default, so the commit doesn't change
anything apart from ability to set it to =y.

I'm not sure if EXPERIMENTAL dependency is needed, I'd rather not add it
for a few reasons:

1) It doesn't matter much, for distro kernels user has no clue that some
   feature is experimental. Majority of defconfigs enable EXPERIMENTAL
   anyway (90 vs. 4, which, btw, means that EXPERIMENTAL is overused
   in Kconfigs);

2) EXPERIMENTAL is a good thing for features that change default
   behaviour of a kernel, while for hibernation user has to explicitly
   issue 'echo disk > /sys/power/state' to trigger any hibernation bugs;

3) Per init/Kconfig, EXPERIMENTAL is a good thing to scare and discourage
   users from 'widespread use of a feature', while we want to encourage
   that use.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The non-debug case in ps3/mm.c uses pr_debug(), so that the compiler
still does type checks etc. and doesn't complain about unused
variables in the non-debug case.

However with DEBUG=n and CONFIG_DYNAMIC_DEBUG=y there's still code
generated for those pr_debugs().

size before:
   text    data     bss     dec     hex filename
  17553	   4112	     88	  21753	   54f9	arch/powerpc/platforms/ps3/mm.o

size after:
   text    data     bss     dec     hex filename
   7377	    776	     88	   8241	   2031	arch/powerpc/platforms/ps3/mm.o
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

* 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: set up mmu_ops before trying to set any ptes

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  ide: Serialize CMD643 and CMD646 to fix a hardware bug with SSD

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (43 commits)
  net: Fix 'Re: PACKET_TX_RING: packet size is too long'
  netdev: usb: dm9601.c can drive a device not supported yet, add support for it
  qlge: Fix firmware mailbox command timeout.
  qlge: Fix EEH handling.
  AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl (v2)
  bonding: fix a race condition in calls to slave MII ioctls
  virtio-net: fix data corruption with OOM
  sfc: Set ip_summed correctly for page buffers passed to GRO
  cnic: Fix L2CTX_STATUSB_NUM offset in context memory.
  MAINTAINERS: rt2x00 list is moderated
  airo: Reorder tests, check bounds before element
  mac80211: fix for incorrect sequence number on hostapd injected frames
  libertas spi: fix sparse errors
  mac80211: trivial: fix spelling in mesh_hwmp
  cfg80211: sme: deauthenticate on assoc failure
  mac80211: keep auth state when assoc fails
  mac80211: fix ibss joining
  b43: add 'struct b43_wl' missing declaration
  b43: Fix Bugzilla #14181 and the bug from the previous 'fix'
  rt2x00: Fix crypto in TX frame for rt2800usb
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  sched: move rq_weight data array out of .percpu
  percpu: allow pcpu_alloc() to be called with IRQs off

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-param-fixes:
  param: fix setting arrays of bool
  param: fix NULL comparison on oom
  param: fix lots of bugs with writing charp params from sysfs, by leaking mem.

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio: order used ring after used index read
  virtio-pci: fix per-vq MSI-X request logic

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  backing-dev: ensure that a removed bdi no longer has super_block referencing it
  block: use after free bug in __blkdev_get
  block: silently error unsupported empty barriers too

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  Revert "PCI: get larger bridge ranges when space is available"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  mlx4_core: Add a new supported 40 GigE device ID

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] zfcp: Flush SCSI registration work when adding unit
  [SCSI] zfcp: Fix timer initialization for ct and els requests
  [SCSI] zfcp: Warn about storage devices with broken PLOGI data
  [SCSI] zfcp: Handle WWPN mismatch in PLOGI payload
  [SCSI] zfcp: fix kfree handling in zfcp_init_device_setup
  [SCSI] fix memory leak in initialization

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/kms: fix kms/fbdev colormap support properly.
  drm: Add the basic check for the detailed timing in EDID
  drm/radeon/kms: ignore vga arbiter return.

* 'sh/for-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix hugetlbfs dependencies for SH-3 && MMU configurations.
  sh: Document uImage.bin target in archhelp.
  sh: add uImage.bin target
  sh: rsk7203 CONFIG_MTD=n fix
  sh: Check for return_to_handler when unwinding the stack
  sh: Build fix: define more __movmem* symbols
  sh: __irq_entry annotate do_IRQ().

Fix up sh/powerpc conflicts in fs/Kconfig

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFSv4: The link() operation should return any delegation on the file
  NFSv4: Fix two unbalanced put_rpccred() issues.
  NFSv4: Fix a bug when the server returns NFS4ERR_RESOURCE
  nfs: Panic when commit fails

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] Fixing to avoid invalid kfree() in cifs_get_tcp_session()

I've not touched the other stuff here but the word "locking" comes to mind.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/ppc64: Use preempt_schedule_irq instead of preempt_schedule
  powerpc: Minor cleanup to lib/Kconfig.debug
  powerpc: Minor cleanup to sound/ppc/Kconfig
  powerpc: Minor cleanup to init/Kconfig
  powerpc: Limit memory hotplug support to PPC64 Book-3S machines
  powerpc: Limit hugetlbfs support to PPC64 Book-3S machines
  powerpc: Fix compile errors found by new ppc64e_defconfig
  powerpc: Add a Book-3E 64-bit defconfig
  powerpc/booke: Fix xmon single step on PowerPC Book-E
  powerpc: Align vDSO base address
  powerpc: Fix segment mapping in vdso32
  powerpc/iseries: Remove compiler version dependent hack
  powerpc/perf_events: Fix priority of MSR HV vs PR bits
  powerpc/5200: Update defconfigs
  drivers/serial/mpc52xx_uart.c: Use UPIO_MEM rather than SERIAL_IO_MEM
  powerpc/boot/dts: drop obsolete 'fsl5200-clocking'
  of: Remove nested function
  mpc5200: support for the MAN mpc5200 based board mucmc52
  mpc5200: support for the MAN mpc5200 based board uc101

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
  mfd: Do not dereference null pointer in twl4030 error path
  mfd: Always initialise WM831x IRQ mutex

* 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
  HWPOISON: fix invalid page count in printk output
  HWPOISON: Allow schedule_on_each_cpu() from keventd
  HWPOISON: fix/proc/meminfo alignment
  HWPOISON: fix oops on ksm pages
  HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page
  HWPOISON: return early on non-LRU pages
  HWPOISON: Add brief hwpoison description to Documentation
  HWPOISON: Clean up PR_MCE_KILL interface

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: fix double IRELE in xfs_dqrele_inode

Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6

* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
  omap4: Fix UART4 platform data on omap4
  omap4: Allow omap_serial_early_init() for OMAP4430 board
  omap3: PM: enable UART3 module wakeups
  omap2: Fix console serial port number for n8x0
  omap2: Fix detection of n8x0
  omap1: Fix DSP public peripherals support for ams-delta
  omap1: Fix redundant UARTs pin muxing that can break other hardware support
  omap: iommu: fix wrong condition check for SUPERSECTION
  omap: SDMA: Fix omap_stop_dma() API for channel linking
  omap: Fix omap-keypad by restoring old keypad.h without breaking omap2 boards that use matrix_keypad

* 'for-linus' of git://git.infradead.org/ubi-2.6:
  UBI: fix check on unsigned long
  UBI: fix backward compatibility

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (it87) Fix VID reading on IT8718F/IT8720F
  hwmon: (dme1737) No vid attributes for SCH311x
  hwmon: (fschmd) Fix check on unsigned in watchdog_write()
  hwmon: (coretemp) Maintainer update

* 'urgent-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
  pcmcia: do not load the pd6729 driver if io_base is NULL
  pcmcia: Fix possible printk format warnings
  pcmcia: do not try to store more than 4 version strings
  pcmcia: pccard_read_tuple and TUPLE_RETURN_COMMON cleanup
  pcmcia: properly close previous dev_printk if kzalloc fails in do_io_probe
  pcmcia: fix controller printk format warnings

* master.kernel.org:/home/rmk/linux-2.6-arm: (22 commits)
  ARM: Fix lubbock defconfig build
  ARM: 5769/1: CPU_ARM920T: remove dead Maverick EP9312 URL
  ARM: 5768/1: ep93xx: remove dead code in ep93xx_gpio_ab_irq_handler()
  ARM: 5767/1: ep93xx: remove ep93xx_init_time() prototype
  ARM: 5765/1: Updated U300 defconfig
  ARM: 5766/1: Fix watchdog enabling for AT91SAM9G45
  ARM: 5764/1: bcmring: add oprofile pmu support
  [ARM] pxa/spitz: add gpio button support (fixes regression)
  [ARM] pxa/cm-x300: fix mmc numbering
  ARM: 5763/1: ARM: SMP: Fix the BUG with CONFIG_PREEMPT enabled
  ARM: 5760/1: ep93xx: fix build error in edb93xx.c
  ARM: 5759/1: Add register information of threads to coredump
  ARM: 5757/1: Thumb-2: Correct "mov.w pc, lr" instruction which is unpredictable
  MXC: fix reset for mx31, mx35 and mx27 SoCs
  fix pcm037_eet compilation with the new SPI driver
  fix compilation of i.MX31 platforms
  pcm970 mmc: Fix ro switch
  pcm038: Add SPI/MC13783 support
  mx25: Add missing copyright / license header
  mx25pdk: remove nand support as it is not present in current tree
  ...

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Move drop_futex_key_refs out of spinlock'ed region
  rcu: Fix TREE_PREEMPT_RCU CPU_HOTPLUG bad-luck hang
  rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCU
  rcu: Prevent RCU IPI storms in presence of high call_rcu() load
  futex: Check for NULL keys in match_futex
  futex: Handle spurious wake up