The current code soft-disables, and then goes to NAP mode which
turns interrupts on. That means that if an interrupt occurs, we
will hit the masked interrupt code path which isn't what we want,
as it will return with EE off, which will either get us out of
NAP mode, or fail to enter it (according to spec).

Instead, let's just rely on the fact that it is safe to take
decrementer interrupts on an offline CPU and leave interrupts
enabled. We can also get rid of the special case in asm for
power4_cpu_offline_powersave() and just use power4_idle().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Those instructions do nothing on non-threaded processors such
as 970's used on those machines.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

Use the generic code, just add the MPIC priority setting,

I don't see any use in mucking around with the decrementer,
as 32-bit will have EE off all along, and 64-bit will be able
to deal with it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

Use generic cpu_state, call idle_task_exit() properly, and
remove smp_core99_cpu_die() which isn't useful, the generic
function does the job just fine.

Remove the last remnants of cpu_enable(), everybody uses the normal
__cpu_up() path now
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Nobody uses it, besides we should always use the normal __cpu_up
path anyways
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This is used by some "soft" hotplug implementations. I needs to
call idle_task_exit() when the CPU is going away, and we remove
the now no-longer needed set_cpu_online() and local_irq_enable()
which are handled by the return to start_secondary
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...

Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.

We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

With some implementations, it is possible that a timer interrupt
occurs every few seconds on an offline CPU. In this case, just
re-arm the decrementer and return immediately
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Fix build breakage - sn_force_interrupt_flag: undefined

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix whitespace coding style issues
  nilfs2: fix oops due to a bad aops initialization
  nilfs2: fix data loss in mmap page write for hole blocks

* git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: Create a new key type "ceph".
  libceph: Get secret from the kernel keys api when mounting with key=NAME.
  ceph: Move secret key parsing earlier.
  libceph: fix null dereference when unregistering linger requests
  ceph: unlock on error in ceph_osdc_start_request()
  ceph: fix possible NULL pointer dereference
  ceph: flush msgr_wq during mds_client shutdown

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

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  avr32: Fix missing irq namespace conversion
  powerpc: qe_ic: Rename get_irq_desc_data and get_irq_desc_chip
  genirq: Remove the now obsolete config options and select statements
  arm: versatile : Fix typo introduced in irq namespace cleanup
  sound: Fixup the last user of the old irq functions
  genirq: Remove obsolete comment
  genirq: Remove now obsolete set_irq_wake()
  sh: Fix irq cleanup fallout
  x86: apb_timer: Fixup genirq fallout
  genirq: Fix misnamed label in handle_edge_eoi_irq

Fix up crazy conflict in arch/powerpc/include/asm/qe_ic.h:

 - commit eead4d5c ("powerpc: qe_ic: Rename get_irq_desc_data and
   get_irq_desc_chip") made the helper functions use
   irq_desc_get_handler_data() instead of the legacy (and no longer
   existing) get_irq_desc_data.

 - commit d4db35e8 ("powerpc/qe_ic: Fix another breakage from the
   irq_data conversion") used irq_desc_get_chip_data() instead.

According to Thomas, the former is the correct direct conversion, but it
does look like both should work (arch/powerpc/sysdev/qe_lib/qe_ic.c
seems to initialize both to the same thing), and the chip data in some
ways is the more logical.  Somebody should really decide on one of the
other.

This merge picks irq_desc_get_handler_data() as the straightforward pure
conversion to new names, as per Thomas.

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/qe_ic: Fix another breakage from the irq_data conversion
  powerpc/8xx: Fix another breakage from the irq_data conversion
  powerpc/cell: Use handle_edge_eoi_irq for real
  powerpc/pseries: Enable Chelsio network and iWARP drivers
  powerpc/mm: Move the STAB0 location to 0x8000 to make room in low memory
  powerpc: Fix accounting of softirq time when idle
  powerpc/pseries/smp: query-cpu-stopped-state support won't change
  powerpc/xics: Use hwirq for xics domain irq number
  powerpc/xics: Fix numberspace mismatch from irq_desc conversion
  powerpc: Wire up new syscalls
  powerpc/booke: Correct the SPRN_MAS5 definition.
  powerpc: ARCH_PFN_OFFSET should be unsigned long
  powerpc: Implement dma_mmap_coherent()
  powerpc/nvram: Don't overwrite oops/panic report on normal shutdown
  powerpc: Restore some misc devices to our configs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin:
  Blackfin: bitops: fix include order after little endian inclusion
  Blackfin: defconfigs: update after misc devices defaulted to N
  Blackfin: use more standard pr_fmt in the module loader

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (65 commits)
  ARM: 6826/1: Merge v6 and v7 DEBUG_LL DCC support
  ARM: 6838/1: etm: fix section mismatch warning
  ARM: 6837/1: remove unused pci_fixup_prpmc1100
  ARM: 6836/1: kprobes/fix emulation of LDR/STR instruction when Rn == PC
  Fix the broken build for Marvell Dove platform.
  ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latency
  ARM: 6834/1: perf: reset counters on all CPUs during initialisation
  ARM: 6833/1: perf: add required isbs() to ARMv7 backend
  ARM: 6825/1: kernel/sleep.S: fix Thumb2 compilation issues
  ARM: 6807/1: realview: Fix secondary GIC initialisation for EB with MPCore tile
  arm: mach-mx3: pcm043: add write-protect and card-detect for SD1
  eukrea_mbimxsd51: add SD Card detect
  eukrea_mbimxsd25-baseboard: add SD card detect
  mx3/eukrea_mbimxsd-baseboard: add SD card detect support
  mx3/eukrea_mbimxsd-baseboard: fix gpio request
  ARM: mxs/mx28evk: add mmc device
  ARM: mxs/mx23evk: add mmc device
  ARM: mxs: dynamically allocate mmc device
  ARM: mx51_efika: update platform data for new mfd changes
  mx2/iomux: Set direction for CSPI2 pins
  ...

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

These two functions disappeared in commit

    0c6f8a8b
    "genirq: Remove compat code"

but they still exist in qe_ic.h.
This patch renames the function to their new names.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Lennert Buytenhek <buytenh@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <20110330132504.GA31832@riccoc20.at.omicron.at>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Commit 6845664(arm: Cleanup the irq namespace) introduces a typo
causing a build failure for the versatile platform.

[ tglx: Sorry, my bad. Have no idea how I fatfingered that ]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <20110330060229.27397.7628.stgit@ponder>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Fixes whitespace coding style issues.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Nilfs in 2.6.39-rc1 hit the following oops:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
 IP: [<ffffffff810ac235>] try_to_release_page+0x2a/0x3d
 PGD 234cb6067 PUD 234c72067 PMD 0
 Oops: 0000 [#1] SMP
 <snip>
 Process truncate (pid: 10995, threadinfo ffff8802353c2000, task ffff880234cfa000)
 Stack:
  ffff8802333c77b8 ffffffff810b64b0 0000000000003802 ffffffffa0052cca
  0000000000000000 ffff8802353c3b58 0000000000000000 ffff8802353c3b58
  0000000000000001 0000000000000000 ffffea0007b92308 ffffea0007b92308
 Call Trace:
  [<ffffffff810b64b0>] ? invalidate_inode_pages2_range+0x15f/0x273
  [<ffffffffa0052cca>] ? nilfs_palloc_get_block+0x2d/0xaf [nilfs2]
  [<ffffffff810589e7>] ? bit_waitqueue+0x14/0xa1
  [<ffffffff81058ab1>] ? wake_up_bit+0x10/0x20
  [<ffffffffa00433fd>] ? nilfs_forget_buffer+0x66/0x7a [nilfs2]
  [<ffffffffa00467b8>] ? nilfs_btree_concat_left+0x5c/0x77 [nilfs2]
  [<ffffffffa00471fc>] ? nilfs_btree_delete+0x395/0x3cf [nilfs2]
  [<ffffffffa00449a3>] ? nilfs_bmap_do_delete+0x6e/0x79 [nilfs2]
  [<ffffffffa0045845>] ? nilfs_btree_last_key+0x14b/0x15e [nilfs2]
  [<ffffffffa00449dd>] ? nilfs_bmap_truncate+0x2f/0x83 [nilfs2]
  [<ffffffffa0044ab2>] ? nilfs_bmap_last_key+0x35/0x62 [nilfs2]
  [<ffffffffa003e99b>] ? nilfs_truncate_bmap+0x6b/0xc7 [nilfs2]
  [<ffffffffa003ee4a>] ? nilfs_truncate+0x79/0xe4 [nilfs2]
  [<ffffffff810b6c00>] ? vmtruncate+0x33/0x3b
  [<ffffffffa003e8f1>] ? nilfs_setattr+0x4d/0x8c [nilfs2]
  [<ffffffff81026106>] ? do_page_fault+0x31b/0x356
  [<ffffffff810f9d61>] ? notify_change+0x17d/0x262
  [<ffffffff810e5046>] ? do_truncate+0x65/0x80
  [<ffffffff810e52af>] ? sys_ftruncate+0xf1/0xf6
  [<ffffffff8132c012>] ? system_call_fastpath+0x16/0x1b
 Code: c3 48 83 ec 08 48 8b 17 48 8b 47 18 80 e2 01 75 04 0f 0b eb fe 48 8b 17 80 e6 20 74 05 31 c0 41 59 c3 48 85 c0 74 11 48 8b 40 58
  8b 40 48 48 85 c0 74 04 41 58 ff e0 59 e9 b1 b5 05 00 41 54
 RIP  [<ffffffff810ac235>] try_to_release_page+0x2a/0x3d
  RSP <ffff8802353c3b08>
 CR2: 0000000000000048

This oops was brought in by the change "block: remove per-queue
plugging" (commit: 7eaceacc).  It initializes mapping->a_ops
with a NULL pointer for some pages in nilfs (e.g. btree node pages),
but mm code doesn't NULL pointer checks against mapping->a_ops. (the
check is done for each callback function)

This corrects the aops initialization and fixes the oops.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Jens Axboe <jaxboe@fusionio.com>

From the result of a function test of mmap, mmap write to shared pages
turned out to be broken for hole blocks.  It doesn't write out filled
blocks and the data will be lost after umount.  This is due to a bug
that the target file is not queued for log writer when filling hole
blocks.

Also, nilfs_page_mkwrite function exits normal code path even after
successfully filled hole blocks due to a change of block_page_mkwrite
function; just after nilfs was merged into the mainline,
block_page_mkwrite() started to return VM_FAULT_LOCKED instead of zero
by the patch "mm: close page_mkwrite races" (commit:
b827e496).  The current nilfs_page_mkwrite() is not handling
this value properly.

This corrects nilfs_page_mkwrite() and will resolve the data loss
problem in mmap write.

[This should be applied to every kernel since 2.6.30 but a fix is
 needed for 2.6.37 and prior kernels]
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: stable <stable@kernel.org>  [2.6.38]

Latest irq changes removed the need for this forcing flag, and the
definition - but missed the code that allowed it to be tweaked via
/proc.  Delete accessor functions too.
Signed-off-by: Tony Luck <tony.luck@intel.com>

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

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

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixes these errors:

  kernel/irq/chip.c: In function 'handle_edge_eoi_irq':
  kernel/irq/chip.c:517: warning: label 'out_unlock' defined but not used
  kernel/irq/chip.c:503: error: label 'out_eoi' used but not defined
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Missed one instance when moving that to the core code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: michael@ellerman.id.au
Cc: mingo@elte.hu
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Ensure the Chelsio T3/T4 network drivers and iWARP drivers are
enabled in the pseries config.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Recent upstream builds with allmodconfig fail due to lack of space
between 0x3000 and 0x6000. We have a hard block at 0x7000 but we can
spare a page by moving the STAB0 from 0x6000 to 0x8000.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit cf9efce0 (powerpc: Account time using timebase rather
than PURR) used in_irq() to detect if the time was spent in
interrupt processing. This only catches hardirq context so if we
are in softirq context and in the idle loop we end up accounting it
as idle time. If we instead use in_interrupt() we catch both softirq
and hardirq time.

The issue was found when running a network intensive workload. top
showed the following:

0.0%us,  1.1%sy,  0.0%ni, 85.7%id,  0.0%wa,  9.9%hi,  3.3%si,  0.0%st

85.7% idle. But this was wildly different to the perf events data.
To confirm the suspicion I ran something to keep the core busy:

# yes > /dev/null &

8.2%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa, 10.3%hi, 81.4%si,  0.0%st

We only got 8.2% of the CPU for the userspace task and softirq has
shot up to 81.4%.

With the patch below top shows the correct stats:

0.0%us,  0.0%sy,  0.0%ni,  5.3%id,  0.0%wa, 13.3%hi, 81.3%si,  0.0%st
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

If a given firmware doesn't have a token to support query-cpu-stopped-state,
its not likely to change during the lifetime of the kernel.

Only print this information once, not once per secondary thread.

While here, make the line wrap grep friendly.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

To try to avoid future confusion, rename irq to hwirq when it refers
to a xics domain number instead of a linux irq number.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit 79f26c26 (powerpc:
platforms/pseries irq_data conversion) pushed irq_desc down into many
functions, dererencing the descriptor irq field as late as possible.

But it incorrectly passed a linix virtural irq number to RTAS,
resulting in the interrupt not being disabled and possibly
other bad things, such as another interrupt being disabled and/or
a checkstop.

In addition this missed the point of xics_mask_unknown_vec and
the seperation of xics_mask_real_irq from xics_mask_irq.  When
xics_mask_unknown_vec is called it's because the hardware delivered an
irq source for which we have no linux irq allocated, and thefore we can
not have an irq_desc allocated.

Revert xics_mask_real_irq to its prior version, naming the argument
hwirq to highlight the difference.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

These syscalls have been added recently:
	name_to_handle_at
	open_by_handle_at
	clock_adjtime
	syncfs
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

339 is the SPR number for MAS5 documented by Power ISA 2.06, and
implemented by e500mc.  It is not yet used anywhere in the kernel,
so nothing should be relying on the wrong number.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

pfns are unsigned long, but MEMORY_START is phys_addr_t.  This leads
to page_to_pfn() returning phys_addr_t, and thus type mismatches in a few
print statements.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>