Commit Graph

143686 Commits

Author SHA1 Message Date
Jens Axboe
40bb54d197 cfq-iosched: no need to save interrupts in cfq_kick_queue()
It's called from the workqueue handlers from process context, so
we always have irqs enabled when entered.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:11:10 +02:00
Nick Piggin
c2572f2b4f brd: fix cacheflushing
brd is missing a flush_dcache_page. On 2nd thoughts, perhaps it is the
pagecache's responsibility to flush user virtual aliases (the driver of
course should flush kernel virtual mappings)... but anyway, there
already exists cache flushing for one direction of transfer, so we
should add the other.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nick Piggin
dfbc4752ea brd: support barriers
brd is always ordered (not that it matters, as it is defined not to
survive when the system goes down). So tell the block layer it is
ordered, which might be of help with testing filesystems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nikanth Karthikesan
297dbf50d7 swap: Remove code handling bio_alloc failure with __GFP_WAIT
Remove code handling bio_alloc failure with __GFP_WAIT.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nikanth Karthikesan
b1fffc9ca6 gfs2: Remove code handling bio_alloc failure with __GFP_WAIT
Remove code handling bio_alloc failure with __GFP_WAIT.
GFP_NOFS implies __GFP_WAIT.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nikanth Karthikesan
226e7dabf5 ext4: Remove code handling bio_alloc failure with __GFP_WAIT
Remove code handling bio_alloc failure with __GFP_WAIT.
GFP_NOIO implies __GFP_WAIT.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nikanth Karthikesan
4d1f9fdb61 dio: Remove code handling bio_alloc failure with __GFP_WAIT
Remove code handling bio_alloc failure with __GFP_WAIT.
GFP_KERNEL implies __GFP_WAIT.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:13 +02:00
Nikanth Karthikesan
15afd1cc7b block: Remove code handling bio_alloc failure with __GFP_WAIT
Remove code handling bio_alloc failure with __GFP_WAIT.
GFP_KERNEL implies __GFP_WAIT.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Jens Axboe
86c824b943 bio: add documentation to bio_alloc()
Explain that with __GFP_WAIT set it will not fail, and that the caller
must never allocate more than 1 bio at the time.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Miklos Szeredi
61e0d47c33 splice: add helpers for locking pipe inode
There are lots of sequences like this, especially in splice code:

	if (pipe->inode)
		mutex_lock(&pipe->inode->i_mutex);
	/* do something */
	if (pipe->inode)
		mutex_unlock(&pipe->inode->i_mutex);

so introduce helpers which do the conditional locking and unlocking.
Also replace the inode_double_lock() call with a pipe_double_lock()
helper to avoid spreading the use of this functionality beyond the
pipe code.

This patch is just a cleanup, and should cause no behavioral changes.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Miklos Szeredi
f8cc774ce4 splice: remove generic_file_splice_write_nolock()
Remove the now unused generic_file_splice_write_nolock() function.
It's conceptually broken anyway, because splice may need to wait for
pipe events so holding locks across the whole operation is wrong.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Miklos Szeredi
328eaaba4e ocfs2: fix i_mutex locking in ocfs2_splice_to_file()
Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:12 +02:00
Miklos Szeredi
eb443e5a25 splice: fix i_mutex locking in generic_splice_write()
Rearrange locking of i_mutex on destination so it's only held while
buffers are copied with the pipe_to_file() actor, and not while
waiting for more data on the pipe.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:11 +02:00
Miklos Szeredi
2933970b96 splice: remove i_mutex locking in splice_from_pipe()
splice_from_pipe() is only called from two places:

  - generic_splice_sendpage()
  - splice_write_null()

Neither of these require i_mutex to be taken on the destination inode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:11 +02:00
Miklos Szeredi
b3c2d2ddd6 splice: split up __splice_from_pipe()
Split up __splice_from_pipe() into four helper functions:

  splice_from_pipe_begin()
  splice_from_pipe_next()
  splice_from_pipe_feed()
  splice_from_pipe_end()

splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe.  splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).

This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().

This patch should not cause any change in behavior.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:11 +02:00
FUJITA Tomonori
91e463c8f5 block: fix SG_IO to return a proper error value
blk_rq_unmap_user() returns -EFAULT if a program passes an invalid
address to kernel. SG_IO path needs to pass the returned value to user
space instead of ignoring it.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 12:10:11 +02:00
Wei Yongjun
ed247e12fe sparc: remove some pointless conditionals before kfree()
Remove some pointless conditionals before kfree().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-15 03:04:56 -07:00
Justin Mattock
83b2086ce2 ALSA: add missing definitions(letters) to HD-Audio.txt
impact: Add missing definitions(letters).

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-04-15 11:51:50 +02:00
Markus Brunner
cbea270714 gianfar: stop send queue before resetting gianfar
After a transmit timed out, the reset task will be called, which will free the
allocated resources(stop_gfar). If gfar_poll will be called before the
resources get allocated again gfar_clean_tx_ring will call
dev_kfree_skb_any(NULL).

Example crash:

ops: Kernel access of bad area, sig: 11 [#1]
PREEMPT RSBBA100
Modules linked in:
NIP: c01a10c4 LR: c013b254 CTR: c013c038
REGS: c02e7d20 TRAP: 0300   Not tainted  (2.6.27.20)
MSR: 00001032 <ME,IR,DR>  CR: 24000082  XER: 20000000
DAR: 000000a0, DSISR: 20000000
TASK = c02ce578[0] 'swapper' THREAD: c02e6000
GPR00: 000000a0 c02e7dd0 c02ce578 00000000 00000040 00000001 c02ec1c0 
00001032
GPR08: c080d1e0 df9ea800 00000000 00000000 24000082 ffffffff 0404f000 
00000000
GPR16: ffffffbf ffffffff ffffffff ffdff7ff ffffffff c02d0fd4 00100100 
00200200
GPR24: c031220c 00000001 00000001 00000000 00000000 df849800 ff109000 
df849b80
NIP [c01a10c4] dev_kfree_skb_irq+0x18/0x70
LR [c013b254] gfar_clean_tx_ring+0x70/0x11c
Call Trace:
[c02e7dd0] [c003e978] update_wall_time+0x730/0x744 (unreliable)
[c02e7df0] [c013b254] gfar_clean_tx_ring+0x70/0x11c
[c02e7e10] [c013c07c] gfar_poll+0x44/0x150
[c02e7e30] [c01a064c] net_rx_action+0xa8/0x19c
[c02e7e70] [c00251d4] __do_softirq+0x64/0xc0
[c02e7e90] [c0006384] do_softirq+0x40/0x58
[c02e7ea0] [c00250a8] irq_exit+0x40/0x9c
[c02e7eb0] [c000642c] do_IRQ+0x90/0xac
[c02e7ec0] [c0010ab4] ret_from_except+0x0/0x14
--- Exception: 501 at cpu_idle+0x9c/0xf8
    LR = cpu_idle+0x9c/0xf8
[c02e7f80] [c0009820] cpu_idle+0x58/0xf8 (unreliable)
[c02e7fa0] [c01fb8c8] __got2_end+0x7c/0x90
[c02e7fc0] [c026c794] start_kernel+0x2c0/0x2d4
[c02e7ff0] [00003438] 0x3438
Instruction dump:
7fa00124 80010024 bba10014 38210020 7c0803a6 4e800020 9421ffe0 7c0802a6
7c6b1b78 90010024 380300a0 bfa10014 <7d200028> 3129ffff 7d20012d 40a2fff4
Kernel panic - not syncing: Fatal exception in interrupt

This Patch calls netif_stop_queue before calling stop_gfar.

Signed-off-by: Markus Brunner <super.firetwister@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-15 02:35:40 -07:00
Stanislaw Gruszka
636d2f68a0 myr10ge: again fix lro_gen_skb() alignment
Add LRO alignment initially committed in
621544eb8c ("[LRO]: fix lro_gen_skb()
alignment") and removed in 0dcffac1a3
("myri10ge: add multislices support") during conversion to
multi-slice.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-15 02:29:33 -07:00
Takashi Iwai
f4723b224d Merge branch 'topic/memdup_user' into for-linus
* topic/memdup_user:
  ALSA: sound/pci: use memdup_user()
  ALSA: sound/usb: use memdup_user()
  ALSA: sound/isa: use memdup_user()
  ALSA: sound/core: use memdup_user()
2009-04-15 11:24:27 +02:00
Takashi Iwai
00610a81df Merge branch 'topic/usb-caiaq' into for-linus
* topic/usb-caiaq:
  ALSA: snd-usb-caiaq: rename files to remove redundant information in file pathes
  ALSA: snd-usb-caiaq: clean up header includes
2009-04-15 11:24:22 +02:00
Takashi Iwai
035f5afb02 Merge branch 'topic/asoc' into for-linus
* topic/asoc:
  ASoC: Disable S3C64xx support in Kconfig
  ASoC: magician: remove un-necessary #include of pxa-regs.h and hardware.h
2009-04-15 11:24:14 +02:00
Takashi Iwai
2e8e59f437 Merge branch 'topic/hda' into for-linus
* topic/hda:
  ALSA: hda - Add quirk mask for Fujitsu Amilo laptops with ALC883
  ALSA: hda - Avoid call of snd_jack_report at release
  ALSA: add private_data to struct snd_jack
2009-04-15 11:24:09 +02:00
Takashi Iwai
ff0c68d03b Merge branch 'topic/jack-free-fix' into topic/hda
* topic/jack-free-fix:
  ALSA: hda - Avoid call of snd_jack_report at release
  ALSA: add private_data to struct snd_jack
2009-04-15 11:23:44 +02:00
Takashi Iwai
45c27fc8c8 Merge branch 'master' of git://git.alsa-project.org/alsa-kernel into for-linus
* 'master' of git://git.alsa-project.org/alsa-kernel:
  [ALSA] intel8x0: add one retry to the ac97_clock measurement routine
  [ALSA] intel8x0: fix wrong conditions in ac97_clock measure routine
  [ALSA] intel8x0: do not use zero value from PICB register
  [ALSA] intel8x0: an attempt to make ac97_clock measurement more reliable
  [ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies
  [ALSA] hda_intel: fix unexpected ring buffer positions
2009-04-15 11:21:13 +02:00
Xu Gang
1328df7252 GFS2: Use DEFINE_SPINLOCK
SPIN_LOCK_UNLOCKED is deprecated, use DEFINE_SPINLOCK instead.
(as suggested in Documentation/spinlocks.txt)

Signed-off-by: Xu Gang <xug@cn.fujitsu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15 10:18:07 +01:00
Christoph Hellwig
10d2198805 GFS2: cleanup file_operations mess
Remove the weird pointer to file_operations mess and replace it with
straight-forward defining of the lockinginstance names to the _nolock
variants.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15 10:17:18 +01:00
Steven Whitehouse
a228df6339 GFS2: Move umount flush rwsem
The rwsem, used only on umount, is in the wrong place in glock.c.
This patch moves it up a bit so that it does not get called under
a spinlock.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15 10:16:13 +01:00
Steven Whitehouse
5cf32524de GFS2: Fix symlink creation race
In certain cases symlinks can appear to have zero size if a lookup
on the inode occurs within a certain (very short) time after the
symlink has been created. The symlink is correctly created on disk
but appears to have zero size when stat()ed. This patch closes the
race and prevents incorrect sizes appearing.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15 10:15:38 +01:00
Steven Whitehouse
7fa5d20d1a GFS2: Make quotad's waiting interruptible
So we don't count its D state in the loadavg.

Reported-by: Nathan Straz <nstraz@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15 10:15:08 +01:00
Takashi Iwai
bfb53037c6 ALSA: hda - Add quirk mask for Fujitsu Amilo laptops with ALC883
Added the models for quirk bitmask 1734:110x and 1734:113x of
Fujitsu laptops.

This will fix the model detection for Amilo Xa3540.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-04-15 11:13:21 +02:00
Hartley Sweeten
d5565f76d3 [ARM] 5451/1: ep93xx:core.c: build warning fix
Fix trivial build warning due to incompatible pointer type.

ep93xx_timer_interrupt() has the wrong return type causing a
warning during the build.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-15 10:01:03 +01:00
Aaro Koskinen
7fccfc00c0 [ARM] 5450/1: Flush only the needed range when unmapping a VMA
When unmapping N pages (e.g. shared memory) the amount of TLB flushes
done can be (N*PAGE_SIZE/ZAP_BLOCK_SIZE)*N although it should be N at
maximum. With PREEMPT kernel ZAP_BLOCK_SIZE is 8 pages, so there is a
noticeable performance penalty when unmapping a large VMA and the system
is spending its time in flush_tlb_range().

The problem is that tlb_end_vma() is always flushing the full VMA
range. The subrange that needs to be flushed can be calculated by
tlb_remove_tlb_entry(). This approach was suggested by Hugh Dickins,
and is also used by other arches.

The speed increase is roughly 3x for 8M mappings and for larger mappings
even more.

Signed-off-by: Aaro Koskinen <Aaro.Koskinen@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-15 10:01:02 +01:00
Mark Brown
41609ff430 [ARM] 5449/1: S3C: Use disable_irq_nosync() to fix boot lockups
With 2.6.30-rc1 on SMDK6410 I experience a soft lockup on bootup when
the Samsung serial driver attempts to disable the transmit interrupt
from within the transmit interrupt handler: it calls disable_irq()
which locks up due to attempting to synchronise with the running handler.
Fix this by using disable_irq_nosync().

Also make the same change in the recieve path.

Backtrace:

[<c002a914>] (__irq_svc+0x34/0x80) from [<c00696c0>] (synchr)
[<c00696c0>] (synchronize_irq+0xc/0xcc) from [<c018d434>] (s)
[<c018d434>] (s3c24xx_serial_stop_tx+0x1c/0x3c) from [<c018d)
[<c018d54c>] (s3c24xx_serial_tx_chars+0xf8/0x104) from [<c00)
[<c0068bcc>] (handle_IRQ_event+0x74/0x118) from [<c006ab04>])
[<c006ab04>] (handle_level_irq+0x100/0x118) from [<c00349c4>)
[<c00349c4>] (s3c_irq_demux_uart+0x94/0xc4) from [<c002a050>)
[<c002a050>] (_text+0x50/0x6c) from [<c002a914>] (__irq_svc+)

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-15 10:01:02 +01:00
Russell King
9fa264d0d3 Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 2009-04-15 09:58:21 +01:00
Jaroslav Kysela
2ec775e705 [ALSA] intel8x0: add one retry to the ac97_clock measurement routine
It seems that on some hardware platforms, the first measurement is wrong.
This patch adds second measurement to this case.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2009-04-15 10:16:24 +02:00
Jens Axboe
d6ceb25e8d cfq-iosched: don't delay queue kick for a merged request
"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> reports that commit
b029195dda introduced a regression
of about 50% with sequential threaded read workloads. The test
case is:

tiotest -k0 -k1 -k3 -f 80 -t 32

which starts 32 threads each reading a 80MB file. Twiddle the kick
queue logic so that we do start IO immediately, if it appears to be
a fully merged request. We can't really detect that, so just check
if the request is bigger than a page or not. The assumption is that
since single bio issues will first queue a single request with just
one page attached and then later do merges on that, if we already
have more than a page worth of data in the request, then the request
is most likely good to go.

Verified that this doesn't cause a regression with the test case that
commit b029195dda was fixing. It does not,
we still see maximum sized requests for the queue-then-merge cases.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:12 +02:00
Jens Axboe
053c525fcf buffer: switch do_emergency_thaw() away from pdflush_operation()
This is (again) a preparatory patch similar to commit
a2a9537ac0. It open codes a simple
async way of executing do_thaw_all() out of context, so we can get
rid of pdflush.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:12 +02:00
Jens Axboe
329007ce25 block: update biodoc.txt on plugging
We do per-device plugging, get rid of any references to tq_disk as that
has been dead since 2.6.5 or so.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:11 +02:00
Jens Axboe
1d6bfbdf38 as-iosched: get rid of private REQ_SYNC/REQ_ASYNC defines
We can just use the block layer BLK_RW_SYNC/ASYNC defines now.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:10 +02:00
Jens Axboe
ff6657c6c8 cfq-iosched: get rid of private SYNC/ASYNC defines
We can just use the block layer BLK_RW_SYNC/ASYNC defines now.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:10 +02:00
Jens Axboe
b0b78f81a5 cfq-iosched: use rw_is_sync() to see if rw flags are sync or not
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:10 +02:00
Jens Axboe
48e70bc18a Document and move the various READ/WRITE types
It's a somewhat twisty maze of hints and behavioural modifiers, try
and clear it up a bit with some documentation.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:10 +02:00
Jens Axboe
f600abe2de block: fix bad spelling of quiesce
Credit goes to Andrew Morton for spotting this one.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:09 +02:00
Christoph Hellwig
8f3d8ba20e block: move bio list helpers into bio.h
It's used by DM and MD and generally useful, so move the bio list
helpers into bio.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:09 +02:00
Sachin Sant
b71a0c296c powerpc: pseries/dtl.c should include asm/firmware.h
A randconfig build on powerpc failed with:

dtl.c: In function 'dtl_init':
dtl.c:238: error: implicit declaration of function 'firmware_has_feature'
dtl.c:238: error: 'FW_FEATURE_SPLPAR' undeclared (first use in this function)

- We need firmware.h for these definitions.

Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-15 15:23:55 +10:00
Paul Mackerras
306a82881b powerpc: Fix data-corrupting bug in __futex_atomic_op
Richard Henderson pointed out that the powerpc __futex_atomic_op has a
bug: it will write the wrong value if the stwcx. fails and it has to
retry the lwarx/stwcx. loop, since 'oparg' will have been overwritten
by the result from the first time around the loop.  This happens
because it uses the same register for 'oparg' (an input) as it uses
for the result.

This fixes it by using separate registers for 'oparg' and 'ret'.

Cc: stable@kernel.org
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-15 15:23:53 +10:00
Mike Mason
c58dc575f3 powerpc/pseries: Set error_state to pci_channel_io_normal in eeh_report_reset()
While adding native EEH support to Emulex and Qlogic drivers, it was
discovered that dev->error_state was set to pci_io_channel_normal too
late in the recovery process. These drivers rely on error_state to
determine if they can access the device in their slot_reset callback,
thus error_state needs to be set to pci_io_channel_normal in
eeh_report_reset(). Below is a detailed explanation (courtesy of Richard
Lary) as to why this is necessary.

Background:
PCI MMIO or DMA accesses to a frozen slot generate additional EEH
errors. If the number of additional EEH errors exceeds EEH_MAX_FAILS the
adapter will be shutdown. To avoid triggering excessive EEH errors and
an undesirable adapter shutdown, some drivers use the
pci_channel_offline(dev) wrapper function to return a Boolean value
based on the value of pci_dev->error_state to determine if PCI MMIO or
DMA accesses are safe. If the wrapper returns TRUE, drivers must not
make PCI MMIO or DMA access to their hardware.

The pci_dev structure member error_state reflects one of three values,
1) pci_channel_io_normal, 2) pci_channel_io_frozen, 3)
pci_channel_io_perm_failure.  Function pci_channel_offline(dev) returns
TRUE if error_state is pci_channel_io_frozen or pci_channel_io_perm_failure.

The EEH driver sets pci_dev->error_state to pci_channel_io_frozen at the
point where the PCI slot is frozen. Currently, the EEH driver restores
dev->error_state to pci_channel_io_normal in eeh_report_resume() before
calling the driver's resume callback. However, when the EEH driver calls
the driver's slot_reset callback() from eeh_report_reset(), it
incorrectly indicates the error state is still pci_channel_io_frozen.

Waiting until eeh_report_resume() to restore dev->error_state to
pci_channel_io_normal is too late for Emulex and QLogic FC drivers and
any other drivers which are designed to use common code paths in these
two cases: i) those called after the driver's slot_reset callback() and
ii) those called after the PCI slot is frozen but before the driver's
slot_reset callback is called. Case i) all driver paths executed to
reinitialize the hardware after a reset and case ii) all code paths
executed by driver kernel threads that run asynchronous to the main
driver thread, such as interrupt handlers and worker threads to process
driver work queues.

Emulex and QLogic FC drivers are designed with common code paths which
require that pci_channel_offline(dev) reflect the true state of the
hardware. The state transitions that the hardware takes from Normal
Operations to Slot Frozen to Reset to Normal Operations are documented
in the Power Architectureâ„¢ Platform Requirements+ (PAPR+) in Table 75.
PE State Control.

PAPR defines the following 3 states:

0 -- Not reset, Not EEH stopped, MMIO load/store allowed, DMA allowed
     (Normal Operations)
1 -- Reset, Not EEH stopped, MMIO load/store disabled, DMA disabled
2 -- Not reset, EEH stopped, MMIO load/store disabled, DMA disabled
     (Slot Frozen)

An EEH error places the slot in state 2 (Frozen) and the adapter driver
is notified that an EEH error was detected. If the adapter driver
returns PCI_ERS_RESULT_NEED_RESET, the EEH driver calls
eeh_reset_device() to place the slot into state 1 (Reset) and
eeh_reset_device completes by placing the slot into State 0 (Normal
Operations). Upon return from eeh_reset_device(), the EEH driver calls
eeh_report_reset, which then calls the adapter's slot_reset callback. At
the time the adapter's slot_reset callback is called, the true state of
the hardware is Normal Operations and should be accurately reflected by
setting dev->error_state to pci_channel_io_normal.

The current implementation of EEH driver does not do so and requires
this change to correct this deficiency.

Signed-off-by: Mike Mason <mmlnx@us.ibm.com>
Acked-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-15 15:23:53 +10:00
Hugh Dickins
adf213c438 powerpc: Allow 256kB pages with SHMEM
Now that shmem's divisions by zero and SHMEM_MAX_BYTES are fixed,
let powerpc 256kB pages coexist with CONFIG_SHMEM again.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-15 15:23:53 +10:00