Linus Torvalds [Mon, 12 Dec 2005 03:57:52 +0000 (19:57 -0800)]
Remove (at least temporarily) the "incomplete PFN mapping" support
With the previous commit, we can handle arbitrary shared re-mappings
even without this complexity, and since the only known private mappings
are for strange users of /dev/mem (which never create an incomplete one),
there seems to be no reason to support it.
Linus Torvalds [Mon, 12 Dec 2005 03:46:02 +0000 (19:46 -0800)]
Allow arbitrary shared PFNMAP's
A shared mapping doesn't cause COW-pages, so we don't need to worry
about the whole vm_pgoff logic to decide if a PFN-remapped page has
gone through COW or not.
This makes it possible to entirely avoid the special "partial remapping"
logic for the common case.
Johannes Berg [Sun, 11 Dec 2005 02:41:50 +0000 (18:41 -0800)]
[PATCH] ppc32: set smp_tb_synchronized on UP with SMP kernel
ppc32 kernel, when built with CONFIG_SMP and booted on a single CPU
machine, will not properly set smp_tb_synchronized, thus causing
gettimeofday() to not use the HW timebase and to be limited to jiffy
resolution. This, among others, causes unacceptable pauses when launching
X.org.
Signed-Off-By: Johannes Berg <johannes@sipsolutions.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
David Gibson [Fri, 9 Dec 2005 05:45:17 +0000 (16:45 +1100)]
[PATCH] powerpc: Fix SLB flushing path in hugepage
On ppc64, when opening a new hugepage region, we need to make sure any
old normal-page SLBs for the area are flushed on all CPUs. There was
a bug in this logic - after putting the new hugepage area masks into
the thread structure, we copied it into the paca (read by the SLB miss
handler) only on one CPU, not on all. This could cause incorrect SLB
entries to be loaded when a multithreaded program was running
simultaneously on several CPUs. This patch corrects the error,
copying the context information into the PACA on all CPUs using the mm
in question before flushing any existing SLB entries.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
David Gibson [Fri, 9 Dec 2005 03:20:52 +0000 (14:20 +1100)]
[PATCH] powerpc: Add missing icache flushes for hugepages
On most powerpc CPUs, the dcache and icache are not coherent so
between writing and executing a page, the caches must be flushed.
Userspace programs assume pages given to them by the kernel are icache
clean, so we must do this flush between the kernel clearing a page and
it being mapped into userspace for execute. We were not doing this
for hugepages, this patch corrects the situation.
We use the same lazy mechanism as we use for normal pages, delaying
the flush until userspace actually attempts to execute from the page
in question.
Tested on G5.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
Olof Johansson [Fri, 9 Dec 2005 01:40:17 +0000 (19:40 -0600)]
[PATCH] powerpc: Set cache info defaults
Cache info is setup by walking the device tree in initialize_cache_info().
However, icache_flush_range might be called before that, in
slb_initialize()->patch_slb_encoding, which modifies the load immediate
instructions used with SLB fault code.
Not only that, but depending on memory layout, we might take SLB faults
during unflatten_device_tree. So that fault will load an SLB entry that
might not contain the right LLP flags for the segment.
Either we can walk the flattened device tree to setup cache info, or
we can pick the known defaults that are known to work. Doing it in the
flattened device tree is hairier since we need to know the machine type
to know what property to look for, etc, etc.
For now, it's just easier to go with the defaults. Worst thing that
happens from it is that we might waste a few cycles doing too small
dcbst/icbi increments.
Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
model_id fields of wf_smu_sys_all_params should match the model ID
they are supposed to represent (as commented). Fixes windfarm on some
iMac 8,1 models.
Signed-off-by: Michal Ostrowski <mostrows at watson ibm com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Some debug code wasn't properly removed from the initial 64k pages
patch, and while it's harmless, it's also slowing down significantly a
very hot code path, thus it should really be removed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
The 64k pages patch changed the meaning of one argument passed to the
low level hash functions (from "large" it became "psize" or page size
index), but one of the call sites wasn't properly updated, causing
potential random weird problems with huge pages. This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Mike Kravetz [Wed, 7 Dec 2005 21:07:23 +0000 (13:07 -0800)]
[PATCH] powerpc/pseries: boot failures on numa if no memory on node
This bug exists in the current code and prevents machines from booting
with numa enabled if there is a node that does not contain memory.
Workaround is to boot with 'numa=off'. Looks like a simple typo.
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Olof Johansson [Tue, 29 Nov 2005 20:04:17 +0000 (14:04 -0600)]
[PATCH] powerpc: remove redundant code in stab init
There's never been a hardware platform that has both pSeries/RPA LPAR
hypervisor and stab (pre-POWER4 segment management). This removes
the redundant code in stab_initalize().
Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
Paul Mackerras [Mon, 5 Dec 2005 03:39:53 +0000 (14:39 +1100)]
ppc: Build in all three of powermac, PREP and CHRP support
This reverts commit da0825fd201a03294dbf7f8f030676d608da122c, making
it so that if you select CONFIG_PPC_MULTIPLATFORM you get support
for PMAC, PREP and CHRP built in.
The reason for not allowing PMAC, PREP and CHRP to be selected
individually for ARCH=ppc is that there is too much interdependency
between them in the platform support code. For example, CHRP uses
the PMAC nvram code.
Configuring with ARCH=powerpc does allow you to select support for
PMAC and CHRP separately. Support for PREP is not there yet but
should be there soon.
Paul Mackerras [Mon, 5 Dec 2005 03:19:10 +0000 (14:19 +1100)]
powerpc/pseries: Optimize IOMMU setup
The previous commit will use the page-at-a-time hypervisor call for
setting up IOMMU entries when we are using 64k pages and setting up
one 64k page, even though that means 16 calls to the hypervisor, since
the hypervisor still works on 4k pages. This optimizes this case by
using the multi-page IOMMU setup hypervisor call instead.
[PATCH] V4L/DVB (3087) fix analog NTSC for pcHDTV 3000
- fix analog NTSC for pcHDTV 3000
- Fix regression: broken analog NTSC for DViCO FusionHDTV3 Gold-T
- add tda9887 to card struct, required for both cards.
Linus Torvalds [Sun, 4 Dec 2005 05:10:42 +0000 (21:10 -0800)]
Linux v2.6.15-rc5
Hey, for no other reason than the fact that I'll be off-line for a
week.
Of course, I could force everybody to just use git (and when I'm emperor
of the world, don't think I won't!), but it seems some people want to
just test official releases. Even if they are just -rc's.
By the time I'm back, Andrew will have fixed all my bugs, and I'll
release it as 2.6.15 and take all the credit.
Linus Torvalds [Sun, 4 Dec 2005 04:50:51 +0000 (20:50 -0800)]
Link USB drivers later in the kernel
We want to link the "regular" SCSI drivers before the USB storage
driver, since historically we've always detected internal SCSI disks
before the external USB storage modules.
The link order matters for initcall ordering, and this got broken by
mistake by commit 7586269c0b52970f60bb69fcb86e765fc1d72309 which moved
the USB host controller PCI quirk handling around.
Linus Torvalds [Sun, 4 Dec 2005 04:48:11 +0000 (20:48 -0800)]
Make vm_insert_page() available to NVidia module
It used to use remap_pfn_range(), which wasn't GPL-only either, and the
new interface is actually simpler and does more checking, so we
shouldn't unnecessarily discourage people from switching over.
Nick Piggin [Sun, 4 Dec 2005 02:55:25 +0000 (13:55 +1100)]
[PATCH] Fix up per-cpu page batch sizes
The code to clamp batch sizes to 2^n - 1 went missing and an extra
check got added, which must have been a hunk of the "higer order pcp
batch refills" work sneaking in.
Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Trond Myklebust [Sat, 3 Dec 2005 20:20:21 +0000 (15:20 -0500)]
NFSv4: Fix an Oops in the synchronous write path
- Missing initialisation of attribute bitmask in _nfs4_proc_write()
- On success, _nfs4_proc_write() must return number of bytes written.
- Missing post_op_update_inode() in _nfs4_proc_write()
- Missing initialisation of attribute bitmask in _nfs4_proc_commit()
- Missing post_op_update_inode() in _nfs4_proc_commit()
Trond Myklebust [Sat, 3 Dec 2005 20:20:07 +0000 (15:20 -0500)]
NFS: Fix a few further cache consistency regressions
Steve Dickson writes:
Doing the following:
1. On server:
$ mkdir ~/t
$ echo Hello > ~/t/tmp
2. On client, wait for a string to appear in this file:
$ until grep -q foo t/tmp ; do echo -n . ; sleep 1 ; done
3. On server, create a *new* file with the same name containing that
string:
$ mv ~/t/tmp ~/t/tmp.old; echo foo > ~/t/tmp
will show how the client will never (and I mean never ;-) ) see
the updated file.
The problem is that we do not update nfsi->cache_change_attribute when the
file changes on the server (we only update it when our client makes the
changes). This again means that functions like nfs_check_verifier() will
fail to register when the parent directory has changed and should trigger
a dentry lookup revalidation.
Herbert Xu [Sat, 3 Dec 2005 04:43:26 +0000 (20:43 -0800)]
[IPV4] Fix EPROTONOSUPPORT error in inet_create
There is a coding error in inet_create that causes it to always return
ESOCKTNOSUPPORT. It should return EPROTONOSUPPORT when there are
protocols registered for a given socket type but none of them match
the requested protocol.
This is based on a patch by Jayachandran C.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Neil Horman [Sat, 3 Dec 2005 04:32:29 +0000 (20:32 -0800)]
[SCTP]: Fix getsockname for sctp when an ipv6 socket accepts a connection from
an ipv4 socket.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Neil Horman [Sat, 3 Dec 2005 04:30:06 +0000 (20:30 -0800)]
[SCTP]: Return socket errors only if the receive queue is empty.
This patch fixes an issue where it is possible to get valid data after
a ENOTCONN error. It returns socket errors only after data queued on
socket receive queue is consumed.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Nick Piggin [Fri, 2 Dec 2005 01:44:19 +0000 (12:44 +1100)]
[PATCH] Fix TIF_POLLING_NRFLAG in ACPI idle routines
Commit 64c7c8f88559624abdbe12b5da6502e8879f8d28 broke the ACPI C2 and C3
sleep states, because it left TIF_POLLING_NRFLAG active even though
those states do not actually poll the reschedule flag at all. As a
result, the CPU wouldn't get sent an IPI when it was to be woken up, and
would only notice that it had runnable processes on the next timer tick.
Hugh Dickins [Fri, 2 Dec 2005 15:58:09 +0000 (15:58 +0000)]
[SCSI] sg: fix a bug in st_map_user_pages failure path
sg's st_map_user_pages is modelled on an earlier version of st's
sgl_map_user_pages, and has the same bug: if get_user_pages got some but
not all of the pages, then those got were released, but the positive res
code returned implied that they were still to be freed.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Douglas Gilbert <dougg@torque.net> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Hugh Dickins [Fri, 2 Dec 2005 15:59:59 +0000 (15:59 +0000)]
[SCSI] sg and st unmap_user_pages allow PageReserved
2.6.15-rc1 made sg's st_unmap_user_pages and st's sgl_unmap_user_pages
BUG on a PageReserved page. But that's wrong: they could be unmapping
the ZERO_PAGE, which is marked PG_reserved; and perhaps others (while
get_user_pages is still permitted on VM_PFNMAP areas - that may change).
More change is needed here: sg claims to dirty even pages written from,
and st claims not to dirty even pages read into; and SetPageDirty is not
adequate for this nowadays. Fixes to those follow in a later patch: for
the moment just fix the 2.6.15 regression.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
[PATCH] powerpc/pseries: Fix TCE building with 64k pagesize
Must adjust tcenum and npages by TCE_PAGE_FACTOR to convert between
64KB pages and TCE (4K) pages. (This is done in other places, except
for this one location.)
Signed-off-by: Michal Ostrowski <mostrows at watson ibm com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Mike Isely [Thu, 1 Dec 2005 08:52:04 +0000 (00:52 -0800)]
[PATCH] V4l/dvb: Restore missing tuner definition for Hauppauge tuner type 0x103
Type 0x103 ("TCL MFNM05-4") in the Hauppauge eeprom is a more recent tuner
that maps to TUNER_PHILIPS_FM1236_MK3. This had been previously defined but
due to some accident the definition got removed. This change restores that
definition. Change committed on advice from Hans Verkuil
<hverkuil@xs4all.nl>, who thinks he's the one who had accidentally removed it
before.
Signed-off-by: Mike Isely <isely@pobox.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Hans Verkuil [Thu, 1 Dec 2005 08:51:42 +0000 (00:51 -0800)]
[PATCH] V4L: Add workaround for Hauppauge PVR150 with certain NTSC tuner models
Add workaround for Hauppauge PVR150 hardware problem with tuner models 85, 99
and 112 (model numbers as reported by tveeprom). The audio standard
autodetection does not always work correctly for these models.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Steven Toth [Thu, 1 Dec 2005 08:51:41 +0000 (00:51 -0800)]
[PATCH] V4L: Fixed eeprom handling for cx88 and added Nova-T PCI model 90003
- Fixed code handling for eeprom on cx88 boards.
- Hauppauge released a new version of the Nova-T-PCI (9002) a few months ago
with a different (compatible) tuner (but lacking RF passthru). The official
model# is 90003. All features are working.
- Adding entry to the known model list after testing.
Signed-off-by: Steven Toth <stoth@hauppauge.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ian Pickworth [Thu, 1 Dec 2005 08:51:28 +0000 (00:51 -0800)]
[PATCH] V4L: Fixes nicam sound
- Resolved problem of sporadic buzz after setting Nicam stereo
- improved setting audio standard with dma reset
- cleaned up comments format
- more sensitive Nicam detection
Signed-off-by: Ian Pickworth <ian@pickworth.me.uk> Signed-off-by: Michal Pytasz <pytasz@lodz.home.pl> Signed-off-by: Marcin Rudowski <mar_rud@poczta.onet.pl> Signed-off-by: Torsten Seeboth <Torsten.Seeboth@t-online.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Steven Toth [Thu, 1 Dec 2005 08:51:27 +0000 (00:51 -0800)]
[PATCH] V4L: tveeprom MAC address parsing/cleanup
- Added a mac address field to the tveeprom structure.
- allow callers to query the MAC address.
- removed some redundant eeprom parsing code in cx88-cards.c (specific to
Hauppauge DVB products) Instead, placed calls directly to the single eeprom
parsing function in tveeprom.c
Signed-off-by: Steven Toth <stoth@hauppauge.com> Signed-off-by: Michael Krufky <mkrufky@m1k.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Increases the minor number limitation for vbi devices from 223 to 255.
This is in agreement with the minor number allocation specified in
Documentation/devices.txt.
- Without this patch it is not possible to use more than 5 Hauppauge
WinTV-PVR 350 cards since each of these allocate 3 vbi devices.
Correctly specify treeboot based image entrypoint. Currently makefile uses
$(ENTRYPOINT) which isn't defined anywhere. Each board port sets
entrypoint-$(CONFIG_BOARD_NAME) instead.
Without this patch I cannot boot Ocotea (PPC440GX eval board) anymore. I
was getting random "OS panic" errors from OpenBIOS for a while, but with
current kernel I get them all the time (probably because image became
bigger).
Signed-off-by: Eugene Surovegin <ebs@ebshome.net> Acked-by: Tom Rini <trini@kernel.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Thomas Graf [Thu, 1 Dec 2005 22:30:00 +0000 (14:30 -0800)]
[NETLINK]: Fix processing of fib_lookup netlink messages
The receive path for fib_lookup netlink messages is lacking sanity
checks for header and payload and is thus vulnerable to malformed
netlink messages causing illegal memory references.
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Phil Oester [Thu, 1 Dec 2005 22:29:24 +0000 (14:29 -0800)]
[NETFILTER]: Fix recent match jiffies wrap mismatches
Around jiffies wrap time (i.e. within first 5 mins after boot), recent
match rules which contain both --seconds and --hitcount arguments
experience false matches.
This is because the last_pkts array is filled with zeros on creation, and
when comparing 'now' to 0 (+ --seconds argument), time_before_eq thinks it
has found a hit.
Below patch adds a break if the packet value is zero. This has the
unfortunate side effect of causing mismatches if a packet was received
when jiffies really was equal to zero. The odds of that happening are
slim compared to the problems caused by not adding the break however.
Plus, the author used this same method just below, so it is "good enough".
This fixes netfilter bugs #383 and #395.
Signed-off-by: Phil Oester <kernel@linuxace.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: Ignore ACKs ACKs on half open connections in TCP conntrack
Mounting NFS file systems after a (warm) reboot could take a long time if
firewalling and connection tracking was enabled.
The reason is that the NFS clients tends to use the same ports (800 and
counting down). Now on reboot, the server would still have a TCB for an
existing TCP connection client:800 -> server:2049. The client sends a
SYN from port 800 to server:2049, which elicits an ACK from the server.
The firewall on the client drops the ACK because (from its point of
view) the connection is still in half-open state, and it expects to see
a SYNACK.
The client will eventually time out after several minutes.
The following patch corrects this, by accepting ACKs on half open
connections as well.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Hugh Dickins [Thu, 1 Dec 2005 20:21:57 +0000 (20:21 +0000)]
[SCSI] st: fix a bug in sgl_map_user_pages failure path
Nick and I had already been looking at drivers/scsi/{sg.c,st.c},
brought there by __put_page in sg.c's peculiar sg_rb_correct4mmap,
which we'd like to remove. But that's irrelevant to your pain, except...
One extract from the patches I'd like to send Doug and Kai for 2.6.15
or 2.6.16 is this below: since the incomplete get_user_pages path omits
to reset res, but has already released all the pages, it will result in
premature freeing of user pages, and behaviour just like you've seen.
Though I'd have thought incomplete get_user_pages was an exceptional
case, and a bit surprised you'd encounter it. Perhaps there's some
other premature freeing in the driver, and this instance has nothing
whatever to do with it.
If the problem were easily reproducible, it'd be great if you could
try this patch; but I think you've said it's not :-(
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Syncronization for Domain Validation workqueue and the initiation of the
alternate controller. Its possible that dv could be terminated if the
workqueue on the 1st channel doesn complete in time before the 2nd channel
begins initialization.
Signed-off-by: Eric Moore <Eric.Moore@lsil.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Fixed various problems in opening sequence of adapters which was previously
changed with NPIV support:
o corrected handling when exchange port data function is not supported,
otherwise adapters on z900 cannot be opened anymore
o corrected setup of timer for exchange port data if called from error
recovery
o corrected check of return code of exchange config data
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Heiko Carstens [Thu, 1 Dec 2005 01:46:32 +0000 (02:46 +0100)]
[SCSI] zfcp: fix spinlock initialization
Move initialization of locks and lists to adapter allocation function.
Otherwise we might end up with some uninitialized locks, like e.g. the
erp locks which only will be inititialized if an error recovery thread
for an adapter will be started.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
James Bottomley [Mon, 28 Nov 2005 21:41:58 +0000 (15:41 -0600)]
[SCSI] SPI DV: be more conservative about echo buffer usage
Some SCSI devices apparently get very confused if we try to use the
echo buffer on a non-DT negotiated bus (this mirrors the problems of
using PPR on non-LVD for some devices). The fix is to be far more
conservative about when we use an echo buffer. With this patch, we'll
now see what parameters are negotiated by the read only test, and only
look for an echo buffer if DT is negotiated.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Arthur Othieno [Thu, 1 Dec 2005 20:58:01 +0000 (20:58 +0000)]
[ARM] sema_count() removal
sema_count() defined only for ARM but not used anywhere.
Signed-off-by: Arthur Othieno <a.othieno@bluewin.ch> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King [Thu, 1 Dec 2005 15:47:24 +0000 (15:47 +0000)]
[ARM SMP] Use event instructions for spinlocks
ARMv6K CPUs have SEV (send event) and WFE (wait for event) instructions
which allow the CPU clock to be suspended until another CPU issues a
SEV, rather than spinning on the lock wasting power. Make use of these
instructions.
Note that WFE does not wait if an event has been sent since the last WFE
cleared the event status, so although it may look racy, the instruction
implementation ensures that these are dealt with.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
projects / linux-2.6-omap-h63xx.git / log