When BIOS SETUP is changed to disable EIST, some BIOS
hand the OS an un-initialized _PSS:
Name (_PSS, Package (0x06)
{
Package (0x06)
{
0x80000000, // frequency [MHz]
0x80000000, // power [mW]
0x80000000, // latency [us]
0x80000000, // BM latency [us]
0x80000000, // control
0x80000000 // status
},
...
These are outrageous values for frequency,
power and latency, raising the question where to draw
the line between legal and illegal. We tend to survive
garbage in the power and latency fields, but we can BUG_ON
when garbage is in the frequency field.
Cpufreq multiplies the frequency by 1000 and stores it in a u32 KHz.
So disregard a _PSS with a frequency so large
that it can't be represented by cpufreq.
https://bugzilla.redhat.com/show_bug.cgi?id=500311
Signed-off-by: Len Brown <len.brown@intel.com>
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] update mach-types
[ARM] Add cmpxchg support for ARMv6+ systems (v5)
[ARM] barriers: improve xchg, bitops and atomic SMP barriers
Gemini: Fix SRAM/ROM location after memory swap
MAINTAINER: Add F: entries for Gemini and FA526
[ARM] disable NX support for OABI-supporting kernels
[ARM] add coherent DMA mask for mv643xx_eth
[ARM] pxa/palm: fix PalmLD/T5/TX AC97 MFP
[ARM] pxa: add parameter to clksrc_read() for pxa168/910
[ARM] pxa: fix the incorrectly defined drive strength macros for pxa{168,910}
[ARM] Orion: Remove explicit name for platform device resources
[ARM] Kirkwood: Correct MPP for SATA activity/presence LEDs of QNAP TS-119/TS-219.
[ARM] pxa/ezx: fix pin configuration for low power mode
[ARM] pxa/spitz: provide spitz_ohci_exit() that unregisters USB_HOST GPIO
[ARM] pxa: enable GPIO receivers after configuring pins
[ARM] pxa: allow gpio_reset drive high during normal work
[ARM] pxa: save/restore PGSR on suspend/resume.
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
Revert "USB: Correct Makefile to make isp1760 buildable"
usb-serial: fix crash when sub-driver updates firmware
USB: isp1760: urb_dequeue doesn't always find the urbs
USB: Yet another Conexant Clone to add to cdc-acm.c
USB: atmel_usb_udc: Use kzalloc() to allocate ep structures
USB: atmel-usba-udc : fix control out requests.
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
Driver Core: do not oops when driver_unregister() is called for unregistered drivers
sysfs: file.c: use create_singlethread_workqueue()
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux:
svcrdma: dma unmap the correct length for the RPCRDMA header page.
nfsd: Revert "svcrpc: take advantage of tcp autotuning"
nfsd: fix hung up of nfs client while sync write data to nfs server
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: libps2 - better handle bad scheduler decisions
Input: usb1400_ts - fix access to "device data" in resume function
Input: multitouch - augment event semantics documentation
Input: multitouch - add tracking ID to the protocol
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
i915: Set object to gtt domain when faulting it back in
drm/i915: Apply a big hammer to 865 GEM object CPU cache flushing.
drm/i915: Fix tiling pitch handling on 8xx.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: hda - Compaq Presario CQ60 patching for Conexant
sound: usb-audio: make the MotU Fastlane work again
ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug mode
ALSA: Fix invalid jiffies check after pause
If you setserial a port which has never been initialised we change the type
but don't update the I/O method pointers. The same problem is true if you
change the io type of a port - but nobody ever does that so nobody noticed!
Remember the old type and when attaching if the type has changed reload the
port accessor pointers. We can't do it blindly as some 8250 drivers load custom
accessors and we must not stomp those.
Tested-by: Victor Seryodkin <vvscore@gmail.com>
Closes-bug: #13367
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The amd8111_edac.c driver will fail allmodconfig on architectures other
than PPC, introduce Kconfig dependency to avoid this, since both AMD8111
and AMD8131 chips are only adopted on Maple so far.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "bus_id" member in the device structure has been obsolete, use
dev_name() instead.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix build warning, "mem_cgroup_is_obsolete defined but not used" when
CONFIG_DEBUG_VM is not set. Also avoid checking for !mem again and again.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13302
hugetlbfs reserves huge pages but does not fault them at mmap() time to
ensure that future faults succeed. The reservation behaviour differs
depending on whether the mapping was mapped MAP_SHARED or MAP_PRIVATE.
For MAP_SHARED mappings, hugepages are reserved when mmap() is first
called and are tracked based on information associated with the inode.
Other processes mapping MAP_SHARED use the same reservation. MAP_PRIVATE
track the reservations based on the VMA created as part of the mmap()
operation. Each process mapping MAP_PRIVATE must make its own
reservation.
hugetlbfs currently checks if a VMA is MAP_SHARED with the VM_SHARED flag
and not VM_MAYSHARE. For file-backed mappings, such as hugetlbfs,
VM_SHARED is set only if the mapping is MAP_SHARED and the file was opened
read-write. If a shared memory mapping was mapped shared-read-write for
populating of data and mapped shared-read-only by other processes, then
hugetlbfs would account for the mapping as if it was MAP_PRIVATE. This
causes processes to fail to map the file MAP_SHARED even though it should
succeed as the reservation is there.
This patch alters mm/hugetlb.c and replaces VM_SHARED with VM_MAYSHARE
when the intent of the code was to check whether the VMA was mapped
MAP_SHARED or MAP_PRIVATE.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <starlight@binnacle.cx>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13302
On x86 and x86-64, it is possible that page tables are shared beween
shared mappings backed by hugetlbfs. As part of this,
page_table_shareable() checks a pair of vma->vm_flags and they must match
if they are to be shared. All VMA flags are taken into account, including
VM_LOCKED.
The problem is that VM_LOCKED is cleared on fork(). When a process with a
shared memory segment forks() to exec() a helper, there will be shared
VMAs with different flags. The impact is that the shared segment is
sometimes considered shareable and other times not, depending on what
process is checking.
What happens is that the segment page tables are being shared but the
count is inaccurate depending on the ordering of events. As the page
tables are freed with put_page(), bad pmd's are found when some of the
children exit. The hugepage counters also get corrupted and the Total and
Free count will no longer match even when all the hugepage-backed regions
are freed. This requires a reboot of the machine to "fix".
This patch addresses the problem by comparing all flags except VM_LOCKED
when deciding if pagetables should be shared or not for hugetlbfs-backed
mapping.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <starlight@binnacle.cx>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove wrong fifo size definition for some AT91 products.
Due to a misunderstanding of some AT91 datasheets, a fifo size of 2048
(words) has been introduced by mistake. In fact, all products (AT91/AT32)
are sharing the same fifo size of 512 words.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <avictor.za@gmail.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correctly restore the FrameBuffer register state in the resume function.
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/serial/8250_gsc.c:44: warning: format '%lx' expects type
'long unsigned int', but argument 2 has type 'resource_size_t'
[akpm@linux-foundation.org: fix it to handle u64's]
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/parport/parport_gsc.c:356: warning: format '%lx' expects type
'long unsigned int', but argument 2 has type 'resource_size_t'
[akpm@linux-foundation.org: fix it to handle u64's]
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The flat loader uses an architecture's flat_stack_align() to align the
stack but assumes word-alignment is enough for the data sections.
However, on the Xtensa S6000 we have registers up to 128bit width
which can be used from userspace and therefor need userspace stack and
data-section alignment of at least this size.
This patch drops flat_stack_align() and uses the same alignment that
is required for slab caches, ARCH_SLAB_MINALIGN, or wordsize if it's
not defined by the architecture.
It also fixes m32r which was obviously kaput, aligning an
uninitialized stack entry instead of the stack pointer.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oskar Schirmer <os@emlix.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Johannes Weiner <jw@emlix.com>
Acked-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The check for an overindexing of mpc52xx_uart_{ports,nodes} has an
off-by-one.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mapping->tree_lock can be acquired from interrupt context. Then,
following dead lock can occur.
Assume "A" as a page.
CPU0:
lock_page_cgroup(A)
interrupted
-> take mapping->tree_lock.
CPU1:
take mapping->tree_lock
-> lock_page_cgroup(A)
This patch tries to fix above deadlock by moving memcg's hook to out of
mapping->tree_lock. charge/uncharge of pagecache/swapcache is protected
by page lock, not tree_lock.
After this patch, lock_page_cgroup() is not called under mapping->tree_lock.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_pident_instantiate() has following call flow.
proc_pident_lookup()
proc_pident_instantiate()
proc_pid_make_inode()
And, proc_pident_lookup() has following error handling.
const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
Then, proc_pident_instantiate should return ENOENT too when racing against
exit(2) occur.
EINAL has two bad reason.
- it implies caller is wrong. bad the race isn't caller's mistake.
- man 2 open don't explain EINVAL. user often don't handle it.
Note: Other proc_pid_make_inode() caller already use ENOENT properly.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
linux/cred.h can't be included as first header (alphabetical order)
because it uses __init which is enough to break compilation on some archs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL
pointer for tasks that have detached mm's since task_lock() is not held
during the tasklist scan. Add the task_lock().
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Entries should be P: name then M: email address.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
http://bugzilla.kernel.org/show_bug.cgi?id=13312
at76_dwork_hw_scan holds a mutex while calling ieee80211_scan_completed,
which then calls at76_config which needs the same mutex. This reworks
the ordering to not hold the lock while calling ieee80211_scan_completed.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Erase errors such as:
"Newly-erased block contained word 0xa4ef223e at offset 0x0296a014"
and failure to write the clean marker,
moves the offending erase block to erasing list before calling
jffs2_erase_failed(). This is bad as jffs2_erase_failed() will
also move the block to the bad_list, but is now moving the
wrong block, causing FS corruption.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The following patch fixes:
- re-initialization of host->col_addr which is used as byte index
between the successive READID flash commands.
- compile error when CONFIG_PM is enabled
- pass on the error code from clk_get()
- return -ENOMEM in case of failed ioremap()
- pass on the return value of platform_driver_probe() directly
- remove excessive printk
- let command line partition table parsing with mxc_nand name.
The cmd_line parsing is done via <mtd-id> name that differs
from mxc_nand by default and looks like "NAND 256MiB 1,8V 8-bit"
Signed-off-by: Vladimir Barinov <vbarinov@embeddedalley.com>
Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Fix the build for CONFIG_NET_POLL_CONTROLLER that I broke with
217cbfa856 ("mac8390: fix regression
caused during net_device_ops conversion").
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Do not call t3_link_fault() under spinlock, as it calls msleep().
Besides, only the access to pi->link_fault needs to be serialized.
Also initialize local variables before checking the link status,
link state fields might otherwise end up containing garbage.
Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 5e68b772e6
cxgb3: map entire Rx page, feed map+offset to Rx ring.
introduced a regression on platforms defining DECLARE_PCI_UNMAP_ADDR()
and related macros as no-ops.
Rx descriptors are fed with the a page buffer bus address + page chunk offset.
The page buffer bus address is set and retrieved through
pci_unamp_addr_set(), pci_unmap_addr().
These functions being meaningless on x86 (if CONFIG_DMA_API_DEBUG is not set).
The HW ends up with a bogus bus address.
This patch saves the page buffer bus address for all plaftorms.
Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Testing the i7300_idle driver on i5000-series hardware required
an edit to i7300_idle.h to "#define SUPPORT_I5000 1" and a re-build
of both i7300_idle and ioat_dma.
Replace that build-time scheme with a load-time module parameter:
"7300_idle.forceload=1" to make it easier to test the driver
on hardware that while not officially validated, works fine
and is much more commonly available.
By default (no modparam) the driver will continue to load
only on the i7300.
Note that ioat_dma runs a copy of i7300_idle's probe routine
to know to reserve an IOAT channel for i7300_idle.
This change makes ioat_dma do that always on the i5000,
just like it does on the i7300.
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Andrew Henroid <andrew.d.henroid@intel.com>
We also fix a problem with cleaning up properly when initializing
drivers and devices, so checks like this will work successfully.
Portions of the patch by Linus and Greg and Ingo.
Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't need a kernel thread per CPU for this application.
Acked-by: Alex Chiang <achiang@hp.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 26e1287594.
A larger patch (f7e7aa585) a few days after this one added the same line
to the Makefile, but in a different place. While it'd be more correct to
revert that one, it's easier to revert this one because this is a
one-liner.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Greg Kroah-Hartman <gregkh@suse.de>
CC: linux-usb@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1244) fixes a crash in usb-serial that occurs when a
sub-driver returns a positive value from its attach method, indicating
that new firmware was loaded and the device will disconnect and
reconnect. The usb-serial core then skips the step of registering the
port devices; when the disconnect occurs, the attempt to unregister
the ports fails dramatically.
This problem shows up with Keyspan devices and it might affect others
as well.
When the attach method returns a positive value, the patch sets
num_ports to 0. This tells usb_serial_disconnect() not to try
unregistering any of the ports; instead they are cleaned up by
destroy_serial().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The option driver (and presumably others) allocates several URBs when it
opens and tries to free them when it closes. The isp1760_urb_dequeue
function gets called, but the packet being dequeued is not necessarily at
the
front of one of the 32 queues. If not, the isp1760_urb_done function doesn't
get called for the URB and the process trying to free it hangs forever on a
wait_queue. This patch does two things. If the URB being dequeued has others
queued behind it, it re-queues them. And it searches the queues looking for
the URB being dequeued rather than just looking at the one at the front of
the queue.
[bigeasy@linutronix] whitespace fixes, reformating
Cc: stable <stable@kernel.org>
Signed-off-by: Warren Free <wfree@ipmn.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds another quirky Conexant USB Modem Clone to usb cdc-acm.c
Signed-off-by: Xiao Kaijian <xiaokj@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This ensures that all fields are properly initialized.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
usbtest #14 was failing with "udc: ep0: TXCOMP: Invalid endpoint state 2, halting endpoint..."
This occured since ep0 is bidirectional and ep->is_in is not valid (must always use ep->state)
Signed-off-by: Martin Fuzzey <mfuzzey@gmail.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add cmpxchg/cmpxchg64 support for ARMv6K and ARMv7 systems
(original patch from Catalin Marinas <catalin.marinas@arm.com>)
The cmpxchg and cmpxchg64 functions can be implemented using the
LDREX*/STREX* instructions. Since operand lengths other than 32bit are
required, the full implementations are only available if the ARMv6K
extensions are present (for the LDREXB, LDREXH and LDREXD instructions).
For ARMv6, only 32-bits cmpxchg is available.
Mathieu :
Make cmpxchg_local always available with best implementation for all type sizes (1, 2, 4 bytes).
Make cmpxchg64_local always available.
Use "Ir" constraint for "old" operand, like atomic.h atomic_cmpxchg does.
Change since v3 :
- Add "memory" clobbers (thanks to Nicolas Pitre)
- removed __asmeq(), only needed for old compilers, very unlikely on ARMv6+.
Note : ARMv7-M should eventually be ifdefed-out of cmpxchg64. But it's not
supported by the Linux kernel currently.
Put back arm < v6 cmpxchg support.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Mathieu Desnoyers pointed out that the ARM barriers were lacking:
- cmpxchg, xchg and atomic add return need memory barriers on
architectures which can reorder the relative order in which memory
read/writes can be seen between CPUs, which seems to include recent
ARM architectures. Those barriers are currently missing on ARM.
- test_and_xxx_bit were missing SMP barriers.
So put these barriers in. Provide separate atomic_add/atomic_sub
operations which do not require barriers.
Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
