of_hwspin_lock_get_id() is protected by the RCU lock, which means that
insertions can occur simultaneously with the lookup. If the radix tree
transitions from a height of 0, we can see a slot with the indirect_ptr
bit set, which will cause us to at least read random memory, and could
cause other havoc.
Fix this by using the newly introduced radix_tree_iter_retry().
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
msb of the regmap_field was mistakenly given the value 32, to set all bits
in the regmap update mask; although incorrect this worked until 921cc294,
where the mask calculation was corrected.
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Add hwspinlock support for the CSR atlas7 SoC.
The Hardware Spinlock device on atlas7 provides hardware assistance
for synchronization between the multiple processors in the system
(dual Cortex-A7, CAN bus Cortex-M3 and audio DSP).
Reviewed-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Wei Chen <wei.chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Add driver for Qualcomm Hardware Mutex block found in many Qualcomm
SoCs.
Based on initial effort by Kumar Gala <galak@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: Andy Gross <agross@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
HwSpinlock IP is present only on OMAP4 and other newer SoCs,
which are all device-tree boot only. This patch adds the
base support for parsing the DT nodes, and removes the code
dealing with the traditional platform device instantiation.
Signed-off-by: Suman Anna <s-anna@ti.com>
[tony@atomide.com: ack for legacy file removal]
Acked-by: Tony Lindgren <tony@atomide.com>
[comment on the imperfect always-zero base_id]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
This patch adds a new OF-friendly API of_hwspin_lock_get_id()
for hwspinlock clients to use/request locks from a hwspinlock
device instantiated through a device-tree blob. This new API
can be used by hwspinlock clients to get the id for a specific
lock using the phandle + args specifier, so that it can be
requested using the available hwspin_lock_request_specific()
API.
Signed-off-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
[small comment clarification]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
HwSpinlocks are supported on TI's AM33xx, AM43xx and DRA7xx SoC
device families as well. The IPs are identical to that of
OMAP4/OMAP5, except for the number of locks.
Add a depends on to the above family of SoCs to enable the
build support for OMAP hwspinlock driver for any of the above
SoC configs.
Signed-off-by: Suman Anna <s-anna@ti.com>
[small commit log changes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
The number of hwspinlocks are determined based on the value read
from the IP block's SYSSTATUS register. However, the module may
not be enabled and clocked, and the read may result in a bus error.
This particular issue is seen rather easily on AM33XX, since the
module wakeup is software controlled, and it is disabled out of
reset. Make sure the module is enabled and clocked before reading
the SYSSTATUS register.
Signed-off-by: Suman Anna <s-anna@ti.com>
[replace pm_runtime_put_sync with lenient pm_runtime_put]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
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Merge tag 'hwspinlock-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock
Pullhwspinlock update from Ohad Ben-Cohen:
"A single patch from Vincent extending OMAP's hwspinlock support to
OMAP5"
* tag 'hwspinlock-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock:
hwspinlock/omap: support OMAP5 as well
Even in failed case of pm_runtime_get_sync, the usage_count
is incremented. In order to keep the usage_count with correct
value and runtime power management to behave correctly, call
pm_runtime_put_noidle in such case.
In __hwspin_lock_request, module_put is also called before
return in pm_runtime_get_sync failed case.
Cc: stable@vger.kernel.org
Signed-off-by Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Li Fei <fei.li@intel.com>
[edit commit log]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dereference should be moved below the NULL test.
spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Commit 300bab9770 (hwspinlock/core: register a bank of hwspinlocks in a
single API call, 2011-09-06) introduced 'hwspin_lock_register_single()'
to register numerous (a bank of) hwspinlock instances in a single API,
'hwspin_lock_register()'.
At which time, 'hwspin_lock_register()' accidentally passes 'local IDs'
to 'hwspin_lock_register_single()', despite that ..._single() requires
'global IDs' to register hwspinlocks.
We have to convert into global IDs by supplying the missing 'base_id'.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[ohad: fix error path of hwspin_lock_register, too]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
drivers/media: video/a5k6aa is a module and so needs module.h
mfd: fix build failures in recently added ab5500 code
hwspinlock/u8500: include linux/module.h
MTD: MAPS: bcm963xx-flash.c: explicitly include module.h
Fix below build error:
CC drivers/hwspinlock/u8500_hsem.o
drivers/hwspinlock/u8500_hsem.c: In function 'u8500_hsem_probe':
drivers/hwspinlock/u8500_hsem.c:113: error: label 'free_state' used but not defined
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Include module.h to fix below build error:
CC drivers/hwspinlock/u8500_hsem.o
drivers/hwspinlock/u8500_hsem.c:177: error: 'THIS_MODULE' undeclared here (not in a function)
[...]
drivers/hwspinlock/u8500_hsem.c:196: warning: type defaults to 'int' in declaration of 'MODULE_AUTHOR'
drivers/hwspinlock/u8500_hsem.c:196: warning: function declaration isn't a prototype
make[2]: *** [drivers/hwspinlock/u8500_hsem.o] Error 1
make[1]: *** [drivers/hwspinlock] Error 2
make: *** [drivers] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Mark omap_hwspinlock_remove with __devexit (and use __devexit_p
appropriately) so the function can be discarded when the conditions are met.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Add hwspinlock driver for U8500's Hsem hardware.
At this point only HSem's protocol 1 is used (i.e. no interrupts).
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
[ohad@wizery.com: adopt recent hwspin_lock_{un}register API changes]
[ohad@wizery.com: set the owner member of the driver]
[ohad@wizery.com: mark ->remove() function as __devexit]
[ohad@wizery.com: write commit log]
[ohad@wizery.com: small cleanups]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Hardware Spinlock devices usually contain numerous locks (known
devices today support between 32 to 256 locks).
Originally hwspinlock core required drivers to register (and later,
when needed, unregister) each lock separately.
That worked, but required hwspinlocks drivers to do a bit extra work
when they were probed/removed.
This patch changes hwspin_lock_{un}register() to allow a bank of
hwspinlocks to be {un}registered in a single invocation.
A new 'struct hwspinlock_device', which contains an array of 'struct
hwspinlock's is now being passed to the core upon registration (so
instead of wrapping each struct hwspinlock, a priv member has been added
to allow drivers to piggyback their private data with each hwspinlock).
While at it, several per-lock members were moved to be per-device:
1. struct device *dev
2. struct hwspinlock_ops *ops
In addition, now that the array of locks is handled by the core,
there's no reason to maintain a per-lock 'int id' member: the id of the
lock anyway equals to its index in the bank's array plus the bank's
base_id.
Remove this per-lock id member too, and instead use a simple pointers
arithmetic to derive it.
As a result of this change, hwspinlocks drivers are now simpler and smaller
(about %20 code reduction) and the memory footprint of the hwspinlock
framework is reduced.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Since we're using non-atomic radix tree allocations, we
should be protecting the tree using a mutex and not a
spinlock.
Non-atomic allocations and process context locking is good enough,
as the tree is manipulated only when locks are registered/
unregistered/requested/freed.
The locks themselves are still protected by spinlocks of course,
and mutexes are not involved in the locking/unlocking paths.
Cc: <stable@kernel.org>
Signed-off-by: Juan Gutierrez <jgutierrez@ti.com>
[ohad@wizery.com: rewrite the commit log, #include mutex.h, add minor
commentary]
[ohad@wizery.com: update register/unregister parts in hwspinlock.txt]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
hwspinlock devices provide system-wide hardware locks that are used
by remote processors that have no other way to achieve synchronization.
To achieve that, each physical lock must have a system-wide id number
that is agreed upon, otherwise remote processors can't possibly assume
they're using the same hardware lock.
Usually boards have a single hwspinlock device, which provides several
hwspinlocks, and in this case, they can be trivially numbered 0 to
(num-of-locks - 1).
In case boards have several hwspinlocks devices, a different base id
should be used for each hwspinlock device (they can't all use 0 as
a starting id!).
While this is certainly not common, it's just plain wrong to just
silently use 0 as a base id whenever the hwspinlock driver is probed.
This patch provides a hwspinlock_pdata structure, that boards can use
to set a different base id for each of the hwspinlock devices they may
have, and demonstrates how to use it with the omap hwspinlock driver.
While we're at it, make sure the hwspinlock core prints an explicit
error message in case an hwspinlock is registered with an id number
that already exists; this will help users catch such base id issues.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Instead of allocating every hwspinlock separately, allocate
them all in one shot.
This both simplifies the driver and helps achieving better
slab utilization.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Use struct device_driver's owner member instead of asking drivers to
explicitly pass the owner again.
This simplifies drivers and also save some memory, since there's no
point now in maintaining a separate owner pointer per hwspinlock.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Simplify hwspinlock's Kconfig by making the global CONFIG_HWSPINLOCK
entry invisible; users will just select it when needed.
This also prepares the ground for adding hwspinlock support for other
platforms (the 'depends on ARCH_OMAP4' was rather hideous, and while
we're at it, a dedicated menu is added).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Currently only OMAP4 supports hwspinlocks, so don't bother asking
anyone else.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add hwspinlock support for the OMAP4 Hardware Spinlock device.
The Hardware Spinlock device on OMAP4 provides hardware assistance
for synchronization between the multiple processors in the system
(dual Cortex-A9, dual Cortex-M3 and a C64x+ DSP).
[ohad@wizery.com: adapt to hwspinlock framework, tidy up]
Signed-off-by: Simon Que <sque@ti.com>
Signed-off-by: Hari Kanigeri <h-kanigeri2@ti.com>
Signed-off-by: Krishnamoorthy, Balaji T <balajitk@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add a platform-independent hwspinlock framework.
Hardware spinlock devices are needed, e.g., in order to access data
that is shared between remote processors, that otherwise have no
alternative mechanism to accomplish synchronization and mutual exclusion
operations.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Hari Kanigeri <h-kanigeri2@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
