Commit Graph

95 Commits

Author SHA1 Message Date
Alexander Shishkin
b4ca34aaf7 stm class: Fix a race in unlinking
There is a window in stm_source_link_drop(), during which the source's
link may change before locks are acquired. When this happens, it throws
a warning, since this is not an expected scenario.

This patch handles the race in such a way that if the link appears to
have changed by the time we took the locks, it will release them and
repeat the whole unlinking procedure from the beginning, unless the
other contender beat us to it.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
f7c81c7176 stm class: Fix unbalanced module/device refcounting
STM code takes references to the stm device and its module for the
duration of the character device's existence or the stm_source link.
Dropping these references is not well balanced everywhere, which may
lead to leaks.

This patch balances the acquisition and releasing of these two
references and annotates each site so that it's easier to verify
correctness by reading the code.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
cde4ad8368 stm class: Guard output assignment against concurrency
It is possible to concurrently assign the same output (a character
device writer or an stm_source device) to different stm devices,
which sets off a strategically placed warning in stm_output_assign().

To avoid this, use a spinlock to serialize (un)assignments between
outputs and stm devices.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
1810f2c448 stm class: Fix unlocking braino in the error path
If an illegal attempt is made to unlink stm source device from an
stm device, the stm device's link spinlock mistakenly remains locked.
While this really shouldn't happen (there's a warning in place), the
locking should remain in order so that we can still recover from this
situation if it indeed does happen.

This patch unifies the unlocking in the exit path of
__stm_source_link_drop() to fix this.

Reported-by: Laurent Fert <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
1192918530 stm class: Add heartbeat stm source device
Heartbeat stm source may have multiple instances (for connecting to
different stm devices). Each instance will send a periodic test message
over its stm device when it is linked. This can be used for testing stm
class framework, stm device drivers or as a heartbeat over the stm link.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
bcfdf8afde stm class: dummy_stm: Create multiple devices
STM framework should be able to handle multiple STM devices at a time,
each one with its own master allocation policy.

This patch changes dummy_stm driver to create multiple STM sinks to
help testing the framework.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
59be422e4c stm class: Support devices with multiple instances
By convention, the name of the stm policy directory in configfs consists of
the device name to which it applies and the actual policy name, separated
by a dot. Now, some devices already have dots in their names that separate
name of the actual device from its instance identifier. Such devices will
result in two (or more, who can tell) dots in the policy directory name.

Existing policy code, however, will treat the first dot as the one that
separates device name from policy name, therefore failing the above case.

This patch makes the last dot in the directory name be the separator, thus
prohibiting dots from being used in policy names.

Suggested-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
f8560a9bc7 stm class: Use driver's packet callback return value
STM drivers provide a callback to generate/send individual STP packets;
it also tells the stm core how many bytes of payload it has consumed.
However, we would also need to use the negative space of this return
value to communicate errors that occur during the packet generation,
in which case the stm core will have to take appropriate action.

For now, we need to account for the possibility that the stm driver may
not support certain combinations of packet type/flags, in which case
it is expected to signal an error.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
14136e368f intel_th: Use real device index in the node names
Most of the intel_th core supports multiple co-existing TH devices,
except for output device nodes, where intel_th device id is hardcoded
to be zero.

Fix this by fetching the actual intel_th device id from the parent
device's drvdata.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
d7b1787161 intel_th: Set root device's drvdata early
Already during the subdevice initialization time, devices will need
to reference Intel TH controller descriptor structure.

This patch moves setting the drvdata from the pci glue to intel_th
core, before subdevices are populated.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
97007500ec intel_th: sth: Sanitize packet callback's return values
According to the stm class interface, the packet callback should return
an error if it is asked to generate packets that it doesn't support.
When it succeeds, it should return number of bytes consumed from its
payload. Currently, for FLAG packet it mistakenly returns 1.

This patch addresses these issues.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Laurent FERT
2bed074aad intel_th: msu: Release resources on read error
Right now, reading from msc character device will leak its's user count
on read error.

This patch makes sure resources are released when there is no data left
to read from the buffer.

Signed-off-by: Laurent FERT <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Laurent FERT
e4eca2a1c7 intel_th: msu: Fix offset for wrapped block
Fix offset for the second pass on the wrapped block when iterating over
memory in multi-block mode, otherwise wrong part of the block will get
copied.

Signed-off-by: Laurent FERT <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
4d02ceff32 intel_th: Update scratchpad bits according to enabled output activity
Intel TH implements a scratchpad register to indicate to the firmware
and external debuggers what trace configuration is enabled so that
everybody plays nicely together. The register is a bit field and the
bit assignment convention is described in the developer's manual.

This patch enables the driver to automatically set scratchpad register
bits according to the output configuration that's enabled.

Based on work by Yann Fouassier.

Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
c1a327c4d3 intel_th: gth: Remove commented-out code
There's a commented-out function in the GTH driver that's a leftover
from previous versions of the driver, where we tried to inherit the
pre-existing configuration, which didn't prove to be a sound idea.

This patch removes the function. No functional changes.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
993c7f1119 intel_th: Depend on HAS_IOMEM
This driver requires io memory to operate, so don't even consider it
for NO_IOMEM architectures.

Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Chunyan Zhang
73a3ed1903 stm class: Fix master deallocation in device unregistering
The device unregister path uses wrong master index range when it tries
to free the allocated masters, it should, as does the rest of the stm
class code, use real master IDs.

This patch fixes the device unregister path to use real master IDs to
avoid memory leaks after unloading the stm driver.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
[alexander.shishkin@intel.com: re-wrote the commit message]
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Lucas Tanure
f45f40ad65 stm class: Use a signed return type for stm_find_master_chan
The return type "unsigned int" was used by the stm_find_master_chan function
despite of the aspect that it will eventually return a negative error code.

Done with the help of Coccinelle.

Signed-off-by: Lucas Tanure <tanure@linux.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:09:14 -08:00
Alexander Shishkin
3f040887a8 intel_th: pci: Add Broxton SOC support
This adds Intel(R) Trace Hub PCI ID for Broxton SOC.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Alexander Shishkin
6396b912f1 intel_th: pci: Add Apollo Lake SOC support
This adds Intel(R) Trace Hub PCI ID for Apollo Lake SOC.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Alexander Shishkin
f08b18266c stm class: Prevent user-controllable allocations
Currently, the character device write method allocates a temporary buffer
for user's data, but the user's data size is not sanitized and can cause
arbitrarily large allocations via kzalloc() or an integer overflow that
will then result in overwriting kernel memory.

This patch trims the input buffer size to avoid these issues.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Chunyan Zhang
7b3bb0e753 stm class: Fix an off-by-one in master array allocation
Since both sw_start and sw_end are master indices, the size of array
that holds them is sw_end - sw_start + 1, which the current code gets
wrong, allocating one item less than required.

This patch corrects the allocation size, avoiding potential slab
corruption.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
[alexander.shishkin@linux.intel.com: re-wrote the commit message]
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Alexander Shishkin
c74f7e8281 stm class: Fix link list locking
Currently, the list of stm_sources linked to an stm device is protected by
a spinlock, which also means that sources' .unlink() method is called under
this spinlock. However, this method may (and does) sleep, which means
trouble.

This patch slightly reworks locking around stm::link_list so that bits that
might_sleep() are called with a mutex held instead. Modification of this
list requires both mutex and spinlock to be held, while looking at the list
can be done under either mutex or spinlock.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Alexander Shishkin
4c127fd16e stm class: Fix locking in unbinding policy path
Right now, if stm device removal has to unbind from a policy (that is,
an stm device that has STP policy, gets removed), it will trigger a
nested lock on the stm device's policy mutex.

This patch fixes the problem by moving the locking from the policy
unbinding to policy removal (configfs path), where it's actually needed;
the other caller of the policy unbinding function already takes the
mutex around the call.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Arnd Bergmann
042d4460b5 stm class: Select CONFIG_SRCU
The newly added STM code uses SRCU, but does not ensure that
this code is part of the kernel:

drivers/built-in.o: In function `stm_source_link_show':
include/linux/srcu.h:221: undefined reference to `__srcu_read_lock'
include/linux/srcu.h:238: undefined reference to `__srcu_read_unlock'
drivers/built-in.o: In function `stm_source_link_drop':
include/linux/srcu.h:221: undefined reference to `__srcu_read_lock'
include/linux/srcu.h:238: undefined reference to `__srcu_read_unlock'

This adds a Kconfig 'select' statement like all the other SRCU using
drivers have.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 7bd1d4093c ("stm class: Introduce an abstraction for System Trace Module devices")
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Geert Uytterhoeven
8d0439369d intel_th: INTEL_TH should depend on HAS_DMA
If NO_DMA=y:

    ERROR: "dma_free_coherent" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined!
    ERROR: "dma_alloc_coherent" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined!
    ERROR: "dma_supported" [drivers/hwtracing/intel_th/intel_th.ko] undefined!

Add a dependency on HAS_DMA to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Geert Uytterhoeven
4a2e2b19f9 stm class: Hide STM-specific options if STM is disabled
If STM=n, it doesn't make sense to ask about STM_DUMMY and
STM_SOURCE_CONSOLE support, which are not even built when enabled
anyway. Hence hide these options if STM=n.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:43:17 -08:00
Mathieu Poirier
52210c8745 coresight: implementing 'cpu_id()' API
Other than plainly parsing the device tree there is no way to
know which CPU a tracer is affined to.  As such adding an
interface to lookup the CPU field enclosed in the etm_drvdata
structure that was initialised at boot time.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:12:18 -08:00
Mathieu Poirier
b15f0fb657 coresight: removing bind/unbind options from sysfs
The coresight drivers have absolutely no control over bind and unbind
operations triggered from sysfs. The operations simply can't be
cancelled or denied event when one or several tracing sessions are
under way.  Since the memory associated to individual device is
invariably freed, the end result is a kernel crash when the path from
source to sink is travelled again as demonstrated here[1].

One solution could be to keep track of all the path (i.e tracing
session) that get created and iterate through the elements of those path
looking for the coresight device that is being removed.  This proposition
doesn't scale well since there is no upper bound on the amount of
concurrent trace session that can be created.

With the above in mind, this patch prevent devices from being unbounded
from their driver by using the driver->suppress_bind_attr option.  That way
trace sessions can be managed without fearing to loose devices.

Since device can't be removed anymore the xyz_remove() functions found in
each driver is also removed.

[1]. http://www.spinics.net/lists/arm-kernel/msg474952.html

Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:12:18 -08:00
Mathieu Poirier
ad725aee07 coresight: remove csdev's link from topology
In function 'coresight_unregister()', all references to the csdev that
is being taken away need to be removed from the topology.  Otherwise
building the next coresight path from source to sink may use memory
that has been released.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:11:10 -08:00
Mathieu Poirier
f2dfab3568 coresight: release reference taken by 'bus_find_device()'
The reference count taken by function bus_find_device() needs
to be released if a child device is found, something this patch
is adding.

Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:11:10 -08:00
Mathieu Poirier
fae5415879 coresight: coresight_unregister() function cleanup
In its current form the code never frees csdev->refcnt allocated
in coresight_register().  There is also a problem with csdev->conns
that is freed before device_unregister() rather than in the device
release function.

This patch addresses both issues by moving kfree(csdev->conns) to
coresight_device_release() and freeing csdev->refcnt, also in
the same function.

Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:11:10 -08:00
Mathieu Poirier
a9ddc71f58 coresight: fixing lockdep error
On some platform the following lockdep error occurs when doing simple
manipulations:

    [   23.197021]
    [   23.198608] ======================================================
    [   23.205078] [ INFO: possible circular locking dependency detected ]
    [   23.211639] 4.4.0-rc8-00025-gbbf360b #172 Not tainted
    [   23.216918] -------------------------------------------------------
    [   23.223480] sh/858 is trying to acquire lock:
    [   23.228057]  (coresight_mutex){+.+.+.}, at: [<c0415d40>] coresight_enable+0x1c/0x1b4
    [   23.236206]
    [   23.236206] but task is already holding lock:
    [   23.242309]  (s_active#52){++++.+}, at: [<c01d4b40>] kernfs_fop_write+0x5c/0x1c0
    [   23.250122]
    [   23.250122] which lock already depends on the new lock.
    [   23.250122]
    [   23.258697]
    [   23.258697] the existing dependency chain (in reverse order) is:
    [   23.266510]
    -> #1 (s_active#52){++++.+}:
    [   23.270843]        [<c01d30ec>] __kernfs_remove+0x294/0x35c
    [   23.276672]        [<c01d3e44>] kernfs_remove_by_name_ns+0x44/0x8c
    [   23.283172]        [<c01d6318>] remove_files+0x3c/0x84
    [   23.288543]        [<c01d66b4>] sysfs_remove_group+0x48/0x9c
    [   23.294494]        [<c01d6734>] sysfs_remove_groups+0x2c/0x3c
    [   23.300506]        [<c030b658>] device_remove_attrs+0x5c/0x74
    [   23.306549]        [<c030c290>] device_del+0x110/0x218
    [   23.311950]        [<c030c3c4>] device_unregister+0x2c/0x6c
    [   23.317779]        [<c04156d8>] coresight_unregister+0x30/0x40
    [   23.323883]        [<c041a290>] etm_probe+0x228/0x2e8
    [   23.329193]        [<c02bc760>] amba_probe+0xe4/0x160
    [   23.334503]        [<c0310540>] driver_probe_device+0x23c/0x480
    [   23.340728]        [<c0310820>] __driver_attach+0x9c/0xa0
    [   23.346374]        [<c030e400>] bus_for_each_dev+0x70/0xa4
    [   23.352142]        [<c030fcf4>] driver_attach+0x24/0x28
    [   23.357604]        [<c030f86c>] bus_add_driver+0x1e0/0x278
    [   23.363372]        [<c0310d48>] driver_register+0x80/0x100
    [   23.369110]        [<c02bc508>] amba_driver_register+0x58/0x5c
    [   23.375244]        [<c0749514>] etm_driver_init+0x18/0x1c
    [   23.380889]        [<c0009918>] do_one_initcall+0xc4/0x20c
    [   23.386657]        [<c0715e7c>] kernel_init_freeable+0x160/0x208
    [   23.392974]        [<c052d7fc>] kernel_init+0x18/0xf0
    [   23.398254]        [<c0010850>] ret_from_fork+0x14/0x24
    [   23.403747]
    -> #0 (coresight_mutex){+.+.+.}:
    [   23.408447]        [<c008ed60>] lock_acquire+0xe4/0x210
    [   23.413909]        [<c0530a30>] mutex_lock_nested+0x74/0x450
    [   23.419860]        [<c0415d40>] coresight_enable+0x1c/0x1b4
    [   23.425689]        [<c0416030>] enable_source_store+0x58/0x68
    [   23.431732]        [<c030b358>] dev_attr_store+0x20/0x2c
    [   23.437286]        [<c01d55e8>] sysfs_kf_write+0x50/0x54
    [   23.442871]        [<c01d4ba8>] kernfs_fop_write+0xc4/0x1c0
    [   23.448699]        [<c015b60c>] __vfs_write+0x34/0xe4
    [   23.454040]        [<c015bf38>] vfs_write+0x98/0x174
    [   23.459228]        [<c015c7a8>] SyS_write+0x4c/0xa8
    [   23.464355]        [<c00107c0>] ret_fast_syscall+0x0/0x1c
    [   23.470031]
    [   23.470031] other info that might help us debug this:
    [   23.470031]
    [   23.478393]  Possible unsafe locking scenario:
    [   23.478393]
    [   23.484619]        CPU0                    CPU1
    [   23.489349]        ----                    ----
    [   23.494079]   lock(s_active#52);
    [   23.497497]                                lock(coresight_mutex);
    [   23.503906]                                lock(s_active#52);
    [   23.509918]   lock(coresight_mutex);
    [   23.513702]
    [   23.513702]  *** DEADLOCK ***
    [   23.513702]
    [   23.519897] 3 locks held by sh/858:
    [   23.523529]  #0:  (sb_writers#7){.+.+.+}, at: [<c015ec38>] __sb_start_write+0xa8/0xd4
    [   23.531799]  #1:  (&of->mutex){+.+...}, at: [<c01d4b38>] kernfs_fop_write+0x54/0x1c0
    [   23.539916]  #2:  (s_active#52){++++.+}, at: [<c01d4b40>] kernfs_fop_write+0x5c/0x1c0
    [   23.548156]
    [   23.548156] stack backtrace:
    [   23.552734] CPU: 0 PID: 858 Comm: sh Not tainted 4.4.0-rc8-00025-gbbf360b #172
    [   23.560302] Hardware name: Generic OMAP4 (Flattened Device Tree)
    [   23.566589] Backtrace:
    [   23.569152] [<c00154d4>] (dump_backtrace) from [<c00156d0>] (show_stack+0x18/0x1c)
    [   23.577087]  r7:ed4b8570 r6:c0936400 r5:c07ae71c r4:00000000
    [   23.583038] [<c00156b8>] (show_stack) from [<c027e69c>] (dump_stack+0x98/0xc0)
    [   23.590606] [<c027e604>] (dump_stack) from [<c008a750>] (print_circular_bug+0x21c/0x33c)
    [   23.599090]  r5:c0939d60 r4:c0936400
    [   23.602874] [<c008a534>] (print_circular_bug) from [<c008e370>] (__lock_acquire+0x1c98/0x1d88)
    [   23.611877]  r10:00000003 r9:c0fd7a5c r8:ed4b8550 r7:ed4b8570 r6:ed4b8000 r5:c0ff69e4
    [   23.620117]  r4:c0936400 r3:ed4b8550
    [   23.623901] [<c008c6d8>] (__lock_acquire) from [<c008ed60>] (lock_acquire+0xe4/0x210)
    [   23.632080]  r10:00000000 r9:00000000 r8:60000013 r7:c07cb7b4 r6:00000001 r5:00000000
    [   23.640350]  r4:00000000
    [   23.643005] [<c008ec7c>] (lock_acquire) from [<c0530a30>] (mutex_lock_nested+0x74/0x450)
    [   23.651458]  r10:ecc0bf80 r9:edbe7dcc r8:ed4b8000 r7:c0fd7a5c r6:c0415d40 r5:00000000
    [   23.659729]  r4:c07cb780
    [   23.662384] [<c05309bc>] (mutex_lock_nested) from [<c0415d40>] (coresight_enable+0x1c/0x1b4)
    [   23.671234]  r10:ecc0bf80 r9:edbe7dcc r8:ed733c00 r7:00000000 r6:ed733c00 r5:00000002
    [   23.679473]  r4:ed762140
    [   23.682128] [<c0415d24>] (coresight_enable) from [<c0416030>] (enable_source_store+0x58/0x68)
    [   23.691070]  r7:00000000 r6:ed733c00 r5:00000002 r4:ed762160
    [   23.697052] [<c0415fd8>] (enable_source_store) from [<c030b358>] (dev_attr_store+0x20/0x2c)
    [   23.705780]  r5:edbe7dc0 r4:c0415fd8
    [   23.709533] [<c030b338>] (dev_attr_store) from [<c01d55e8>] (sysfs_kf_write+0x50/0x54)
    [   23.717834]  r5:edbe7dc0 r4:c030b338
    [   23.721618] [<c01d5598>] (sysfs_kf_write) from [<c01d4ba8>] (kernfs_fop_write+0xc4/0x1c0)
    [   23.730163]  r7:00000000 r6:00000000 r5:00000002 r4:edbe7dc0
    [   23.736145] [<c01d4ae4>] (kernfs_fop_write) from [<c015b60c>] (__vfs_write+0x34/0xe4)
    [   23.744323]  r10:00000000 r9:ecc0a000 r8:c0010964 r7:ecc0bf80 r6:00000002 r5:c01d4ae4
    [   23.752593]  r4:ee385a40
    [   23.755249] [<c015b5d8>] (__vfs_write) from [<c015bf38>] (vfs_write+0x98/0x174)
    [   23.762908]  r9:ecc0a000 r8:c0010964 r7:ecc0bf80 r6:000ab0d8 r5:00000002 r4:ee385a40
    [   23.771057] [<c015bea0>] (vfs_write) from [<c015c7a8>] (SyS_write+0x4c/0xa8)
    [   23.778442]  r8:c0010964 r7:00000002 r6:000ab0d8 r5:ee385a40 r4:ee385a40
    [   23.785522] [<c015c75c>] (SyS_write) from [<c00107c0>] (ret_fast_syscall+0x0/0x1c)
    [   23.793457]  r7:00000004 r6:00000001 r5:000ab0d8 r4:00000002
    [   23.799652] coresight-etb10 54162000.etb: ETB enabled
    [   23.805084] coresight-funnel 54164000.funnel: FUNNEL inport 0 enabled
    [   23.811859] coresight-replicator 44000000.ocp:replicator: REPLICATOR enabled
    [   23.819335] coresight-funnel 54158000.funnel: FUNNEL inport 0 enabled
    [   23.826110] coresight-etm3x 5414c000.ptm: ETM tracing enabled

The locking in coresight_unregister() is not required as the only customers of
the function are drivers themselves when an initialisation failure has been
encoutered.

Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:11:10 -08:00
Mathieu Poirier
ff8742279f coresight: fixing indentation problem
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 22:11:10 -08:00
Andrew F. Davis
b9884d3b79 coresight: Fix a typo in Kconfig
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:31:31 -08:00
Mathieu Poirier
fadf3a44e9 coresight: checking for NULL string in coresight_name_match()
Connection child names associated to ports can sometimes be NULL,
which is the case when booting a system on QEMU or when the Coresight
power domain isn't switched on.

This patch is adding a check to make sure a NULL string isn't fed
to strcmp(), something that avoid crashing the system.

Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:31:31 -08:00
Linus Torvalds
9aa3d651a9 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "This series contains HCH's changes to absorb configfs attribute
  ->show() + ->store() function pointer usage from it's original
  tree-wide consumers, into common configfs code.

  It includes usb-gadget, target w/ drivers, netconsole and ocfs2
  changes to realize the improved simplicity, that now renders the
  original include/target/configfs_macros.h CPP magic for fabric drivers
  and others, unnecessary and obsolete.

  And with common code in place, new configfs attributes can be added
  easier than ever before.

  Note, there are further improvements in-flight from other folks for
  v4.5 code in configfs land, plus number of target fixes for post -rc1
  code"

In the meantime, a new user of the now-removed old configfs API came in
through the char/misc tree in commit 7bd1d4093c ("stm class: Introduce
an abstraction for System Trace Module devices").

This merge resolution comes from Alexander Shishkin, who updated his stm
class tracing abstraction to account for the removal of the old
show_attribute and store_attribute methods in commit 517982229f
("configfs: remove old API") from this pull.  As Alexander says about
that patch:

 "There's no need to keep an extra wrapper structure per item and the
  awkward show_attribute/store_attribute item ops are no longer needed.

  This patch converts policy code to the new api, all the while making
  the code quite a bit smaller and easier on the eyes.

  Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>"

That patch was folded into the merge so that the tree should be fully
bisectable.

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (23 commits)
  configfs: remove old API
  ocfs2/cluster: use per-attribute show and store methods
  ocfs2/cluster: move locking into attribute store methods
  netconsole: use per-attribute show and store methods
  target: use per-attribute show and store methods
  spear13xx_pcie_gadget: use per-attribute show and store methods
  dlm: use per-attribute show and store methods
  usb-gadget/f_serial: use per-attribute show and store methods
  usb-gadget/f_phonet: use per-attribute show and store methods
  usb-gadget/f_obex: use per-attribute show and store methods
  usb-gadget/f_uac2: use per-attribute show and store methods
  usb-gadget/f_uac1: use per-attribute show and store methods
  usb-gadget/f_mass_storage: use per-attribute show and store methods
  usb-gadget/f_sourcesink: use per-attribute show and store methods
  usb-gadget/f_printer: use per-attribute show and store methods
  usb-gadget/f_midi: use per-attribute show and store methods
  usb-gadget/f_loopback: use per-attribute show and store methods
  usb-gadget/ether: use per-attribute show and store methods
  usb-gadget/f_acm: use per-attribute show and store methods
  usb-gadget/f_hid: use per-attribute show and store methods
  ...
2015-11-13 20:04:17 -08:00
Dan Carpenter
73061da07d intel_th: Check for NULL instead of ERR_PTR
devm_ioremap() returns NULL on error, it doesn't return an ERR_PTR,
which is what the current code does. This patch corrects these
checks.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-16 23:25:48 -07:00
Alexander Shishkin
1c090575b0 stm class: Select configfs
STM policy handling is basically configfs, I honestly don't know how we
ended up without a Kconfig dependency, but thanks to randconfig testing,
it's now caught.

Reported-by: Jim Davis <jim.epost@gmail.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-16 23:25:48 -07:00
Alexander Shishkin
ed392688b5 intel_th: Fix integer mismatch warnings
Use unsigned long in place of size_t to operate on buffer sizes and
offsets to clean up the 32 bit build.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-10 12:24:47 -07:00
Alexander Shishkin
0df771dedf stm class: Mark src::link __rcu
Source device's link is protected with srcu, mark it as such to have
proper build-time validation of accesses to this field. The update
side that's dereferencing it under an update lock also needs an
accessor to dereference this field to keep sparse happy.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-10 12:24:47 -07:00
Mathieu Poirier
af6162155e coresight: etm3x: making error message unambiguous
By adding the function name at the beginning of the error
message there is no doubt as to where the failing condition
occurred.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-07 17:54:09 +01:00
Mathieu Poirier
7253e4c956 coresight: etm3x: breaking down sysFS status interface
SysFS rules stipulate that only one value can be conveyed per
file.  As such splitting the "status" interface in individual files.

This is also useful for user space applications - that way they can
probe each file individually rather than having to parse a list of entries.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-07 17:54:09 +01:00
Mathieu Poirier
adfad8745c coresight: etm3x: adding cpu affinity to sysFS interface
Without access to the device tree, it is impossible to know
what CPU a tracer is affined to.  As such adding a new sysFS
interface to convey the information.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-07 17:54:09 +01:00
Mathieu Poirier
58b8d51b84 coresight: adding comments to remove ambiguity
Add comment to function coresight_enable_path() to make
sure there is no misunderstanding about what the code does.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-07 17:54:09 +01:00
Chunyan Zhang
497b59565b Coresight: ETMv4: Prevent TRCRSCTLR0&1 from being accessed
1. TRCRSCTLRn - Resource Selection Control Registers n=0~1 are reserved,
   we shouldn't access them.
2. The max number of 'n' here is defined in TRCIDR4.NUMRSPAIR whoes value
   indicates the number of resource selection *pairs*, and 0 indicates
   one resource selection pair, 1 indicates two pairs, and so on ...

So, the total number of resource selection control registers which we can
access is (TRCIDR4.NUMRSPAIR * 2)

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-07 17:54:09 +01:00
Alexander Shishkin
14cdbf0417 intel_th: Add PTI output driver
Parallel Trace Interface (PTI) unit is a trace output device that sends
data over a PTI port.

The driver provides interfaces to configure bus width, bus clock divider
and mode. Tracing is enabled via output device's "active" attribute.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00
Alexander Shishkin
ba82664c13 intel_th: Add Memory Storage Unit driver
Memory Storage Unit (MSU) is a trace output device that collects trace
data to system memory. It consists of 2 independent Memory Storage
Controllers (MSCs).

This driver provides userspace interfaces to configure in-memory tracing
parameters, such as contiguous (high-order allocation) buffer or multiblock
(scatter list) buffer mode, wrapping (data overwrite) and number and sizes
of windows in multiblock mode. Userspace can read the buffers via mmap()ing
or read()ing of the corresponding device node.

Signed-off-by: Laurent Fert <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00
Alexander Shishkin
f04e449fc7 intel_th: Add Software Trace Hub driver
Software Trace Hub (STH) is a trace source device in the Intel TH
architecture, it generates data that then goes through the switch into
one or several output ports.

STH collects data from software sources using the stm device class
abstraction.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00
Alexander Shishkin
b27a6a3f97 intel_th: Add Global Trace Hub driver
Global Trace Hub (GTH) is the central component of Intel TH architecture;
it carries out switching between the trace sources and trace outputs, can
enable/disable tracing, perform STP encoding, internal buffering, control
backpressure from outputs to sources and so on.

This property is also reflected in the software model; GTH (switch) driver
is required for the other subdevices to probe, because it matches trace
output devices against its output ports and configures them accordingly.

It also implements an interface for output ports to request trace enabling
or disabling and a few other useful things.

For userspace, it provides an attribute group "masters", which allows
configuration of per-master trace output destinations for up to master 255
and "256+" meaning "masters 256 and above". It also provides an attribute
group to discover and configure some of the parameters of its output ports,
called "outputs". Via these the user can set up data retention policy for
an individual output port or check if it is in reset state.

Signed-off-by: Laurent Fert <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00