Commit Graph

320 Commits

Author SHA1 Message Date
Mathieu Poirier 8e67cdbc2f coresight: perf: deal with error condition properly
Function coresight_build_path() should return -ENOMEM when kzalloc
fails to allocated the requested memory.  That way callers can deal
with the error condition in a similar way.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-09 13:52:59 +02:00
Mathieu Poirier e97b1c6a8d coresight: etm4x: adding configurable start/stop filtering
With this patch we add start/stop filtering as specified on
the perf cmd line.  When the IP matches the start address
trace generation gets triggered.  The stop condition is
achieved when the IP matches the stop address.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:44 +02:00
Mathieu Poirier 2703d74c13 coresight: etm4x: adding configurable address range filtering
This patch adds the capability to specify address ranges from
the perf cmd line using the --filter option.  If the IP
falls within the range(s) program flow traces are generated.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:44 +02:00
Mathieu Poirier f0d30cc30e coresight: etm4x: configuring include/exclude function
The include/exclude function of a tracer is applicable to address
range and start/stop filters.  To avoid duplication and reuse code
moving the include/exclude configuration to a function of its own.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:44 +02:00
Mathieu Poirier 6cccf66354 coresight: etm4x: adding range filter configuration function
Introducing a new function to do address range configuration
generic enough to work for any address range and any comparator.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier 5edd944b43 coresight: etm4x: cleaning up default filter configuration
The default filter configuration was hard to read and included
some redundancy.  This patch attempts to stream line configuration
and improve readability.

No change of functionality is included.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier 2a5695a585 coresight: etm4x: split default and filter configuration
Splitting the steps involved in the configuration of a tracer.
The first part is generic and can be reused for both sysFS and
Perf methods.

The second part pertains to the configuration of filters
themselves where the source of the information used to
configure the filters will vary depending on the access
methods.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier ca878b1466 coresight: etm-perf: configuring filters from perf core
This patch implements the required API needed to access
and retrieve range and start/stop filters from the perf core.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier 2b7adc460f coresight: remove duplicated enumeration
Both ETMv3 and ETMv4 drivers are declaring an 'enum etm_addr_type',
creating reduncancy.

This patch removes the enumeration from the driver files and adds
it to a common header.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier 68905d73df coresight: etm-perf: pass struct perf_event to source::enable/disable()
With this commit [1] address range filter information is now found
in the struct hw_perf_event::addr_filters.  As such pass the event
itself to the coresight_source::enable/disable() functions so that
both event attribute and filter can be accessible for configuration.

[1] 'commit 375637bc52 ("perf/core: Introduce address range filtering")'

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Sudeep Holla 3224dcc5a6 coresight: fix handling of ETM trace register access via sysfs
The ETM registers are classified into 2 categories: trace and management.
The core power domain contains most of the trace unit logic including
all(except TRCOSLAR and TRCOSLSR) the trace registers. The debug power
domain contains the external debugger interface including all management
registers.

This patch adds coresight unit specific function coresight_simple_func
which can be used for ETM trace registers by providing a ETM specific
read function which does smp cross call to ensure the trace core is
powered up before the register is accessed.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Sudeep Holla 46a3d5cdb0 coresight: etm4x: request to retain power to the trace unit when active
The Coresight ETMv4 architecture provides a way to request to keep the
power to the trace unit. This might help to collect the traces without
the need to disable the CPU power management(entering/exiting deeper
idle states).

Trace PowerDown Control Register provides powerup request bit which when
set requests the system to retain power to the trace unit and emulate
the powerdown request.

Typically, a trace unit drives a signal to the power controller to
request that the trace unit core power domain is powered up. However,
if the trace unit and the CPU are in the same power domain then the
implementation might combine the trace unit power up status with a
signal from the CPU.

This patch requests to retain power to the trace unit when active and
to remove when inactive. Note this change will only request but the
behaviour depends on the implementation. However, it matches the
exact behaviour expected when the external debugger is connected with
respect to CPU power states.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Markus Elfring 1d37ae5067 coresight: tmc: Delete an unnecessary check before the function call "kfree"
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Wei Yongjun 57a3668beb coresight: etm4x: remove duplicated include from coresight-etm4x.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Suzuki K Poulose 9486295ad1 coresight: Use local coresight_desc instances
Each coresight device prepares a description for coresight_register()
in struct coresight_desc. Once we register the device, the description is
useless and can be freed. The coresight_desc is small enough (48bytes on
64bit)i to be allocated on the stack. Hence use an automatic variable to
avoid a needless dynamic allocation and wasting the memory(which will only
be free'd when the device is destroyed).

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Peter Chen 7f73b0b9fa hwtracing: coresight: of_coresight: add missing of_node_put after calling of_parse_phandle
of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using.

Cc: linux-arm-kernel@lists.infradead.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Olivier Schonken 2a18d7267a coresight-etm3x: Add ARM ETM 3.5 Cortex-A5 peripheral ID
Signed-off-by: Olivier Schonken <olivier.schonken@gmail.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:43 +02:00
Mathieu Poirier cd9e3474bb coresight: add PM runtime calls to coresight_simple_func()
It is mandatory to enable a coresight block's power domain before
trying to access management registers.  Otherwise the transaction
simply stalls, leading to a system hang.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Mathieu Poirier 62d39ac934 coresight: delay initialisation when children are missing
Depending on when CoreSight device are discovered it is possible
that some IP block may be referencing devices that have not been
added to the bus yet.  The end result is missing nodes in the
CoreSight topology even when the devices are present and properly
initialised.

This patch solves the problem by asking the driver core to
try initialising the device at a later time when the children
of a CoreSight node are missing.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 67337e8d8d coresight: Add better messages for coresight_timeout
When we encounter a timeout waiting for a status change via
coresight_timeout, the caller always print the offset which
was tried. This is pretty much useless as it doesn't specify
the bit position we wait for. Also, one needs to lookup the
TRM to figure out, what was wrong. This patch changes all
such error messages to print something more meaningful.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 1c9cbe1184 coresight: Cleanup TMC status check
Use the defined symbol rather than hardcoding the value to
check whether the TMC buffer is full.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 78247e25e8 coresight: etmv4: Fix ETMv4x peripheral ID table
This patch cleans up the peripheral id table for different ETMv4
implementations.

As per Cortex-A53 TRM, the ETM has following id values:

Peripheral ID0	0x5D	0xFE0
Peripheral ID1	0xB9	0xFE4
Peripheral ID2	0x4B	0xFE8
Peripheral ID3	0x00	0xFEC

where, PID2: has the following format:

[7:4]   Revision
[3]     JEDEC   0b1     res1. Indicates a JEP106 identity code is used
[2:0]   DES_1   0b011   ARM Limited. This is bits[6:4] of JEP106 ID code

The existing table entry checks only the bits [1:0], which is not
sufficient enough. Fix it to match bits [3:0], just like the other
entries do. While at it, correct the comment for A57 and the A53 entry.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 8505feaed9 coresight: tmc: Limit the trace to available data
At present the ETF or ETR gives out the entire device
buffer, even if there is less or even no trace data
available. This patch limits the trace data given out to
the actual trace data collected.

Cc: mathieu.poirier@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 068c0a542f coresight: Fix csdev connections initialisation
This is a cleanup patch.

coresight_device->conns holds an array to point to the devices
connected to the OUT ports of a component. Sinks, e.g ETR, do not
have an OUT port (nr_outport = 0), as it streams the trace to
memory via AXI.

At coresight_register() we do :

	conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
	if (!conns) {
		ret = -ENOMEM;
		goto err_kzalloc_conns;
	}

For ETR, since the total size requested for kcalloc is zero, the return
value is, ZERO_SIZE_PTR ( != NULL). Hence, csdev->conns = ZERO_SIZE_PTR
which cannot be verified later to contain a valid pointer. The code which
accesses the csdev->conns is bounded by the csdev->nr_outport check,
hence we don't try to dereference the ZERO_SIZE_PTR. This patch cleans
up the csdev->conns initialisation to make sure we initialise it
properly(i.e, either NULL or valid conns array).

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 3afd0634a2 coresight: Consolidate error handling path for tmc_probe
This patch cleans up the error handling path for tmc_probe
as a side effect of the removal of the spurious dma_free_coherent().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Suzuki K Poulose 481e46fe7a coresight: Remove erroneous dma_free_coherent in tmc_probe
commit de5461970b ("coresight: tmc: allocating memory when needed")
removed the static allocation of buffer for the trace data in ETR mode in
tmc_probe. However it failed to remove the "devm_free_coherent" in
tmc_probe when the probe fails due to other reasons. This patch gets
rid of the incorrect dma_free_coherent() call.

Fixes: commit de5461970b ("coresight: tmc: allocating memory when needed")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Sudeep Holla b1149ad917 coresight: always use stashed trace id value in etm4_trace_id
etm4_trace_id is not guaranteed to be executed on the CPU whose ETM is
being accessed. This leads to exception similar to below one if the
CPU whose ETM is being accessed is in deeper idle states. So it must
be executed on the CPU whose ETM is being accessed.

Unhandled fault: synchronous external abort (0x96000210) at 0xffff000008db4040
Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 5 PID: 5979 Comm: etm.sh Not tainted 4.7.0-rc3 #159
Hardware name: ARM Juno development board (r2) (DT)
task: ffff80096dd34b00 ti: ffff80096dfe4000 task.ti: ffff80096dfe4000
PC is at etm4_trace_id+0x5c/0x90
LR is at etm4_trace_id+0x3c/0x90
Call trace:
 etm4_trace_id+0x5c/0x90
 coresight_id_match+0x78/0xa8
 bus_for_each_dev+0x60/0xa0
 coresight_enable+0xc0/0x1b8
 enable_source_store+0x3c/0x70
 dev_attr_store+0x18/0x28
 sysfs_kf_write+0x48/0x58
 kernfs_fop_write+0x14c/0x1e0
 __vfs_write+0x1c/0x100
 vfs_write+0xa0/0x1b8
 SyS_write+0x44/0xa0
 el0_svc_naked+0x24/0x28

However, TRCTRACEIDR is not guaranteed to hold the previous programmed
trace id if it enters deeper idle states. Further, the trace id that is
computed in etm4_init_trace_id is programmed into TRCTRACEIDR only in
etm4_enable_hw which happens much later in the sequence after
coresight_id_match is executed from enable_source_store.

This patch simplifies etm4_trace_id by returning the stashed trace id
value similar to etm4_cpu_id.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Chunyan Zhang f3864d8562 coresight-stm: support mmapping channel regions with mmio_addr
CoreSight STM device allows direct mapping of the channel regions to
userspace for zero-copy writing. To support this ability, the STM
framework has provided a hook 'mmio_addr', this patch just implemented
this hook for CoreSight STM.

This patch also added an item into 'channel_space' to save the physical
base address of channel region which mmap operation needs to know.

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>
2016-08-31 13:05:42 +02:00
Sudeep Holla b839215372 coresight: access conn->child_name only if it's initialised
If the addition of the coresight devices get deferred, then there's a
window before child_name is populated by of_get_coresight_platform_data
from the respective component driver's probe and the attempted to access
the same from coresight_orphan_match resulting in kernel NULL pointer
dereference as below:

Unable to handle kernel NULL pointer dereference at virtual address 0x0
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1038 Comm: kworker/0:1 Not tainted 4.7.0-rc3 #124
Hardware name: ARM Juno development board (r2) (DT)
Workqueue: events amba_deferred_retry_func
PC is at strcmp+0x1c/0x160
LR is at coresight_orphan_match+0x7c/0xd0
Call trace:
 strcmp+0x1c/0x160
 bus_for_each_dev+0x60/0xa0
 coresight_register+0x264/0x2e0
 tmc_probe+0x130/0x310
 amba_probe+0xd4/0x1c8
 driver_probe_device+0x22c/0x418
 __device_attach_driver+0xbc/0x158
 bus_for_each_drv+0x58/0x98
 __device_attach+0xc4/0x160
 device_initial_probe+0x10/0x18
 bus_probe_device+0x94/0xa0
 device_add+0x344/0x580
 amba_device_try_add+0x194/0x238
 amba_deferred_retry_func+0x48/0xd0
 process_one_work+0x118/0x378
 worker_thread+0x48/0x498
 kthread+0xd0/0xe8
 ret_from_fork+0x10/0x40

This patch adds a check for non-NULL conn->child_name before accessing
the same.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Linus Torvalds a6408f6cb6 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner:
 "This is the next part of the hotplug rework.

   - Convert all notifiers with a priority assigned

   - Convert all CPU_STARTING/DYING notifiers

     The final removal of the STARTING/DYING infrastructure will happen
     when the merge window closes.

  Another 700 hundred line of unpenetrable maze gone :)"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  timers/core: Correct callback order during CPU hot plug
  leds/trigger/cpu: Move from CPU_STARTING to ONLINE level
  powerpc/numa: Convert to hotplug state machine
  arm/perf: Fix hotplug state machine conversion
  irqchip/armada: Avoid unused function warnings
  ARC/time: Convert to hotplug state machine
  clocksource/atlas7: Convert to hotplug state machine
  clocksource/armada-370-xp: Convert to hotplug state machine
  clocksource/exynos_mct: Convert to hotplug state machine
  clocksource/arm_global_timer: Convert to hotplug state machine
  rcu: Convert rcutree to hotplug state machine
  KVM/arm/arm64/vgic-new: Convert to hotplug state machine
  smp/cfd: Convert core to hotplug state machine
  x86/x2apic: Convert to CPU hotplug state machine
  profile: Convert to hotplug state machine
  timers/core: Convert to hotplug state machine
  hrtimer: Convert to hotplug state machine
  x86/tboot: Convert to hotplug state machine
  arm64/armv8 deprecated: Convert to hotplug state machine
  hwtracing/coresight-etm4x: Convert to hotplug state machine
  ...
2016-07-29 13:55:30 -07:00
Sebastian Andrzej Siewior 58eb457be0 hwtracing/coresight-etm4x: Convert to hotplug state machine
This driver has an asymmetry of ONLINE code without any corresponding tear
down code. Otherwise, this is a straightforward conversion.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.228918408@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:40:30 +02:00
Richard Cochran 2b5283d12f hwtracing/coresight-etm3x: Convert to hotplug state machine
This driver has an asymmetry of ONLINE code without any corresponding tear
down code. Otherwise, this is a straightforward conversion.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.147128995@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:40:29 +02:00
Greg Kroah-Hartman 80f7631963 intel_th: Fixes -stable
These are:
  * a fix for a modprobe time deadlock
  * a new PCI ID for Kaby Lake PCH-H
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Merge tag 'stm-for-greg-20160714' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-next

Alexander writes:

intel_th: Fixes -t://git.kernel.org/pub/scm/linux/kernel/git/ash/stm.git
tags/stm-for-greg-20160714
stable

These are:
 * a fix for a modprobe time deadlock
 * a new PCI ID for Kaby Lake PCH-H
2016-07-15 14:19:11 +09:00
Alexander Shishkin 7a1a47ce35 intel_th: pci: Add Kaby Lake PCH-H support
This adds Intel(R) Trace Hub PCI ID for Kaby Lake PCH-H.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <stable@vger.kernel.org>
2016-07-14 13:16:56 +03:00
Alexander Shishkin a36aa80f3c intel_th: Fix a deadlock in modprobing
Driver initialization tries to request a hub (GTH) driver module from
its probe callback, resulting in a deadlock.

This patch solves the problem by adding a deferred work for requesting
the hub module.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
2016-07-14 13:02:39 +03:00
Greg Kroah-Hartman b25948afcc stm class/intel_th: Updates for 4.8
These are:
  * runtime power management implementation for both intel_th and stm class
  * semi-random kerneldoc fixes
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Merge tag 'stm-for-greg-20160701' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-testing

Alexander writes:

stm class/intel_th: Updates for 4.8

These are:
 * runtime power management implementation for both intel_th and stm class
 * semi-random kerneldoc fixes
2016-07-14 12:02:35 +09:00
Alexander Shishkin bd581f239f intel_th: Document output device callbacks
'output' type device callbacks are missing from the kerneldoc description
of the 'intel_th_driver' structure. Fix this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-01 11:01:13 +03:00
Alexander Shishkin 53c189f176 intel_th: gth: Fix a source comment
There's a kerneldoc comment that'd been derived from another one by way
of copying-and-pasting but hadn't been subsequently amended to reflect
the purpose of the function. Fix this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-01 11:01:02 +03:00
Alexander Shishkin 142dfeb202 intel_th: Add runtime power management handling
Currently, an Intel TH (pci) device will be always active, because the
devices on the 'intel_th' bus don't implement runtime pm to track their
usage.

To address this, this patch adds runtime pm support to the 'intel_th'
bus and some additional bits for the hub. The 'output' type device is
in use while a capture is active; the 'source' type device (STH) relies
on its child stm class device for runtime pm tracking.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-01 11:01:01 +03:00
Alexander Shishkin 8e0469a4f3 stm class: Add runtime power management handling
Currently, there's no runtime pm in stm class devices, which makes it
harder for the underlying hardware drivers to handle their power
management.

This patch applies the following runtime pm policy to stm class devices,
which their parents can rely on for their power management tracking:

  * device is in use during character device writes,
  * delayed autosuspend is used to keep it active between adjacent
  writes,
  * device is in use while mmio regions are mapped,
  * device is is use while any stm_source devices are linked to it.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Chunyan Zhang <zhang.chunyan@linaro.org>
2016-07-01 11:00:14 +03:00
Suzuki K Poulose 5014e90468 coresight: Handle build path error
Enabling a component via sysfs (echo 1 > enable_source), would
trigger building a path from the enabled sources to the sink.
If there is an error in the process (e.g, sink not enabled or
the device (CPU corresponding to ETM) is not online), we never report
failure, except for leaving a message in the dmesg.

Do proper error checking for the build path and return the error.

Before:
 $ echo 0 > /sys/devices/system/cpu/cpu2/online
 $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source
 $ echo $?
 0

After:
 $ echo 0 > /sys/devices/system/cpu/cpu2/online
 $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source
 -bash: echo: write error: No such device or address

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-16 00:13:06 -07:00
Suzuki K Poulose f3b8172fe1 coresight: Fix erroneous memset in tmc_read_unprepare_etr
At the end of a trace collection, we try to clear the entire buffer
and enable the ETR back if it was already enabled. But, we would have
adjusted the drvdata->buf to point to the beginning of the trace data
in the trace buffer @drvdata->vaddr. So, the following code which
clears the buffer is dangerous and can cause crashes, like below :

	memset(drvdata->buf, 0, drvdata->size);

 Unable to handle kernel paging request at virtual address ffffff800a145000
 pgd = ffffffc974726000
 *pgd=00000009f3e91003, *pud=00000009f3e91003, *pmd=0000000000000000
 PREEMPT SMP
 Modules linked in:
 CPU: 4 PID: 1692 Comm: dd Not tainted 4.7.0-rc2+ #1721
 Hardware name: ARM Juno development board (r0) (DT)
 task: ffffffc9734a0080 ti: ffffffc974460000 task.ti: ffffffc974460000
 PC is at __memset+0x1ac/0x200
 LR is at tmc_read_unprepare_etr+0x144/0x1bc
 pc : [<ffffff80083a05ac>] lr : [<ffffff800859c984>] pstate: 200001c5
 ...
 [<ffffff80083a05ac>] __memset+0x1ac/0x200
 [<ffffff800859b2e4>] tmc_release+0x90/0x94
 [<ffffff8008202f58>] __fput+0xa8/0x1ec
 [<ffffff80082030f4>] ____fput+0xc/0x14
 [<ffffff80080c3ef8>] task_work_run+0xb0/0xe4
 [<ffffff8008088bf4>] do_notify_resume+0x64/0x6c
 [<ffffff8008084d5c>] work_pending+0x10/0x14
 Code: 91010108 54ffff4a 8b040108 cb050042 (d50b7428)

Since we clear the buffer anyway in the following call to
tmc_etr_enable_hw(), remove the erroneous memset().

Fixes: commit de5461970b ("coresight: tmc: allocating memory when needed")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-16 00:13:06 -07:00
Suzuki K Poulose 8e215298a1 coresight: Fix tmc_read_unprepare_etr
At the end of the trace capture, we free the allocated memory,
resetting the drvdata->buf to NULL, to indicate that trace data
was collected and the next trace session should allocate the
memory in tmc_enable_etr_sink_sysfs.

The tmc_enable_etr_sink_sysfs, we only allocate memory if drvdata->vaddr
is not NULL (which is not performed at the end of previous session).
This can cause, drvdata->vaddr getting assigned NULL and later we do
memset() which causes a crash as below :

Unable to handle kernel NULL pointer dereference at virtual
 address  00000000
pgd = ffffffc9747f0000
[00000000] *pgd=00000009f402e003, *pud=00000009f402e003,
 *pmd=0000000000000000
Internal error: Oops: 96000046 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1592 Comm: bash Not tainted 4.7.0-rc1+ #1712
Hardware name: ARM Juno development board (r0) (DT)
task: ffffffc078fe0080 ti: ffffffc974178000 task.ti: ffffffc974178000
PC is at __memset+0x1ac/0x200
LR is at tmc_enable_etr_sink+0xf8/0x304
pc : [<ffffff80083a002c>] lr : [<ffffff800859be44>] pstate: 400001c5
sp : ffffffc97417bc00
x29: ffffffc97417bc00 x28: ffffffc974178000

Call trace:
Exception stack(0xffffffc97417ba40 to 0xffffffc97417bb60)
ba40: 0000000000000001 ffffffc974a5d098 ffffffc97417bc00 ffffff80083a002c
ba60: ffffffc974a5d118 0000000000000000 0000000000000000 0000000000000000
ba80: 0000000000000001 0000000000000000 ffffff800859bdec 0000000000000040
baa0: ffffff8008b45b58 00000000000001c0 ffffffc97417baf0 ffffff80080eddb4
bac0: 0000000000000003 ffffffc078fe0080 ffffffc078fe0960 ffffffc078fe0940
bae0: 0000000000000000 0000000000000000 00000000007fffc0 0000000000000004
bb00: 0000000000000000 0000000000000040 000000000000003f 0000000000000000
bb20: 0000000000000000 0000000000000000 0000000000000000 0000000000000001
bb40: ffffffc078fe0960 0000000000000018 ffffffffffffffff 0008669628000000
[<ffffff80083a002c>] __memset+0x1ac/0x200
[<ffffff8008599814>] coresight_enable_path+0xa8/0x1dc
[<ffffff8008599b10>] coresight_enable+0x88/0x1b8
[<ffffff8008599d88>] enable_source_store+0x3c/0x6c
[<ffffff800845eaf4>] dev_attr_store+0x18/0x28
[<ffffff80082829e8>] sysfs_kf_write+0x54/0x64
[<ffffff8008281c30>] kernfs_fop_write+0x148/0x1d8
[<ffffff8008200128>] __vfs_write+0x28/0x110
[<ffffff8008200e88>] vfs_write+0xa0/0x198
[<ffffff80082021b0>] SyS_write+0x44/0xa0
[<ffffff8008084e70>] el0_svc_naked+0x24/0x28
Code: 91010108 54ffff4a 8b040108 cb050042 (d50b7428)

This patch fixes the issue by clearing the drvdata->vaddr while we free
the allocated buffer at the end of a session, so that we allocate the
memory again.

Cc: mathieu.poirier@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-16 00:13:06 -07:00
Suzuki K Poulose ec48a1d981 coresight: Fix NULL pointer dereference in _coresight_build_path
_coresight_build_path assumes that all the connections of a csdev
has the child_dev initialised. This may not be true if the particular
component is not supported by the kernel config(e.g TPIU) but is
present in the DT. In which case, building a path can cause a crash like this :

  Unable to handle kernel NULL pointer dereference at virtual address 00000010
  pgd = ffffffc9750dd000
  [00000010] *pgd=00000009f5e90003, *pud=00000009f5e90003, *pmd=0000000000000000
  Internal error: Oops: 96000006 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 4 PID: 1348 Comm: bash Not tainted 4.6.0-next-20160517 #1646
  Hardware name: ARM Juno development board (r0) (DT)
  task: ffffffc97517a280 ti: ffffffc9762c4000 task.ti: ffffffc9762c4000
  PC is at _coresight_build_path+0x18/0xe4
  LR is at _coresight_build_path+0xc0/0xe4
  pc : [<ffffff80083d5130>] lr : [<ffffff80083d51d8>] pstate: 20000145
  sp : ffffffc9762c7ba0

  [<ffffff80083d5130>] _coresight_build_path+0x18/0xe4
  [<ffffff80083d51d8>] _coresight_build_path+0xc0/0xe4
  [<ffffff80083d51d8>] _coresight_build_path+0xc0/0xe4
  [<ffffff80083d51d8>] _coresight_build_path+0xc0/0xe4
  [<ffffff80083d51d8>] _coresight_build_path+0xc0/0xe4
  [<ffffff80083d51d8>] _coresight_build_path+0xc0/0xe4
  [<ffffff80083d5cdc>] coresight_build_path+0x40/0x68
  [<ffffff80083d5e14>] coresight_enable+0x74/0x1bc
  [<ffffff80083d60a0>] enable_source_store+0x3c/0x6c
  [<ffffff800830b17c>] dev_attr_store+0x18/0x28
  [<ffffff80081ca9c4>] sysfs_kf_write+0x40/0x50
  [<ffffff80081c9e38>] kernfs_fop_write+0x140/0x1cc
  [<ffffff8008163ec8>] __vfs_write+0x28/0x110
  [<ffffff8008164bf0>] vfs_write+0xa0/0x174
  [<ffffff8008165d18>] SyS_write+0x44/0xa0
  [<ffffff8008084e70>] el0_svc_naked+0x24/0x28

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-16 00:13:06 -07:00
Linus Torvalds 5af2344013 Char / Misc driver update for 4.7-rc1
Here's the big char and misc driver update for 4.7-rc1.
 
 Lots of different tiny driver subsystems have updates here with new
 drivers and functionality.  Details in the shortlog.
 
 All have been in linux-next with no reported issues for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc driver updates from Greg KH:
 "Here's the big char and misc driver update for 4.7-rc1.

  Lots of different tiny driver subsystems have updates here with new
  drivers and functionality.  Details in the shortlog.

  All have been in linux-next with no reported issues for a while"

* tag 'char-misc-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (125 commits)
  mcb: Delete num_cells variable which is not required
  mcb: Fixed bar number assignment for the gdd
  mcb: Replace ioremap and request_region with the devm version
  mcb: Implement bus->dev.release callback
  mcb: export bus information via sysfs
  mcb: Correctly initialize the bus's device
  mei: bus: call mei_cl_read_start under device lock
  coresight: etb10: adjust read pointer only when needed
  coresight: configuring ETF in FIFO mode when acting as link
  coresight: tmc: implementing TMC-ETF AUX space API
  coresight: moving struct cs_buffers to header file
  coresight: tmc: keep track of memory width
  coresight: tmc: make sysFS and Perf mode mutually exclusive
  coresight: tmc: dump system memory content only when needed
  coresight: tmc: adding mode of operation for link/sinks
  coresight: tmc: getting rid of multiple read access
  coresight: tmc: allocating memory when needed
  coresight: tmc: making prepare/unprepare functions generic
  coresight: tmc: splitting driver in ETB/ETF and ETR components
  coresight: tmc: cleaning up header file
  ...
2016-05-20 21:20:31 -07:00
Joonsoo Kim 0139aa7b7f mm: rename _count, field of the struct page, to _refcount
Many developers already know that field for reference count of the
struct page is _count and atomic type.  They would try to handle it
directly and this could break the purpose of page reference count
tracepoint.  To prevent direct _count modification, this patch rename it
to _refcount and add warning message on the code.  After that, developer
who need to handle reference count will find that field should not be
accessed directly.

[akpm@linux-foundation.org: fix comments, per Vlastimil]
[akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
[sfr@canb.auug.org.au: sync ethernet driver changes]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sunil Goutham <sgoutham@cavium.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Yuval Mintz <yuval.mintz@qlogic.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19 19:12:14 -07:00
Mathieu Poirier bedffda8ca coresight: etb10: adjust read pointer only when needed
The read pointer (read_ptr) needs to be adjusted only if its value
has gone beyond the length of the memory buffer.

Reported-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier dc2c4ef141 coresight: configuring ETF in FIFO mode when acting as link
When part of a path but not identified as a sink, the EFT has to
be configured as a link and placed in HW FIFO mode.  As such when
enabling a path, call the right configuration function based on
the role the ETF if playing in this trace run.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 2e499bbc1a coresight: tmc: implementing TMC-ETF AUX space API
This patch implement the AUX area interfaces required to
use the TMC (configured as an ETF) from the Perf sub-system.

The heuristic is heavily borrowed from the ETB10 implementation.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier a02e81f7a3 coresight: moving struct cs_buffers to header file
That way we can re-use the structure in other drivers.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 4f1ff3de92 coresight: tmc: keep track of memory width
Accessing the HW configuration register each time the memory
width is needed simply doesn't make sense.  It is much more
efficient to read the value once and keep a reference for
later use.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier b217601e9a coresight: tmc: make sysFS and Perf mode mutually exclusive
The sysFS and Perf access methods can't be allowed to interfere
with one another.  As such introducing guards to access
functions that prevents moving forward if a TMC is already
being used.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier a40318fb01 coresight: tmc: dump system memory content only when needed
Calling tmc_etf/etr_dump_hw() is required only when operating from
sysFS.  When working from Perf, the system memory is harvested
from the AUX trace API.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier f2facc3366 coresight: tmc: adding mode of operation for link/sinks
Moving tmc_drvdata::enable to a local_t mode.  That way the
sink interface is aware of it's orgin and the foundation for
mutual exclusion between the sysFS and Perf interface can be
laid out.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier f74debbea0 coresight: tmc: getting rid of multiple read access
Allowing multiple readers to access the trace data simultaniously
via sysFS provides no shortage of opportunity for race condition,
mandates two variable to be maintained (drvdata::read_count and
drvdata::reading), makes the code complex and provide little
advantages, if any.

This patch streamlines the read process by restricting trace data
access to a single user.  That way drvdata::read_count can
be eliminated and race conditions (along with faulty error handling)
in function tmc_open() and tmc_release() eliminated.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier de5461970b coresight: tmc: allocating memory when needed
In it's current form the TMC probe() function allocates
trace buffer memory at boot time, event if coresight isn't
used.  This is highly inefficient since trace buffers can
occupy a lot of memory that could be used otherwised.

This patch allocates trace buffers on the fly, when the
coresight subsystem is solicited.  Allocated buffers are
released when traces are read using the device descriptors
under /dev.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 4525412a50 coresight: tmc: making prepare/unprepare functions generic
Dealing with HW related matters in tmc_read_prepare/unprepare
becomes convoluted when many cases need to be handled distinctively.

As such moving processing related to HW setup to individual driver
files and keep the core driver generic.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 6c6ed1e244 coresight: tmc: splitting driver in ETB/ETF and ETR components
The TMC block can operate in 3 modes (ETB, ETF and ETR) and accessed
via two interfaces (sysFS and Perf).  That makes 6 mode to cover, which
is way too much coupling for a single file.

This patch splits the original TMC driver in 2 halves, one for ETB/ETF
and another one for ETR mode.  A common core is kept for functionality
common to all 3 modes.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier a8ab4268e0 coresight: tmc: cleaning up header file
This patch first move the TMC_STS_TMCREADY_BIT and
TMC_FFCR_FLUSHMAN_BIT defines to their respective section.
It also removes TMC_FFCR_FLUSHMAN, since the same result
can easily be obtained using the BIT() macro.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 4c324b5f0e coresight: tmc: introducing new header file
The amount of #define, enumeration and structure definition
is big enough to justify moving them to a new header file.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier ebba56e7b2 coresight: tmc: clearly define number of transfers per burst
This patch makes the name of the define reflect the amount of
data tranfers per burst, in this case 16.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier b1789b793e coresight: tmc: re-implementing tmc_read_prepare/unprepare() functions
In their current implementation the tmc_read_prepare/unprepare()
are a lump of if/else that is difficult to read.  This patch is
alleviating that by using a switch statement.  The latter also
allows for a better control on the error path.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 358f42184e coresight: tmc: waiting for TMCReady bit before programming
According to the TRM before programming the TMC in circular
buffer mode (and that for any configuration, ETB, ETR, ETF),
the TMCReady bit in the status register has to be set.

This patch adds a check to make sure the state machine is in
a state where it can be configured, and complains otherwise.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 580ff804ec coresight: tmc: modifying naming convention
According to the TMC architectural state machine, the 'stopped'
state is reached when bit 2 (TMCReady) of the TMC Status register
turns to '1'.  The code is correct but the naming convention isn't.

The 'Triggered' bit occupies position '1' of the TMC Status register
and has nothing to do with the indication of the TMC entering the
stopped state. As such renaming function "tmc_wait_for_triggered()"
and changing the #define to reflect what the code is really doing.

This patch has no effect other than clarifying the semantic.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier 7d83d17795 coresight: tmc: adding sysFS management entries
Adding management registers that convey implementation
specific characteristics.  Those are useful for trace
configuration and collection along with general trouble
shooting.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Li Pengcheng 960e309599 coresight: etm4x: add tracer ID for A72 Maia processor.
This patch adds a cellID for the ETMv4 tracer found on
HiSillicon's A72 Maia processor.

Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com>
Signed-off-by: Li Zhong <lizhong11@hisilicon.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier b5af0a26da coresight: etb10: fixing the right amount of words to read
This patch rectifies the amount of words to read when the internal
buffer is deemed bigger than the amount of space available in the
perf ring buffer.

The amount to read is set to the amount of space in the perf ring
buffer rather than being subtracted by it.

Reported-by: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Pratik Patel 237483aa5c coresight: stm: adding driver for CoreSight STM component
This driver adds support for the STM CoreSight IP block, allowing any
system compoment (HW or SW) to log and aggregate messages via a
single entity.

The CoreSight STM exposes an application defined number of channels
called stimulus port.  Configuration is done using entries in sysfs
and channels made available to userspace via configfs.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Michael Williams <michael.williams@arm.com>
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier a685d68328 coresight: adding path for STM device
>From a core framework point of view an STM device is a source that is
treated the same way as any other tracers.  Unlike tracers though STM
devices are not associated with a CPU.  As such it doesn't make sense
to associate the path from an STM device to its sink with a per-cpu
variable as it is done for tracers.

This patch simply adds another global variable to keep STM paths and the
processing in coresight_enable/disable() is updated to deal with STM
devices properly.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Alexander Shishkin 8e996a2874 stm class: Support devices that override software assigned masters
Some STM devices adjust software assigned master numbers depending on
the trace source and its runtime state and whatnot. This patch adds
a sysfs attribute to inform the trace-side software that master numbers
assigned to software sources will not match those in the STP stream,
so that, for example, master/channel allocation policy can be adjusted
accordingly.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Li Pengcheng 6327a454a8 coresight: etm4x: modify q_support type
Because this operation exceed the range of boolean,
so we should modify q_support to unit8 bit.
drvdata->q_support = BMVAL(etmidr0, 15, 16)

Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com>
Signed-off-by: Li Zhong <lizhong11@hisilicon.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Li Pengcheng e8dc27d0ee coresight: no need to do the forced type conversion
activated and enable are already unsigned type,
no need to change them to unsigned.

Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com>
Signed-off-by: Li Zhong <lizhong11@hisilicon.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-03 14:59:30 -07:00
Mathieu Poirier ef0fd640e3 coresight: removing gratuitous boot time log messages
Removing boot time log for drivers that don't report useful information
other than they came up properly.  The same information can be found in
sysFS once the system has booted and as such doesn't provide any value
in the boot log.

Reported-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier ad352acbb9 coresight: etb10: splitting sysFS "status" entry
The sysFS "status" entry conveys a wealth of information about
the status of the HW but goes agains the sysFS rule of one topic
per file.

This patch rectify the situation by adding read-only entries for
each of the field formaly displayed by "status".  The ABI
documentation is kept up to date.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 154f3520fe coresight: moving coresight_simple_func() to header file
Macro "coresight_simple_func()" can be used by several drivers.
As such making the structure type generic and moving to a
globally available header file.  That way individual drivers
can use the functionality by simply specifying the structure
they need to work with.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 37fbbdbde9 coresight: etm4x: implementing the perf PMU API
Adding a set of API allowing the Perf core to treat ETMv4
tracers like other PMUs.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 4f6fce5452 coresight: etm4x: implementing user/kernel mode tracing
Adding new mode to limit tracing to kernel or user space.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier c38a9ec2b2 coresight: etm4x: moving etm_drvdata::enable to atomic field
Similarly to ETMv3, moving etmv4_drvdata::enable to an atomic
type that gives the 'mode' of a tracer and prevents multiple,
simultanious access by different subsystems.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 66bbbb7754 coresight: etm4x: unlocking tracers in default arch init
As with the ETMv3.x driver, calling 'smp_call_function_single()'
twice in a row is highly ineffective.  As such moving function
'etm4_os_unlock()' before the default initialisation takes
place, which results in the same outcome.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier fc208abef3 coresight: etm4x: splitting etmv4 default configuration
Splitting and updating the default initialisation for each etmv4
configuration so that it can be called at the beginning of each
session rather than initialisation time only.

Since the trace ID isn't expected to change with every session,
moving it with the default tracer initialisation.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 54ff892b76 coresight: etm4x: splitting struct etmv4_drvdata
Similar to what was done on etm3x, splitting driver structure
etmv4_drvdata in two.  One half is concerned with the HW
characteristics that are generally static in nature.  The other
half deals with user configuration and will change from one
trace session to another.

No gain/loss of functionality is incurred from this patch.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier 7c38aa4b03 coresight: etm4x: adding config and traceid registers
Adding new sysFS management interface to query the configuration
and the traceid registers.  Both are required to convey information
to the perf cmd line tools when using ETMv4 tracers as PMU.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Mathieu Poirier a77de2637c coresight: etm4x: moving sysFS entries to a dedicated file
As with the etm3x driver, sysFS entries are big enough to justify
their own file. As such moving all sysFS related declarations to
a dedicated location.

No gain/loss of functionality is incurred from this patch.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:12:14 -07:00
Alexander Shishkin aaa3ca8228 intel_th: pci: Add Broxton-M SOC support
This adds Intel(R) Trace Hub PCI ID for Broxton-M SOC.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-19 22:54:05 +03:00
Alexander Shishkin f152dfee19 intel_th: msu: Release resources on removal
Do release the resources when msu subdevice gets removed: stop the
capture if it is active (which is still possible even though the
module in pinned) and free the capture buffers.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 17:45:46 +03:00
Alexander Shishkin 8e9a2beb5f intel_th: msu: Set fops::owner to prevent module from unloading
Right now it's possible to unload the msu driver while its character
device is open. Prevent it by setting fops::owner, which will result
in the module reference being held while the device node is open.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 17:43:34 +03:00
Alexander Shishkin e2ea295baf intel_th: Hold output driver module reference while capture is active
Right now it's possible to unload the output subdevice's driver while
the capture to this output is active. Prevent this by holding the
output driver's module reference.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 17:41:25 +03:00
Alexander Shishkin a45ff6ed74 intel_th: msu: Serialize enabling/disabling
In order to guarantee that readers don't race with trace enabling,
both should happen under the same mutex. Having two mutexes seems
like an overkill, considering that because of the above, they'll
have to be acquired together, around trace enabling and char device
opening.

This patch makes both buffer accesses and readers serialize on
msc::buf_mutex and makes sure that 'enabled' flag accesses are also
serialized on it.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:59 +03:00
Alexander Shishkin f18a9531f6 intel_th: Fix activating a subdevice without a driver
If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:58 +03:00
Alexander Shishkin e8644e4c2a intel_th: pti: Create sysfs attributes using core driver's facility
The core intel_th driver allows subdevices to bring in their sysfs
attributes. Use this instead of taking care of them in probe and
remove.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:57 +03:00
Alexander Shishkin 9d482aedd0 intel_th: msu: Create sysfs attributes using core driver's facility
The core intel_th driver allows subdevices to bring in their sysfs
attributes. Use this instead of taking care of them in probe and
remove.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:57 +03:00
Alexander Shishkin b5edbf1ea3 intel_th: Allow subdevice drivers to bring in own attribute groups
Some subdevices (MSU, PTI) need to register their own driver-specific
attribute groups. Provide a way for those to pass their attribute
groups to the core driver in their driver structure so that the
core can take care of creating and removing them.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:56 +03:00
Alexander Shishkin 6575cbd671 intel_th: msu: Handle kstrndup() failure
Currently, the nr_pages attribute store does not check if kstrndup()
succeeded. Fix this.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:55 +03:00
Alexander Shishkin 8f1127ea09 intel_th: pti: Do remove sysfs group on device removal
Right now, the PTI output driver forgets to clean up its sysfs group
when it gets removed. Fix this.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:54 +03:00
Alexander Shishkin fb0801904b stm class: Remove unnecessary pointer increment
Readability: a postfix increment is used on a pointer which is not
used anywhere afterwards, which may send the reader looking through
the function one extra time. Drop the unnecessary increment.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:54 +03:00
Alexander Shishkin 389b6699a2 stm class: Fix stm device initialization order
Currently, stm_register_device() makes the device visible and then
proceeds to initializing spinlocks and other properties, which leaves
a window when the device can already be opened but is not yet fully
operational.

Fix this by reversing the initialization order.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:53 +03:00
Alexander Shishkin cbe4a61d1d stm class: Do not leak the chrdev in error path
Currently, the error path of stm_register_device() forgets to unregister
the chrdev. Fix this.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:52 +03:00
Alexander Shishkin 8fa11d1c13 stm class: Remove a pointless line
No point in explicitly setting something to zero right after we
explicitly checked that it is zero. Fix this.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:52 +03:00
Alexander Shishkin c8be489944 stm class: stm_heartbeat: Make nr_devs parameter read-only
Changing nr_devs after the module has been loaded doesn't actually
change anything, so just make it read-only.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:51 +03:00
Alexander Shishkin 118b4515aa stm class: dummy_stm: Make nr_dummies parameter read-only
Changing nr_dummies after the module has been loaded doesn't actually
change anything, so just make it read-only.

Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:11:50 +03:00
Chunyan Zhang f57af6df6a stm class: Fix integer boundary checks for master range
Master IDs are of unsigned int type, yet in the configfs policy code
we're validating user's input against INT_MAX. This is both pointless
and misleading as the real limits are imposed by the stm device's
[sw_start..sw_end] (which are also limited by the spec to be no larger
than 2^16-1).

Clean this up by getting rid of the redundant comparisons.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08 16:08:00 +03:00
Paul Gortmaker ca48fa22c3 drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
In commit 941943cf51 ("drivers/hwtracing:
make coresight-* explicitly non-modular") we removed all uses of
modular functions/macros in favour of their built-in equivlents in
this subsystem.

However that commit and commit 0bcbf2e30f
("coresight: etm-perf: new PMU driver for ETM tracers") were in flight
at the same time, and hence one new non-modular user of module_init
crept back in.  Fix it up like we did all the others.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-05 12:19:39 -08:00
Paul Gortmaker 941943cf51 drivers/hwtracing: make coresight-* explicitly non-modular
None of the Kconfig currently controlling compilation of any of
the files here are tristate, meaning that none of it currently
is being built as a module by anyone.

We need not be concerned about .remove functions and blocking the
unbind sysfs operations, since that was already done in a recent
commit.

Lets remove any remaining modular references, so that when reading the
drivers there is no doubt they are builtin-only.

All drivers get mostly the same changes, so they are handled in batch.
Changes are (1) convert to builtin_amba_driver, (2) delete module.h
include where unused, and (3) relocate the description into the
comments so we don't need MODULE_DESCRIPTION and associated tags.

The etm3x and etm4x use module_param_named, and have been adjusted
to just include moduleparam.h for that purpose.

In commit f309d44431 ("platform_device:
better support builtin boilerplate avoidance") we introduced the
builtin_driver macro.

Here we use that support and extend it to amba driver registration,
so where a driver is clearly non-modular and builtin-only, we can
update with the simple mapping of

     module_amba_driver(...)  ---> builtin_amba_driver(...)

Since module_amba_driver() uses the same init level priority as
builtin_amba_driver() the init ordering remains unchanged with
this commit.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 17534ceb83 coresight: introducing a global trace ID function
TraceID values have to be unique for all tracers and
consistent between drivers and user space.  As such
introducing a central function to be used whenever a
traceID value is required.

The patch also account for data traceIDs, which are usually
I(N) + 1.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 0bcbf2e30f coresight: etm-perf: new PMU driver for ETM tracers
Perf is a well known and used tool for performance monitoring
and much more. A such it is an ideal candidate for integration
with coresight based HW tracing.

This patch introduces a PMU that represent a coresight tracer to
the Perf core.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 2997aa4063 coresight: etb10: implementing AUX API
Adding an ETB10 specific AUX area operations to be used
by the perf framework when events are initialised.

Part of this operation involves modeling the mmap'ed area
based on the specific ways a sink buffer gathers information.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier e827d4550a coresight: etb10: adding operation mode for sink->enable()
Adding an operation mode to the sink->enable() API in order
to prevent simultaneous access from different callers.

TPIU and TMC won't be supplemented with the AUX area
API immediately and as such ignore the new mode.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 27b10da8ff coresight: etb10: moving to local atomic operations
Moving to use local atomic operations to take advantage of the
lockless implementation, something that will come handy when
the ETB is accessed from the Perf subsystem. Also changing the
name of the variable to something more meaningful.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 882d5e1124 coresight: etm3x: implementing perf_enable/disable() API
That way traces can be enabled and disabled automatically
from the Perf subystem using the PMU abstraction.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 2127154d11 coresight: etm3x: implementing user/kernel mode tracing
Adding new mode to limit tracing to kernel or user space.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier c528a25ac7 coresight: etm3x: consolidating initial config
There is really no point in having two functions to take care
of doing the initial tracer configuration.  As such moving
everything to 'etm_set_default()'.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier e19217299c coresight: etm3x: changing default trace configuration
Changing default configuration to include the entire address
range rather than just the kernel.  That way traces are more
inclusive and it is easier to narrow down if needed.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 47cd066cd0 coresight: etm3x: set progbit to stop trace collection
There is no need to use the event enable's "always false" event to
stop trace collection.  For that purpose setting the programming bit
(ETMCR:10) is enough.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 22fd532eaa coresight: etm3x: adding operation mode for etm_enable()
Adding a new mode to source API enable() in order to
distinguish where the request comes from.  That way it is
possible to perform different operations based on where
the request was issued from.

The ETM4x driver is also modified to keep in sync with the
new interface.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 1925a470ce coresight: etm3x: splitting struct etm_drvdata
Splitting "etm_drvdata" in two sections, one for the HW specific
data and another for user configuration.

That way it is easier to manipulate and zero out the configuration
data when more than one concurrent tracing session configuration
is active.

Also taking care of up-lifting all the code affected by this new
arrangement.  No loss or gain of functionality (other than what is
mentioned above) is introduced by this patch.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier ae69a1da39 coresight: etm3x: unlocking tracers in default arch init
Calling function 'smp_call_function_single()' to unlock a
tracer and calling it again right after to perform the
default initialisation doesn't make sense.

Moving 'etm_os_unlock()' just before making the default
initialisation results in the same outcome while saving
one call to 'smp_call_function_single()'.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier c04148e708 coresight: etm3x: moving sysFS entries to dedicated file
SysFS entries are big enough to justify their own file.
As such moving all sysFS related declarations to a dedicated
location.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier c1f8e57c9e coresight: etm3x: moving etm_readl/writel to header file
Moving functions etm_readl/writel to file "coresight-etm.h"
so that the main ETM3x driver can be split in more than one
file.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier 5da5325fa8 coresight: moving PM runtime operations to core framework
Moving PM runtime operations in Coresight devices enable() and
disable() API to the framework core when a path is setup.  That
way the runtime core doesn't have to be involved everytime a
path is enabled.  It also avoids calling runtime PM operations
in IRQ context.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier b6404e21f0 coresight: add API to get sink from path
Add an API allowing external code to quickly get a handle on the
sink within a path.  The sink is always last, but adding an API allows
to keep the path's node structure private and remove redundant checks.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Mathieu Poirier b3e9440594 coresight: associating path with session rather than tracer
When using the Coresight framework from the sysFS interface a
tracer is always handling a single session and as such, a path
can be associated with a tracer.  But when supporting multiple
session per tracer there is no guarantee that sessions will always
have the same path from source to sink.

This patch is removing the automatic association between path and
tracers.  The building of a path and enablement of the components
in the path are decoupled, allowing for the association of a path
with a session rather than a tracer.

To keep backward functionality with the current sysFS access methods
a per-cpu place holder is used to keep a handle on the path built when
tracers are enabled.  Lastly APIs to build paths and enable tracers are
made public so that other subsystem can interact with the Coresight
framework.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Eric Long 61390593f7 coresight: etm4x: Check every parameter used by dma_xx_coherent.
The dma_alloc_coherent return an "void *" not an "void __iomen *".
It uses the wrong parameters when calls dma_free_coherent function.

The sparse tool output logs as the following:
coresight-tmc.c:199:23:    expected void *<noident>
coresight-tmc.c:199:23:    got void [noderef] <asn:2>*vaddr
coresight-tmc.c:336:30: warning: incorrect type in assignment
(different address spaces)
coresight-tmc.c:336:30:    expected char *buf
coresight-tmc.c:336:30:    got void [noderef] <asn:2>*
coresight-tmc.c:769:50: warning: incorrect type in argument 4
(different base types)
coresight-tmc.c:769:50:    expected unsigned long long
[unsigned] [usertype] dma_handle
coresight-tmc.c:769:50:    got restricted gfp_t

Signed-off-by: Eric Long <eric.long@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Eric Long bf16e5b8cd coresight: "DEVICE_ATTR_RO" should defined as static.
"DEVICE_ATTR_RO(name)" should be defined as static. And
there is an unnecessary space at the front of the code.

The sparse tool output logs as the following:
coresight-etm4x.c:2224:1: warning: symbol 'dev_attr_trcoslsr' was
not declared. Should it be static?
coresight-etm4x.c:2225:1: warning: symbol 'dev_attr_trcpdcr' was
not declared. Should it be static?
coresight-etm4x.c:2226:1: warning: symbol 'dev_attr_trcpdsr' was
not declared. Should it be static?
And the smatch tool output logs as the following:
of_coresight.c:89 of_coresight_alloc_memory() warn:
inconsistent indenting

Signed-off-by: Eric Long <eric.long@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20 14:11:01 -08:00
Alexander Shishkin adcde635f5 stm class: dummy_stm: Add link callback for fault injection
STM device's link callback has the power to abort master/channel
assignment by returning a negative error code. Use this in dummy
stm device to optionally abort assigning certain channel IDs.
This is useful as fault injection into the stm class core, for
testing purposes.

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 cc8424074e stm class: Plug stm device's unlink callback
STM device's unlink callback is never actually called from anywhere in
the stm class code.

This patch adds calls to stm driver's unlink method after the unlinking
has succeeded.

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 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