Commit Graph

148 Commits

Author SHA1 Message Date
Baoyou Xie
0ef7528d15 coresight: tmc: mark symbols static where possible
We get a few warnings when building kernel with W=1:
drivers/hwtracing/coresight/coresight-tmc-etr.c:23:6: warning: no previous prototype for 'tmc_etr_enable_hw' [-Wmissing-prototypes]
drivers/hwtracing/coresight/coresight-tmc-etf.c:25:6: warning: no previous prototype for 'tmc_etb_enable_hw' [-Wmissing-prototypes]
drivers/hwtracing/coresight/coresight-tmc.c:250:9: warning: no previous prototype for ‘trigger_cntr_show’ [-Wmissing-prototypes]
...

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-09 13:53:00 +02:00
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
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
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
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