Commit 2f01c200d4 ("perf cs-etm: Remove callback cs_etm_find_snapshot()")
has removed the function cs_etm_find_snapshot() from the perf tool in the
user space, now CoreSight trace directly uses the perf common function
__auxtrace_mmap__read() to calcualte the head and size for AUX trace data
in snapshot mode.
This patch updates the comments in drivers to make them generic and not
stick to any specific function from perf tool.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20210912125748.2816606-3-leo.yan@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Since the function CS_LOCK() has contained memory barrier mb(), it
ensures the visibility of the AUX trace data before updating the
aux_head, thus it's needless to add any explicit barrier anymore.
Add comment to make clear for the barrier usage for ETF.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20210809111407.596077-4-leo.yan@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
commit 6f755e85c3 ("coresight: Add helper for inserting synchronization
packets") removed trailing '\0' from barrier_pkt array and updated the
call sites like etb_update_buffer() to have proper checks for barrier_pkt
size before read but missed updating tmc_update_etf_buffer() which still
reads barrier_pkt past the array size resulting in KASAN out-of-bounds
bug. Fix this by adding a check for barrier_pkt size before accessing
like it is done in etb_update_buffer().
BUG: KASAN: global-out-of-bounds in tmc_update_etf_buffer+0x4b8/0x698
Read of size 4 at addr ffffffd05b7d1030 by task perf/2629
Call trace:
dump_backtrace+0x0/0x27c
show_stack+0x20/0x2c
dump_stack+0x11c/0x188
print_address_description+0x3c/0x4a4
__kasan_report+0x140/0x164
kasan_report+0x10/0x18
__asan_report_load4_noabort+0x1c/0x24
tmc_update_etf_buffer+0x4b8/0x698
etm_event_stop+0x248/0x2d8
etm_event_del+0x20/0x2c
event_sched_out+0x214/0x6f0
group_sched_out+0xd0/0x270
ctx_sched_out+0x2ec/0x518
__perf_event_task_sched_out+0x4fc/0xe6c
__schedule+0x1094/0x16a0
preempt_schedule_irq+0x88/0x170
arm64_preempt_schedule_irq+0xf0/0x18c
el1_irq+0xe8/0x180
perf_event_exec+0x4d8/0x56c
setup_new_exec+0x204/0x400
load_elf_binary+0x72c/0x18c0
search_binary_handler+0x13c/0x420
load_script+0x500/0x6c4
search_binary_handler+0x13c/0x420
exec_binprm+0x118/0x654
__do_execve_file+0x77c/0xba4
__arm64_compat_sys_execve+0x98/0xac
el0_svc_common+0x1f8/0x5e0
el0_svc_compat_handler+0x84/0xb0
el0_svc_compat+0x10/0x50
The buggy address belongs to the variable:
barrier_pkt+0x10/0x40
Memory state around the buggy address:
ffffffd05b7d0f00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
ffffffd05b7d0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffd05b7d1000: 00 00 00 00 00 00 fa fa fa fa fa fa 00 00 00 03
^
ffffffd05b7d1080: fa fa fa fa 00 02 fa fa fa fa fa fa 03 fa fa fa
ffffffd05b7d1100: fa fa fa fa 00 00 00 00 05 fa fa fa fa fa fa fa
==================================================================
Link: https://lore.kernel.org/r/20210505093430.18445-1-saiprakash.ranjan@codeaurora.org
Fixes: 0c3fc4d5fa ("coresight: Add barrier packet for synchronisation")
Cc: stable@vger.kernel.org
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210614175901.532683-6-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There was a report of NULL pointer dereference in ETF enable
path for perf CS mode with PID monitoring. It is almost 100%
reproducible when the process to monitor is something very
active such as chrome and with ETF as the sink and not ETR.
Currently in a bid to find the pid, the owner is dereferenced
via task_pid_nr() call in tmc_enable_etf_sink_perf() and with
owner being NULL, we get a NULL pointer dereference.
Looking at the ETR and other places in the kernel, ETF and the
ETB are the only places trying to dereference the task(owner)
in tmc_enable_etf_sink_perf() which is also called from the
sched_in path as in the call trace. Owner(task) is NULL even
in the case of ETR in tmc_enable_etr_sink_perf(), but since we
cache the PID in alloc_buffer() callback and it is done as part
of etm_setup_aux() when allocating buffer for ETR sink, we never
dereference this NULL pointer and we are safe. So lets do the
same thing with ETF and cache the PID to which the cs_buffer
belongs in tmc_alloc_etf_buffer() as done for ETR. This will
also remove the unnecessary function calls(task_pid_nr()) since
we are caching the PID.
Easily reproducible running below:
perf record -e cs_etm/@tmc_etf0/ -N -p <pid>
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000548
Mem abort info:
ESR = 0x96000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
<snip>...
Call trace:
tmc_enable_etf_sink+0xe4/0x280
coresight_enable_path+0x168/0x1fc
etm_event_start+0x8c/0xf8
etm_event_add+0x38/0x54
event_sched_in+0x194/0x2ac
group_sched_in+0x54/0x12c
flexible_sched_in+0xd8/0x120
visit_groups_merge+0x100/0x16c
ctx_flexible_sched_in+0x50/0x74
ctx_sched_in+0xa4/0xa8
perf_event_sched_in+0x60/0x6c
perf_event_context_sched_in+0x98/0xe0
__perf_event_task_sched_in+0x5c/0xd8
finish_task_switch+0x184/0x1cc
schedule_tail+0x20/0xec
ret_from_fork+0x4/0x18
Fixes: 880af782c6 ("coresight: tmc-etf: Add support for CPU-wide trace scenarios")
Cc: stable@vger.kernel.org
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201127175256.1092685-10-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add coresight prefix to make it specific. It will be a export symbol.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-5-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On some QCOM platforms like SC7180, SDM845 and SM8150,
reading TMC mode register without proper coresight power
management can lead to async exceptions like the one in
the call trace below in tmc_read_prepare_etb(). This can
happen if the user tries to read the TMC etf data via
device node without setting up source and the sink first.
Fix this by having a check for coresight sysfs mode
before reading TMC mode management register.
Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 7 PID: 2605 Comm: hexdump Tainted: G S 5.4.30 #122
Call trace:
dump_backtrace+0x0/0x188
show_stack+0x20/0x2c
dump_stack+0xdc/0x144
panic+0x168/0x36c
panic+0x0/0x36c
arm64_serror_panic+0x78/0x84
do_serror+0x130/0x138
el1_error+0x84/0xf8
tmc_read_prepare_etb+0x88/0xb8
tmc_open+0x40/0xd8
misc_open+0x120/0x158
chrdev_open+0xb8/0x1a4
do_dentry_open+0x268/0x3a0
vfs_open+0x34/0x40
path_openat+0x39c/0xdf4
do_filp_open+0x90/0x10c
do_sys_open+0x150/0x3e8
__arm64_compat_sys_openat+0x28/0x34
el0_svc_common+0xa8/0x160
el0_svc_compat_handler+0x2c/0x38
el0_svc_compat+0x8/0x10
Fixes: 4525412a50 ("coresight: tmc: making prepare/unprepare functions generic")
Reported-by: Stephen Boyd <swboyd@chromium.org>
Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-14-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When tracing etm data of multiple threads on multiple cpus through perf
interface, some link devices are shared between paths of different cpus.
It creates race conditions when different cpus wants to enable/disable
the same link device at the same time.
Example 1:
Two cpus want to enable different ports of a coresight funnel, thus
calling the funnel enable operation at the same time. But the funnel
enable operation isn't reentrantable.
Example 2:
For an enabled coresight dynamic replicator with refcnt=1, one cpu wants
to disable it, while another cpu wants to enable it. Ideally we still have
an enabled replicator with refcnt=1 at the end. But in reality the result
is uncertain.
Since coresight devices claim themselves when enabled for self-hosted
usage, the race conditions above usually make the link devices not usable
after many cycles.
To fix the race conditions, this patch uses spinlocks to serialize
enabling/disabling link devices.
Fixes: a06ae8609b ("coresight: add CoreSight core layer framework")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: stable <stable@vger.kernel.org> # 5.3
Link: https://lore.kernel.org/r/20191104181251.26732-14-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the computation of a memory mask representing the width of the memory
bus into a function so that it can be re-used by the ETR driver.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20190829202842.580-16-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During a perf session we try to allocate buffers on the "node" associated
with the CPU the event is bound to. If it is not bound to a CPU, we
use the current CPU node, using smp_processor_id(). However this is unsafe
in a pre-emptible context and could generate the splats as below :
BUG: using smp_processor_id() in preemptible [00000000] code: perf/2544
caller is tmc_alloc_etf_buffer+0x5c/0x60
CPU: 2 PID: 2544 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019
Call trace:
dump_backtrace+0x0/0x150
show_stack+0x14/0x20
dump_stack+0x9c/0xc4
debug_smp_processor_id+0x10c/0x110
tmc_alloc_etf_buffer+0x5c/0x60
etm_setup_aux+0x1c4/0x230
rb_alloc_aux+0x1b8/0x2b8
perf_mmap+0x35c/0x478
mmap_region+0x34c/0x4f0
do_mmap+0x2d8/0x418
vm_mmap_pgoff+0xd0/0xf8
ksys_mmap_pgoff+0x88/0xf8
__arm64_sys_mmap+0x28/0x38
el0_svc_handler+0xd8/0x138
el0_svc+0x8/0xc
Use NUMA_NO_NODE hint instead of using the current node for events
not bound to CPUs.
Fixes: 2e499bbc1a ("coresight: tmc: implementing TMC-ETF AUX space API")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: stable <stable@vger.kernel.org> # 4.7+
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190620221237.3536-4-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation to use a consistent device naming scheme,
clean up the device link tracking in replicator driver.
Use the "coresight" device instead of the "real" parent device
for all internal purposes. All other requests (e.g, power management,
DMA operations) must use the "real" device which is the parent device.
Since the CATU driver also uses the TMC-SG infrastructure, update
the callers to ensure they pass the appropriate device argument
for the tables.
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>
This patch avoids setting the truncated flag when operating in snapshot
mode since the trace buffer is expected to be truncated and discontinuous
from one snapshot to another. Moreover when the truncated flag is set
the perf core stops enabling the event, waiting for user space to consume
the data. In snapshot mode this is clearly not what we want since it
results in stale data.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When working in snapshot mode function perf_aux_output_begin()
does not set the handle->size because the size is expected to be
deduced by the placement of the "head" and "old" pointers in user
space. As such there is no point in trying to adjust the amount
of data to copy to the ring buffer.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unify amongst sink drivers how the AUX ring buffer head is communicated
to user space. That way the same algorithm in user space can be used to
determine where the latest data is and how much of it to access.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support for CPU-wide trace scenarios by making sure that
only the sources monitoring the same process have access to a common sink.
Because the sink is shared between sources, the first source to use the
sink switches it on while the last one does the cleanup. Any attempt to
modify the HW is overlooked for as long as more than one source is using
a sink.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make struct perf_event available to sink buffer allocation functions in
order to use the pid they carry to allocate and free buffer memory along
with regimenting access to what source a sink can collect data for.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When operating in CPU-wide trace scenarios and working with an N:1
source/sink HW topology, update() functions need to be made atomic
in order to avoid racing with start and stop operations.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When disabling a sink the reference counter ensures the operation goes
through if nobody else is using it. As such if drvdata::mode is already
set do CS_MODE_DISABLED, it is an error and should be reported as such.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When operating in CPU-wide mode with an N:1 source/sink HW topology,
multiple CPUs can access a sink concurrently. As such reference counting
needs to happen when the device's spinlock is held to avoid racing with
other operations (start(), update(), stop()), such as:
session A Session B
----- -------
enable_sink
atomic_inc(refcount) = 1
...
atomic_dec(refcount) = 0 enable_sink
if (refcount == 0) disable_sink
atomic_inc()
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation to handle device reference counting inside of the sink
drivers, add a return code to the sink::disable() operation so that
proper action can be taken if a sink has not been disabled.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch rectifies the sequence of events in function
tmc_etb_disable_hw() by disabling the HW first and then releasing the
CLAIM tag. Otherwise we could be corrupting the configuration done by an
external agent that would have claimed the device after we have released
it.
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>
Use CLAIM tags to make sure the device is available for use.
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>
Prepare to handle errors in enabling the hardware and
report it back to the core driver.
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>
>From the comment in the code, it claims the requirement for byte-address
alignment for RRP register: 'for 32-bit, 64-bit and 128-bit wide trace
memory, the four LSBs must be 0s. For 256-bit wide trace memory, the
five LSBs must be 0s'. This isn't consistent with the program, the
program sets five LSBs as zeros for 32/64/128-bit wide trace memory and
set six LSBs zeros for 256-bit wide trace memory.
After checking with the CoreSight Trace Memory Controller technical
reference manual (ARM DDI 0461B, section 3.3.4 RAM Read Pointer
Register), it proves the comment is right and the program does wrong
setting.
This patch fixes byte-address alignment for RRP by following correct
definition in the technical reference manual.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In ETB dump function tmc_etb_dump_hw() it has nested loops. The second
level loop is to iterate index in the range [0 .. drvdata->memwidth);
but the index isn't really used in the code, thus the second level
loop is useless.
This patch is to remove the second level loop; the refactor also reduces
indentation and we can use 'break' to replace 'goto' tag.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In coresight perf mode, we need to prepare the sink before
starting a session, which is done via set_buffer call back.
We then proceed to enable the tracing. If we fail to start
the session successfully, we leave the sink configuration
unchanged. In order to make the operation atomic and to
avoid yet another call back to clear the buffer, we get
rid of the "set_buffer" call back and pass the buffer details
via enable() call back to the sink.
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>
Right now we issue an update_buffer() and reset_buffer() call backs
in succession when we stop tracing an event. The update_buffer is
supposed to check the status of the buffer and make sure the ring buffer
is updated with the trace data. And we store information about the
size of the data collected only to be consumed by the reset_buffer
callback which always follows the update_buffer. This was originally
designed for handling future IPs which could trigger a buffer overflow
interrupt. This patch gets rid of the reset_buffer callback altogether
and performs the actions in update_buffer, making it return the size
collected. We can always add the support for handling the overflow
interrupt case later.
This removes some not-so pretty hack (storing the new head in the
size field for snapshot mode) and cleans it up a little bit.
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>
Convert component enable/disable messages from dev_info to dev_dbg.
When used with perf, the components in the paths are enabled/disabled
during each schedule of the run, which can flood the dmesg with these
messages. Moreover, they are only useful for debug purposes. So,
convert such messages to dev_dbg() which can be turned on as
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>
Right now we open code filling the trace buffer with synchronization
packets when the circular buffer wraps around in different drivers.
Move this to a common place. While at it, clean up the barrier_pkt
array to strip off the trailing '\0'.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@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>
At the moment we adjust the buffer pointers for reading the trace
data via misc device in the common code for ETF/ETB and ETR. Since
we are going to change how we manage the buffer for ETR, let us
move the buffer manipulation to the respective driver files, hiding
it from the common code. We do so by adding type specific helpers
for finding the length of data and the pointer to the buffer,
for a given length at a file position.
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>
Moving all kernel side CoreSight framework and drivers to SPDX identifier.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coresight TMC splits 64bit registers into a pair of 32bit registers
(e.g DBA, RRP, RWP). Provide helpers to read/write to these registers.
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>
When a buffer overflow happens the synchronisation patckets usually
present at the beginning of the buffer are lost, a situation that
prevents the decoder from knowing the context of the traces being
decoded.
This patch adds a barrier packet to be used by sink IPs when a buffer
overflow condition is detected. These barrier packets are then used
by the decoding library as markers to force re-synchronisation.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many conditions may cause synchronisation to be lost when updating
the perf ring buffer but the end result is still the same: synchronisation
is lost. As such there is no need to increment the lost count for each
condition, just once will suffice.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In current code the output logs are not well symmetric for sink and link
enabling and disabling. This patch is to fix that so can output paired
logs.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for adding more flags to perf AUX records, introduce a
separate API for setting the flags for a session, rather than appending
more bool arguments to perf_aux_output_end. This allows to set each
flag at the time a corresponding condition is detected, instead of
tracking it in each driver's private state.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170220133352.17995-3-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Get rid of the superfluous mode parameter and the check for
the mode in tmc_etX_enable_sink_{perf/sysfs}. While at it, also
remove the unnecessary WARN_ON() checks.
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>
The mode of operation of the TMC tracked in drvdata->mode is defined
as a local_t type. This is always checked and modified under the
drvdata->spinlock and hence we don't need local_t for it and the
unnecessary synchronisation instructions that comes with it. This
change makes the code a bit more cleaner.
Also fixes the order in which we update the drvdata->mode to
CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
which in turn depends on the mode to decide whether to dump the
trace to a buffer.
Applies on mathieu's coresight/next tree [1]
https://git.linaro.org/kernel/coresight.git next
Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
