enable_req_count is only ever accessed inside the spinlock, so to avoid
confusion that there are concurrent accesses and simplify the code,
change it to an int.
One access outside of the spinlock is in enable_show() which appears to
allow partially written data to be displayed between enable_req_count,
powered and enabled so move this one inside the spin lock too.
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-4-james.clark@arm.com
Writing 0 to the enable control repeatedly results in a negative value
for enable_req_count. After this, writing 1 to the enable control
appears to not work until the count returns to positive.
Change it so that it's impossible for enable_req_count to be < 0.
Return an error to indicate that the disable request was invalid.
Fixes: 835d722ba1 ("coresight: cti: Initial CoreSight CTI Driver")
Tested-by: Jinlong Mao <quic_jinlmao@quicinc.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-2-james.clark@arm.com
cti_enable_hw() and cti_disable_hw() are called from an atomic context
so shouldn't use runtime PM because it can result in a sleep when
communicating with firmware.
Since commit 3c66563378 ("Revert "firmware: arm_scmi: Add clock
management to the SCMI power domain""), this causes a hang on Juno when
running the Perf Coresight tests or running this command:
perf record -e cs_etm//u -- ls
This was also missed until the revert commit because pm_runtime_put()
was called with the wrong device until commit 692c9a499b ("coresight:
cti: Correct the parameter for pm_runtime_put")
With lock and scheduler debugging enabled the following is output:
coresight cti_sys0: cti_enable_hw -- dev:cti_sys0 parent: 20020000.cti
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1151
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 330, name: perf-exec
preempt_count: 2, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last enabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 3 PID: 330 Comm: perf-exec Not tainted 6.0.0-00053-g042116d99298 #7
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Sep 13 2022
Call trace:
dump_backtrace+0x134/0x140
show_stack+0x20/0x58
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
__might_resched+0x180/0x228
__might_sleep+0x50/0x88
__pm_runtime_resume+0xac/0xb0
cti_enable+0x44/0x120
coresight_control_assoc_ectdev+0xc0/0x150
coresight_enable_path+0xb4/0x288
etm_event_start+0x138/0x170
etm_event_add+0x48/0x70
event_sched_in.isra.122+0xb4/0x280
merge_sched_in+0x1fc/0x3d0
visit_groups_merge.constprop.137+0x16c/0x4b0
ctx_sched_in+0x114/0x1f0
perf_event_sched_in+0x60/0x90
ctx_resched+0x68/0xb0
perf_event_exec+0x138/0x508
begin_new_exec+0x52c/0xd40
load_elf_binary+0x6b8/0x17d0
bprm_execve+0x360/0x7f8
do_execveat_common.isra.47+0x218/0x238
__arm64_sys_execve+0x48/0x60
invoke_syscall+0x4c/0x110
el0_svc_common.constprop.4+0xfc/0x120
do_el0_svc+0x34/0xc0
el0_svc+0x40/0x98
el0t_64_sync_handler+0x98/0xc0
el0t_64_sync+0x170/0x174
Fix the issue by removing the runtime PM calls completely. They are not
needed here because it must have already been done when building the
path for a trace.
Fixes: 835d722ba1 ("coresight: cti: Initial CoreSight CTI Driver")
Cc: stable <stable@kernel.org>
Reported-by: Aishwarya TCV <Aishwarya.TCV@arm.com>
Reported-by: Cristian Marussi <Cristian.Marussi@arm.com>
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
[ Fix build warnings ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20221025131032.1149459-1-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cti_enable_hw() and cti_disable_hw() are called from an atomic context
so shouldn't use runtime PM because it can result in a sleep when
communicating with firmware.
Since commit 3c66563378 ("Revert "firmware: arm_scmi: Add clock
management to the SCMI power domain""), this causes a hang on Juno when
running the Perf Coresight tests or running this command:
perf record -e cs_etm//u -- ls
This was also missed until the revert commit because pm_runtime_put()
was called with the wrong device until commit 692c9a499b ("coresight:
cti: Correct the parameter for pm_runtime_put")
With lock and scheduler debugging enabled the following is output:
coresight cti_sys0: cti_enable_hw -- dev:cti_sys0 parent: 20020000.cti
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1151
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 330, name: perf-exec
preempt_count: 2, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last enabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 3 PID: 330 Comm: perf-exec Not tainted 6.0.0-00053-g042116d99298 #7
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Sep 13 2022
Call trace:
dump_backtrace+0x134/0x140
show_stack+0x20/0x58
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
__might_resched+0x180/0x228
__might_sleep+0x50/0x88
__pm_runtime_resume+0xac/0xb0
cti_enable+0x44/0x120
coresight_control_assoc_ectdev+0xc0/0x150
coresight_enable_path+0xb4/0x288
etm_event_start+0x138/0x170
etm_event_add+0x48/0x70
event_sched_in.isra.122+0xb4/0x280
merge_sched_in+0x1fc/0x3d0
visit_groups_merge.constprop.137+0x16c/0x4b0
ctx_sched_in+0x114/0x1f0
perf_event_sched_in+0x60/0x90
ctx_resched+0x68/0xb0
perf_event_exec+0x138/0x508
begin_new_exec+0x52c/0xd40
load_elf_binary+0x6b8/0x17d0
bprm_execve+0x360/0x7f8
do_execveat_common.isra.47+0x218/0x238
__arm64_sys_execve+0x48/0x60
invoke_syscall+0x4c/0x110
el0_svc_common.constprop.4+0xfc/0x120
do_el0_svc+0x34/0xc0
el0_svc+0x40/0x98
el0t_64_sync_handler+0x98/0xc0
el0t_64_sync+0x170/0x174
Fix the issue by removing the runtime PM calls completely. They are not
needed here because it must have already been done when building the
path for a trace.
Fixes: 835d722ba1 ("coresight: cti: Initial CoreSight CTI Driver")
Reported-by: Aishwarya TCV <Aishwarya.TCV@arm.com>
Reported-by: Cristian Marussi <Cristian.Marussi@arm.com>
Suggested-by: Suzuki Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20221005131452.1506328-1-james.clark@arm.com
With lockdeps enabled, we get the following warning:
======================================================
WARNING: possible circular locking dependency detected
------------------------------------------------------
kworker/u12:1/53 is trying to acquire lock:
ffff80000adce220 (coresight_mutex){+.+.}-{4:4}, at: coresight_set_assoc_ectdev_mutex+0x3c/0x5c
but task is already holding lock:
ffff80000add1f60 (ect_mutex){+.+.}-{4:4}, at: cti_probe+0x318/0x394
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (ect_mutex){+.+.}-{4:4}:
__mutex_lock_common+0xd8/0xe60
mutex_lock_nested+0x44/0x50
cti_add_assoc_to_csdev+0x4c/0x184
coresight_register+0x2f0/0x314
tmc_probe+0x33c/0x414
-> #0 (coresight_mutex){+.+.}-{4:4}:
__lock_acquire+0x1a20/0x32d0
lock_acquire+0x160/0x308
__mutex_lock_common+0xd8/0xe60
mutex_lock_nested+0x44/0x50
coresight_set_assoc_ectdev_mutex+0x3c/0x5c
cti_update_conn_xrefs+0x6c/0xf8
cti_probe+0x33c/0x394
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(ect_mutex);
lock(coresight_mutex);
lock(ect_mutex);
lock(coresight_mutex);
*** DEADLOCK ***
4 locks held by kworker/u12:1/53:
#0: ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1fc/0x63c
#1: (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x228/0x63c
#2: (&dev->mutex){....}-{4:4}, at: __device_attach+0x48/0x1a8
#3: (ect_mutex){+.+.}-{4:4}, at: cti_probe+0x318/0x394
To fix the same, call cti_add_assoc_to_csdev without the holding
coresight_mutex and confine the locking while setting the associated
ect / cti device using coresight_set_assoc_ectdev_mutex().
Fixes: 177af8285b ("coresight: cti: Enable CTI associated with devices")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220721130329.3787211-1-sudeep.holla@arm.com
The input parameter of the function pm_runtime_put should be the
same in the function cti_enable_hw and cti_disable_hw. The correct
parameter to use here should be dev->parent.
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Fixes: 835d722ba1 ("coresight: cti: Initial CoreSight CTI Driver")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1629365377-5937-1-git-send-email-quic_taozha@quicinc.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
This merges from linux-arm at 860660fd82 ("ARM: 9055/1: mailbox:
arm_mhuv2: make remove callback return void") into char-misc-next to get
the amba fixes from Uwe.
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are about to introduce support for sysreg access to ETMv4.4+
component. Since there are generic routines that access the
registers (e.g, CS_LOCK/UNLOCK , claim/disclaim operations, timeout)
and in order to preserve the logic of these operations at a
single place we introduce an abstraction layer for the accesses
to a given device.
Link: https://lore.kernel.org/r/20210110224850.1880240-4-suzuki.poulose@arm.com
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>
Link: https://lore.kernel.org/r/20210201181351.1475223-6-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All amba drivers return 0 in their remove callback. Together with the
driver core ignoring the return value anyhow, it doesn't make sense to
return a value here.
Change the remove prototype to return void, which makes it explicit that
returning an error value doesn't work as expected. This simplifies changing
the core remove callback to return void, too.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # for drivers/memory
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> # for hwtracing/coresight
Acked-By: Vinod Koul <vkoul@kernel.org> # for dmaengine
Acked-by: Guenter Roeck <linux@roeck-us.net> # for watchdog
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Takashi Iwai <tiwai@suse.de> # for sound
Acked-by: Vladimir Zapolskiy <vz@mleia.com> # for memory/pl172
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210126165835.687514-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Functions that are annotated __exit are discarded for built-in drivers,
but the .remove callback in a device driver must still be kept around
to allow bind/unbind operations.
There is now a linker warning for the discarded symbol references:
`tmc_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tmc-core.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tmc-core.o
`tpiu_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpiu.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpiu.o
`etb_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-etb10.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-etb10.o
`static_funnel_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-funnel.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-funnel.o
`dynamic_funnel_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-funnel.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-funnel.o
`static_replicator_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-replicator.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-replicator.o
`dynamic_replicator_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-replicator.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-replicator.o
`catu_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-catu.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-catu.o
Remove all those annotations.
Fixes: 8b0cf82677 ("coresight: stm: Allow to build coresight-stm as a module")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208182651.1597945-3-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow to build coresight-cti as a module, for ease of development.
- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to
be called coresight-cti by the Makefile
- add an cti_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
- move cti_remove_conn_xrefs to cti_remove since all sysfs links
have gone when system calls device_release.
Reviewed-by Mike Leach <mike.leach@linaro.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-22-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
James Clark