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9cae77cf |
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29-Jan-2024 |
James Clark <james.clark@arm.com> |
coresight: Move mode to struct coresight_device Most devices use mode, so move the mode definition out of the individual devices and up to the Coresight device. This will allow the core code to also know the mode which will be useful in a later commit. This also fixes the inconsistency of the documentation of the mode field on the individual device types. For example ETB10 had "this ETB is being used". Two devices didn't require an atomic mode type, so these usages have been converted to atomic_get() and atomic_set() only to make it compile, but the documentation of the field in struct coresight_device explains this type of usage. In the future, manipulation of the mode could be completely moved out of the individual devices and into the core code because it's almost all duplicate code, and this change is a step towards that. Signed-off-by: James Clark <james.clark@arm.com> Link: https://lore.kernel.org/r/20240129154050.569566-5-james.clark@arm.com Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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b8411287 |
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14-Nov-2023 |
Junhao He <hejunhao3@huawei.com> |
coresight: ultrasoc-smb: Fix sleep while close preempt in enable_smb When we to enable the SMB by perf, the perf sched will call perf_ctx_lock() to close system preempt in event_function_call(). But SMB::enable_smb() use mutex to lock the critical section, which may sleep. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 153023, name: perf 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): [<ffffa2983f5c5f40>] copy_process+0xae8/0x2b48 softirqs last enabled at (0): [<ffffa2983f5c5f40>] copy_process+0xae8/0x2b48 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 2 PID: 153023 Comm: perf Kdump: loaded Tainted: G W O 6.5.0-rc4+ #1 Call trace: ... __mutex_lock+0xbc/0xa70 mutex_lock_nested+0x34/0x48 smb_update_buffer+0x58/0x360 [ultrasoc_smb] etm_event_stop+0x204/0x2d8 [coresight] etm_event_del+0x1c/0x30 [coresight] event_sched_out+0x17c/0x3b8 group_sched_out.part.0+0x5c/0x208 __perf_event_disable+0x15c/0x210 event_function+0xe0/0x230 remote_function+0xb4/0xe8 generic_exec_single+0x160/0x268 smp_call_function_single+0x20c/0x2a0 event_function_call+0x20c/0x220 _perf_event_disable+0x5c/0x90 perf_event_for_each_child+0x58/0xc0 _perf_ioctl+0x34c/0x1250 perf_ioctl+0x64/0x98 ... Use spinlock to replace mutex to control driver data access to one at a time. The function copy_to_user() may sleep, it cannot be in a spinlock context, so we can't simply replace it in smb_read(). But we can ensure that only one user gets the SMB device fd by smb_open(), so remove the locks from smb_read() and buffer synchronization is guaranteed by the user. Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer driver") Signed-off-by: Junhao He <hejunhao3@huawei.com> Reviewed-by: James Clark <james.clark@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20231114133346.30489-2-hejunhao3@huawei.com
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9fa36828 |
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25-Apr-2023 |
James Clark <james.clark@arm.com> |
coresight: Use enum type for cs_mode wherever possible mode is stored as a local_t, but it is also passed around a lot as a plain u32, so use the correct type wherever local_t isn't currently used. This helps a little bit with readability. Reviewed-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: James Clark <james.clark@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20230425143542.2305069-3-james.clark@arm.com
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06f5c292 |
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14-Jan-2023 |
Qi Liu <liuqi115@huawei.com> |
drivers/coresight: Add UltraSoc System Memory Buffer driver Add driver for UltraSoc SMB(System Memory Buffer) device. SMB provides a way to buffer messages from ETM, and store these "CPU instructions trace" in system memory. The SMB device is identifier as ACPI HID "HISI03A1". Device system memory address resources are allocated using the _CRS method and buffer modes is the circular buffer mode. SMB is developed by UltraSoc technology, which is acquired by Siemens, and we still use "UltraSoc" to name driver. Signed-off-by: Qi Liu <liuqi115@huawei.com> Signed-off-by: Junhao He <hejunhao3@huawei.com> Tested-by: JunHao He <hejunhao3@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20230114101302.62320-2-hejunhao3@huawei.com
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