diff options
Diffstat (limited to 'include/linux/coresight.h')
| -rw-r--r-- | include/linux/coresight.h | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 6de59ce8ef8c..2b48be97fcd0 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -251,15 +251,11 @@ struct coresight_trace_id_map { * by @coresight_ops. * @access: Device i/o access abstraction for this device. * @dev: The device entity associated to this component. - * @mode: This tracer's mode, i.e sysFS, Perf or disabled. This is - * actually an 'enum cs_mode', but is stored in an atomic type. - * This is always accessed through local_read() and local_set(), - * but wherever it's done from within the Coresight device's lock, - * a non-atomic read would also work. This is the main point of - * synchronisation between code happening inside the sysfs mode's - * coresight_mutex and outside when running in Perf mode. A compare - * and exchange swap is done to atomically claim one mode or the - * other. + * @mode: The device mode, i.e sysFS, Perf or disabled. This is actually + * an 'enum cs_mode' but stored in an atomic type. Access is always + * through atomic APIs, ensuring SMP-safe synchronisation between + * racing from sysFS and Perf mode. A compare-and-exchange + * operation is done to atomically claim one mode or the other. * @refcnt: keep track of what is in use. Only access this outside of the * device's spinlock when the coresight_mutex held and mode == * CS_MODE_SYSFS. Otherwise it must be accessed from inside the @@ -288,7 +284,7 @@ struct coresight_device { const struct coresight_ops *ops; struct csdev_access access; struct device dev; - local_t mode; + atomic_t mode; int refcnt; bool orphan; /* sink specific fields */ @@ -332,12 +328,14 @@ static struct coresight_dev_list (var) = { \ /** * struct coresight_path - data needed by enable/disable path - * @path_list: path from source to sink. - * @trace_id: trace_id of the whole path. + * @path_list: path from source to sink. + * @trace_id: trace_id of the whole path. + * @handle: handle of the aux_event. */ struct coresight_path { - struct list_head path_list; - u8 trace_id; + struct list_head path_list; + u8 trace_id; + struct perf_output_handle *handle; }; enum cs_mode { @@ -365,7 +363,7 @@ enum cs_mode { */ struct coresight_ops_sink { int (*enable)(struct coresight_device *csdev, enum cs_mode mode, - void *data); + struct coresight_path *path); int (*disable)(struct coresight_device *csdev); void *(*alloc_buffer)(struct coresight_device *csdev, struct perf_event *event, void **pages, @@ -422,8 +420,9 @@ struct coresight_ops_source { */ struct coresight_ops_helper { int (*enable)(struct coresight_device *csdev, enum cs_mode mode, - void *data); - int (*disable)(struct coresight_device *csdev, void *data); + struct coresight_path *path); + int (*disable)(struct coresight_device *csdev, + struct coresight_path *path); }; @@ -621,13 +620,14 @@ static inline bool coresight_is_percpu_sink(struct coresight_device *csdev) static inline bool coresight_take_mode(struct coresight_device *csdev, enum cs_mode new_mode) { - return local_cmpxchg(&csdev->mode, CS_MODE_DISABLED, new_mode) == - CS_MODE_DISABLED; + int curr = CS_MODE_DISABLED; + + return atomic_try_cmpxchg_acquire(&csdev->mode, &curr, new_mode); } static inline enum cs_mode coresight_get_mode(struct coresight_device *csdev) { - return local_read(&csdev->mode); + return atomic_read_acquire(&csdev->mode); } static inline void coresight_set_mode(struct coresight_device *csdev, @@ -643,7 +643,7 @@ static inline void coresight_set_mode(struct coresight_device *csdev, WARN(new_mode != CS_MODE_DISABLED && current_mode != CS_MODE_DISABLED && current_mode != new_mode, "Device already in use\n"); - local_set(&csdev->mode, new_mode); + atomic_set_release(&csdev->mode, new_mode); } struct coresight_device *coresight_register(struct coresight_desc *desc); |