| @@ -769,6 +769,171 @@ void coresight_release_path(struct list_head *path) · 768 unmodified lines |
| 769 | 769 | path = NULL; |
| 770 | 770 | } |
| 771 | 771 | |
| 772 | +/* return true if the device is a suitable type for a default sink */ |
| 773 | +static inline bool coresight_is_def_sink_type(struct coresight_device *csdev) |
| 774 | +{ |
| 775 | + /* sink & correct subtype */ |
| 776 | + if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) || |
| 777 | + (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) && |
| 778 | + (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER)) |
| 779 | + return true; |
| 780 | + return false; |
| 781 | +} |
| 782 | + |
| 783 | +/** |
| 784 | + * coresight_select_best_sink - return the best sink for use as default from |
| 785 | + * the two provided. |
| 786 | + * |
| 787 | + * @sink: current best sink. |
| 788 | + * @depth: search depth where current sink was found. |
| 789 | + * @new_sink: new sink for comparison with current sink. |
| 790 | + * @new_depth: search depth where new sink was found. |
| 791 | + * |
| 792 | + * Sinks prioritised according to coresight_dev_subtype_sink, with only |
| 793 | + * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used. |
| 794 | + * |
| 795 | + * Where two sinks of equal priority are found, the sink closest to the |
| 796 | + * source is used (smallest search depth). |
| 797 | + * |
| 798 | + * return @new_sink & update @depth if better than @sink, else return @sink. |
| 799 | + */ |
| 800 | +static struct coresight_device * |
| 801 | +coresight_select_best_sink(struct coresight_device *sink, int *depth, |
| 802 | + struct coresight_device *new_sink, int new_depth) |
| 803 | +{ |
| 804 | + bool update = false; |
| 805 | + |
| 806 | + if (!sink) { |
| 807 | + /* first found at this level */ |
| 808 | + update = true; |
| 809 | + } else if (new_sink->subtype.sink_subtype > |
| 810 | + sink->subtype.sink_subtype) { |
| 811 | + /* found better sink */ |
| 812 | + update = true; |
| 813 | + } else if ((new_sink->subtype.sink_subtype == |
| 814 | + sink->subtype.sink_subtype) && |
| 815 | + (*depth > new_depth)) { |
| 816 | + /* found same but closer sink */ |
| 817 | + update = true; |
| 818 | + } |
| 819 | + |
| 820 | + if (update) |
| 821 | + *depth = new_depth; |
| 822 | + return update ? new_sink : sink; |
| 823 | +} |
| 824 | + |
| 825 | +/** |
| 826 | + * coresight_find_sink - recursive function to walk trace connections from |
| 827 | + * source to find a suitable default sink. |
| 828 | + * |
| 829 | + * @csdev: source / current device to check. |
| 830 | + * @depth: [in] search depth of calling dev, [out] depth of found sink. |
| 831 | + * |
| 832 | + * This will walk the connection path from a source (ETM) till a suitable |
| 833 | + * sink is encountered and return that sink to the original caller. |
| 834 | + * |
| 835 | + * If current device is a plain sink return that & depth, otherwise recursively |
| 836 | + * call child connections looking for a sink. Select best possible using |
| 837 | + * coresight_select_best_sink. |
| 838 | + * |
| 839 | + * return best sink found, or NULL if not found at this node or child nodes. |
| 840 | + */ |
| 841 | +static struct coresight_device * |
| 842 | +coresight_find_sink(struct coresight_device *csdev, int *depth) |
| 843 | +{ |
| 844 | + int i, curr_depth = *depth + 1, found_depth = 0; |
| 845 | + struct coresight_device *found_sink = NULL; |
| 846 | + |
| 847 | + if (coresight_is_def_sink_type(csdev)) { |
| 848 | + found_depth = curr_depth; |
| 849 | + found_sink = csdev; |
| 850 | + if (csdev->type == CORESIGHT_DEV_TYPE_SINK) |
| 851 | + goto return_def_sink; |
| 852 | + /* look past LINKSINK for something better */ |
| 853 | + } |
| 854 | + |
| 855 | + /* |
| 856 | + * Not a sink we want - or possible child sink may be better. |
| 857 | + * recursively explore each port found on this element. |
| 858 | + */ |
| 859 | + for (i = 0; i < csdev->pdata->nr_outport; i++) { |
| 860 | + struct coresight_device *child_dev, *sink = NULL; |
| 861 | + int child_depth = curr_depth; |
| 862 | + |
| 863 | + child_dev = csdev->pdata->conns[i].child_dev; |
| 864 | + if (child_dev) |
| 865 | + sink = coresight_find_sink(child_dev, &child_depth); |
| 866 | + |
| 867 | + if (sink) |
| 868 | + found_sink = coresight_select_best_sink(found_sink, |
| 869 | + &found_depth, |
| 870 | + sink, |
| 871 | + child_depth); |
| 872 | + } |
| 873 | + |
| 874 | +return_def_sink: |
| 875 | + /* return found sink and depth */ |
| 876 | + if (found_sink) |
| 877 | + *depth = found_depth; |
| 878 | + return found_sink; |
| 879 | +} |
| 880 | + |
| 881 | +/** |
| 882 | + * coresight_find_default_sink: Find a sink suitable for use as a |
| 883 | + * default sink. |
| 884 | + * |
| 885 | + * @csdev: starting source to find a connected sink. |
| 886 | + * |
| 887 | + * Walks connections graph looking for a suitable sink to enable for the |
| 888 | + * supplied source. Uses CoreSight device subtypes and distance from source |
| 889 | + * to select the best sink. |
| 890 | + * |
| 891 | + * If a sink is found, then the default sink for this device is set and |
| 892 | + * will be automatically used in future. |
| 893 | + * |
| 894 | + * Used in cases where the CoreSight user (perf / sysfs) has not selected a |
| 895 | + * sink. |
| 896 | + */ |
| 897 | +struct coresight_device * |
| 898 | +coresight_find_default_sink(struct coresight_device *csdev) |
| 899 | +{ |
| 900 | + int depth = 0; |
| 901 | + |
| 902 | + /* look for a default sink if we have not found for this device */ |
| 903 | + if (!csdev->def_sink) |
| 904 | + csdev->def_sink = coresight_find_sink(csdev, &depth); |
| 905 | + return csdev->def_sink; |
| 906 | +} |
| 907 | + |
| 908 | +static int coresight_remove_sink_ref(struct device *dev, void *data) |
| 909 | +{ |
| 910 | + struct coresight_device *sink = data; |
| 911 | + struct coresight_device *source = to_coresight_device(dev); |
| 912 | + |
| 913 | + if (source->def_sink == sink) |
| 914 | + source->def_sink = NULL; |
| 915 | + return 0; |
| 916 | +} |
| 917 | + |
| 918 | +/** |
| 919 | + * coresight_clear_default_sink: Remove all default sink references to the |
| 920 | + * supplied sink. |
| 921 | + * |
| 922 | + * If supplied device is a sink, then check all the bus devices and clear |
| 923 | + * out all the references to this sink from the coresight_device def_sink |
| 924 | + * parameter. |
| 925 | + * |
| 926 | + * @csdev: coresight sink - remove references to this from all sources. |
| 927 | + */ |
| 928 | +static void coresight_clear_default_sink(struct coresight_device *csdev) |
| 929 | +{ |
| 930 | + if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) || |
| 931 | + (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) { |
| 932 | + bus_for_each_dev(&coresight_bustype, NULL, csdev, |
| 933 | + coresight_remove_sink_ref); |
| 934 | + } |
| 935 | +} |
| 936 | + |
| 772 | 937 | /** coresight_validate_source - make sure a source has the right credentials |
| 773 | 938 | * @csdev: the device structure for a source. |
| 774 | 939 | * @function: the function this was called from. |
| @@ -1358,6 +1523,7 @@ void coresight_unregister(struct coresight_device *csdev) · 583 unmodified lines |
| 1358 | 1523 | etm_perf_del_symlink_sink(csdev); |
| 1359 | 1524 | /* Remove references of that device in the topology */ |
| 1360 | 1525 | coresight_remove_conns(csdev); |
| 1526 | + coresight_clear_default_sink(csdev); |
| 1361 | 1527 | coresight_release_platform_data(csdev, csdev->pdata); |
| 1362 | 1528 | device_unregister(&csdev->dev); |
| 1363 | 1529 | } |