This commit extends control over CoreSight components on an activated path during CPU PM.
An activated path is recorded in the 'path' field of coresight_device structure. The patch pointer is cleared when the path is disabled. Traverses the links on the path to disable and re-enable components during CPU low-power modes.
Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 8f565bb3c535..075d485dcea5 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -596,6 +596,94 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode, goto out; }
+static int coresight_save_path(struct coresight_path *path) +{ + u32 type; + struct coresight_node *nd; + struct coresight_device *source, *sink; + + if (!path) + return 0; + + source = coresight_get_source(path); + + /* + * Do a sanity check as the source device must have been enabled when + * run at here. + */ + if (coresight_get_mode(source) == CS_MODE_DISABLED) + return -EINVAL; + + sink = coresight_get_sink(path); + + /* + * Disable links. Deliberately to skip disabling the sink to avoid + * latency. + */ + nd = list_first_entry(&path->path_list, struct coresight_node, link); + list_for_each_entry_continue(nd, &path->path_list, link) { + struct coresight_device *csdev, *parent, *child; + + csdev = nd->csdev; + type = csdev->type; + + /* Adjust type for LINKSINK */ + if (type == CORESIGHT_DEV_TYPE_LINKSINK) + type = (csdev == sink) ? CORESIGHT_DEV_TYPE_SINK : + CORESIGHT_DEV_TYPE_LINK; + + if (type != CORESIGHT_DEV_TYPE_LINK) + continue; + + parent = list_prev_entry(nd, link)->csdev; + child = list_next_entry(nd, link)->csdev; + coresight_disable_link(csdev, parent, child, source); + } + + return 0; +} + +static void coresight_restore_path(struct coresight_path *path) +{ + int ret; + u32 type; + struct coresight_device *source, *sink; + struct coresight_node *nd; + + if (!path) + return; + + source = coresight_get_source(path); + if (coresight_get_mode(source) == CS_MODE_DISABLED) + return; + + sink = coresight_get_sink(path); + + list_for_each_entry_reverse(nd, &path->path_list, link) { + struct coresight_device *csdev, *parent, *child; + + csdev = nd->csdev; + type = csdev->type; + + if (type == CORESIGHT_DEV_TYPE_LINKSINK) + type = (csdev == sink) ? CORESIGHT_DEV_TYPE_SINK : + CORESIGHT_DEV_TYPE_LINK; + + if (type != CORESIGHT_DEV_TYPE_LINK) + continue; + + parent = list_prev_entry(nd, link)->csdev; + child = list_next_entry(nd, link)->csdev; + ret = coresight_enable_link(csdev, parent, child, + coresight_get_source(path)); + if (ret) { + dev_err(&csdev->dev, "Failed to restore\n"); + coresight_disable_path_from(path, nd); + return; + } + } +} + struct coresight_device *coresight_get_sink(struct coresight_path *path) { struct coresight_device *csdev; @@ -1605,9 +1693,15 @@ static int coresight_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, case CPU_PM_ENTER: if (coresight_save_source(source)) return NOTIFY_BAD; + + if (coresight_save_path(source->path)) { + coresight_restore_source(source); + return NOTIFY_BAD; + } break; case CPU_PM_EXIT: case CPU_PM_ENTER_FAILED: + coresight_restore_path(source->path); coresight_restore_source(source); break; default: