// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2012, The Linux Foundation. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coresight-etm-perf.h" #include "coresight-priv.h" #include "coresight-syscfg.h" static DEFINE_MUTEX(coresight_mutex); static DEFINE_PER_CPU(struct coresight_device *, csdev_sink); /** * struct coresight_node - elements of a path, from source to sink * @csdev: Address of an element. * @link: hook to the list. */ struct coresight_node { struct coresight_device *csdev; struct list_head link; }; /* * When operating Coresight drivers from the sysFS interface, only a single * path can exist from a tracer (associated to a CPU) to a sink. */ static DEFINE_PER_CPU(struct list_head *, tracer_path); /* * As of this writing only a single STM can be found in CS topologies. Since * there is no way to know if we'll ever see more and what kind of * configuration they will enact, for the time being only define a single path * for STM. */ static struct list_head *stm_path; /* * When losing synchronisation a new barrier packet needs to be inserted at the * beginning of the data collected in a buffer. That way the decoder knows that * it needs to look for another sync sequence. */ const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff}; EXPORT_SYMBOL_GPL(coresight_barrier_pkt); static const struct cti_assoc_op *cti_assoc_ops; void coresight_set_cti_ops(const struct cti_assoc_op *cti_op) { cti_assoc_ops = cti_op; } EXPORT_SYMBOL_GPL(coresight_set_cti_ops); void coresight_remove_cti_ops(void) { cti_assoc_ops = NULL; } EXPORT_SYMBOL_GPL(coresight_remove_cti_ops); void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev) { per_cpu(csdev_sink, cpu) = csdev; } EXPORT_SYMBOL_GPL(coresight_set_percpu_sink); struct coresight_device *coresight_get_percpu_sink(int cpu) { return per_cpu(csdev_sink, cpu); } EXPORT_SYMBOL_GPL(coresight_get_percpu_sink); static int coresight_id_match(struct device *dev, void *data) { int trace_id, i_trace_id; struct coresight_device *csdev, *i_csdev; csdev = data; i_csdev = to_coresight_device(dev); /* * No need to care about oneself and components that are not * sources or not enabled */ if (i_csdev == csdev || !i_csdev->enable || i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE) return 0; /* Get the source ID for both components */ trace_id = source_ops(csdev)->trace_id(csdev); i_trace_id = source_ops(i_csdev)->trace_id(i_csdev); /* All you need is one */ if (trace_id == i_trace_id) return 1; return 0; } static int coresight_source_is_unique(struct coresight_device *csdev) { int trace_id = source_ops(csdev)->trace_id(csdev); /* this shouldn't happen */ if (trace_id < 0) return 0; return !bus_for_each_dev(&coresight_bustype, NULL, csdev, coresight_id_match); } static int coresight_find_link_inport(struct coresight_device *csdev, struct coresight_device *parent) { int i; struct coresight_connection *conn; for (i = 0; i < parent->pdata->nr_outport; i++) { conn = &parent->pdata->conns[i]; if (conn->child_dev == csdev) return conn->child_port; } dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n", dev_name(&parent->dev), dev_name(&csdev->dev)); return -ENODEV; } static int coresight_find_link_outport(struct coresight_device *csdev, struct coresight_device *child) { int i; struct coresight_connection *conn; for (i = 0; i < csdev->pdata->nr_outport; i++) { conn = &csdev->pdata->conns[i]; if (conn->child_dev == child) return conn->outport; } dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n", dev_name(&csdev->dev), dev_name(&child->dev)); return -ENODEV; } static inline u32 coresight_read_claim_tags(struct coresight_device *csdev) { return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR); } static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev) { return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED; } static inline bool coresight_is_claimed_any(struct coresight_device *csdev) { return coresight_read_claim_tags(csdev) != 0; } static inline void coresight_set_claim_tags(struct coresight_device *csdev) { csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED, CORESIGHT_CLAIMSET); isb(); } static inline void coresight_clear_claim_tags(struct coresight_device *csdev) { csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED, CORESIGHT_CLAIMCLR); isb(); } /* * coresight_claim_device_unlocked : Claim the device for self-hosted usage * to prevent an external tool from touching this device. As per PSCI * standards, section "Preserving the execution context" => "Debug and Trace * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and * DBGCLAIM[0] is reserved for external tools. * * Called with CS_UNLOCKed for the component. * Returns : 0 on success */ int coresight_claim_device_unlocked(struct coresight_device *csdev) { if (WARN_ON(!csdev)) return -EINVAL; if (coresight_is_claimed_any(csdev)) return -EBUSY; coresight_set_claim_tags(csdev); if (coresight_is_claimed_self_hosted(csdev)) return 0; /* There was a race setting the tags, clean up and fail */ coresight_clear_claim_tags(csdev); return -EBUSY; } EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked); int coresight_claim_device(struct coresight_device *csdev) { int rc; if (WARN_ON(!csdev)) return -EINVAL; CS_UNLOCK(csdev->access.base); rc = coresight_claim_device_unlocked(csdev); CS_LOCK(csdev->access.base); return rc; } EXPORT_SYMBOL_GPL(coresight_claim_device); /* * coresight_disclaim_device_unlocked : Clear the claim tags for the device. * Called with CS_UNLOCKed for the component. */ void coresight_disclaim_device_unlocked(struct coresight_device *csdev) { if (WARN_ON(!csdev)) return; if (coresight_is_claimed_self_hosted(csdev)) coresight_clear_claim_tags(csdev); else /* * The external agent may have not honoured our claim * and has manipulated it. Or something else has seriously * gone wrong in our driver. */ WARN_ON_ONCE(1); } EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked); void coresight_disclaim_device(struct coresight_device *csdev) { if (WARN_ON(!csdev)) return; CS_UNLOCK(csdev->access.base); coresight_disclaim_device_unlocked(csdev); CS_LOCK(csdev->access.base); } EXPORT_SYMBOL_GPL(coresight_disclaim_device); /* enable or disable an associated CTI device of the supplied CS device */ static int coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable) { int ect_ret = 0; struct coresight_device *ect_csdev = csdev->ect_dev; struct module *mod; if (!ect_csdev) return 0; if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable)) return 0; mod = ect_csdev->dev.parent->driver->owner; if (enable) { if (try_module_get(mod)) { ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); if (ect_ret) { module_put(mod); } else { get_device(ect_csdev->dev.parent); csdev->ect_enabled = true; } } else ect_ret = -ENODEV; } else { if (csdev->ect_enabled) { ect_ret = ect_ops(ect_csdev)->disable(ect_csdev); put_device(ect_csdev->dev.parent); module_put(mod); csdev->ect_enabled = false; } } /* output warning if ECT enable is preventing trace operation */ if (ect_ret) dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n", dev_name(&ect_csdev->dev), enable ? "enable" : "disable"); return ect_ret; } /* * Set the associated ect / cti device while holding the coresight_mutex * to avoid a race with coresight_enable that may try to use this value. */ void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev, struct coresight_device *ect_csdev) { mutex_lock(&coresight_mutex); csdev->ect_dev = ect_csdev; mutex_unlock(&coresight_mutex); } EXPORT_SYMBOL_GPL(coresight_set_assoc_ectdev_mutex); static int coresight_enable_sink(struct coresight_device *csdev, u32 mode, void *data) { int ret; /* * We need to make sure the "new" session is compatible with the * existing "mode" of operation. */ if (!sink_ops(csdev)->enable) return -EINVAL; ret = coresight_control_assoc_ectdev(csdev, true); if (ret) return ret; ret = sink_ops(csdev)->enable(csdev, mode, data); if (ret) { coresight_control_assoc_ectdev(csdev, false); return ret; } csdev->enable = true; return 0; } static void coresight_disable_sink(struct coresight_device *csdev) { int ret; if (!sink_ops(csdev)->disable) return; ret = sink_ops(csdev)->disable(csdev); if (ret) return; coresight_control_assoc_ectdev(csdev, false); csdev->enable = false; } static int coresight_enable_link(struct coresight_device *csdev, struct coresight_device *parent, struct coresight_device *child) { int ret = 0; int link_subtype; int inport, outport; if (!parent || !child) return -EINVAL; inport = coresight_find_link_inport(csdev, parent); outport = coresight_find_link_outport(csdev, child); link_subtype = csdev->subtype.link_subtype; if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && inport < 0) return inport; if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0) return outport; if (link_ops(csdev)->enable) { ret = coresight_control_assoc_ectdev(csdev, true); if (!ret) { ret = link_ops(csdev)->enable(csdev, inport, outport); if (ret) coresight_control_assoc_ectdev(csdev, false); } } if (!ret) csdev->enable = true; return ret; } static void coresight_disable_link(struct coresight_device *csdev, struct coresight_device *parent, struct coresight_device *child) { int i, nr_conns; int link_subtype; int inport, outport; if (!parent || !child) return; inport = coresight_find_link_inport(csdev, parent); outport = coresight_find_link_outport(csdev, child); link_subtype = csdev->subtype.link_subtype; if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) { nr_conns = csdev->pdata->nr_inport; } else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) { nr_conns = csdev->pdata->nr_outport; } else { nr_conns = 1; } if (link_ops(csdev)->disable) { link_ops(csdev)->disable(csdev, inport, outport); coresight_control_assoc_ectdev(csdev, false); } for (i = 0; i < nr_conns; i++) if (atomic_read(&csdev->refcnt[i]) != 0) return; csdev->enable = false; } static int coresight_enable_source(struct coresight_device *csdev, u32 mode) { int ret; if (!coresight_source_is_unique(csdev)) { dev_warn(&csdev->dev, "traceID %d not unique\n", source_ops(csdev)->trace_id(csdev)); return -EINVAL; } if (!csdev->enable) { if (source_ops(csdev)->enable) { ret = coresight_control_assoc_ectdev(csdev, true); if (ret) return ret; ret = source_ops(csdev)->enable(csdev, NULL, mode); if (ret) { coresight_control_assoc_ectdev(csdev, false); return ret; } } csdev->enable = true; } atomic_inc(csdev->refcnt); return 0; } /** * coresight_disable_source - Drop the reference count by 1 and disable * the device if there are no users left. * * @csdev: The coresight device to disable * * Returns true if the device has been disabled. */ static bool coresight_disable_source(struct coresight_device *csdev) { if (atomic_dec_return(csdev->refcnt) == 0) { if (source_ops(csdev)->disable) source_ops(csdev)->disable(csdev, NULL); coresight_control_assoc_ectdev(csdev, false); csdev->enable = false; } return !csdev->enable; } /* * coresight_disable_path_from : Disable components in the given path beyond * @nd in the list. If @nd is NULL, all the components, except the SOURCE are * disabled. */ static void coresight_disable_path_from(struct list_head *path, struct coresight_node *nd) { u32 type; struct coresight_device *csdev, *parent, *child; if (!nd) nd = list_first_entry(path, struct coresight_node, link); list_for_each_entry_continue(nd, path, link) { csdev = nd->csdev; type = csdev->type; /* * ETF devices are tricky... They can be a link or a sink, * depending on how they are configured. If an ETF has been * "activated" it will be configured as a sink, otherwise * go ahead with the link configuration. */ if (type == CORESIGHT_DEV_TYPE_LINKSINK) type = (csdev == coresight_get_sink(path)) ? CORESIGHT_DEV_TYPE_SINK : CORESIGHT_DEV_TYPE_LINK; switch (type) { case CORESIGHT_DEV_TYPE_SINK: coresight_disable_sink(csdev); break; case CORESIGHT_DEV_TYPE_SOURCE: /* * We skip the first node in the path assuming that it * is the source. So we don't expect a source device in * the middle of a path. */ WARN_ON(1); break; case CORESIGHT_DEV_TYPE_LINK: parent = list_prev_entry(nd, link)->csdev; child = list_next_entry(nd, link)->csdev; coresight_disable_link(csdev, parent, child); break; default: break; } } } void coresight_disable_path(struct list_head *path) { coresight_disable_path_from(path, NULL); } EXPORT_SYMBOL_GPL(coresight_disable_path); int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data) { int ret = 0; u32 type; struct coresight_node *nd; struct coresight_device *csdev, *parent, *child; list_for_each_entry_reverse(nd, path, link) { csdev = nd->csdev; type = csdev->type; /* * ETF devices are tricky... They can be a link or a sink, * depending on how they are configured. If an ETF has been * "activated" it will be configured as a sink, otherwise * go ahead with the link configuration. */ if (type == CORESIGHT_DEV_TYPE_LINKSINK) type = (csdev == coresight_get_sink(path)) ? CORESIGHT_DEV_TYPE_SINK : CORESIGHT_DEV_TYPE_LINK; switch (type) { case CORESIGHT_DEV_TYPE_SINK: ret = coresight_enable_sink(csdev, mode, sink_data); /* * Sink is the first component turned on. If we * failed to enable the sink, there are no components * that need disabling. Disabling the path here * would mean we could disrupt an existing session. */ if (ret) goto out; break; case CORESIGHT_DEV_TYPE_SOURCE: /* sources are enabled from either sysFS or Perf */ break; case CORESIGHT_DEV_TYPE_LINK: parent = list_prev_entry(nd, link)->csdev; child = list_next_entry(nd, link)->csdev; ret = coresight_enable_link(csdev, parent, child); if (ret) goto err; break; default: goto err; } } out: return ret; err: coresight_disable_path_from(path, nd); goto out; } struct coresight_device *coresight_get_sink(struct list_head *path) { struct coresight_device *csdev; if (!path) return NULL; csdev = list_last_entry(path, struct coresight_node, link)->csdev; if (csdev->type != CORESIGHT_DEV_TYPE_SINK && csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) return NULL; return csdev; } static struct coresight_device * coresight_find_enabled_sink(struct coresight_device *csdev) { int i; struct coresight_device *sink = NULL; if ((csdev->type == CORESIGHT_DEV_TYPE_SINK || csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && csdev->activated) return csdev; /* * Recursively explore each port found on this element. */ for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_device *child_dev; child_dev = csdev->pdata->conns[i].child_dev; if (child_dev) sink = coresight_find_enabled_sink(child_dev); if (sink) return sink; } return NULL; } /** * coresight_get_enabled_sink - returns the first enabled sink using * connection based search starting from the source reference * * @source: Coresight source device reference */ struct coresight_device * coresight_get_enabled_sink(struct coresight_device *source) { if (!source) return NULL; return coresight_find_enabled_sink(source); } static int coresight_sink_by_id(struct device *dev, const void *data) { struct coresight_device *csdev = to_coresight_device(dev); unsigned long hash; if (csdev->type == CORESIGHT_DEV_TYPE_SINK || csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) { if (!csdev->ea) return 0; /* * See function etm_perf_add_symlink_sink() to know where * this comes from. */ hash = (unsigned long)csdev->ea->var; if ((u32)hash == *(u32 *)data) return 1; } return 0; } /** * coresight_get_sink_by_id - returns the sink that matches the id * @id: Id of the sink to match * * The name of a sink is unique, whether it is found on the AMBA bus or * otherwise. As such the hash of that name can easily be used to identify * a sink. */ struct coresight_device *coresight_get_sink_by_id(u32 id) { struct device *dev = NULL; dev = bus_find_device(&coresight_bustype, NULL, &id, coresight_sink_by_id); return dev ? to_coresight_device(dev) : NULL; } /** * coresight_get_ref- Helper function to increase reference count to module * and device. * * @csdev: The coresight device to get a reference on. * * Return true in successful case and power up the device. * Return false when failed to get reference of module. */ static inline bool coresight_get_ref(struct coresight_device *csdev) { struct device *dev = csdev->dev.parent; /* Make sure the driver can't be removed */ if (!try_module_get(dev->driver->owner)) return false; /* Make sure the device can't go away */ get_device(dev); pm_runtime_get_sync(dev); return true; } /** * coresight_put_ref- Helper function to decrease reference count to module * and device. Power off the device. * * @csdev: The coresight device to decrement a reference from. */ static inline void coresight_put_ref(struct coresight_device *csdev) { struct device *dev = csdev->dev.parent; pm_runtime_put(dev); put_device(dev); module_put(dev->driver->owner); } /* * coresight_grab_device - Power up this device and any of the helper * devices connected to it for trace operation. Since the helper devices * don't appear on the trace path, they should be handled along with the * master device. */ static int coresight_grab_device(struct coresight_device *csdev) { int i; for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_device *child; child = csdev->pdata->conns[i].child_dev; if (child && child->type == CORESIGHT_DEV_TYPE_HELPER) if (!coresight_get_ref(child)) goto err; } if (coresight_get_ref(csdev)) return 0; err: for (i--; i >= 0; i--) { struct coresight_device *child; child = csdev->pdata->conns[i].child_dev; if (child && child->type == CORESIGHT_DEV_TYPE_HELPER) coresight_put_ref(child); } return -ENODEV; } /* * coresight_drop_device - Release this device and any of the helper * devices connected to it. */ static void coresight_drop_device(struct coresight_device *csdev) { int i; coresight_put_ref(csdev); for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_device *child; child = csdev->pdata->conns[i].child_dev; if (child && child->type == CORESIGHT_DEV_TYPE_HELPER) coresight_put_ref(child); } } /** * _coresight_build_path - recursively build a path from a @csdev to a sink. * @csdev: The device to start from. * @sink: The final sink we want in this path. * @path: The list to add devices to. * * The tree of Coresight device is traversed until an activated sink is * found. From there the sink is added to the list along with all the * devices that led to that point - the end result is a list from source * to sink. In that list the source is the first device and the sink the * last one. */ static int _coresight_build_path(struct coresight_device *csdev, struct coresight_device *sink, struct list_head *path) { int i, ret; bool found = false; struct coresight_node *node; /* An activated sink has been found. Enqueue the element */ if (csdev == sink) goto out; if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) && sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) { if (_coresight_build_path(sink, sink, path) == 0) { found = true; goto out; } } /* Not a sink - recursively explore each port found on this element */ for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_device *child_dev; child_dev = csdev->pdata->conns[i].child_dev; if (child_dev && _coresight_build_path(child_dev, sink, path) == 0) { found = true; break; } } if (!found) return -ENODEV; out: /* * A path from this element to a sink has been found. The elements * leading to the sink are already enqueued, all that is left to do * is tell the PM runtime core we need this element and add a node * for it. */ ret = coresight_grab_device(csdev); if (ret) return ret; node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL); if (!node) return -ENOMEM; node->csdev = csdev; list_add(&node->link, path); return 0; } struct list_head *coresight_build_path(struct coresight_device *source, struct coresight_device *sink) { struct list_head *path; int rc; if (!sink) return ERR_PTR(-EINVAL); path = kzalloc(sizeof(struct list_head), GFP_KERNEL); if (!path) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(path); rc = _coresight_build_path(source, sink, path); if (rc) { kfree(path); return ERR_PTR(rc); } return path; } /** * coresight_release_path - release a previously built path. * @path: the path to release. * * Go through all the elements of a path and 1) removed it from the list and * 2) free the memory allocated for each node. */ void coresight_release_path(struct list_head *path) { struct coresight_device *csdev; struct coresight_node *nd, *next; list_for_each_entry_safe(nd, next, path, link) { csdev = nd->csdev; coresight_drop_device(csdev); list_del(&nd->link); kfree(nd); } kfree(path); } /* return true if the device is a suitable type for a default sink */ static inline bool coresight_is_def_sink_type(struct coresight_device *csdev) { /* sink & correct subtype */ if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) || (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) && (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER)) return true; return false; } /** * coresight_select_best_sink - return the best sink for use as default from * the two provided. * * @sink: current best sink. * @depth: search depth where current sink was found. * @new_sink: new sink for comparison with current sink. * @new_depth: search depth where new sink was found. * * Sinks prioritised according to coresight_dev_subtype_sink, with only * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used. * * Where two sinks of equal priority are found, the sink closest to the * source is used (smallest search depth). * * return @new_sink & update @depth if better than @sink, else return @sink. */ static struct coresight_device * coresight_select_best_sink(struct coresight_device *sink, int *depth, struct coresight_device *new_sink, int new_depth) { bool update = false; if (!sink) { /* first found at this level */ update = true; } else if (new_sink->subtype.sink_subtype > sink->subtype.sink_subtype) { /* found better sink */ update = true; } else if ((new_sink->subtype.sink_subtype == sink->subtype.sink_subtype) && (*depth > new_depth)) { /* found same but closer sink */ update = true; } if (update) *depth = new_depth; return update ? new_sink : sink; } /** * coresight_find_sink - recursive function to walk trace connections from * source to find a suitable default sink. * * @csdev: source / current device to check. * @depth: [in] search depth of calling dev, [out] depth of found sink. * * This will walk the connection path from a source (ETM) till a suitable * sink is encountered and return that sink to the original caller. * * If current device is a plain sink return that & depth, otherwise recursively * call child connections looking for a sink. Select best possible using * coresight_select_best_sink. * * return best sink found, or NULL if not found at this node or child nodes. */ static struct coresight_device * coresight_find_sink(struct coresight_device *csdev, int *depth) { int i, curr_depth = *depth + 1, found_depth = 0; struct coresight_device *found_sink = NULL; if (coresight_is_def_sink_type(csdev)) { found_depth = curr_depth; found_sink = csdev; if (csdev->type == CORESIGHT_DEV_TYPE_SINK) goto return_def_sink; /* look past LINKSINK for something better */ } /* * Not a sink we want - or possible child sink may be better. * recursively explore each port found on this element. */ for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_device *child_dev, *sink = NULL; int child_depth = curr_depth; child_dev = csdev->pdata->conns[i].child_dev; if (child_dev) sink = coresight_find_sink(child_dev, &child_depth); if (sink) found_sink = coresight_select_best_sink(found_sink, &found_depth, sink, child_depth); } return_def_sink: /* return found sink and depth */ if (found_sink) *depth = found_depth; return found_sink; } /** * coresight_find_default_sink: Find a sink suitable for use as a * default sink. * * @csdev: starting source to find a connected sink. * * Walks connections graph looking for a suitable sink to enable for the * supplied source. Uses CoreSight device subtypes and distance from source * to select the best sink. * * If a sink is found, then the default sink for this device is set and * will be automatically used in future. * * Used in cases where the CoreSight user (perf / sysfs) has not selected a * sink. */ struct coresight_device * coresight_find_default_sink(struct coresight_device *csdev) { int depth = 0; /* look for a default sink if we have not found for this device */ if (!csdev->def_sink) { if (coresight_is_percpu_source(csdev)) csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); if (!csdev->def_sink) csdev->def_sink = coresight_find_sink(csdev, &depth); } return csdev->def_sink; } static int coresight_remove_sink_ref(struct device *dev, void *data) { struct coresight_device *sink = data; struct coresight_device *source = to_coresight_device(dev); if (source->def_sink == sink) source->def_sink = NULL; return 0; } /** * coresight_clear_default_sink: Remove all default sink references to the * supplied sink. * * If supplied device is a sink, then check all the bus devices and clear * out all the references to this sink from the coresight_device def_sink * parameter. * * @csdev: coresight sink - remove references to this from all sources. */ static void coresight_clear_default_sink(struct coresight_device *csdev) { if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) || (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) { bus_for_each_dev(&coresight_bustype, NULL, csdev, coresight_remove_sink_ref); } } /** coresight_validate_source - make sure a source has the right credentials * @csdev: the device structure for a source. * @function: the function this was called from. * * Assumes the coresight_mutex is held. */ static int coresight_validate_source(struct coresight_device *csdev, const char *function) { u32 type, subtype; type = csdev->type; subtype = csdev->subtype.source_subtype; if (type != CORESIGHT_DEV_TYPE_SOURCE) { dev_err(&csdev->dev, "wrong device type in %s\n", function); return -EINVAL; } if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC && subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) { dev_err(&csdev->dev, "wrong device subtype in %s\n", function); return -EINVAL; } return 0; } int coresight_enable(struct coresight_device *csdev) { int cpu, ret = 0; struct coresight_device *sink; struct list_head *path; enum coresight_dev_subtype_source subtype; subtype = csdev->subtype.source_subtype; mutex_lock(&coresight_mutex); ret = coresight_validate_source(csdev, __func__); if (ret) goto out; if (csdev->enable) { /* * There could be multiple applications driving the software * source. So keep the refcount for each such user when the * source is already enabled. */ if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) atomic_inc(csdev->refcnt); goto out; } sink = coresight_get_enabled_sink(csdev); if (!sink) { ret = -EINVAL; goto out; } path = coresight_build_path(csdev, sink); if (IS_ERR(path)) { pr_err("building path(s) failed\n"); ret = PTR_ERR(path); goto out; } ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL); if (ret) goto err_path; ret = coresight_enable_source(csdev, CS_MODE_SYSFS); if (ret) goto err_source; switch (subtype) { case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC: /* * When working from sysFS it is important to keep track * of the paths that were created so that they can be * undone in 'coresight_disable()'. Since there can only * be a single session per tracer (when working from sysFS) * a per-cpu variable will do just fine. */ cpu = source_ops(csdev)->cpu_id(csdev); per_cpu(tracer_path, cpu) = path; break; case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE: stm_path = path; break; default: /* We can't be here */ break; } out: mutex_unlock(&coresight_mutex); return ret; err_source: coresight_disable_path(path); err_path: coresight_release_path(path); goto out; } EXPORT_SYMBOL_GPL(coresight_enable); void coresight_disable(struct coresight_device *csdev) { int cpu, ret; struct list_head *path = NULL; mutex_lock(&coresight_mutex); ret = coresight_validate_source(csdev, __func__); if (ret) goto out; if (!csdev->enable || !coresight_disable_source(csdev)) goto out; switch (csdev->subtype.source_subtype) { case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC: cpu = source_ops(csdev)->cpu_id(csdev); path = per_cpu(tracer_path, cpu); per_cpu(tracer_path, cpu) = NULL; break; case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE: path = stm_path; stm_path = NULL; break; default: /* We can't be here */ break; } coresight_disable_path(path); coresight_release_path(path); out: mutex_unlock(&coresight_mutex); } EXPORT_SYMBOL_GPL(coresight_disable); static ssize_t enable_sink_show(struct device *dev, struct device_attribute *attr, char *buf) { struct coresight_device *csdev = to_coresight_device(dev); return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated); } static ssize_t enable_sink_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { int ret; unsigned long val; struct coresight_device *csdev = to_coresight_device(dev); ret = kstrtoul(buf, 10, &val); if (ret) return ret; if (val) csdev->activated = true; else csdev->activated = false; return size; } static DEVICE_ATTR_RW(enable_sink); static ssize_t enable_source_show(struct device *dev, struct device_attribute *attr, char *buf) { struct coresight_device *csdev = to_coresight_device(dev); return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable); } static ssize_t enable_source_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { int ret = 0; unsigned long val; struct coresight_device *csdev = to_coresight_device(dev); ret = kstrtoul(buf, 10, &val); if (ret) return ret; if (val) { ret = coresight_enable(csdev); if (ret) return ret; } else { coresight_disable(csdev); } return size; } static DEVICE_ATTR_RW(enable_source); static struct attribute *coresight_sink_attrs[] = { &dev_attr_enable_sink.attr, NULL, }; ATTRIBUTE_GROUPS(coresight_sink); static struct attribute *coresight_source_attrs[] = { &dev_attr_enable_source.attr, NULL, }; ATTRIBUTE_GROUPS(coresight_source); static struct device_type coresight_dev_type[] = { { .name = "sink", .groups = coresight_sink_groups, }, { .name = "link", }, { .name = "linksink", .groups = coresight_sink_groups, }, { .name = "source", .groups = coresight_source_groups, }, { .name = "helper", }, { .name = "ect", }, }; static void coresight_device_release(struct device *dev) { struct coresight_device *csdev = to_coresight_device(dev); fwnode_handle_put(csdev->dev.fwnode); kfree(csdev->refcnt); kfree(csdev); } static int coresight_orphan_match(struct device *dev, void *data) { int i, ret = 0; bool still_orphan = false; struct coresight_device *csdev, *i_csdev; struct coresight_connection *conn; csdev = data; i_csdev = to_coresight_device(dev); /* No need to check oneself */ if (csdev == i_csdev) return 0; /* Move on to another component if no connection is orphan */ if (!i_csdev->orphan) return 0; /* * Circle throuch all the connection of that component. If we find * an orphan connection whose name matches @csdev, link it. */ for (i = 0; i < i_csdev->pdata->nr_outport; i++) { conn = &i_csdev->pdata->conns[i]; /* Skip the port if FW doesn't describe it */ if (!conn->child_fwnode) continue; /* We have found at least one orphan connection */ if (conn->child_dev == NULL) { /* Does it match this newly added device? */ if (conn->child_fwnode == csdev->dev.fwnode) { ret = coresight_make_links(i_csdev, conn, csdev); if (ret) return ret; } else { /* This component still has an orphan */ still_orphan = true; } } } i_csdev->orphan = still_orphan; /* * Returning '0' in case we didn't encounter any error, * ensures that all known component on the bus will be checked. */ return 0; } static int coresight_fixup_orphan_conns(struct coresight_device *csdev) { return bus_for_each_dev(&coresight_bustype, NULL, csdev, coresight_orphan_match); } static int coresight_fixup_device_conns(struct coresight_device *csdev) { int i, ret = 0; for (i = 0; i < csdev->pdata->nr_outport; i++) { struct coresight_connection *conn = &csdev->pdata->conns[i]; if (!conn->child_fwnode) continue; conn->child_dev = coresight_find_csdev_by_fwnode(conn->child_fwnode); if (conn->child_dev && conn->child_dev->has_conns_grp) { ret = coresight_make_links(csdev, conn, conn->child_dev); if (ret) break; } else { csdev->orphan = true; } } return ret; } static int coresight_remove_match(struct device *dev, void *data) { int i; struct coresight_device *csdev, *iterator; struct coresight_connection *conn; csdev = data; iterator = to_coresight_device(dev); /* No need to check oneself */ if (csdev == iterator) return 0; /* * Circle throuch all the connection of that component. If we find * a connection whose name matches @csdev, remove it. */ for (i = 0; i < iterator->pdata->nr_outport; i++) { conn = &iterator->pdata->conns[i]; if (conn->child_dev == NULL || conn->child_fwnode == NULL) continue; if (csdev->dev.fwnode == conn->child_fwnode) { iterator->orphan = true; coresight_remove_links(iterator, conn); /* * Drop the reference to the handle for the remote * device acquired in parsing the connections from * platform data. */ fwnode_handle_put(conn->child_fwnode); /* No need to continue */ break; } } /* * Returning '0' ensures that all known component on the * bus will be checked. */ return 0; } /* * coresight_remove_conns - Remove references to this given devices * from the connections of other devices. */ static void coresight_remove_conns(struct coresight_device *csdev) { /* * Another device will point to this device only if there is * an output port connected to this one. i.e, if the device * doesn't have at least one input port, there is no point * in searching all the devices. */ if (csdev->pdata->nr_inport) bus_for_each_dev(&coresight_bustype, NULL, csdev, coresight_remove_match); } /** * coresight_timeout - loop until a bit has changed to a specific register * state. * @csa: coresight device access for the device * @offset: Offset of the register from the base of the device. * @position: the position of the bit of interest. * @value: the value the bit should have. * * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if * TIMEOUT_US has elapsed, which ever happens first. */ int coresight_timeout(struct csdev_access *csa, u32 offset, int position, int value) { int i; u32 val; for (i = TIMEOUT_US; i > 0; i--) { val = csdev_access_read32(csa, offset); /* waiting on the bit to go from 0 to 1 */ if (value) { if (val & BIT(position)) return 0; /* waiting on the bit to go from 1 to 0 */ } else { if (!(val & BIT(position))) return 0; } /* * Delay is arbitrary - the specification doesn't say how long * we are expected to wait. Extra check required to make sure * we don't wait needlessly on the last iteration. */ if (i - 1) udelay(1); } return -EAGAIN; } EXPORT_SYMBOL_GPL(coresight_timeout); u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset) { return csdev_access_relaxed_read32(&csdev->access, offset); } u32 coresight_read32(struct coresight_device *csdev, u32 offset) { return csdev_access_read32(&csdev->access, offset); } void coresight_relaxed_write32(struct coresight_device *csdev, u32 val, u32 offset) { csdev_access_relaxed_write32(&csdev->access, val, offset); } void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset) { csdev_access_write32(&csdev->access, val, offset); } u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset) { return csdev_access_relaxed_read64(&csdev->access, offset); } u64 coresight_read64(struct coresight_device *csdev, u32 offset) { return csdev_access_read64(&csdev->access, offset); } void coresight_relaxed_write64(struct coresight_device *csdev, u64 val, u32 offset) { csdev_access_relaxed_write64(&csdev->access, val, offset); } void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset) { csdev_access_write64(&csdev->access, val, offset); } /* * coresight_release_platform_data: Release references to the devices connected * to the output port of this device. */ void coresight_release_platform_data(struct coresight_device *csdev, struct coresight_platform_data *pdata) { int i; struct coresight_connection *conns = pdata->conns; for (i = 0; i < pdata->nr_outport; i++) { /* If we have made the links, remove them now */ if (csdev && conns[i].child_dev) coresight_remove_links(csdev, &conns[i]); /* * Drop the refcount and clear the handle as this device * is going away */ if (conns[i].child_fwnode) { fwnode_handle_put(conns[i].child_fwnode); pdata->conns[i].child_fwnode = NULL; } } if (csdev) coresight_remove_conns_sysfs_group(csdev); } struct coresight_device *coresight_register(struct coresight_desc *desc) { int ret; int link_subtype; int nr_refcnts = 1; atomic_t *refcnts = NULL; struct coresight_device *csdev; bool registered = false; csdev = kzalloc(sizeof(*csdev), GFP_KERNEL); if (!csdev) { ret = -ENOMEM; goto err_out; } if (desc->type == CORESIGHT_DEV_TYPE_LINK || desc->type == CORESIGHT_DEV_TYPE_LINKSINK) { link_subtype = desc->subtype.link_subtype; if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) nr_refcnts = desc->pdata->nr_inport; else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) nr_refcnts = desc->pdata->nr_outport; } refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL); if (!refcnts) { ret = -ENOMEM; kfree(csdev); goto err_out; } csdev->refcnt = refcnts; csdev->pdata = desc->pdata; csdev->type = desc->type; csdev->subtype = desc->subtype; csdev->ops = desc->ops; csdev->access = desc->access; csdev->orphan = false; csdev->dev.type = &coresight_dev_type[desc->type]; csdev->dev.groups = desc->groups; csdev->dev.parent = desc->dev; csdev->dev.release = coresight_device_release; csdev->dev.bus = &coresight_bustype; /* * Hold the reference to our parent device. This will be * dropped only in coresight_device_release(). */ csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev)); dev_set_name(&csdev->dev, "%s", desc->name); /* * Make sure the device registration and the connection fixup * are synchronised, so that we don't see uninitialised devices * on the coresight bus while trying to resolve the connections. */ mutex_lock(&coresight_mutex); ret = device_register(&csdev->dev); if (ret) { put_device(&csdev->dev); /* * All resources are free'd explicitly via * coresight_device_release(), triggered from put_device(). */ goto out_unlock; } if (csdev->type == CORESIGHT_DEV_TYPE_SINK || csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) { ret = etm_perf_add_symlink_sink(csdev); if (ret) { device_unregister(&csdev->dev); /* * As with the above, all resources are free'd * explicitly via coresight_device_release() triggered * from put_device(), which is in turn called from * function device_unregister(). */ goto out_unlock; } } /* Device is now registered */ registered = true; ret = coresight_create_conns_sysfs_group(csdev); if (!ret) ret = coresight_fixup_device_conns(csdev); if (!ret) ret = coresight_fixup_orphan_conns(csdev); if (!ret && cti_assoc_ops && cti_assoc_ops->add) cti_assoc_ops->add(csdev); out_unlock: mutex_unlock(&coresight_mutex); /* Success */ if (!ret) return csdev; /* Unregister the device if needed */ if (registered) { coresight_unregister(csdev); return ERR_PTR(ret); } err_out: /* Cleanup the connection information */ coresight_release_platform_data(NULL, desc->pdata); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(coresight_register); void coresight_unregister(struct coresight_device *csdev) { etm_perf_del_symlink_sink(csdev); /* Remove references of that device in the topology */ if (cti_assoc_ops && cti_assoc_ops->remove) cti_assoc_ops->remove(csdev); coresight_remove_conns(csdev); coresight_clear_default_sink(csdev); coresight_release_platform_data(csdev, csdev->pdata); device_unregister(&csdev->dev); } EXPORT_SYMBOL_GPL(coresight_unregister); /* * coresight_search_device_idx - Search the fwnode handle of a device * in the given dev_idx list. Must be called with the coresight_mutex held. * * Returns the index of the entry, when found. Otherwise, -ENOENT. */ static inline int coresight_search_device_idx(struct coresight_dev_list *dict, struct fwnode_handle *fwnode) { int i; for (i = 0; i < dict->nr_idx; i++) if (dict->fwnode_list[i] == fwnode) return i; return -ENOENT; } bool coresight_loses_context_with_cpu(struct device *dev) { return fwnode_property_present(dev_fwnode(dev), "arm,coresight-loses-context-with-cpu"); } EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu); /* * coresight_alloc_device_name - Get an index for a given device in the * device index list specific to a driver. An index is allocated for a * device and is tracked with the fwnode_handle to prevent allocating * duplicate indices for the same device (e.g, if we defer probing of * a device due to dependencies), in case the index is requested again. */ char *coresight_alloc_device_name(struct coresight_dev_list *dict, struct device *dev) { int idx; char *name = NULL; struct fwnode_handle **list; mutex_lock(&coresight_mutex); idx = coresight_search_device_idx(dict, dev_fwnode(dev)); if (idx < 0) { /* Make space for the new entry */ idx = dict->nr_idx; list = krealloc_array(dict->fwnode_list, idx + 1, sizeof(*dict->fwnode_list), GFP_KERNEL); if (ZERO_OR_NULL_PTR(list)) { idx = -ENOMEM; goto done; } list[idx] = dev_fwnode(dev); dict->fwnode_list = list; dict->nr_idx = idx + 1; } name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx); done: mutex_unlock(&coresight_mutex); return name; } EXPORT_SYMBOL_GPL(coresight_alloc_device_name); struct bus_type coresight_bustype = { .name = "coresight", }; static int __init coresight_init(void) { int ret; ret = bus_register(&coresight_bustype); if (ret) return ret; ret = etm_perf_init(); if (ret) goto exit_bus_unregister; /* initialise the coresight syscfg API */ ret = cscfg_init(); if (!ret) return 0; etm_perf_exit(); exit_bus_unregister: bus_unregister(&coresight_bustype); return ret; } static void __exit coresight_exit(void) { cscfg_exit(); etm_perf_exit(); bus_unregister(&coresight_bustype); } module_init(coresight_init); module_exit(coresight_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Pratik Patel "); MODULE_AUTHOR("Mathieu Poirier "); MODULE_DESCRIPTION("Arm CoreSight tracer driver");