Add support for parsing the ACPI platform description for CoreSight. The connections are encoded in a DSD graph property with CoreSight specific variation of the property.
The ETMs are listed as the children device of the respective CPU.
Cc: "Rafael J. Wysocki" rjw@rjwysocki.net Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- drivers/hwtracing/coresight/coresight-platform.c | 464 +++++++++++++++++++++++ 1 file changed, 464 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c index 49112a5..6fef873 100644 --- a/drivers/hwtracing/coresight/coresight-platform.c +++ b/drivers/hwtracing/coresight/coresight-platform.c @@ -3,6 +3,7 @@ * Copyright (c) 2012, The Linux Foundation. All rights reserved. */
+#include <linux/acpi.h> #include <linux/types.h> #include <linux/err.h> #include <linux/slab.h> @@ -308,10 +309,471 @@ of_get_coresight_platform_data(struct device *dev, } #endif
+#ifdef CONFIG_ACPI + +#include <acpi/actypes.h> +#include <acpi/processor.h> + +/* ACPI Graph _DSD UUID : "ab02a46b-74c7-45a2-bd68-f7d344ef2153" */ +static const guid_t acpi_graph_uuid = GUID_INIT(0xab02a46b, 0x74c7, 0x45a2, + 0xbd, 0x68, 0xf7, 0xd3, + 0x44, 0xef, 0x21, 0x53); +/* Coresight ACPI Graph UUID : "3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd" */ +static const guid_t coresight_graph_uuid = GUID_INIT(0x3ecbc8b6, 0x1d0e, 0x4fb3, + 0x81, 0x07, 0xe6, 0x27, + 0xf8, 0x05, 0xc6, 0xcd); +#define ACPI_CORESIGHT_LINK_SLAVE 0 +#define ACPI_CORESIGHT_LINK_MASTER 1 + +static inline bool is_acpi_guid(const union acpi_object *obj) +{ + return (obj->type == ACPI_TYPE_BUFFER) && (obj->buffer.length == 16); +} + +/* + * acpi_guid_matches - Checks if the given object is a GUID object and + * that it matches the supplied the GUID. + */ +static inline bool acpi_guid_matches(const union acpi_object *obj, + const guid_t *guid) +{ + return is_acpi_guid(obj) && + guid_equal((guid_t *)obj->buffer.pointer, guid); +} + +static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj) +{ + return acpi_guid_matches(obj, &acpi_graph_uuid); +} + +static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj) +{ + return acpi_guid_matches(obj, &coresight_graph_uuid); +} + +static inline bool is_acpi_coresight_graph(const union acpi_object *obj) +{ + const union acpi_object *graphid, *guid, *links; + + if (obj->type != ACPI_TYPE_PACKAGE || + obj->package.count < 3) + return false; + + graphid = &obj->package.elements[0]; + guid = &obj->package.elements[1]; + links = &obj->package.elements[2]; + + if (graphid->type != ACPI_TYPE_INTEGER || + links->type != ACPI_TYPE_INTEGER) + return false; + + return is_acpi_coresight_graph_guid(guid); +} + +/* + * acpi_validate_dsd_graph - Make sure the given _DSD graph conforms + * to the ACPI _DSD Graph specification. + * + * ACPI Devices Graph property has the following format: + * { + * Revision - Integer, must be 0 + * NumberOfGraphs - Integer, N indicating the following list. + * Graph[1], + * ... + * Graph[N] + * } + * + * And each Graph entry has the following format: + * { + * GraphID - Integer, identifying a graph the device belongs to. + * UUID - UUID identifying the specification that governs + * this graph. (e.g, see is_acpi_coresight_graph()) + * NumberOfLinks - Number "N" of connections on this node of the graph. + * Links[1] + * ... + * Links[N] + * } + * + * Where each "Links" entry has the following format: + * + * { + * SourcePortAddress - Integer + * DestinationPortAddress - Integer + * DestinationDeviceName - Reference to another device + * ( --- CoreSight specific extensions below ---) + * DirectionOfFlow - Integer 1 for output(master) + * 0 for input(slave) + * } + * + * e.g: + * For a Funnel device + * + * Device(MFUN) { + * ... + * + * Name (_DSD, Package() { + * // DSD Package contains tuples of { Proeprty_Type_UUID, Package() } + * ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), //Std. Property UUID + * Package() { + * Package(2) { "property-name", <property-value> } + * }, + * + * ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), // ACPI Graph UUID + * Package() { + * 0, // Revision + * 1, // NumberOfGraphs. + * Package() { // Graph[0] Package + * 1, // GraphID + * // Coresight Graph UUID + * ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"), + * 3, // NumberOfLinks aka ports + * // Link[0]: Output_0 -> Replicator:Input_0 + * Package () { 0, 0, _SB_.RPL0, 1 }, + * // Link[1]: Input_0 <- Cluster0_Funnel0:Output_0 + * Package () { 0, 0, _SB_.CLU0.FUN0, 0 }, + * // Link[2]: Input_1 <- Cluster1_Funnel0:Output_0 + * Package () { 1, 0, _SB_.CLU1.FUN0, 0 }, + * } // End of Graph[0] Package + * + * }, // End of ACPI Graph Property + * }) + */ +static inline bool acpi_validate_dsd_graph(const union acpi_object *graph) +{ + int i, n; + const union acpi_object *rev, *nr_graphs; + + /* The graph must contain at least the Revision and Number of Graphs */ + if (graph->package.count < 2) + return false; + + rev = &graph->package.elements[0]; + nr_graphs = &graph->package.elements[1]; + + if (rev->type != ACPI_TYPE_INTEGER || + nr_graphs->type != ACPI_TYPE_INTEGER) + return false; + + /* We only support revision 0 */ + if (rev->integer.value != 0) + return false; + + n = nr_graphs->integer.value; + /* CoreSight devices are only part of a single Graph */ + if (n != 1) + return false; + + /* Make sure the ACPI graph package has right number of elements */ + if (graph->package.count != (n + 2)) + return false; + + /* + * Each entry must be a graph package with at least 3 members : + * { GraphID, UUID, NumberOfLinks(n), Links[.],... } + */ + for (i = 2; i < n + 2; i++) { + const union acpi_object *obj = &graph->package.elements[i]; + + if (obj->type != ACPI_TYPE_PACKAGE || + obj->package.count < 3) + return false; + } + + return true; +} + +/* acpi_get_dsd_graph - Find the _DSD Graph property for the given device. */ +const union acpi_object * +acpi_get_dsd_graph(struct acpi_device *adev) +{ + int i; + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; + acpi_status status; + const union acpi_object *dsd; + + status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, + &buf, ACPI_TYPE_PACKAGE); + if (ACPI_FAILURE(status)) + return NULL; + + dsd = buf.pointer; + + /* + * _DSD property consists tuples { Prop_UUID, Package() } + * Iterate through all the packages and find the Graph. + */ + for (i = 0; i + 1 < dsd->package.count; i += 2) { + const union acpi_object *guid, *package; + + guid = &dsd->package.elements[i]; + package = &dsd->package.elements[i + 1]; + + /* All _DSD elements must have a UUID and a Package */ + if (!is_acpi_guid(guid) || package->type != ACPI_TYPE_PACKAGE) + break; + /* Skip the non-Graph _DSD packages */ + if (!is_acpi_dsd_graph_guid(guid)) + continue; + if (acpi_validate_dsd_graph(package)) + return package; + /* Invalid graph format, continue */ + dev_warn(&adev->dev, "Invalid Graph _DSD property\n"); + } + + return NULL; +} + +static inline bool +acpi_validate_coresight_graph(const union acpi_object *cs_graph) +{ + int nlinks; + + nlinks = cs_graph->package.elements[2].integer.value; + /* + * Graph must have the following fields : + * { GraphID, GraphUUID, NumberOfLinks, Links... } + */ + if (cs_graph->package.count != (nlinks + 3)) + return false; + /* The links are validated in acpi_coresight_parse_link() */ + return true; +} + +/* + * acpi_get_coresight_graph - Parse the device _DSD tables and find + * the Graph property matching the CoreSight Graphs. + * + * Returns the pointer to the CoreSight Graph Package when found. Otherwise + * returns NULL. + */ +const union acpi_object * +acpi_get_coresight_graph(struct acpi_device *adev) +{ + const union acpi_object *graph_list, *graph; + int i, nr_graphs; + + graph_list = acpi_get_dsd_graph(adev); + if (!graph_list) + return graph_list; + + nr_graphs = graph_list->package.elements[1].integer.value; + + for (i = 2; i < nr_graphs + 2; i++) { + graph = &graph_list->package.elements[i]; + if (!is_acpi_coresight_graph(graph)) + continue; + if (acpi_validate_coresight_graph(graph)) + return graph; + /* Invalid graph format */ + break; + } + + return NULL; +} + +/* + * acpi_coresight_parse_link - Parse the given Graph connection + * of the device and populate the coresight_connection for an output + * connection. + * + * CoreSight Graph specification mandates that the direction of the data + * flow must be specified in the link. i.e, + * + * SourcePortAddress, // Integer + * DestinationPortAddress, // Integer + * DestinationDeviceName, // Reference to another device + * DirectionOfFlow, // 1 for output(master), 0 for input(slave) + * + * Returns the direction of the data flow [ Input(slave) or Output(master) ] + * upon success. + * Returns an negative error number otherwise. + */ +static int acpi_coresight_parse_link(struct acpi_device *adev, + const union acpi_object *link, + struct coresight_connection *conn) +{ + int rc, dir; + const union acpi_object *fields; + struct acpi_device *r_adev; + struct device *rdev; + + if (link->type != ACPI_TYPE_PACKAGE || + link->package.count != 4) + return -EINVAL; + + fields = link->package.elements; + + if (fields[0].type != ACPI_TYPE_INTEGER || + fields[1].type != ACPI_TYPE_INTEGER || + fields[2].type != ACPI_TYPE_LOCAL_REFERENCE || + fields[3].type != ACPI_TYPE_INTEGER) + return -EINVAL; + + rc = acpi_bus_get_device(fields[2].reference.handle, &r_adev); + if (rc) + return rc; + + dir = fields[3].integer.value; + if (dir == ACPI_CORESIGHT_LINK_MASTER) { + conn->outport = fields[0].integer.value; + conn->child_port = fields[1].integer.value; + rdev = coresight_find_device_by_fwnode(&r_adev->fwnode); + if (!rdev) + return -EPROBE_DEFER; + /* + * Hold the refcount to the target device. This could be + * released via: + * 1) coresight_release_platform_data() if the probe fails or + * this device is unregistered. + * 2) While removing the target device via + * coresight_remove_match(). + */ + conn->child_fwnode = fwnode_handle_get(&r_adev->fwnode); + } + + return dir; +} + +/* + * acpi_coresight_parse_graph - Parse the _DSD CoreSight graph + * connection information and populate the supplied coresight_platform_data + * instance. + */ +static int acpi_coresight_parse_graph(struct acpi_device *adev, + struct coresight_platform_data *pdata) +{ + int rc, i, nlinks; + const union acpi_object *graph; + struct coresight_connection *conns, *ptr; + + pdata->nr_inport = pdata->nr_outport = 0; + graph = acpi_get_coresight_graph(adev); + if (!graph) + return -ENOENT; + + nlinks = graph->package.elements[2].integer.value; + if (!nlinks) + return 0; + + /* + * To avoid scanning the table twice (once for finding the number of + * output links and then later for parsing the output links), + * cache the links information in one go and then later copy + * it to the pdata. + */ + conns = devm_kcalloc(&adev->dev, nlinks, sizeof(*conns), GFP_KERNEL); + if (!conns) + return -ENOMEM; + ptr = conns; + for (i = 0; i < nlinks; i++) { + const union acpi_object *link = &graph->package.elements[3 + i]; + int dir; + + dir = acpi_coresight_parse_link(adev, link, ptr); + if (dir < 0) + return dir; + + if (dir == ACPI_CORESIGHT_LINK_MASTER) { + pdata->nr_outport++; + ptr++; + } else { + pdata->nr_inport++; + } + } + + rc = coresight_alloc_conns(&adev->dev, pdata); + if (rc) + return rc; + + /* Copy the connection information to the final location */ + for (i = 0; i < pdata->nr_outport; i++) + pdata->conns[i] = conns[i]; + + devm_kfree(&adev->dev, conns); + return 0; +} + +/* + * acpi_handle_to_logical_cpuid - Map a given acpi_handle to the + * logical CPU id of the corresponding CPU device. + * + * Returns the logical CPU id when found. Otherwise returns >= nr_cpus_id. + */ +static int +acpi_handle_to_logical_cpuid(acpi_handle handle) +{ + int i; + struct acpi_processor *pr; + + for_each_possible_cpu(i) { + pr = per_cpu(processors, i); + if (pr && pr->handle == handle) + break; + } + + return i; +} + +/* + * acpi_coresigh_get_cpu - Find the logical CPU id of the CPU associated + * with this coresight device. With ACPI bindings, the CoreSight components + * are listed as child device of the associated CPU. + * + * Returns the logical CPU id when found. Otherwise returns 0. + */ +static int acpi_coresight_get_cpu(struct device *dev) +{ + int cpu; + acpi_handle cpu_handle; + acpi_status status; + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (!adev) + return 0; + status = acpi_get_parent(adev->handle, &cpu_handle); + if (ACPI_FAILURE(status)) + return 0; + + cpu = acpi_handle_to_logical_cpuid(cpu_handle); + if (cpu >= nr_cpu_ids) + return 0; + return cpu; +} + +static int +acpi_get_coresight_platform_data(struct device *dev, + struct coresight_platform_data *pdata) +{ + struct acpi_device *adev; + + adev = ACPI_COMPANION(dev); + if (!adev) + return -EINVAL; + + return acpi_coresight_parse_graph(adev, pdata); +} + +#else + +static inline int +acpi_get_coresight_platform_data(struct device *dev, + struct coresight_platform_data *pdata) +{ + return -ENOENT; +} + +static inline int acpi_coresight_get_cpu(struct device *dev) +{ + return 0; +} +#endif + int coresight_get_cpu(struct device *dev) { if (is_of_node(dev->fwnode)) return of_coresight_get_cpu(dev); + else if (is_acpi_device_node(dev->fwnode)) + return acpi_coresight_get_cpu(dev); return 0; } EXPORT_SYMBOL_GPL(coresight_get_cpu); @@ -334,6 +796,8 @@ coresight_get_platform_data(struct device *dev)
if (is_of_node(fwnode)) ret = of_get_coresight_platform_data(dev, pdata); + else if (is_acpi_device_node(fwnode)) + ret = acpi_get_coresight_platform_data(dev, pdata);
if (!ret) return pdata;