]> asedeno.scripts.mit.edu Git - linux.git/commitdiff
coresight: Support for ACPI bindings
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Wed, 19 Jun 2019 19:53:06 +0000 (13:53 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 20 Jun 2019 05:56:14 +0000 (07:56 +0200)
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>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight-platform.c

index 49112a58478e984b369ea555eea4e6e980eb5103..6fef8732eea5f376df9ef3a03ff3c99db4b77f84 100644 (file)
@@ -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;