[PATCH v9 06/15] coresight: cti: Add device tree support for v8 arch CTI

Mike Leach
2020-02-10T21:40:01Z

The v8 architecture defines the relationship between a PE, its optional ETM
and a CTI. Unlike non-architectural CTIs which are implementation defined,
this has a fixed set of connections which can therefore be represented as a
simple tag in the device tree.

This patch defines the tags needed to create an entry for this PE/ETM/CTI
relationship, and provides functionality to implement the connection model
in the CTI driver.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
.../coresight/coresight-cti-platform.c | 205 ++++++++++++++++++
.../hwtracing/coresight/coresight-platform.c | 20 ++
drivers/hwtracing/coresight/coresight-priv.h | 2 +
drivers/hwtracing/coresight/coresight.c | 12 +-
4 files changed, 230 insertions(+), 9 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-platform.c b/drivers/hwtracing/coresight/coresight-cti-platform.c
index 665be86c585d..36a276eda50a 100644
--- a/drivers/hwtracing/coresight/coresight-cti-platform.c
+++ b/drivers/hwtracing/coresight/coresight-cti-platform.c
@@ -3,10 +3,208 @@
* Copyright (c) 2019, The Linaro Limited. All rights reserved.
*/

+#include <dt-bindings/arm/coresight-cti-dt.h>
#include <linux/of.h>

#include "coresight-cti.h"

+/* Number of CTI signals in the v8 architecturally defined connection */
+#define NR_V8PE_IN_SIGS 2
+#define NR_V8PE_OUT_SIGS 3
+#define NR_V8ETM_INOUT_SIGS 4
+
+/* CTI device tree connection property keywords */
+#define CTI_DT_V8ARCH_COMPAT "arm,coresight-cti-v8-arch"
+#define CTI_DT_CSDEV_ASSOC "arm,cs-dev-assoc"
+
+#ifdef CONFIG_OF
+/*
+ * CTI can be bound to a CPU, or a system device.
+ * CPU can be declared at the device top level or in a connections node
+ * so need to check relative to node not device.
+ */
+static int of_cti_get_cpu_at_node(const struct device_node *node)
+{
+ int cpu;
+ struct device_node *dn;
+
+ if (node == NULL)
+ return -1;
+
+ dn = of_parse_phandle(node, "cpu", 0);
+ /* CTI affinity defaults to no cpu */
+ if (!dn)
+ return -1;
+ cpu = of_cpu_node_to_id(dn);
+ of_node_put(dn);
+
+ /* No Affinity if no cpu nodes are found */
+ return (cpu < 0) ? -1 : cpu;
+}
+
+#else
+static int of_cti_get_cpu_at_node(const struct device_node *node)
+{
+ return -1;
+}
+
+#endif
+
+/*
+ * CTI can be bound to a CPU, or a system device.
+ * CPU can be declared at the device top level or in a connections node
+ * so need to check relative to node not device.
+ */
+static int cti_plat_get_cpu_at_node(struct fwnode_handle *fwnode)
+{
+ if (is_of_node(fwnode))
+ return of_cti_get_cpu_at_node(to_of_node(fwnode));
+ return -1;
+}
+
+const char *cti_plat_get_node_name(struct fwnode_handle *fwnode)
+{
+ if (is_of_node(fwnode))
+ return of_node_full_name(to_of_node(fwnode));
+ return "unknown";
+}
+
+/*
+ * Extract a name from the fwnode.
+ * If the device associated with the node is a coresight_device, then return
+ * that name and the coresight_device pointer, otherwise return the node name.
+ */
+static const char *
+cti_plat_get_csdev_or_node_name(struct fwnode_handle *fwnode,
+ struct coresight_device **csdev)
+{
+ const char *name = NULL;
+ *csdev = coresight_find_csdev_by_fwnode(fwnode);
+ if (*csdev)
+ name = dev_name(&(*csdev)->dev);
+ else
+ name = cti_plat_get_node_name(fwnode);
+ return name;
+}
+
+static int cti_plat_create_v8_etm_connection(struct device *dev,
+ struct cti_drvdata *drvdata)
+{
+ int ret = -ENOMEM, i;
+ struct fwnode_handle *root_fwnode, *cs_fwnode;
+ const char *assoc_name = NULL;
+ struct coresight_device *csdev;
+ struct cti_trig_con *tc = NULL;
+
+ root_fwnode = dev_fwnode(dev);
+ if (IS_ERR_OR_NULL(root_fwnode))
+ return -EINVAL;
+
+ /* Can optionally have an etm node - return if not */
+ cs_fwnode = fwnode_find_reference(root_fwnode, CTI_DT_CSDEV_ASSOC, 0);
+ if (IS_ERR_OR_NULL(cs_fwnode))
+ return 0;
+
+ /* allocate memory */
+ tc = cti_allocate_trig_con(dev, NR_V8ETM_INOUT_SIGS,
+ NR_V8ETM_INOUT_SIGS);
+ if (!tc)
+ goto create_v8_etm_out;
+
+ /* build connection data */
+ tc->con_in->used_mask = 0xF0; /* sigs <4,5,6,7> */
+ tc->con_out->used_mask = 0xF0; /* sigs <4,5,6,7> */
+
+ /*
+ * The EXTOUT type signals from the ETM are connected to a set of input
+ * triggers on the CTI, the EXTIN being connected to output triggers.
+ */
+ for (i = 0; i < NR_V8ETM_INOUT_SIGS; i++) {
+ tc->con_in->sig_types[i] = ETM_EXTOUT;
+ tc->con_out->sig_types[i] = ETM_EXTIN;
+ }
+
+ /*
+ * We look to see if the ETM coresight device associated with this
+ * handle has been registered with the system - i.e. probed before
+ * this CTI. If so csdev will be non NULL and we can use the device
+ * name and pass the csdev to the connection entry function where
+ * the association will be recorded.
+ * If not, then simply record the name in the connection data, the
+ * probing of the ETM will call into the CTI driver API to update the
+ * association then.
+ */
+ assoc_name = cti_plat_get_csdev_or_node_name(cs_fwnode, &csdev);
+ ret = cti_add_connection_entry(dev, drvdata, tc, csdev, assoc_name);
+
+create_v8_etm_out:
+ fwnode_handle_put(cs_fwnode);
+ return ret;
+}
+
+/*
+ * Create an architecturally defined v8 connection
+ * must have a cpu, can have an ETM.
+ */
+static int cti_plat_create_v8_connections(struct device *dev,
+ struct cti_drvdata *drvdata)
+{
+ struct cti_device *cti_dev = &drvdata->ctidev;
+ struct cti_trig_con *tc = NULL;
+ int cpuid = 0;
+ char cpu_name_str[16];
+ int ret = -ENOMEM;
+
+ /* Must have a cpu node */
+ cpuid = cti_plat_get_cpu_at_node(dev_fwnode(dev));
+ if (cpuid < 0) {
+ dev_warn(dev,
+ "ARM v8 architectural CTI connection: missing cpu\n");
+ return -EINVAL;
+ }
+ cti_dev->cpu = cpuid;
+
+ /* Allocate the v8 cpu connection memory */
+ tc = cti_allocate_trig_con(dev, NR_V8PE_IN_SIGS, NR_V8PE_OUT_SIGS);
+ if (!tc)
+ goto of_create_v8_out;
+
+ /* Set the v8 PE CTI connection data */
+ tc->con_in->used_mask = 0x3; /* sigs <0 1> */
+ tc->con_in->sig_types[0] = PE_DBGTRIGGER;
+ tc->con_in->sig_types[1] = PE_PMUIRQ;
+ tc->con_out->used_mask = 0x7; /* sigs <0 1 2 > */
+ tc->con_out->sig_types[0] = PE_EDBGREQ;
+ tc->con_out->sig_types[1] = PE_DBGRESTART;
+ tc->con_out->sig_types[2] = PE_CTIIRQ;
+ scnprintf(cpu_name_str, sizeof(cpu_name_str), "cpu%d", cpuid);
+
+ ret = cti_add_connection_entry(dev, drvdata, tc, NULL, cpu_name_str);
+ if (ret)
+ goto of_create_v8_out;
+
+ /* Create the v8 ETM associated connection */
+ ret = cti_plat_create_v8_etm_connection(dev, drvdata);
+ if (ret)
+ goto of_create_v8_out;
+
+ /* filter pe_edbgreq - PE trigout sig <0> */
+ drvdata->config.trig_out_filter |= 0x1;
+
+of_create_v8_out:
+ return ret;
+}
+
+static int cti_plat_check_v8_arch_compatible(struct device *dev)
+{
+ struct fwnode_handle *fwnode = dev_fwnode(dev);
+
+ if (is_of_node(fwnode))
+ return of_device_is_compatible(to_of_node(fwnode),
+ CTI_DT_V8ARCH_COMPAT);
+ return 0;
+}
+
/* get the hardware configuration & connection data. */
int cti_plat_get_hw_data(struct device *dev,
struct cti_drvdata *drvdata)
@@ -14,6 +212,13 @@ int cti_plat_get_hw_data(struct device *dev,
int rc = 0;
struct cti_device *cti_dev = &drvdata->ctidev;

+ /* check for a v8 architectural CTI device */
+ if (cti_plat_check_v8_arch_compatible(dev)) {
+ rc = cti_plat_create_v8_connections(dev, drvdata);
+ if (rc)
+ return rc;
+ }
+
/* if no connections, just add a single default based on max IN-OUT */
if (cti_dev->nr_trig_con == 0)
rc = cti_add_default_connection(dev, drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 3c5bee429105..43418a2126ff 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -57,6 +57,26 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
return bus_find_device_by_fwnode(&amba_bustype, fwnode);
}

+/*
+ * Find a registered coresight device from a device fwnode.
+ * The node info is associated with the AMBA parent, but the
+ * csdev keeps a copy so iterate round the coresight bus to
+ * find the device.
+ */
+struct coresight_device *
+coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode)
+{
+ struct device *dev;
+ struct coresight_device *csdev = NULL;
+
+ dev = bus_find_device_by_fwnode(&coresight_bustype, r_fwnode);
+ if (dev) {
+ csdev = to_coresight_device(dev);
+ put_device(dev);
+ }
+ return csdev;
+}
+
#ifdef CONFIG_OF
static inline bool of_coresight_legacy_ep_is_input(struct device_node *ep)
{
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index aba6b789c969..357ffef7b825 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -202,5 +202,7 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
}

void coresight_release_platform_data(struct coresight_platform_data *pdata);
+struct coresight_device *
+coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode);

#endif
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 1a5fdf2710ff..39a5d9f7a395 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -1030,17 +1030,11 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)

for (i = 0; i < csdev->pdata->nr_outport; i++) {
struct coresight_connection *conn = &csdev->pdata->conns[i];
- struct device *dev = NULL;

- dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
- if (dev) {
- conn->child_dev = to_coresight_device(dev);
- /* and put reference from 'bus_find_device()' */
- put_device(dev);
- } else {
+ conn->child_dev =
+ coresight_find_csdev_by_fwnode(conn->child_fwnode);
+ if (!conn->child_dev)
csdev->orphan = true;
- conn->child_dev = NULL;
- }
}
}

--
2.17.1