Re: [PATCH v5 07/14] coresight: cti: Add device tree support for custom CTI.

Mike Leach
2019-12-03T14:06:09Z

Hi Suzuki,

On Fri, 29 Nov 2019 at 14:18, Suzuki Kuruppassery Poulose
<suzuki.poulose@arm.com> wrote:
>
> On 19/11/2019 23:19, Mike Leach wrote:
> > Adds support for CTIs whose connections are implementation defined at
> > hardware design time, and not constrained by v8 architecture.
> >
> > These CTIs have no standard connection setup, all the settings have to
> > be defined in the device tree files. The patch creates a set of connections
> > and trigger signals based on the information provided.
> >
> > Signed-off-by: Mike Leach <mike.leach@linaro.org>
> > ---
> > .../coresight/coresight-cti-platform.c | 250 +++++++++++++++++-
> > .../hwtracing/coresight/coresight-cti-sysfs.c | 11 +
> > 2 files changed, 257 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-cti-platform.c b/drivers/hwtracing/coresight/coresight-cti-platform.c
> > index 790dd30b85f5..9c1ff432b487 100644
> > --- a/drivers/hwtracing/coresight/coresight-cti-platform.c
> > +++ b/drivers/hwtracing/coresight/coresight-cti-platform.c
> > @@ -13,9 +13,19 @@
> > #define NR_V8PE_OUT_SIGS 3
> > #define NR_V8ETM_INOUT_SIGS 4
> >
> > +/* CTI device tree trigger connection node keyword */
> > +#define CTI_DT_CONNS "trig-conns"
> > +
> > /* CTI device tree connection property keywords */
> > #define CTI_DT_V8ARCH "arm,cti-v8-arch"
> > #define CTI_DT_CSDEV_ASSOC "arm,cs-dev-assoc"
> > +#define CTI_DT_TRIGIN_SIGS "arm,trig-in-sigs"
> > +#define CTI_DT_TRIGOUT_SIGS "arm,trig-out-sigs"
> > +#define CTI_DT_TRIGIN_TYPES "arm,trig-in-types"
> > +#define CTI_DT_TRIGOUT_TYPES "arm,trig-out-types"
> > +#define CTI_DT_FILTER_OUT_SIGS "arm,trig-filters"
> > +#define CTI_DT_CONN_NAME "arm,trig-conn-name"
> > +#define CTI_DT_CTM_ID "arm,cti-ctm-id"
> >
> > /*
> > * Find a registered coresight device from a device fwnode.
> > @@ -68,6 +78,12 @@ static const char *of_cti_get_node_name(const struct device_node *node)
> > return node->full_name;
> > return "unknown";
> > }
> > +
> > +static bool of_cti_node_name_eq(const struct device_node *node,
> > + const char *name)
> > +{
> > + return of_node_name_eq(node, name);
> > +}
> > #else
> > static int of_cti_get_cpu_at_node(const struct device_node *node)
> > {
> > @@ -78,6 +94,12 @@ static const char *of_cti_get_node_name(const struct device_node *node)
> > {
> > return "unknown";
> > }
> > +
> > +static bool of_cti_node_name_eq(const struct device_node *node,
> > + const char *name)
> > +{
> > + return false;
> > +}
> > #endif
>
> nit: You don't need this wrapper of_node_name_eq() is already defined to
> return false for !CONFIG_OF.
>
>

OK.

> >
> > static int cti_plat_get_cpu_at_node(struct fwnode_handle *fwnode)
> > @@ -94,6 +116,14 @@ static const char *cti_plat_get_node_name(struct fwnode_handle *fwnode)
> > return "unknown";
> > }
> >
> > +static bool cti_plat_node_name_eq(struct fwnode_handle *fwnode,
> > + const char *name)
> > +{
> > + if (is_of_node(fwnode))
> > + return of_cti_node_name_eq(to_of_node(fwnode), name);
>
> As mentioned above you could simply use of_node_name_eq() here.
>
> > + return false;
> > +}
> > +
> > static int cti_plat_create_v8_etm_connection(struct device *dev,
> > struct cti_drvdata *drvdata)
> > {
> > @@ -205,6 +235,214 @@ static int cti_plat_create_v8_connections(struct device *dev,
> > return ret;
> > }
> >
> > +static int cti_plat_count_sig_elements(const struct fwnode_handle *fwnode,
> > + const char *name)
> > +{
> > + int nr_elem = fwnode_property_count_u32(fwnode, name);
> > +
> > + return (nr_elem < 0 ? 0 : nr_elem);
> > +}
> > +
> > +static int cti_plat_read_trig_group(struct cti_trig_grp *tgrp,
> > + const struct fwnode_handle *fwnode,
> > + const char *grp_name)
> > +{
> > + int idx, err = 0;
> > + u32 *values;
> > +
> > + if (!tgrp->nr_sigs)
> > + return 0;
> > +
> > + values = kcalloc(tgrp->nr_sigs, sizeof(u32), GFP_KERNEL);
> > + if (!values)
> > + return -ENOMEM;
> > +
> > + err = fwnode_property_read_u32_array(fwnode, grp_name,
> > + values, tgrp->nr_sigs);
> > +
> > + if (!err) {
> > + /* set the signal usage mask */
> > + for (idx = 0; idx < tgrp->nr_sigs; idx++)
> > + tgrp->used_mask |= BIT(values[idx]);
> > + }
> > +
> > + kfree(values);
> > + return err;
> > +}
> > +
> > +static int cti_plat_read_trig_types(struct cti_trig_grp *tgrp,
> > + const struct fwnode_handle *fwnode,
> > + const char *type_name)
> > +{
> > + int items, used = 0, err = 0, nr_sigs;
> > + u32 *values = NULL, i;
> > +
> > + /* allocate an array according to number of signals in connection */
> > + nr_sigs = tgrp->nr_sigs;
> > + if (!nr_sigs)
> > + return 0;
> > +
> > + /* see if any types have been included in the device description */
> > + items = cti_plat_count_sig_elements(fwnode, type_name);
> > + if (items > nr_sigs)
> > + return -EINVAL;
> > +
> > + /* need an array to store the values iff there are any */
> > + if (items) {
> > + values = kcalloc(items, sizeof(u32), GFP_KERNEL);
> > + if (!values)
> > + return -ENOMEM;
> > +
> > + err = fwnode_property_read_u32_array(fwnode, type_name,
> > + values, items);
> > + if (err)
> > + goto read_trig_types_out;
> > + }
> > +
> > + /*
> > + * Match type id to signal index, 1st type to 1st index etc.
> > + * If fewer types than signals default remainder to GEN_IO.
> > + */
> > + for (i = 0; i < nr_sigs; i++) {
> > + if (used < items) {
> > + tgrp->sig_types[i] =
> > + values[i] < CTI_TRIG_MAX ? values[i] : GEN_IO;
> > + used++;
>
> Do we really need "used" here ? Couldn't this be :
>
No we don't - I'll fix it.

> if (i < items) {
>
> }
>
> > + } else {
>
> + /* Mark the undefined connections as GEN_IO */ ?
>
> > + tgrp->sig_types[i] = GEN_IO;
> > + }
> > + }
>
> ...
>
> > +
> > + /* read the connection name if set - may be overridden by later */
> > + fwnode_property_read_string(fwnode, CTI_DT_CONN_NAME, &assoc_name);
> > +
> > + /* associated cpu ? */
> > + cpuid = cti_plat_get_cpu_at_node(fwnode);
> > + if (cpuid >= 0) {
> > + drvdata->ctidev.cpu = cpuid;
> > + scnprintf(cpu_name_str, sizeof(cpu_name_str), "cpu%d", cpuid);
> > + assoc_name = cpu_name_str;
> > + } else {
> > + /* associated device ? */
> > + cs_fwnode = fwnode_find_reference(fwnode,
> > + CTI_DT_CSDEV_ASSOC, 0);
>
> > + if (!IS_ERR_OR_NULL(cs_fwnode)) {
>
> --- Cut - here --
> > + csdev = cti_get_assoc_csdev_by_fwnode(cs_fwnode);
> > + if (csdev) /* use device name if csdev found */
> > + assoc_name = dev_name(&csdev->dev);
> > + else /* otherwise node name for later association */
> > + assoc_name = cti_plat_get_node_name(cs_fwnode);
>
> --- end - here --
>
> I believe we do this for arm_v8 architected connections too. May be make
> this a helper ?
>
OK

> > + fwnode_handle_put(cs_fwnode);
> > + }
> > + }
> > + /* set up a connection */
> > + err = cti_add_connection_entry(dev, drvdata, tc, csdev, assoc_name);
> > +
> > +create_con_err:
> > + return err;
> > +}
> > +
> > +static int cti_plat_create_impdef_connections(struct device *dev,
> > + struct cti_drvdata *drvdata)
> > +{
> > + int rc = 0;
> > + struct fwnode_handle *fwnode = dev_fwnode(dev);
> > + struct fwnode_handle *child = NULL;
> > +
> > + if (IS_ERR_OR_NULL(fwnode))
> > + return -EINVAL;
> > +
> > + fwnode_for_each_child_node(fwnode, child) {
> > + if (cti_plat_node_name_eq(child, CTI_DT_CONNS))
> > + rc = cti_plat_create_connection(dev, drvdata, child);
> > + if (rc != 0)
> > + break;
>
> minor nit: To make it more obvious :
>
> if (cti_plat_node_name_eq(child, CTI_DT_CONNS)) {
> rc = cti_plat_create_connection(dev, drvdata,
> child);
> if (rc)
> break;
> }
>
> Suzuki

Thanks

Mike

--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK