Funnels associated with CPU clusters reside in the cluster's power domain. Unlike dynamic funnels (which are typically system-wide), these per-cluster funnels are only accessible when the cluster is powered on. Standard runtime PM may not suffice to wake up a cluster from low-power states, making direct register access unreliable.
Enhance the funnel driver to support these per-cluster devices:
1. Safe Initialization: - Identify CPU cluster funnels via "qcom,cpu-bound-components". - Use smp_call_function_single() to perform hardware initialization (claim tag clearing) on a CPU within the cluster. - Refactor the probe flow to encapsulate device registration in funnel_add_coresight_dev().
2. Cross-CPU Enablement: - Update funnel_enable() to use smp_call_function_single() when enabling the hardware on a cluster-bound funnel.
3. Debug Interface Support: - Update funnel_ctrl_show() to safely read the control register via cross-CPU calls when necessary.
This ensures that funnel operations remain safe and functional even when the associated CPU cluster is in aggressive low-power states.
Signed-off-by: Yuanfang Zhang yuanfang.zhang@oss.qualcomm.com --- drivers/hwtracing/coresight/coresight-funnel.c | 183 ++++++++++++++++++++----- 1 file changed, 152 insertions(+), 31 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c index 3b248e54471a38f501777fe162fea850d1c851b3..a1264df84ab4c625c63dfbb9b7710b983a10c6b4 100644 --- a/drivers/hwtracing/coresight/coresight-funnel.c +++ b/drivers/hwtracing/coresight/coresight-funnel.c @@ -15,6 +15,7 @@ #include <linux/slab.h> #include <linux/of.h> #include <linux/platform_device.h> +#include <linux/pm_domain.h> #include <linux/pm_runtime.h> #include <linux/coresight.h> #include <linux/amba/bus.h> @@ -40,6 +41,7 @@ DEFINE_CORESIGHT_DEVLIST(funnel_devs, "funnel"); * @csdev: component vitals needed by the framework. * @priority: port selection order. * @spinlock: serialize enable/disable operations. + * @supported_cpus: Represent the CPUs related to this funnel. */ struct funnel_drvdata { void __iomem *base; @@ -48,6 +50,13 @@ struct funnel_drvdata { struct coresight_device *csdev; unsigned long priority; raw_spinlock_t spinlock; + struct cpumask *supported_cpus; +}; + +struct funnel_smp_arg { + struct funnel_drvdata *drvdata; + int port; + int rc; };
static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port) @@ -76,6 +85,33 @@ static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port) return rc; }
+static void funnel_enable_hw_smp_call(void *info) +{ + struct funnel_smp_arg *arg = info; + + arg->rc = dynamic_funnel_enable_hw(arg->drvdata, arg->port); +} + +static int funnel_enable_hw(struct funnel_drvdata *drvdata, int port) +{ + int cpu, ret; + struct funnel_smp_arg arg = { 0 }; + + if (!drvdata->supported_cpus) + return dynamic_funnel_enable_hw(drvdata, port); + + arg.drvdata = drvdata; + arg.port = port; + + for_each_cpu(cpu, drvdata->supported_cpus) { + ret = smp_call_function_single(cpu, + funnel_enable_hw_smp_call, &arg, 1); + if (!ret) + return arg.rc; + } + return ret; +} + static int funnel_enable(struct coresight_device *csdev, struct coresight_connection *in, struct coresight_connection *out) @@ -86,19 +122,24 @@ static int funnel_enable(struct coresight_device *csdev, bool first_enable = false;
raw_spin_lock_irqsave(&drvdata->spinlock, flags); - if (in->dest_refcnt == 0) { - if (drvdata->base) - rc = dynamic_funnel_enable_hw(drvdata, in->dest_port); - if (!rc) - first_enable = true; - } - if (!rc) + + if (in->dest_refcnt == 0) + first_enable = true; + else in->dest_refcnt++; + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
- if (first_enable) - dev_dbg(&csdev->dev, "FUNNEL inport %d enabled\n", - in->dest_port); + if (first_enable) { + if (drvdata->base) + rc = funnel_enable_hw(drvdata, in->dest_port); + if (!rc) { + in->dest_refcnt++; + dev_dbg(&csdev->dev, "FUNNEL inport %d enabled\n", + in->dest_port); + } + } + return rc; }
@@ -188,15 +229,39 @@ static u32 get_funnel_ctrl_hw(struct funnel_drvdata *drvdata) return functl; }
+static void get_funnel_ctrl_smp_call(void *info) +{ + struct funnel_smp_arg *arg = info; + + arg->rc = get_funnel_ctrl_hw(arg->drvdata); +} + static ssize_t funnel_ctrl_show(struct device *dev, struct device_attribute *attr, char *buf) { u32 val; + int cpu, ret; struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent); + struct funnel_smp_arg arg = { 0 };
pm_runtime_get_sync(dev->parent); - - val = get_funnel_ctrl_hw(drvdata); + if (!drvdata->supported_cpus) { + val = get_funnel_ctrl_hw(drvdata); + } else { + arg.drvdata = drvdata; + for_each_cpu(cpu, drvdata->supported_cpus) { + ret = smp_call_function_single(cpu, + get_funnel_ctrl_smp_call, &arg, 1); + if (!ret) + break; + } + if (!ret) { + val = arg.rc; + } else { + pm_runtime_put(dev->parent); + return ret; + } + }
pm_runtime_put(dev->parent);
@@ -211,22 +276,68 @@ static struct attribute *coresight_funnel_attrs[] = { }; ATTRIBUTE_GROUPS(coresight_funnel);
+static void funnel_clear_self_claim_tag(struct funnel_drvdata *drvdata) +{ + struct csdev_access access = CSDEV_ACCESS_IOMEM(drvdata->base); + + coresight_clear_self_claim_tag(&access); +} + +static void funnel_init_on_cpu(void *info) +{ + struct funnel_drvdata *drvdata = info; + + funnel_clear_self_claim_tag(drvdata); +} + +static int funnel_add_coresight_dev(struct device *dev) +{ + struct coresight_desc desc = { 0 }; + struct funnel_drvdata *drvdata = dev_get_drvdata(dev); + + if (drvdata->base) { + desc.groups = coresight_funnel_groups; + desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); + } + + desc.name = coresight_alloc_device_name(&funnel_devs, dev); + if (!desc.name) + return -ENOMEM; + + desc.type = CORESIGHT_DEV_TYPE_LINK; + desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG; + desc.ops = &funnel_cs_ops; + desc.pdata = dev->platform_data; + desc.dev = dev; + + drvdata->csdev = coresight_register(&desc); + if (IS_ERR(drvdata->csdev)) + return PTR_ERR(drvdata->csdev); + return 0; +} + +static struct cpumask *funnel_get_supported_cpus(struct device *dev) +{ + struct generic_pm_domain *pd; + + pd = pd_to_genpd(dev->pm_domain); + if (pd) + return pd->cpus; + + return NULL; +} + static int funnel_probe(struct device *dev, struct resource *res) { void __iomem *base; struct coresight_platform_data *pdata = NULL; struct funnel_drvdata *drvdata; - struct coresight_desc desc = { 0 }; - int ret; + int cpu, ret;
if (is_of_node(dev_fwnode(dev)) && of_device_is_compatible(dev->of_node, "arm,coresight-funnel")) dev_warn_once(dev, "Uses OBSOLETE CoreSight funnel binding\n");
- desc.name = coresight_alloc_device_name(&funnel_devs, dev); - if (!desc.name) - return -ENOMEM; - drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); if (!drvdata) return -ENOMEM; @@ -244,9 +355,6 @@ static int funnel_probe(struct device *dev, struct resource *res) if (IS_ERR(base)) return PTR_ERR(base); drvdata->base = base; - desc.groups = coresight_funnel_groups; - desc.access = CSDEV_ACCESS_IOMEM(base); - coresight_clear_self_claim_tag(&desc.access); }
dev_set_drvdata(dev, drvdata); @@ -258,23 +366,36 @@ static int funnel_probe(struct device *dev, struct resource *res) dev->platform_data = pdata;
raw_spin_lock_init(&drvdata->spinlock); - desc.type = CORESIGHT_DEV_TYPE_LINK; - desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG; - desc.ops = &funnel_cs_ops; - desc.pdata = pdata; - desc.dev = dev; - drvdata->csdev = coresight_register(&desc); - if (IS_ERR(drvdata->csdev)) - return PTR_ERR(drvdata->csdev);
- return 0; + if (fwnode_property_present(dev_fwnode(dev), "qcom,cpu-bound-components")) { + drvdata->supported_cpus = funnel_get_supported_cpus(dev); + if (!drvdata->supported_cpus) + return -EINVAL; + + cpus_read_lock(); + for_each_cpu(cpu, drvdata->supported_cpus) { + ret = smp_call_function_single(cpu, + funnel_init_on_cpu, drvdata, 1); + if (!ret) + break; + } + cpus_read_unlock(); + + if (ret) + return 0; + } else if (res) { + funnel_clear_self_claim_tag(drvdata); + } + + return funnel_add_coresight_dev(dev); }
static int funnel_remove(struct device *dev) { struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
- coresight_unregister(drvdata->csdev); + if (drvdata->csdev) + coresight_unregister(drvdata->csdev);
return 0; }