From: liangzhen zhen.liang@spacemit.com
Add initial implementation of RISC-V trace ATB Bridge driver. The ATB Bridge is defined in the RISC-V Trace Control Interface specification.
Signed-off-by: liangzhen zhen.liang@spacemit.com --- drivers/hwtracing/coresight/Kconfig | 12 + drivers/hwtracing/coresight/Makefile | 1 + .../hwtracing/coresight/rvtrace-atbbridge.c | 239 ++++++++++++++++++ 3 files changed, 252 insertions(+) create mode 100644 drivers/hwtracing/coresight/rvtrace-atbbridge.c
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig index 8381a84e2699..1cd88a1a7d08 100644 --- a/drivers/hwtracing/coresight/Kconfig +++ b/drivers/hwtracing/coresight/Kconfig @@ -288,6 +288,17 @@ config RVTRACE dynamically aggregated with CoreSight trace infrastructure at run time to form a complete trace path.
+config RVTRACE_ATBBRIDGE + tristate "RISCV Trace ATB Bridge driver" + depends on RVTRACE + help + This driver provides support for the ATB Bridge driver. The ATB + Bridge allows sending RISC-V trace to Arm CoreSight infrastructure + (instead of RISC-V compliant sink) as an ATB initiator. + + To compile this driver as a module, choose M here: the module + will be called rvtrace-atbbridge. + config RVTRACE_FUNNEL tristate "RISCV Trace Funnel driver" depends on RVTRACE @@ -303,6 +314,7 @@ config RVTRACE_ENCODER tristate "RISCV Trace Encoder driver" depends on RVTRACE select RVTRACE_FUNNEL + select RVTRACE_ATBBRIDGE help This driver provides support for the Trace Encoder module, tracing the instructions that a processor is executing. This is primarily diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index 409a0abf0642..2264a313a773 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -59,6 +59,7 @@ coresight-ctcu-y := coresight-ctcu-core.o obj-$(CONFIG_CORESIGHT_KUNIT_TESTS) += coresight-kunit-tests.o obj-$(CONFIG_RVTRACE) += rvtrace.o rvtrace-y := rvtrace-core.o +obj-$(CONFIG_RVTRACE_ATBBRIDGE) += rvtrace-atbbridge.o obj-$(CONFIG_RVTRACE_FUNNEL) += rvtrace-funnel.o obj-$(CONFIG_RVTRACE_ENCODER) += rvtrace-encoder.o rvtrace-encoder-y := rvtrace-encoder-core.o rvtrace-encoder-sysfs.o diff --git a/drivers/hwtracing/coresight/rvtrace-atbbridge.c b/drivers/hwtracing/coresight/rvtrace-atbbridge.c new file mode 100644 index 000000000000..a931be322a2f --- /dev/null +++ b/drivers/hwtracing/coresight/rvtrace-atbbridge.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright(C) 2026 Spacemit Limited. All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/coresight.h> +#include <linux/platform_device.h> +#include <linux/bitfield.h> +#include <linux/rvtrace.h> + +#include "coresight-priv.h" +#include "coresight-trace-id.h" + +#define RVTRACE_ATBBRIDGE_CONTROL_ID_MASK GENMASK(14, 8) +/** + * struct atbbridge_data - specifics associated to a ATB bridge component + * @csdev: Component vitals needed by the framework. + * @spinlock: Only one at a time pls. + * @traceid: Value of the current ID for this component. + */ +struct atbbridge_data { + struct coresight_device *csdev; + spinlock_t spinlock; + u8 traceid; +}; + +DEFINE_CORESIGHT_DEVLIST(atbbridge_devs, "atbbridge"); + +static int atbbridge_enable(struct coresight_device *csdev, + struct coresight_connection *in, + struct coresight_connection *out) +{ + u32 control; + int ret = 0; + struct rvtrace_component *comp = dev_get_drvdata(csdev->dev.parent); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + unsigned long flags; + + spin_lock_irqsave(&atbbridge_data->spinlock, flags); + if (!comp->was_reset) { + ret = rvtrace_component_reset(comp); + if (ret) + goto done; + } + + control = readl_relaxed(comp->base + RVTRACE_COMPONENT_CTRL_OFFSET); + control |= FIELD_PREP(RVTRACE_ATBBRIDGE_CONTROL_ID_MASK, atbbridge_data->traceid); + writel_relaxed(control, comp->base + RVTRACE_COMPONENT_CTRL_OFFSET); + + ret = rvtrace_enable_component(comp); + if (ret) + goto done; + + spin_unlock_irqrestore(&atbbridge_data->spinlock, flags); + + dev_dbg(&csdev->dev, "Trace ATB bridge enabled\n"); +done: + return ret; +} + +static void atbbridge_disable(struct coresight_device *csdev, + struct coresight_connection *in, + struct coresight_connection *out) +{ + struct rvtrace_component *comp = dev_get_drvdata(csdev->dev.parent); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + unsigned long flags; + + spin_lock_irqsave(&atbbridge_data->spinlock, flags); + + if (rvtrace_disable_component(comp)) + dev_err(&csdev->dev, + "timeout while waiting for Trace ATB Bridge to be disabled\n"); + + if (rvtrace_comp_is_empty(comp)) + dev_err(&csdev->dev, + "timeout while waiting for Trace ATB Bridge internal buffers become empty\n"); + + spin_unlock_irqrestore(&atbbridge_data->spinlock, flags); + + dev_dbg(&csdev->dev, "Trace ATB bridge disabled\n"); +} + +static int atbbridge_link_trace_id(struct coresight_device *csdev, __maybe_unused enum cs_mode mode, + __maybe_unused struct coresight_device *sink) +{ + struct rvtrace_component *comp = dev_get_drvdata(csdev->dev.parent); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + + return atbbridge_data->traceid; +} + +static const struct coresight_ops_link atbbridge_link_ops = { + .enable = atbbridge_enable, + .disable = atbbridge_disable, +}; + +static const struct coresight_ops atbbridge_cs_ops = { + .trace_id = atbbridge_link_trace_id, + .link_ops = &atbbridge_link_ops, +}; + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned long val; + struct rvtrace_component *comp = dev_get_drvdata(dev->parent); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + unsigned long flags; + + if (kstrtoul(buf, 16, &val)) + return -EINVAL; + + if (val) { + if (rvtrace_component_reset(comp)) { + comp->was_reset = false; + spin_unlock_irqrestore(&atbbridge_data->spinlock, flags); + return -EINVAL; + } + } + + spin_unlock_irqrestore(&atbbridge_data->spinlock, flags); + + return size; +} +static DEVICE_ATTR_WO(reset); + +static ssize_t cpu_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + unsigned long val; + struct rvtrace_component *comp = dev_get_drvdata(dev->parent); + + val = comp->cpu; + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val); +} +static DEVICE_ATTR_RO(cpu); + +static ssize_t traceid_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + unsigned long val; + struct rvtrace_component *comp = dev_get_drvdata(dev->parent); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + + val = atbbridge_data->traceid; + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val); +} +static DEVICE_ATTR_RO(traceid); + +static struct attribute *trace_atbbridge_attrs[] = { + coresight_simple_reg32(control, RVTRACE_COMPONENT_CTRL_OFFSET), + coresight_simple_reg32(impl, RVTRACE_COMPONENT_IMPL_OFFSET), + &dev_attr_reset.attr, + &dev_attr_cpu.attr, + &dev_attr_traceid.attr, + NULL, +}; +ATTRIBUTE_GROUPS(trace_atbbridge); + +static int atbbridge_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct coresight_platform_data *pdata; + struct atbbridge_data *atbbridge_data; + struct rvtrace_component *comp; + struct coresight_desc desc = { 0 }; + int trace_id = 0; + + comp = rvtrace_register_component(pdev); + if (IS_ERR(comp)) + return PTR_ERR(comp); + + atbbridge_data = devm_kzalloc(dev, sizeof(*atbbridge_data), GFP_KERNEL); + if (!atbbridge_data) + return -ENOMEM; + + spin_lock_init(&atbbridge_data->spinlock); + + pdata = coresight_get_platform_data(dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + pdev->dev.platform_data = pdata; + + platform_set_drvdata(pdev, comp); + + desc.name = coresight_alloc_device_name(&atbbridge_devs, dev); + desc.access = CSDEV_ACCESS_IOMEM(comp->base); + desc.type = CORESIGHT_DEV_TYPE_LINK; + desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_FIFO; + desc.ops = &atbbridge_cs_ops; + desc.pdata = pdata; + desc.dev = dev; + desc.groups = trace_atbbridge_groups; + atbbridge_data->csdev = coresight_register(&desc); + if (IS_ERR(atbbridge_data->csdev)) + return PTR_ERR(atbbridge_data->csdev); + + trace_id = coresight_trace_id_get_system_id(); + if (trace_id < 0) + return -EINVAL; + atbbridge_data->traceid = (u8)trace_id; + + comp->id.data = atbbridge_data; + + dev_dbg(dev, "Trace ATB Bridge initialized\n"); + + return 0; +} + +static void atbbridge_remove(struct platform_device *pdev) +{ + struct rvtrace_component *comp = platform_get_drvdata(pdev); + struct atbbridge_data *atbbridge_data = rvtrace_component_data(comp); + + coresight_trace_id_put_system_id(atbbridge_data->traceid); + coresight_unregister(atbbridge_data->csdev); +} + +static const struct of_device_id atbbridge_match[] = { + {.compatible = "riscv,trace-atbbridge"}, + {}, +}; + +static struct platform_driver atbbridge_driver = { + .probe = atbbridge_probe, + .remove = atbbridge_remove, + .driver = { + .name = "trace-atbbridge", + .of_match_table = atbbridge_match, + }, +}; + +module_platform_driver(atbbridge_driver); + +MODULE_DESCRIPTION("RISC-V Trace ATB Bridge driver"); +MODULE_LICENSE("GPL");